Characterisation of Regional Human Meniscal Progenitor Cells

Abstract Background The surgical treatment of meniscus injury has represented a clinical challenge for decades. Stimulating meniscus regeneration using transplanted meniscal progenitor cells has been suggested as a promising new strategy. However, there is a lack of studies which decisively identify and characterise progenitor cell populations in human meniscus tissues. Methods In this study, donor-matched progenitor cells were isolated via selective fibronectin adhesion from the avascular (PAvas) and vascular (PVas) regions of the meniscus and chondroprogenitors (PChs) from articular cartilage (n=5 donors). In addition, whole mixed populations of cells (MAvas, MVas, MChs) from the same regions were obtained by standard isolation techniques for comparison. The colony formation efficacy of PAvas, PVas and PChs was monitored using Cell-IQ® live cell imaging. Proliferation rates of progenitors were compared with their mixed population counterparts. Cell surface markers indicative of mesenchymal stromal cells (MSCs) profile and progenitor markers were characterised by flow cytometry in all populations. The chondrogenic capacity was assessed via pellet culture assays and measuring chondrogenic gene expression levels, GAG/DNA content and morphology. Results All meniscal progenitor and chondroprogenitor populations showed colony forming capacity in monolayer culture, whereas mixed populations were distributed randomly at passage 0. PVas had significantly lower population doubling times compare to MVas and proliferated faster than PAvas and PChs based on colony forming efficacy. Progenitor populations showed significantly higher positivity for CD49b and CD49c compared to their mixed population counterparts and PChs had a higher positivity level of CD166 compared to mixed chondrocytes. Collagen types II and X expression was significantly downregulated in pellets formed by progenitor populations. GAG/DNA analysis demonstrated that progenitor cells generally produced more GAG than mixed populations. Conclusions Our study demonstrates that the human meniscus contains meniscal progenitor populations in both the avascular and vascular regions. Meniscal progenitors derived from the vascular region exhibit enhanced proliferative and chondrogenic characteristics compared to those from the avascular region; this may associate with the enhanced meniscal healing potential in the vascular region. These findings build on the body of evidence which suggests that meniscal progenitors represent an attractive cell therapy strategy for meniscal regeneration.

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Effect of Inflammation on Gingival Mesenchymal Stem/Progenitor Cells’ Proliferation and Migration through Microperforated Membranes: An In Vitro Study

Stem Cells International ◽

10.1155/2020/5373418 ◽

2020 ◽

Vol 2020 ◽

pp. 1-10 ◽

Cited By ~ 3

Author(s):

M. Al Bahrawy ◽

K. Ghaffar ◽

A. Gamal ◽

K. El-Sayed ◽

V. Iacono

Keyword(s):

Pore Size ◽

Progenitor Cells ◽

Cellular Migration ◽

Gingival Tissue ◽

Population Doubling ◽

Population Doubling Time ◽

Electron Microscopic ◽

Healthy Human ◽

Membrane Pores ◽

Scanning Electron

Background. In the field of periodontal guided tissue regeneration, microperforated membranes have recently proved to be very promising periodontal regenerative tissue engineering tools. Regenerative periodontal approaches, employing gingival mesenchymal stem/progenitor cells in combination with these novel membranes, would occur mostly in inflamed microenvironmental conditions intraorally. This in turn entails the investigation into how inflammation would affect the proliferation as well as the migration dynamics of gingival mesenchymal stem/progenitor cells. Materials and Methods. Clones of human gingival mesenchymal stem/progenitor cells (GMSCs) from inflamed gingival tissues were characterized for stem/progenitor cells’ characteristics and compared to clones of healthy human GMSCs (n=3), to be subsequently seeded on perforated collagen-coated poly-tetra-floro-ethylene (PTFE) membranes with a pore size 0.4 and 3 microns and polycarbonic acid membranes of 8 microns pore size in Transwell systems. The population doubling time and the MTT test of both populations were determined. Fetal bovine serum (FBS) was used as a chemoattractant in the culturing systems, and both groups were compared to their negative controls without FBS. Following 24 hours of incubation period, migrating cells were determined on the undersurface of microperforated membranes and the membrane-seeded cells were examined by scanning electron microscopy. Results. GMSCs demonstrated all predefined stem/progenitor cell characteristics. GMSCs from inflamed gingival tissues showed significantly shorter population doubling times. GMSCs of inflamed and healthy tissues did not show significant differences in their migration abilities towards the chemoattractant, with no cellular migration observed in the absence of FBS. GMSCs from healthy gingival tissue migrated significantly better through larger micropores (8 microns). Scanning electron microscopic images proved the migratory activity of the cells through the membrane pores. Conclusions. Inflammation appears to boost the proliferative abilities of GMSCs. In terms of migration through membrane pores, GMSCs from healthy as well as inflamed gingival tissues do not demonstrate a difference in their migration abilities through smaller pore sizes, whereas GMSCs from healthy gingival tissues appear to migrate significantly better through larger micropores.

