Differentiation of umbilical cord mesenchymal stem cells into steroidogenic cells in comparison to bone marrow mesenchymal stem cells

Bovine Peripheral Blood-Derived Mesenchymal Stem Cells (PB-MSCs) and Spermatogonial Stem Cells (SSCs) Display Contrasting Expression Patterns of Pluripotency and Germ Cell Markers under the Effect of Sertoli Cell Conditioned Medium

In vitro gamete derivation has been proposed as an interesting strategy for treatment of infertility, improvement of genetic traits, and conservation of endangered animals. Spermatogonial stem cells (SSCs) are primary candidates for in vitro gamete derivation; however, recently, mesenchymal stem cells (MSCs) have also been proposed as candidates for germ cell (GCs) differentiation mainly due to their transdifferentiating capacity. The objective of the present study was to compare the potential for GC differentiation of bovine peripheral blood-derived MSCs (PB-MSCs) and SSCs under the effect of conditioned medium (CM) derived from Sertoli cells (SCs/CM). Samples were collected every 7 days for 21 days and analyzed for pluripotent, GC, and MSC marker expression. The absence of OCT4 and the increased (p < 0.05) expression of NANOG seems to play a role in SSC differentiation, whereas the absence of NANOG and the increased expression (p < 0.05) of OCT4 may be required for PB-MSC differentiation into GCs. SSCs cultured with SCs/CM increased (p < 0.05) the expression of PIWIL2 and DAZL, while PB-MSCs cultured under the same condition only increased (p < 0.05) the expression of DAZL. Overall, the patterns of markers expression suggest that PB-MSCs and SSCs activate different signaling pathways after exposure to SCs/CM and during differentiation into GCs.

Generation of glucocorticoid-producing cells derived from human pluripotent stem cells

Adrenal insufficiency is a life-threatening condition resulting from the inability to produce adrenal hormones in a dose- and time-dependent manner. Establishing a cell-based therapy would provide a physiologically responsive approach for the treatment of this condition. We report the generation of large numbers of human-induced steroidogenic cells (hiSCs) from human pluripotent stem cells (hPSCs). Directed differentiation of hPSCs into hiSCs recapitulates the initial stages of human adrenal development. Following expression of steroidogenic factor 1, activation of protein kinase A signaling drives a steroidogenic gene expression profile most comparable to human fetal adrenal cells, and leads to dynamic secretion of steroid hormones, in vitro. Moreover, expression of the adrenocorticotrophic hormone (ACTH) receptor/co-receptor (MC2R/MRAP) results in dose-dependent ACTH responsiveness. This protocol recapitulates adrenal insufficiency resulting from loss-of-function mutations in AAAS, which cause the enigmatic triple A syndrome. Our differentiation protocol generates sufficient numbers of hiSCs for cell-based therapy and offers a platform to study disorders causing adrenal insufficiency.

Differentiation of human adipose tissue-derived mesenchymal stromal cells into steroidogenic cells by adenovirus-mediated overexpression of NR5A1 and implantation into adrenal insufficient mice

BACKGROUND AIMS

Cell therapy for adrenal insufficiency is a potential method for physiological glucocorticoid and mineralocorticoid replacement. We have previously shown that mouse mesenchymal stromal cells (MSCs) differentiated into steroidogenic cells by the viral vector-mediated overexpression of nuclear receptor subfamily 5 group A member 1 (NR5A1), an essential regulator of steroidogenesis, and their implantation extended the survival of bilateral adrenalectomized (bADX) mice.

METHODS

In this study, we examined the capability of NR5A1-induced steroidogenic cells prepared from human adipose tissue-derived MSCs (MSC [AT]) and the therapeutic effect of the implantation of human NR5A1-induced steroidogenic cells into immunodeficient bADX mice.

