Samantha Khoury and Pamela Ajuyah are supported by the Australian Postgraduate Award. We would also like to acknowledge the Translational Cancer Research Network, Lowy Cancer Research Centre, University of New South Wales and the Northern Translational Cancer Research Unit for their additional support of Samantha Khoury.

Note: Human serum samples from healthy patients or patients with cancer were obtained with informed consent under approved human ethical protocols from the Royal Prince Alfred Hospital Sydney (Protocol number X10-0016 and HREC/10/RPAH/24) and the University of Technology, Sydney. Serum samples were collected from patients before surgery from various Sydney hospitals and placed in storage at -80 &#176;C.
1. Small RNA Isolation from Serum&#160;
Total RNA was prepared from human serum using a modified version of the Tri-Reagent RT LS protocol.
<ol>
	<li>Thaw frozen serum sample on ice and then transfer 400 &#181;l of the freshly thawed serum into a labeled microcentrifuge tube.</li>
	<li>Dilute the serum with 100 &#181;l of RNase free H2O and add proteinase K at a concentration of 1 mg/ml.</li>
	<li>Incubate at 37&#160;&#176;C for 20 min&#160;to allow protein digestion by proteinase K.</li>
	<li>To ensure complete solubilization, add 1.5 times its volume of Tri-Reagent RT LS and 100 &#181;l of 4-bromoanisole.</li>
	<li>Briefly invert the homogenate, perform repetitive pipetting for 5 sec&#160;and transfer into a labeled 2&#160;ml Heavy Phase Lock tube.</li>
	<li>Spin the homogenate at 12,000 &#215; g for 20 min&#160;at 4 &#176;C.</li>
	<li>Carefully decant at least 1 ml of the resulting aqueous solution into a fresh DNA Lobind tube. The organic and interphase should be trapped underneath the white gel of the Phase Lock tube.</li>
	<li>Add 5.0 &#181;l of glycogen (5 mg/ml) and 500 &#181;l of 100% isopropanol to the aqueous solution, mix by inversion, and incubate O/N at -20 &#176;C.</li>
	<li>Following O/N&#160;incubation, centrifuge the sample for 20 min&#160;at 12,000 &#215; g in a 4 &#176;C centrifuge.</li>
	<li>Discard the clear supernatant and perform a &#34;flash&#34; spin for 2 min&#160;at 16,000 &#215; g in a 4 &#176;C centrifuge.</li>
	<li>Carefully remove the clear solution surrounding the pellet using a pipette.</li>
	<li>Wash the pellet with 1 ml&#160;of 70% ethanol and centrifuge at 10,000 &#215; g for 10 min. Decant the wash solution and repeat wash step.</li>
</ol>
2. RNA Resuspension&#160;into Solution
<ol>
	<li>Resuspend the pellet in 10 &#181;l of RNase free H2O, ensuring the pellet is completely dissolved. To ensure that the RNA is completely solubilized the sample can be heated to 55 &#176;C for 5 min. During this time, mix the sample with repeated pipetting. For a higher total RNA yield, pool two RNA preparations from the same patient.</li>
	<li>Quantitate the resuspended RNA using a UV-Vis spectrophotometer and assess the RNA quality using a 2100 Bioanalyzer. Store the pooled RNA samples at -80 &#176;C for use in downstream applications.</li>
</ol>

