In vitro Culture and Morphometry of Porcine Adipose Derived Mesenchymal Stem Cells (pAD-MSCs)

Background: Mesenchymal stem cells are well known for their self-renewal capacity and ability to differentiate into multiple cell lineages. The aim of the study was to develop a simple technique for isolation of mesenchymal stem cells from porcine adipose tissue and to study the morphometric characteristics of porcine mesenchymal stem cells. Methods: Porcine adipose derived mesenchymal stem cells were isolated in vitro by using collagenase type II enzyme. Cell yield and viability of the cells were calculated by using trypan blue exclusion method using Neubauer’s chamber. Characterization of MSCs were done by using specific cell markers. The morphological changes, morphometry were analysed in culture using Leishman’s stain. The cell doubling (CD) and Population doubling time (PDT) were also calculated. Result: The isolated adherent cells start forming colony and demonstrated an elongated, round and spindle like fibroblastic morphology by day 1. Almost 80-90 per cent confluency was attained on day 8-9 after the initial seeding and was reduced to day 3-4 in the subsequent passages. RT-PCR reactions revealed positive expression of mesenchymal stem cell markers CD44, CD73 and negative expression of CD34, a hematopoietic cell surface marker. Immunocytochemistry also revealed positive expression for CD44 and negative for CD34. In morphometric studies, the cell length, nucleus length, cell width and nucleus width were increased between 24 and 48 hours in both P2 and P3.

in Vitro Effect of Methamphetamine on Proliferation, Differentiation and Apoptosis of Adipose Tissue Stem Cells

Purpose: Among abused substances, methamphetamine is a psychostimulant drug widely used recreationally with public health importance. This study investigated the effect of methamphetamine on proliferation, differentiation, and apoptosis of human adipose tissue stem cells (AdSCs). Methods: AdSCs were isolated from human abdominal adipose tissue and were characterized for mesenchymal properties and growth kinetics. MTT assay was undertaken to assess methamphetamine toxicity on proliferation and differentiation properties and apoptosis of hAdSCs. Results: Isolated cells were shown to have mesenchymal properties and a population doubling time (PDT) of 40.1 h. Following methamphetamine treatment, expressions of KI-67 and TPX2 as proliferation genes and Col1A1 and PPARg as differentiation genes decreased. Methamphetamine administration increased the expression of Bax and decreased Bcl-2 genes responsible for apoptosis. Conclusions: Our data suggested when AdSCs were exposed to methamphetamine, it decreased proliferation and differentiation properties of stem cells together with an increase in apoptosis. These findings can be added to the literature, especially when methamphetamine is used recreationally for weight loss purposes.

Comparative Analysis of Mesenchymal Stem Cells Cultivated in Serum Free Media

Stem cells are attractive candidates for the regeneration of tissue and organ. Mesenchymal stem cells (MSCs) have been extensively investigated for their potential applications in regenerative medicine and cell therapy. For developing effective stem cell therapy, the mass production of consistent quality cells is required. The cell culture medium is the most critical aspect of the mass production of qualified stem cells. Classically, fetal bovine serum (FBS) has been used as a culture supplement for MSCs. Due to the undefined and heterologous composition of animal origin components in FBS, efforts to replace animal-derived components with non-animal-derived substances led to safe serum free media (SFM). Adipose derived mesenchymal stem cells (ADSCs) cultivated in SFM provided a more stable population doubling time (PDT) to later passage and more cells in a shorter time compared to FBS containing media. ADSCs cultivated in SFM had lower cellular senescence, lower immunogenicity, and higher genetic stability than ADSCs cultivated in FBS containing media. Differential expression analysis of mRNAs and proteins showed that the expression of genes related with apoptosis, immune response, and inflammatory response were significantly up-regulated in ADSCs cultivated in FBS containing media. ADSCs cultivated in SFM showed similar therapeutic efficacy in an acute pancreatitis mouse model to ADSCs cultivated in FBS containing media. Consideration of clinical trials, not only pre-clinical trial, suggests that cultivation of MSCs using SFM might offer more safe cell therapeutics as well as repeated administration due to low immunogenicity.