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A new species of bandy-bandy (Vermicella: Serpentes: Elapidae) from the Weipa region, Cape York, Australia

Zootaxa ◽

10.11646/zootaxa.4446.1.1 ◽

2018 ◽

Vol 4446 (1) ◽

pp. 1

Author(s):

CHANTELLE M. DEREZ ◽

KEVIN ARBUCKLE ◽

ZHIQIANG RUAN ◽

BING XIE ◽

YU HUANG ◽

...

Keyword(s):

New Species ◽

Dna Analysis ◽

Morphological Characteristics ◽

The Body ◽

Black And White ◽

Potential Habitat ◽

Cape York ◽

Tropical Monsoon ◽

Conservation Concern ◽

A New Species

Bandy-bandies (genus Vermicella) are small (50–100cm) black and white burrowing elapids with a highly specialised diet of blindsnakes (Typhlopidae). There are currently 5 recognized species in the genus, all located in Australia, with Vermicella annulata the most encountered species with the largest distribution. Morphological and mitochondrial analyses of specimens collected from the Weipa area, Cape York, Queensland reveal the existence of a new species, which we describe as Vermicella parscauda sp. nov. Mitochondrial DNA analysis (16S and ND4) and external morphological characteristics indicate that the closest relatives of the new species are not V. annulata, which also occurs on Cape York, but rather species from Western Australia and the Northern Territory (V. intermedia and V. multifasciata) which, like V. parscauda, occupy monsoon habitats. Internasal scales are present in V. parscauda sp. nov., similar to V. annulata, but V. intermedia and V. multifasciata do not have nasal scales. V. parscauda sp. nov. has 55–94 black dorsal bands and mottled or black ventral scales terminating approximately 2/3rds of the body into formed black rings, suggesting that hyper-banding is a characteristic of the tropical monsoon snakes (V. intermedia, V. multifasciata and V. parscauda). The confined locality, potential habitat disruption due to mining activities, and scarcity of specimens indicates an urgent conservation concern for this species.

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A Wnt5a pathway underlies outgrowth of multiple structures in the vertebrate embryo

Development ◽

10.1242/dev.126.6.1211 ◽

1999 ◽

Vol 126 (6) ◽

pp. 1211-1223 ◽

Cited By ~ 30

Author(s):

T.P. Yamaguchi ◽

A. Bradley ◽

A.P. McMahon ◽

S. Jones

Keyword(s):

Progenitor Cells ◽

Primitive Streak ◽

The Body ◽

Loss Of Function ◽

Proliferating Cells ◽

Precise Control ◽

Cellular Processes ◽

Cell Proliferation And Differentiation ◽

Primary Body ◽

Multiple Structures

Morphogenesis depends on the precise control of basic cellular processes such as cell proliferation and differentiation. Wnt5a may regulate these processes since it is expressed in a gradient at the caudal end of the growing embryo during gastrulation, and later in the distal-most aspect of several structures that extend from the body. A loss-of-function mutation of Wnt5a leads to an inability to extend the A-P axis due to a progressive reduction in the size of caudal structures. In the limbs, truncation of the proximal skeleton and absence of distal digits correlates with reduced proliferation of putative progenitor cells within the progress zone. However, expression of progress zone markers, and several genes implicated in distal outgrowth and patterning including Distalless, Hoxd and Fgf family members was not altered. Taken together with the outgrowth defects observed in the developing face, ears and genitals, our data indicates that Wnt5a regulates a pathway common to many structures whose development requires extension from the primary body axis. The reduced number of proliferating cells in both the progress zone and the primitive streak mesoderm suggests that one function of Wnt5a is to regulate the proliferation of progenitor cells.