<ol>
	<li>Babu, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Monitoring+extraction+efficiency+of+small+RNAs+with+the+Agilent+2100+Bioanalyzer+and+the+Small+RNA+Kit.">Monitoring extraction efficiency of small RNAs with the Agilent 2100 Bioanalyzer and the Small RNA Kit.</a> Agilent Application Note. , (2010).</li><li>Tran, N., Hutvagner, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biogenesis+and+the+regulation+of+the+maturation+of+miRNAs.">Biogenesis and the regulation of the maturation of miRNAs.</a> Essays Biochem. 54, 17-28 (2013).</li><li>Chim, S. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detection+and+characterization+of+placental+microRNAs+in+maternal+plasma.">Detection and characterization of placental microRNAs in maternal plasma.</a> Clin. Chem. 54, 482-490 (2008).</li><li>Lodes, M. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Detection+of+cancer+with+serum+miRNAs+on+an+oligonucleotide+microarray.">Detection of cancer with serum miRNAs on an oligonucleotide microarray.</a> PLoS One. 4, (2009).</li><li>Chen, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+microRNAs+in+serum:+a+novel+class+of+biomarkers+for+diagnosis+of+cancer+and+other+diseases.">Characterization of microRNAs in serum: a novel class of biomarkers for diagnosis of cancer and other diseases.</a> Cell Res. 18, 997-1006 (2008).</li><li>Burgos, K. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+extracellular+miRNA+in+human+cerebrospinal+fluid+by+next-generation+sequencing.">Identification of extracellular miRNA in human cerebrospinal fluid by next-generation sequencing.</a> RNA. 19, 712-722 (2013).</li><li>Chomczynski, P., Sacchi, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single-step+method+of+RNA+isolation+by+acid+guanidinium+thiocyanate-phenol-chloroform+extraction.">Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction.</a> Anal. Biochem. 162, 156-159 (1987).</li><li>Zhang, X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Alterations+in+miRNA+processing+and+expression+in+pleomorphic+adenomas+of+the+salivary+gland.">Alterations in miRNA processing and expression in pleomorphic adenomas of the salivary gland.</a> Int. J. Cancer. 124, 2855-2863 (2009).</li><li>Chomczynski, P., Sacchi, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+single-step+method+of+RNA+isolation+by+acid+guanidinium+thiocyanate-phenol-chloroform+extraction:+twenty-something+years+on.">The single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction: twenty-something years on.</a> Nat. Protoc. 1, 581-585 (2006).</li><li>Kirschner, M. 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There is nothing to disclose.

The population of microRNAs constitutes approximately 0.4-0.5% of the total RNA found in serum. Further there is also a high protein content found in human serum. To improve RNA and reduce both protein and phenol contaminates we have modified the traditional Chomczynski approach9 with the addition of several steps.
Total RNA was isolated from serum using the standard Tri-Reagent RT-LS (Molecular Research Centre) however when performed in our laboratory, this method yielded RNA in lo...

In recent years, there has been a growing push to discover novel biomarkers for the early detection of human diseases. Much attention has been focused on using small RNAs such as microRNAs2 (miRNAs or miRs) as potential markers. These small RNAs are found in body fluids such as serum and studies have shown they are resilient to degradation and are stable over a range of varying environmental conditions3. Given these features, serum or circulating miRNAs are the ideal biomarker4,5. Currently there are two main approaches for the isolation of small RNA from biological fluids. The first approach uses column-based technology to bind and elute the small RNAs6, while the second approach uses the long-standing protocol with phenol and guanidinium thiocyanate reagents7. We have developed a simple, effective, column-free protocol to isolate small RNAs from human serum. The isolated RNA is immediately usable in downstream applications, including DNA oligonucleotide arrays and RNA sequencing.
This protocol was developed because we were confronted with several issues when using phenol-based methods to isolate RNA from serum. The traditional Chomczynski approach is frequently used in most laboratories with a range of reagents available from most commercial vendors. However considering their widespread use, stringent guidelines have not been developed to consistently produce high quality RNA from bodily fluids, in particular blood or serum.
Common problems associated with isolating RNA from serum include low RNA yields and contamination with reagents used during the isolation, particularly phenol. Our approach eliminates these phenol contaminants to provide high quality RNA for downstream analysis such as quantitative PCR (qPCR) and RNA sequencing. We have further tested this RNA on miRNA arrays.