RESULTS

Human NR5A1-induced steroidogenic cells secreted adrenal and gonadal steroids and exhibited responsiveness to adrenocorticotropic hormone and angiotensin II in vitro. In vivo, the survival time of bADX mice implanted with NR5A1-induced steroidogenic cells was significantly prolonged compared with that of bADX mice implanted with control MSC (AT). Serum cortisol levels, which indicate hormone secretion from the graft, were detected in bADX mice implanted with steroidogenic cells.

CONCLUSIONS

This is the first report to demonstrate steroid replacement by the implantation of steroid-producing cells derived from human MSC (AT). These results indicate the potential of human MSC (AT) to be a source of steroid hormone-producing cells.

Partially brain effects of injection of human umbilical cord mesenchymal stem cells at injury sites in a mouse model of thoracic spinal cord contusion

Purpose

The pain caused by spinal cord injury (SCI) poses a major burden on patients, and pain management is becoming a focus of treatment. Few reports have described changes in the brain after SCI. Particularly, the exact mechanism through which brain regions affect post-injury pain remains unclear. In this study, we aimed to determine the potential therapeutic mechanisms of pain. A mouse model of spinal cord contusion was established, and molecular expression in the anterior cingulate cortex (ACC) and periaqueductal gray (PAG) in the brain and animal behavior was observed after local injection of human umbilical cord mesenchymal stem cells (HU-MSCs) at the site of SCI.

Method

Sixty-three female C57BL/6J mice were divided into four groups: a sham operation group (n = 15); a spinal injury group (SCI, n = 16); an SCI + HU-MSCs group (n = 16) and an SCI + PBS group (n = 16), in which the SCI site was injected with HU-MSCs/phosphate buffer. The BMS score was determined, and the von Frey test and Hargreaves test were used to assess behavior every week after surgery. Mice were sacrificed in the fourth week after operation, and samples were collected. The expression of CGRP, Substance P, C-Fos and KCC2 in the ACC and PAG were observed with immunohistochemistry. Chromic cyanine staining was used to observe transverse sections of the injured spinal cord.

Result

In the ACC and PAG after SCI, the expression of CGRP, SP and C-Fos increased, and the expression of KCC2 decreased, whereas after HU-MSC injection, the expression of CGRP, SP and C-Fos decreased, and the expression of KCC2 increased. The SCI + HU-MSC group showed better exercise ability from 2 to 4 weeks after surgery than the SCI/SCI + PBS groups (P < 0.001). Local injection of HU-MSCs significantly improved the mechanical hyperalgesia caused by SCI in the fourth week after surgery (P < 0.0001), and sensation was significantly recovered 2 weeks after surgery (P < 0.0001); no improvement in thermal hypersensitivity was observed (P > 0.05). The HU-MSC group retained more white matter than the SCI/SCI + PBS groups (P < 0.0001).

Conclusion

Local transplantation of HU-MSCs at the site of SCI partially relieves the neuropathic pain and promotes recovery of motor function. These findings suggest a feasible direction for the future treatment of SCI.

Spermidine Retarded the Senescence of Multipotent Mesenchymal Stromal Cells In Vitro and In Vivo through SIRT3-Mediated Antioxidation

Multipotent mesenchymal stromal cells (MSCs) expand in vitro and undergo replicative senescence, thereby restricting their clinical utilization. Thus, an effective strategy is required to impede MSC senescence. Since spermidine (SPD) supplementation can prolong the lifespan of yeast by inhibiting oxidative stress, spermidine is a potential option for delaying MSC senescence. In this study, to test our hypothesis, we first isolated primary human umbilical cord mesenchymal stem cells (hUCMSCs). Subsequently, the appropriate SPD dose was administered during continuous cell cultivation. Next, we evaluated the antisenescence effects by SA-β-gal staining, Ki67 expression, reactive oxygen species (ROS) levels, adipogenic or osteogenic ability, senescence-associated markers, and DNA damage markers. The results revealed that early SPD intervention significantly delays the replicative senescence of hUCMSCs and constrains premature H₂O₂-induced senescence. Additionally, by silencing SIRT3, the SPD-mediated antisenescence effects disappear, further demonstrating that SIRT3 is necessary for SPD to exert its antisenescence effects on hUCMSCs. Besides, the findings of this study also suggest that SPD in vivo protects MSCs against oxidative stress and delays cell senescence. Thus, MSCs maintain the ability to proliferate and differentiate efficiently in vitro and in vivo, which reflects the potential clinical utilization of MSCs in the future.