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Insulin Signaling in Intestinal Stem and Progenitor Cells as an Important Determinant of Physiological and Metabolic Traits in Drosophila

Cells ◽

10.3390/cells9040803 ◽

2020 ◽

Vol 9 (4) ◽

pp. 803 ◽

Cited By ~ 1

Author(s):

Olha M. Strilbytska ◽

Uliana V. Semaniuk ◽

Kenneth B. Storey ◽

Ihor S. Yurkevych ◽

Oleh Lushchak

Keyword(s):

Progenitor Cells ◽

Insulin Signaling ◽

Egf Receptor ◽

The Body ◽

Receptor Ligands ◽

Adipokinetic Hormone ◽

Peripheral Tissues ◽

Genes Encoding ◽

Stem And Progenitor Cells ◽

Multicellular Organisms

The insulin–IGF-1 signaling (IIS) pathway is conserved throughout multicellular organisms and regulates many traits, including aging, reproduction, feeding, metabolism, stress resistance, and growth. Here, we present evidence of a survival-sustaining role for IIS in a subset of gut cells in Drosophila melanogaster, namely the intestinal stem cells (ISCs) and progenitor cells. Using RNAi to knockdown the insulin receptor, we found that inhibition of IIS in ISCs statistically shortened the lifespan of experimental flies compared with non-knockdown controls, and also shortened their survival under starvation or malnutrition conditions. These flies also showed decreased reproduction and feeding, and had lower amounts of glycogen and glucose in the body. In addition, increased expression was observed for the Drosophila transcripts for the insulin-like peptides dilp2, dilp5, and dilp6. This may reflect increased insulin signaling in peripheral tissues supported by up-regulation of the target of the brain insulin gene (tobi). In contrast, activation of IIS (via knockdown of the insulin pathway inhibitor PTEN) in intestinal stem and progenitor cells decreased fly resistance to malnutrition, potentially by affecting adipokinetic hormone signaling. Finally, Pten knockdown to enhance IIS also activated JAK–STAT signaling in gut tissue by up-regulation of upd2, upd3, and soc36 genes, as well as genes encoding the EGF receptor ligands spitz and vein. These results clearly demonstrate that manipulating insulin levels may be used to modulate various fly traits, which are important determinants of organismal survival.

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Micro- and Nanofluidics for Cell Biology, Cell Therapy, and Cell-Based Drug Testing

ASME 2009 7th International Conference on Nanochannels, Microchannels and Minichannels ◽

10.1115/icnmm2009-82151 ◽

2009 ◽

Author(s):

Shuichi Takayama ◽

Dongeun Huh ◽

Jonathan Song ◽

Wansik Cha ◽

Yunseok Heo

Keyword(s):

Cell Biology ◽

Mammalian Cells ◽

Cancer Metastasis ◽

Dna Analysis ◽

The Body ◽

Biological Information ◽

Screening Methods ◽

Biological Studies

Many biological studies, drug screening methods, and cellular therapies require culture and manipulation of living cells outside of their natural environment in the body. The gap between the cellular microenvironment in vivo and in vitro, however, poses challenges for obtaining physiologically relevant responses from cells used in basic biological studies or drug screens and for drawing out the maximum functional potential from cells used therapeutically. One of the reasons for this gap is because the fluidic environment of mammalian cells in vivo is microscale and dynamic whereas typical in vitro cultures are macroscopic and static. This presentation will give an overview of efforts in our laboratory to develop microfluidic systems that enable spatio-temporal control of both the chemical and fluid mechanical environment of cells. The technologies and methods close the physiology gap to provide biological information otherwise unobtainable and to enhance cellular performance in therapeutic applications. Specific biomedical topics that will be discussed include, in vitro fertilization on a chip, microfluidic tissue engineering of small airway injuries, breast cancer metastasis on a chip, electrochemical biosensors, and development of tuneable nanofluidic systems towards applications in single molecule DNA analysis.

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Dimensional Analyses of Taxonic Data

Psychological Reports ◽

10.2466/pr0.101.2.617-635 ◽

2007 ◽

Vol 101 (2) ◽

pp. 617-635 ◽

Cited By ~ 1

Author(s):

William M. Grove

Keyword(s):

Principal Component Analysis ◽

Factor Analysis ◽

Data Structures ◽

Principal Components ◽

Common Factor ◽

Principal Component ◽

Mixed Population ◽

Single Population ◽

Factor Analytic ◽

Mixed Populations

Principal component analysis (PCA) and common factor analysis are often used to model latent data structures. Typically, such analyses assume a single population whose correlation or covariance matrix is modelled. However, data may sometimes be unwittingly sampled from mixed populations containing a taxon (nonarbitrary subpopulation) and its complement class. One derives relations between values of PCA parameters within subpopulations and their values in the mixed population. These results are then extended to factor analysis in mixed populations. As relationships between subpopulation and mixed-population principal components and factors sensitively depend on within-subpopulation structures and between-subpopulation differences, naive interpretation of PCA or factor analytic findings can potentially mislead. Several analyses, better suited to the dimensional analysis of admixture data structures, are presented and compared.