<table border="0" cellpadding="0" cellspacing="0" style="width:852px;" width="851">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="22">
			<td height="22" style="height:22px;width:259px;">Name of the Material/Equipment&#160;</td>
			<td style="width:223px;">Company&#160;</td>
			<td style="width:123px;">Catalog Number&#160;</td>
			<td style="width:248px;">Comments/ Description (optional)&#160;</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:259px;">Tri-Reagent RT LS</td>
			<td style="width:223px;">Molecular Research Centre, USA</td>
			<td style="width:123px;">TR 118</td>
			<td style="width:248px;">-</td>
		</tr>
		<tr height="26">
			<td height="26" style="height:26px;width:259px;">RNase free H20</td>
			<td style="width:223px;">GIBCO Invitrogen</td>
			<td style="width:123px;">10977-023</td>
			<td style="width:248px;">-</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:259px;">Proteinase K&#160;</td>
			<td style="width:223px;">Finnzymes, Finland</td>
			<td style="width:123px;">EO0491</td>
			<td style="width:248px;">-</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:259px;">Heavy Phaselock Tube</td>
			<td style="width:223px;">5PRIME</td>
			<td>2302830</td>
			<td style="width:248px;">2ml capacity</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:259px;">DNA Lobind tube</td>
			<td style="width:223px;">Eppendorf</td>
			<td style="width:123px;">0030 108.078</td>
			<td style="width:248px;">1.5ml capacity</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:259px;">Glycogen&#160;</td>
			<td style="width:223px;">Invitrogen, USA</td>
			<td style="width:123px;">10814-010</td>
			<td style="width:248px;">5mg/ml</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:259px;">RNA grade Isopropanol&#160;</td>
			<td style="width:223px;">Sigma Aldrich, USA</td>
			<td style="width:123px;">I9516</td>
			<td style="width:248px;">100%</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:259px;">Refrigerated Centrifuge</td>
			<td style="width:223px;">John Morris</td>
			<td style="width:123px;">-</td>
			<td style="width:248px;">-</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:259px;">Nanodrop UV-Vis spectrophotometer</td>
			<td style="width:223px;">Thermo Fisher Scientific, USA</td>
			<td style="width:123px;">-</td>
			<td style="width:248px;">-</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:259px;">RNA grade Ethanol</td>
			<td style="width:223px;">Sigma Aldrich, USA</td>
			<td style="width:123px;">E7023</td>
			<td style="width:248px;">70%</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:259px;">Agilent 2100 Bioanalyser</td>
			<td style="width:223px;">Agilent, USA</td>
			<td style="width:123px;">-</td>
			<td style="width:248px;">-</td>
		</tr>
	</tbody>
</table>

isolation of small noncoding rnas from human serum

The analysis of RNA and its expression is a common feature in many laboratories. Of significance is the emergence of small RNAs like microRNAs, which are found in mammalian cells. These small RNAs are potent gene regulators controlling vital pathways such as growth, development and death and much interest has been directed at their expression in bodily fluids. This is due to their dysregulation in human diseases such as cancer and their potential application as serum biomarkers. However, the analysis of miRNA expression in serum may be problematic. In most cases the amount of serum is limiting and serum contains low amounts of total RNA, of which small RNAs only constitute 0.4-0.5%1. Thus the isolation of sufficient amounts of quality RNA from serum is a major challenge to researchers today. In this technical paper, we demonstrate a method which uses only 400 &#181;l of human serum to obtain sufficient RNA for either DNA arrays or qPCR analysis. The advantages of this method are its simplicity and ability to yield high quality RNA. It requires no specialized columns for purification of small RNAs and utilizes general reagents and hardware found in common laboratories. Our method utilizes a Phase Lock Gel to eliminate phenol contamination while at the same time yielding high quality RNA. We also introduce an additional step to further remove all contaminants during the isolation step. This protocol is very effective in isolating yields of total RNA of up to 100 ng/&#181;l from serum but can also be adapted for other biological tissues.

Figure 1 represents a typical UV/Vis spectrum of RNA isolated from serum. From this profile we noted protein contamination at 280 nm with phenol and organic contaminants both at 270 nm and 230 nm, respectively. Residue guanidinium thiocyanate was also noted at 260 nm. To reduce contaminants, a series of optimization steps were made to the standard Tri-Reagent RT-LS procedure. We added 5 mg/ml of glycogen to increase both the total RNA yield and reduce contamination (black line, Figure 1A...