Models of Congenital Adrenal Hyperplasia for Gene Therapies Testing

The adrenal glands are important endocrine organs that play a major role in the stress response. Some adrenal glands abnormalities are treated with hormone replacement therapy, which does not address physiological requirements. Modern technologies make it possible to develop gene therapy drugs that can completely cure diseases caused by mutations in specific genes. Congenital adrenal hyperplasia (CAH) is an example of such a potentially treatable monogenic disease. CAH is an autosomal recessive inherited disease with an overall incidence of 1:9500–1:20,000 newborns. To date, there are several promising drugs for CAH gene therapy. At the same time, it remains unclear how new approaches can be tested, as there are no models for this disease. The present review focuses on modern models for inherited adrenal gland insufficiency and their detailed characterization. In addition, the advantages and disadvantages of various pathological models are discussed, and ways of further development are suggested.

Steroidogenic Factor 1, a Goldilocks Transcription Factor from Adrenocortical Organogenesis to Malignancy

Steroidogenic factor-1 (SF-1, also termed Ad4BP; NR5A1 in the official nomenclature) is a nuclear receptor transcription factor that plays a crucial role in the regulation of adrenal and gonadal development, function and maintenance. In addition to its classical role in regulating the expression of P450 steroid hydroxylases and other steroidogenic genes, involvement in other key processes such as cell survival/proliferation and cytoskeleton dynamics have also been highlighted for SF-1. SF-1 has a restricted pattern of expression, being expressed along the hypothalamic-pituitary axis and in steroidogenic organs since the time of their establishment. Reduced SF-1 expression affects proper gonadal and adrenal organogenesis and function. On the other hand, SF-1 overexpression is found in adrenocortical carcinoma and represents a prognostic marker for patients' survival. This review is focused on the current knowledge about SF-1 and the crucial importance of its dosage for adrenal gland development and function, from its involvement in adrenal cortex formation to tumorigenesis. Overall, data converge towards SF-1 being a key player in the complex network of transcriptional regulation within the adrenal gland in a dosage-dependent manner.

Comparative Analysis of the Potential for Germ Cell (GC) Differentiation of Bovine Peripheral Blood Derived-Mesenchymal Stem Cells (PB-MSC) and Spermatogonial Stem Cells (SSC) in Co-Culture System with Sertoli Cells (SC)

Although spermatogonial stem cells (SSC) constitute primary candidates for in vitro germ cell (GC) derivation, they are scarce and difficult to maintain in an undifferentiated state. Alternatively, mesenchymal stem cells (MSC) are also candidates for GC derivation due to their simplicity for culture and multipotential for transdifferentiation. The aim of the present study was to compare the GC differentiation potentials of bull peripheral blood-derived MSC (PB-MSC) and SSC using an in vitro 3D co-culture system with Sertoli cells (SC). Samples of PB-MSC or SSC co-cultures with SC were collected on days 0, 7, 14 and 21 and analyzed for pluripotency, GC and mesenchymal marker expression. Co-culture of PB-MSC+SC resulted in down-regulation of NANOG and up-regulation of OCT4 at day 7. In comparison, co-culture of SSC+SC resulted in consistent expression of NANOG, OCT4 and SOX2 at day 14. During co-culture, SSC+SC increased the expression of DAZL, PIWIL2, FRAGILIS and STELLA and activated the expression of STRA8, whereas co-culture of PB-MSC+SC only increased the expression of DAZL and PIWIL2. Thus, co-culture of bull PB-MSC+SC and SSC+SC in 3D SACS results in differential expression of pluripotency and GC markers, where bull SSC display a more robust GC differentiation profile compared to PB-MSC.