Growth kinetics and phenotypic markers expression in human dermal stem cells

Human dermal stem cells (DSCs) have generated significant interest in the field of regenerative medicine due to their prospects of autologous transplantation. The present study evaluated the growth kinetics and phenotypic markers expression in human DSCs. The primary cultures of DSCs (n=3) were established by explant culture and characterization of the cells was carried out by assessing morphology, viability, proliferation rate, population doubling time (PDT), cell cycle status and the expression of cell surface markers such as CD29, CD73, CD90 and CD166. The cells released from tissue explants showed spindleshaped fibroblast morphology with the mean percentage viability varying between 93.43% and 100% from passages 1 to 4. DSCs displayed a strong and steady proliferative potential with an average PDT of 42.55 hrs. Cell cycle profile of DSCs demonstrated the majority of cells (59.80% to 76.29%) at G0/G1 phase. Further, the phenotypic profile of markers confirmed the stromal origin of DSCs by exhibiting positivity for CD29, CD73, CD90 and CD166. In conclusion, the growth kinetics and expression of phenotypic markers are consistent with the notion that skin dermis contains a population of stem cells and can serve as a potential autologous source for therapeutic applications.

Effects of B-azolemiteacrylic on life-history traits and demographic parameters of two-spotted spider mite, Tetranychus urticae (Acari: Tetranychidae)

The present study was conducted to evaluate sublethal effects of B-azolemiteacrylic on the two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae). Female adults of T. urticae were exposed to LC10 and LC30 of the acaricide, and the effects on treated females and their offspring were evaluated. The results showed that the fecundity of F0 female adults treated with LC10 and LC30 of B-azolemiteacrylic was reduced by 30.9 and 39.2%, respectively. Longevity and oviposition period of the females were significantly reduced as well. The developmental duration of egg and deutonymph stage of the F1 generation were not significantly different from that of the control. The protonymph stage after LC30 treatment lasted significantly longer, whereas the larva, deutonymph and female stage were significantly shorter than the control. The oviposition period of the F1 generation was significantly shortened, the fecundity of each female decreased significantly, and the ratio of female-to-male was reduced too. Moreover, the average generation period of T. urticae after LC10 and LC30 treatments was shorter than that of the control, and the net production rate (R0), intrinsic rate of increase (rm) and finite rate of increase (λ) were all reduced by 33.3, 7.5 and 1.9% (LC10 treatment) and by 51.3, 14.8 and 3.6% (LC30 treatment), respectively. The population doubling time was prolonged by 7.5 and 14.8% after LC10 and LC30 treatments, respectively, compared with the control. These results indicate that B-azolemiteacrylic may effectively inhibit the development rate of the F0 and F1 populations of T. urticae, which will help design integrated strategies for the comprehensive control of T. urticae and rational use of pesticides in the field.

The “friend and foe” of deterministic and stochastic cell-cell variations

By diversifying, cells in a clonal population can together overcome the limits of individuals. Diversity in single-cell growth rates allows the population to survive environmental stresses, such as antibiotics, and grow faster than undiversified population. These functional cell-cell variations can arise stochastically, from noise in biochemical reactions, or deterministically, by asymmetrically distributing damaged components. While each of the mechanism is well understood, the effect of the combined mechanisms is unclear. To evaluate the contribution of the deterministic component we mapped the growing population to the Ising model. Model results, confirmed by simulations and experimental data, show that cell-cell variations increase near-linearly with stress. As a consequence, we predict that the entropic gain — the gain in population doubling time compared to an “average” cell — is primarily stochastic at low stress but crosses over to deterministic at higher stresses. Furthermore, we find that while the deterministic component minimizes population damage, stochastic variations antagonize this effect. Together our results may help identifying stress-tolerant pathogenic cells and thus inspire novel antibiotic strategies.

Cultural Properties of Cryopreserved Thymic Multipotent Stromal Cells and Fetal Skin and Muscle-Derived Cells

The paper provides a comparison of properties of cryopreserved fetal murine multipotent stromal cells (MSCs) of skin-muscular origin and those derived from adult thymus in culture in vitro. Fetal MSCs showed a 30% higher number of average population doublings within 24 hrs, and 41% lower average population doubling time. It was found that the fetal MSCs of the 4th passage had a 39% higher clonogenic activity than the adult thymus-derived ones. Fetal MSCs and those derived from adult thymus differentiated in osteogenic and adipogenic lineages with equal efficiency in special culture media. Fetal and thymus-derived MSCs were characterized by almost the same high ability of contact interaction with thymocytes, and the fibroblast-lymphocyte rosette (FLR) formation. They were far less active in FLR formation with lymph node cells. This indicated the presence of membrane affinity for immature lymphoid cells in both MSC subpopulations. The results showed the fetal MSCs to be significantly different from the adult thymus-derived MSCs by more active kinetics of growth and clonogenic potential. However, both cell subpopulations had virtually the same ability for linear differentiation and showed high activity during contact with immature lymphoid cells. Linear differentiation and the ability to interact with lymphocytes were found to be quite stable properties of MSCs, but a proliferative activity and in vitro colony formation distinguished significantly in different types of MSCs. This can be taken into account when choosing the cells for therapy, research and results assessment.