Watch this Scientific Journal Video about Isolation of Small Noncoding RNAs from Human Serum at JoVE.com

Isolation of Small Noncoding RNAs from Human Serum

This protocol describes a method for extracting small RNAs from human serum. We have used this method to isolate microRNAs from cancer serum for use in DNA arrays and also singleplex quantitative PCR. The protocol utilizes phenol and guanidinium thiocyanate reagents with modifications to yield high quality RNA.

The analysis of RNA and its expression is a common feature in many laboratories. Of significance is the emergence of small RNAs like microRNAs, which are ...

isolation-of-small-noncoding-rnas-from-human-serum

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18.0K Views.  University of Technology, Sydney. This protocol describes a method for extracting small RNAs from human serum. We have used this method to isolate microRNAs from cancer serum for use in DNA arrays and also singleplex quantitative PCR. The protocol utilizes phenol and guanidinium thiocyanate reagents with modifications to yield high quality RNA.

Video: Isolation of Small Noncoding RNAs from Human Serum

Neuronal Nuclei Isolation from Human Postmortem Brain Tissue

Neurons in the human brain become postmitotic largely during prenatal development, and thus maintain their nuclei throughout the full lifespan. However, little is known about changes in neuronal chromatin and nuclear organization during the course of development and aging, or in chronic neuropsychiatric disease. However, to date most chromatin and DNA based assays (other than FISH) lack single cell resolution. To this end, the considerable cellular heterogeneity of brain tissue poses a significant limitation, because typically various subpopulations of neurons are intermingled with different types of glia and other non-neuronal cells. One possible solution would be to grow cell-type specific cultures, but most CNS cells, including neurons, are ex vivo sustainable, at best, for only a few weeks and thus would provide an incomplete model for epigenetic mechanisms potentially operating across the full lifespan.  Here, we provide a protocol to extract and purify nuclei from frozen (never fixed) human postmortem brain. The method involves extraction of nuclei in hypotonic lysis buffer, followed by ultracentrifugation and immunotagging with anti-NeuN antibody. Labeled neuronal nuclei are then collected separately using fluorescence-activated sorting. This method should be applicable to any brain region in a wide range of species and suitable for chromatin immunoprecipitation studies with site- and modification-specific anti-histone antibodies, and for DNA methylation and other assays. 

The cellular heterogeneity of brain tissue poses a significant limitation for the study of epigenetic markings in chromatin because most assays lack single cell resolution. Neurons typically are intermingled with glia and other non-neuronal cells. We provide a protocol to extract and collect neuronal nuclei from human brain.

Neurons in the human brain become postmitotic largely during prenatal development, and thus maintain their nuclei throughout the full lifespan. However, ...

Isolation of Stem Cells from Human Pancreatic Cancer Xenografts

Cancer stem cells (CSCs) have been identified in a growing number of malignancies and are functionally defined by their ability to undergo self-renewal and produce differentiated progeny1. These properties allow CSCs to recapitulate the original tumor when injected into immunocompromised mice. CSCs within an epithelial malignancy were first described in breast cancer and found to display specific cell surface antigen expression (CD44+CD24low/-)2. Since then, CSCs have been identified in an increasing number of other human malignancies using CD44 and CD24 as well as a number of other surface antigens. Physiologic properties, including aldehyde dehydrogenase (ALDH) activity, have also been used to isolate CSCs from malignant tissues3-5.
Recently, we and others identified CSCs from pancreatic adenocarcinoma based on
ALDH activity and the expression of the cell surface antigens CD44 and CD24, and CD1336-8. These highly tumorigenic populations may or may not be overlapping and display other functions. We found that ALDH+ and CD44+CD24+ pancreatic CSCs are similarly tumorigenic, but ALDH+ cells are relatively more invasive8. In this protocol we describe a method to isolate viable pancreatic CSCs from low-passage human
xenografts9. Xenografted tumors are harvested from mice and made into a single-cell suspension. Tissue debris and dead cells are separated from live cells and then stained using antibodies against CD44 and CD24 and using the ALDEFLUOR reagent,
a fluorescent substrate of ALDH10. CSCs are then isolated by fluorescence activated cell sorting. Isolated CSCs can then be used for analytical or functional assays requiring viable cells.