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Myeloperoxidase expression in CD34+ normal human hematopoietic cells

Blood ◽

10.1182/blood.v82.7.2069.2069 ◽

1993 ◽

Vol 82 (7) ◽

pp. 2069-2078 ◽

Cited By ~ 6

Author(s):

H Strobl ◽

M Takimoto ◽

O Majdic ◽

G Fritsch ◽

C Scheinecker ◽

...

Keyword(s):

Progenitor Cells ◽

Transferrin Receptor ◽

Staining Pattern ◽

Hematopoietic Progenitor ◽

Colony Forming Unit ◽

Cd34 Cells ◽

Normal Human ◽

Colony Forming Capacity ◽

Adult Peripheral Blood

Abstract Bone marrow (BM), adult peripheral blood (aPB), and umbilical cord blood (CB) samples contain small proportions of CD34+ cells that include virtually all hematopoietic progenitor cells. Myeloperoxidase (MPO) is considered to be selectively expressed in cells committed to granulomonocytic differentiation. Using flow cytometry and an antibody against MPO, we studied at which stage of normal hematopoietic differentiation CD34+ cells being to express MPO. We consistently observed a characteristic MPO/CD34 staining pattern and found that 35% +/- 9% of CD34+ BM cells express MPO. The MPO+ CD34+ subset and the CD33+ CD34+ subset were of similar size and overlapped considerably. MPO+ CD34+ cells expressed high levels of HLA-D molecules, were weakly CD71/transferrin receptor positive to negative, were CD45RA+ and lacked the CD45RO isoform of the leukocyte common antigen. Additionally, MPO+ CD34+ cells were on average larger in size than MPO- CD34+ cells. Virtually identical phenotypic features have previously been described for in vitro colony-forming granulomonocytic progenitor cells. In vitro clonogenic assays performed with MPO-enriched and MPO-depleted fractions of CD34+ BM cells performed by us also suggest, but do not formally prove, that at least a portion of MPO+ CD34+ cells have in vitro cluster (10 to 50 cells/colony) or colony-forming unit granulocyte-macrophage (> or = 50 cells/colony) forming capacity. CD34+ cells from CB and aPB resembled CD34+ BM cells in that considerable proportions of them coexpressed CD33. However, in contrast to BM, CD34+ cells from CB and aPB samples lacked significant MPO expression and, in line with this, the majority of them (CB, 59% +/- 7%; aPB, 66% +/- 5%) coexpressed CD45RO.

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Exercise Increases the Frequency of Circulating Hematopoietic Progenitor Cells, But Reduces Hematopoietic Colony-Forming Capacity

Stem Cells and Development ◽

10.1089/scd.2012.0017 ◽

2012 ◽

Vol 21 (16) ◽

pp. 2915-2925 ◽

Cited By ~ 23

Author(s):

Julia Maria Kroepfl ◽

Karin Pekovits ◽

Ingeborg Stelzer ◽

Robert Fuchs ◽

Sieglinde Zelzer ◽

...

Keyword(s):

Progenitor Cells ◽

Hematopoietic Progenitor Cells ◽

Hematopoietic Progenitor ◽

Colony Forming Capacity

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Isolation and Characterization of Living Cord Blood CD34+ Cells with Telomerase Reverse Transcriptase (TERT) Expression.

Blood ◽

10.1182/blood.v104.11.3559.3559 ◽

2004 ◽

Vol 104 (11) ◽

pp. 3559-3559

Author(s):

Marcus Nilsson-Jaras ◽

Anna Edqvist ◽

Johan Rebetz ◽

Bengt Widegren ◽

Stefan Karlsson ◽

...