Selection of Highly Proliferative and Multipotent Meniscus Progenitors through Differential Adhesion to Fibronectin: A Novel Approach in Meniscus Tissue Engineering

Meniscus injuries can be highly debilitating and lead to knee osteoarthritis. Progenitor cells from the meniscus could be a superior cell type for meniscus repair and tissue-engineering. The purpose of this study is to characterize meniscus progenitor cells isolated by differential adhesion to fibronectin (FN-prog). Human osteoarthritic menisci were digested, and FN-prog were selected by differential adhesion to fibronectin. Multilineage differentiation, population doubling time, colony formation, and MSC surface markers were assessed in the FN-prog and the total meniscus population (Men). Colony formation was compared between outer and inner zone meniscus digest. Chondrogenic pellet cultures were performed for redifferentiation. FN-prog demonstrated multipotency. The outer zone FN-prog formed more colonies than the inner zone FN-prog. FN-prog displayed more colony formation and a higher proliferation rate than Men. FN-prog redifferentiated in pellet culture and mostly adhered to the MSC surface marker profile, except for HLA-DR receptor expression. This is the first study that demonstrates differential adhesion to fibronectin for the isolation of a progenitor-like population from the meniscus. The high proliferation rates and ability to form meniscus extracellular matrix upon redifferentiation, together with the broad availability of osteoarthritis meniscus tissue, make FN-prog a promising cell type for clinical translation in meniscus tissue-engineering.

Platelet Microparticles Accelerate Proliferation and Growth of Mesenchymal Stem Cells through Longevity-Related Genes

Background: Due to their self-renewal and differentiation ability, the mesenchymal stem cells (MSCs) have been studied extensively. However, the MSCs lifespan is restricted; they undergo several divisions in vitro that cause several alternations in cellular features and relatively lessens their application. Thus, this study was aimed to assess the effect of platelet-derived microparticles (PMPs), a valuable source of proteins, microRNAs (miRNAs), and growth factors, on the expression of hTERT, c-MYC, p16, p53, and p21 as the most important aging and cell longevity genes alongside with population doubling time (PDT) of PMP-treated cells in comparison to a control group. Methods: Umbilical cord MSCs (UC-MSCs) were used in this study, whereby they reached a confluency of 30%. MSCs were treated by PMPs (50 µg/mL), and then, PDT was determined for both groups. Quantitative expression of hTERT, c-MYC, p16, p53, and p21 was examined through quantitative real-time PCR at various intervals (i.e. after five and thirty days as well as freezing-thawing process). Results: Our results demonstrated that the treated group had a shorter PDT in comparison to the control group (P<0.050). The real-Time PCR data also indicated that PMPs were able to remarkably up-regulate hTERT and c-MYC genes expression while down-regulating the expression of p16, p21, and p53 genes (P<0.050), especially following five days of treatment. Conclusion: According to these data, it appears that PMPs are a safe and effective candidate for prolonging the lifespan of UC-MSCs; however, further investigations are needed to corroborate this finding.

Ectopic expression of KRASG12D and p53R167H in porcine mammary epithelial cells results in transformation and tumorigenesis

We describe our initial studies in the development of an orthotopic, genetically-defined, large animal model of breast cancer, using immunocompetent pigs. Primary mammary epithelial cells were isolated from the porcine gland. Primary mammary cells were immortalized with hTERT, and then transformed cell lines were generated from these immortalized cells with oncogenic KRAS and dominant negative p53. The transformed cell lines outperformed the primary cells in terms proliferation, population doubling time, soft agar growth, 2D migration, and Matrigel invasion. Three transformed cell lines were selected based on in vitro performance, and were able to grow tumors when injected subcutaneously in nude mice, with undifferentiated morphology. Tumorigenic porcine mammary cell lines were generated in this report.