Cancer stem cells (CSCs) have been identified in a number of malignancies. In this protocol we describe a flow cytometric method utilizing aldehyde dehydrogenase activity and CD44 and CD24 expression to isolate CSCs from human pancreatic adenocarcinoma xenografts. These viable cells can then be used in functional and analytical studies.

Cancer stem cells (CSCs) have been identified in a growing number of malignancies and are functionally defined by their ability to undergo self-renewal ...

Isolation and Culture of Adult Epithelial Stem Cells from Human Skin

The homeostasis of all self-renewing tissues is dependent on adult stem cells. As undifferentiated stem cells undergo asymmetric divisions, they generate daughter cells that retain the stem cell phenotype and transit-amplifying cells (TA cells) that migrate from the stem cell niche, undergo rapid proliferation and terminally differentiate to repopulate the tissue.
Epithelial stem cells have been identified in the epidermis, hair follicle, and intestine as cells with a high in vitro proliferative potential and as slow-cycling label-retaining cells in vivo 1-3. Adult, tissue-specific stem cells are responsible for the regeneration of the tissues in which they reside during normal physiologic turnover as well as during times of stress 4-5. Moreover, stem cells are generally considered to be multi-potent, possessing the capacity to give rise to multiple cell types within the tissue 6. For example, rodent hair follicle stem cells can generate epidermis, sebaceous glands, and hair follicles 7-9. We have shown that stem cells from the human hair follicle bulge region exhibit multi-potentiality 10.
Stem cells have become a valuable tool in biomedical research, due to their utility as an in vitro system for studying developmental biology, differentiation, tumorigenesis and for their possible therapeutic utility. It is likely that adult epithelial stem cells will be useful in the treatment of diseases such as ectodermal dysplasias, monilethrix, Netherton syndrome, Menkes disease, hereditary epidermolysis bullosa and alopecias 11-13. Additionally, other skin problems such as burn wounds, chronic wounds and ulcers will benefit from stem cell related therapies 14,15. Given the potential for reprogramming of adult cells into a pluripotent state (iPS cells)16,17, the readily accessible and expandable adult stem cells in human skin may provide a valuable source of cells for induction and downstream therapy for a wide range of disease including diabetes and Parkinson's disease.

A rapid, robust way of isolating viable adult epithelial stem cells from human skin is described. The method utilizes enzymatic digestion of skin collagen matrix , followed by plucking of hair follicles and isolation of single cell suspensions or tissue fragments for cell culture.

The homeostasis of all self-renewing tissues is dependent on adult stem cells. As undifferentiated stem cells undergo asymmetric divisions, they generate ...

Efficient Derivation of Human Cardiac Precursors and Cardiomyocytes from Pluripotent Human Embryonic Stem Cells with Small Molecule Induction

To date, the lack of a suitable human cardiac cell source has been the major setback in regenerating the human myocardium, either by cell-based transplantation or by cardiac tissue engineering1-3. Cardiomyocytes become terminally-differentiated soon after birth and lose their ability to proliferate. There is no evidence that stem/progenitor cells derived from other sources, such as the bone marrow or the cord blood, are able to give rise to the contractile heart muscle cells following transplantation into the heart1-3. The need to regenerate or repair the damaged heart muscle has not been met by adult stem cell therapy, either endogenous or via cell delivery1-3. The genetically stable human embryonic stem cells (hESCs) have unlimited expansion ability and unrestricted plasticity, proffering a pluripotent reservoir for in vitro derivation of large supplies of human somatic cells that are restricted to the lineage in need of repair and regeneration4,5. Due to the prevalence of cardiovascular disease worldwide and acute shortage of donor organs, there is intense interest in developing hESC-based therapies as an alternative approach. However, how to channel the wide differentiation potential of pluripotent hESCs efficiently and predictably to a desired phenotype has been a major challenge for both developmental study and clinical translation. Conventional approaches rely on multi-lineage inclination of pluripotent cells through spontaneous germ layer differentiation, resulting in inefficient and uncontrollable lineage-commitment that is often followed by phenotypic heterogeneity and instability, hence, a high risk of tumorigenicity6-8 (see a schematic in Fig. 1A). In addition, undefined foreign/animal biological supplements and/or feeders that have typically been used for the isolation, expansion, and differentiation of hESCs may make direct use of such cell-specialized grafts in patients problematic9-11. To overcome these obstacles, we have resolved the elements of a defined culture system necessary and sufficient for sustaining the epiblast pluripotence of hESCs, serving as a platform for de novo derivation of clinically-suitable hESCs and effectively directing such hESCs uniformly towards clinically-relevant lineages by small molecules12 (see a schematic in Fig. 1B). After screening a variety of small molecules and growth factors, we found that such defined conditions rendered nicotinamide (NAM) sufficient to induce the specification of cardiomesoderm direct from pluripotent hESCs that further progressed to cardioblasts that generated human beating cardiomyocytes with high efficiency (Fig. 2). We defined conditions for induction of cardioblasts direct from pluripotent hESCs without an intervening multi-lineage embryoid body stage, enabling well-controlled efficient derivation of a large supply of human cardiac cells across the spectrum of developmental stages for cell-based therapeutics.