Keyword(s):

Cell Cycle ◽

Progenitor Cells ◽

Adenoviral Vector ◽

Telomerase Activity ◽

Telomerase Reverse Transcriptase ◽

Cd34 Cells ◽

M Phase ◽

Colony Forming Capacity ◽

Tert Expression ◽

Vector Transduction

Abstract In the hematopoietic system, telomerase activity is suggested to be differentiation- and proliferation status-dependent. High telomerase activity has been demonstrated in bulk CD34+ progenitor cells. The telomerase activity is mainly controlled at the transcriptional level of the telomerase reverse transcriptase (TERT) gene. In this study, we functionally characterized living cord blood (CB) CD34+ cells with TERT promoter activity by using a TERT reporting adenoviral vector with Ad35 tropism. Such fiber retargeted Ad5F35 vectors allow efficient gene transfer into hematopoietic cells by using the ubiquitously expressed CD46 as a cellular receptor. An adenoviral vector (cTERTdGFP) encoding destabilized EGFP (half-life of 2 hours) under the control of the human TERT promoter and the chicken b-like globin gene insulator was constructed. The background expression of GFP from cTERTdGFP was assessed in the telomerase(−) CB CD15/33+ cells, WI-38 cells and fibroblast cells. Less than 3 percent of these cell types expressed low levels of GFP following transduction with cTERTdGFP in comparison to the control vector Ad5F35-GFP (PGK-promoter) transduced cells (78 to 95% expressed GFP). Under similar conditions, more than 95% of the telomerase(+) A549 cells expressed GFP+ following the cTERTdGFP vector transduction. Therefore, the cTERTdGFP vector allowed d2GFP expression in a telomerase activity-dependent manner. Telomerase activity levels were quantified using the TRAP assay. All transductions were performed at an MOI of 100. The CB CD34+ cells were cultured in serum-free medium supplemented with thrombopoietin. When transduced with the Ad5F35-GFP vector at an MOI of 100, 47±6.7% of the CD34+ cells expressed GFP after two days, while 17±4.3% of the cells expressed GFP following the cTERTdGFP vector transduction. Sorted GFP+ cells following transduction with the cTERTdGFP (TERT sorted) or the Ad5F35-GFP (control sorted) vector were assessed for cell cycle distribution, colony forming capacity and repopulating capacity. Staining for the Ki-67 antigen and 7-AAD revealed that the TERT sorted cells had a greater proportion of cells in the S/G2/M phase of the cell cycle compared to the control sorted cells (55±1.2% versus 37±3.6%, p<0.01), and fewer cells in G0 phase (8.7±2.3% versus 21±3.7%, p<0.05). The colony forming capacity of TERT- and control-sorted cells was similar. Fourteen days following plating of 500 TERT sorted cells, 99±28 BFU-E and 59±18 CFU-G/M colonies were scored compared to the control sorted cells that formed 92±28 BFU-E and 59±11 CFU-G/M colonies. To further assess whether the TERT expressing cells contained repopulating primitive progenitor cells, 1x105 TERT sorted cells were transplanted via tail vein injection into NOD/SCIDBeta2m−/− mice. Human cell reconstitution in the bone marrow was examined at 6 weeks post-transplant in two independent experiments. The TERT sorted cells showed an average of 34±18% (n=9) engraftment with both B- and myeloid-lineage differentiation. Similar engraftment was observed for control sorted cells (35±11%, n=8). In summary, the cTERTdGFP vector allowed isolation of single living primitive hematopoietic progenitor cells with TERT expression. This cell population is enriched for cells in the S/G2/M phase of cell cycle and contains colony-forming progenitor cells and NOD/SCIDBeta2m−/− repopulating progenitor cells.

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A Note on the Failure Rates in Finite Mixed Populations

Journal of Applied Probability ◽

10.1239/jap/1339878794 ◽

2012 ◽

Vol 49 (2) ◽

pp. 405-415

Author(s):

Ji Hwan Cha ◽

Massimiliano Giorgio

Keyword(s):

Failure Rate ◽

Real World ◽

Finite Population ◽

Mixed Population ◽

Failure Rates ◽

Finite Populations ◽

Modeling And Analysis ◽

Mixed Populations ◽

Survival Patterns ◽

Almost All

Almost all populations existing in the real world are finite populations. Specifically, in the areas relevant to lifetime modeling and analysis, finite populations are frequently encountered. However, descriptions of failure/survival patterns of elements in the finite population have not yet been properly established. In particular, it is questionable whether the ordinary failure rate can be defined for finite populations in the same way and whether the corresponding interpretations are still valid. In this paper we consider two kinds of finite mixed population and provide new definitions for their failure rates. Then we clarify the notion of failure rate in finite populations.

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