We have established a protocol for induction of cardioblasts direct from pluripotent human embryonic stem cells maintained under defined conditions with small molecules, which enables derivation of a large supply of human cardiac progenitors and functional cardiomyocytes for cardiovascular repair.

To date, the lack of a suitable human cardiac cell source has been the major setback in regenerating the human myocardium, either by cell-based ...

Na&iuml;ve Adult Stem Cells Isolation from Primary Human Fibroblast Cultures

Over the last decade, several adult stem cell populations have been identified in human skin 1-4. The isolation of multipotent adult dermal precursors was first reported by Miller F. D laboratory 5, 6. These early studies described a multipotent precursor cell population from adult mammalian dermis 5. These cells--termed SKPs, for skin-derived precursors-- were isolated and expanded from rodent and human skin and differentiated into both neural and mesodermal progeny, including cell types never found in skin, such as neurons 5. Immunocytochemical studies on cultured SKPs revealed that cells expressed vimentin and nestin, an intermediate filament protein expressed in neural and skeletal muscle precursors, in addition to fibronectin and multipotent stem cell markers 6. Until now, the adult stem cells population SKPs have been isolated from freshly collected mammalian skin biopsies.
Recently, we have established and reported that a population of skin derived precursor cells could remain present in primary fibroblast cultures established from skin biopsies 7. The assumption that a few somatic stem cells might reside in primary fibroblast cultures at early population doublings was based upon the following observations: (1) SKPs and primary fibroblast cultures are derived from the dermis, and therefore a small number of SKP cells could remain present in primary dermal fibroblast cultures and (2) primary fibroblast cultures grown from frozen aliquots that have been subjected to unfavorable temperature during storage or transfer contained a small number of cells that remained viable 7. These rare cells were able to expand and could be passaged several times. This observation suggested that a small number of cells with high proliferation potency and resistance to stress were present in human fibroblast cultures 7.
We took advantage of these findings to establish a protocol for rapid isolation of adult stem cells from primary fibroblast cultures that are readily available from tissue banks around the world (Figure 1). This method has important significance as it allows the isolation of precursor cells when skin samples are not accessible while fibroblast cultures may be available from tissue banks, thus, opening new opportunities to dissect the molecular mechanisms underlying rare genetic diseases as well as modeling diseases in a dish.

Na&#239;ve Adult Stem Cells Isolation from Primary Human Fibroblast Cultures

We report a method to isolate na&#239;ve multipotent skin-derived precursor (SKP) cells from primary human fibroblast cultures. We show that these SKPs derived from fibroblast cultures share similar stem cell properties to the ones derived directly from human skin biopsies. These cells express the neural crest marker, nestin, in addition to the multipotent markers such as OCT4 and Nanog.

Over the last decade, several adult stem cell  populations have been identified in human skin 1-4.  The isolation of multipotent adult dermal precursors ...

Manual Isolation of Adipose-derived Stem Cells from Human Lipoaspirates

In 2001, researchers at the University of California, Los Angeles, described the isolation of a new population of adult stem cells from liposuctioned adipose tissue that they initially termed Processed Lipoaspirate Cells or PLA cells. Since then, these stem cells have been renamed as Adipose-derived Stem Cells or ASCs and have gone on to become one of the most popular adult stem cells populations in the fields of stem cell research and regenerative medicine. Thousands of articles now describe the use of ASCs in a variety of regenerative animal models, including bone regeneration, peripheral nerve repair and cardiovascular engineering. Recent articles have begun to describe the myriad of uses for ASCs in the clinic. The protocol shown in this article outlines the basic procedure for manually and enzymatically isolating ASCs from large amounts of lipoaspirates obtained from cosmetic procedures. This protocol can easily be scaled up or down to accommodate the volume of lipoaspirate and can be adapted to isolate ASCs from fat tissue obtained through abdominoplasties and other similar procedures.

In 2001, researchers at UCLA described the isolation of a population of adult stem cells, termed Adipose-derived Stem Cells or ASCs, from adipose tissue. This article outlines the isolation of ASCs from lipoaspirates using a manual, enzymatic digestion protocol using collagenase.

In 2001, researchers at the University of  California, Los Angeles, described the isolation of a new population of adult  stem cells from liposuctioned ...

Isolation of Primary Myofibroblasts from Mouse and Human Colon Tissue

The myofibroblast is a stromal cell of the gastrointestinal (GI) tract that has been gaining considerable attention for its critical role in many GI functions. While several myofibroblast cell lines are commercially available to study these cells in vitro, research results from a cell line exposed to experimental cell culture conditions have inherent limitations due to the overly reductionist nature of the work. Use of primary myofibroblasts offers a great advantage in terms of confirming experimental findings identified in a cell line. Isolation of primary myofibroblasts from an animal model allows for the study of myofibroblasts under conditions that more closely mimic the disease state being studied. Isolation of primary myofibroblasts from human colon tissue provides arguably the most relevant experimental data, since the cells come directly from patients with the underlying disease. We describe a well-established technique that can be utilized to isolate primary myofibroblasts from both mouse and human colon tissue. These isolated cells have been characterized to be alpha-smooth muscle actin and vimentin-positive, and desmin-negative, consistent with subepithelial intestinal myofibroblasts. Primary myofibroblast cells can be grown in cell culture and used for experimental purposes over a limited number of passages.

The myofibroblast is an influential stromal cell of the gastrointestinal tract that regulates important physiologic processes in both normal and disease states. We describe a technique that allows for the isolation of primary myofibroblasts from both mouse and human colon tissue, which can be utilized for in vitro experimentation.

The myofibroblast is  a stromal cell of the gastrointestinal (GI) tract that has been gaining  considerable attention for its critical role in many GI ...

Isolation of Blood-vessel-derived Multipotent Precursors from Human Skeletal Muscle

Since the discovery of mesenchymal stem/stromal cells (MSCs), the native identity and localization&#160;of MSCs have been obscured by their retrospective isolation in culture. Recently, using fluorescence-activated cell sorting (FACS), we and other researchers prospectively identified and purified three subpopulations of multipotent precursor cells associated with the vasculature of human skeletal muscle. These three cell populations: myogenic endothelial cells (MECs), pericytes (PCs), and adventitial cells (ACs), are localized respectively to the three structural layers of blood vessels: intima, media, and adventitia. All of these human blood-vessel-derived stem cell (hBVSC) populations not only express classic MSC markers but also possess mesodermal developmental potentials similar to typical MSCs. Previously, MECs, PCs, and ACs have been isolated through distinct protocols and subsequently characterized in separate studies. The current isolation protocol, through modifications to the isolation process and adjustments in the selective cell surface markers, allows us to simultaneously purify all three hBVSC subpopulations by FACS from a single human muscle biopsy. This new method will not only streamline the isolation of multiple BVSC subpopulations but also facilitate future clinical applications of hBVSCs for distinct therapeutic purposes.

Blood vessels within human skeletal muscle harbor several multi-lineage precursor populations that are ideal for regenerative applications. This isolation method allows simultaneous purification of three multipotent precursor cell populations respectively from three structural layers of blood vessels: myogenic endothelial cells from intima, pericytes from media, and adventitial cells from adventitia.

Since the discovery of mesenchymal stem/stromal cells (MSCs), the native identity and localization&#160;of MSCs have been obscured by their retrospective ...

Isolation of Myofibroblasts from Mouse and Human Esophagus

Murine and human esophageal myofibroblasts are generated via enzymatic digestion. Neonate (8-12 day old) murine esophagus is harvested, minced, washed, and subjected to enzymatic digestion with collagenase and dispase for 25 min. Human esophageal resection specimens are stripped of muscularis propria and adventitia and the remaining mucosa is minced, and subjected to enzymatic digestion with collagenase and dispase for up to 6 hr. Cultured cells express &#945;-SMA and vimentin and express desmin weakly or not at all. Culture conditions are not conducive to growth of epithelial, hematopoietic, or endothelial cells. Culture purity is further confirmed by flow cytometric evaluation of cell surface marker expression of potential contaminating hematopoietic and endothelial cells. The described technique is straightforward and results in consistent generation of non-hematopoieitc, non-endothelial stromal cells. Limitations of this technique are inherent to the use of primary cultures in molecular biology studies, i.e., the unavoidable variability encountered among cultures established across different mice or humans. Primary cultures however are a more representative reflection of the in vivo state compared to cell lines. These methods also provide investigators the ability to isolate and culture stromal cells from different clinical and experimental conditions, allowing comparisons between groups. Characterized esophageal stromal cells can also be used in functional studies investigating epithelial-stromal interactions in esophageal disorders.

We present a protocol to generate primary cultures of murine and human esophageal stromal cells with a myofibroblast phenotype. Cultured cells have spindle shaped morphology, express &#945;-SMA and vimentin, and lack epithelial, hematopoietic and endothelial cell surface markers. Characterized stromal cells can be used in functional studies of epithelial-stromal interactions.

Murine and human esophageal myofibroblasts are generated via enzymatic digestion. Neonate (8-12 day old) murine esophagus is harvested, minced, washed, ...

Isolation of Mitochondria from Minimal Quantities of Mouse Skeletal Muscle for High Throughput Microplate Respiratory Measurements

Dysfunctional skeletal muscle mitochondria play a role in altered metabolism observed with aging, obesity and Type II diabetes. Mitochondrial respirometric assays from isolated mitochondrial preparations allow for the assessment of mitochondrial function, as well as determination of the mechanism(s) of action of drugs and proteins that modulate metabolism. Current isolation procedures often require large quantities of tissue to yield high quality mitochondria necessary for respirometric assays. The methods presented herein describe how high quality purified mitochondria (~ 450 &#181;g) can be isolated from minimal quantities (~75-100 mg) of mouse skeletal muscle for use in high throughput respiratory measurements. We determined that our isolation method yields 92.5&#177; 2.0% intact mitochondria by measuring citrate synthase activity spectrophotometrically. In addition, Western blot analysis in isolated mitochondria resulted in the faint expression of the cytosolic protein, GAPDH, and the robust expression of the mitochondrial protein, COXIV. The absence of a prominent GAPDH band in the isolated mitochondria is indicative of little contamination from non-mitochondrial sources during the isolation procedure. Most importantly, the measurement of O2 consumption rate with micro-plate based technology and determining the respiratory control ratio (RCR) for coupled respirometric assays shows highly coupled (RCR; &#62;6 for all assays) and functional mitochondria. In conclusion, the addition of a separate mincing step and significantly reducing motor driven homogenization speed of a previously reported method has allowed the isolation of high quality and purified mitochondria from smaller quantities of mouse skeletal muscle that results in highly coupled mitochondria that respire with high function during microplate based respirometirc assays.

Here, we present a modification of a previously reported method that allows for the isolation of high quality and purified mitochondria from smaller quantities of mouse skeletal muscle. This procedure results in highly coupled mitochondria that respire with high function during microplate based respirometirc assays.