Future directions for adrenal insufficiency: cellular transplantation and genetic therapies

Primary adrenal insufficiency occurs in 1 in 5-7000 adults. Leading aetiologies are autoimmune adrenalitis in adults and congenital adrenal hyperplasia (CAH) in children. Oral replacement of cortisol is lifesaving, but poor quality of life, repeated adrenal crises and dosing uncertainty related to lack of a validated biomarker for glucocorticoid sufficiency, persists. Adrenocortical cell therapy and gene therapy may obviate many of the shortcomings of adrenal hormone replacement. Physiological cortisol secretion regulated by pituitary adrenocorticotropin, could be achieved through allogeneic adrenocortical cell transplantation, production of adrenal-like steroidogenic cells from either stem cells or lineage conversion of differentiated cells, or for CAH, gene therapy to replace or repair a defective gene. The adrenal cortex is a high turnover organ and thus failure to incorporate progenitor cells within a transplant will ultimately result in graft exhaustion. Identification of adrenocortical progenitor cells is equally important in gene therapy where new genetic material must be specifically integrated into the genome of progenitors to ensure a durable effect. Delivery of gene editing machinery and a donor template, allowing targeted correction of the 21-hydroxylase gene, has the potential to achieve this. This review describes advances in adrenal cell transplants and gene therapy that may allow physiological cortisol production for children and adults with primary adrenal insufficiency.

Mesenchymal stromal cell treatment improves outcomes in children with pneumonia post-hematopoietic stem cell transplantation: a retrospective cohort study

BACKGROUND

Hematopoietic stem cell transplantation (HSCT) is a standard therapy strategy for most malignant disorders in children. However, transplant-related pneumonia remains a major therapy challenge and mesenchymal stromal cells (MSCs) are rarely reported in HSCT-related pneumonia. The aim of our study was to assess the efficacy of MSC for HSCT-related pneumonia in children.

METHODS

We retrospectively retrieved HSCT-related (severe and non-severe) pneumonia cases (aged < 18 years), which underwent MSC treatment (MSC group) or non-MSC treatment (non-MSC group) in Guangzhou Women and Children's Medical Center, from December 2017 to December 2019. We investigated outcomes of the two different treatments among severe cases and non-severe cases, respectively. The primary endpoints were differences in overall cure rate and time to cure between MSC and non-MSC groups. The secondary endpoints were 180-day overall survival and cumulative cure rate.

RESULTS

Finally, 31 severe pneumonia cases (16 in MSC group, 15 in non-MSC group) and 76 non-severe cases (31 in MSC group, 45 in non-MSC group) were enrolled in this study. Among severe pneumonia cases, overall cure rate in MSC group was significant higher than that in non-MSC group (12[75.0%] vs. 5[33.3%]; OR = 6.00, 95% CI [1.26-28.5]; p = 0.020); the time (days) to cure in MSC group was dramatically reduced compared with that in non-MSC group (36 [19-52] vs. 62 [42-81]; OR = 0.32, 95% CI [0.12-0.88]; p = 0.009); the 180-day overall survival in MSC group was better than that in non-MSC group (74.5% [45.4-89.6] vs. 33.3% [12.2-56.4]; p = 0.013). Among non-severe pneumonia cases, the time (days) to cure in MSC group was notably decreased compared with that in non-MSC group (28 [24-31] vs. 33 [26-39]; OR = 0.31, 95% CI [0.18-0.56]; p = 0.003). Compared with non-MSC group, MSC-treated patients achieved significant improvements of cumulative cure rate not only in severe pneumonia cases (p = 0.027), but also in non-severe cases (p < 0.001).

CONCLUSIONS

This study revealed that MSC treatment could contribute to improving outcomes in children with pneumonia post-HSCT, especially in severe cases. These findings suggest MSC treatment as a promising therapy for HSCT-related pneumonia in children.

[Gene and cell therapy of adrenal pathology: achievements and prospects]

Our current understanding of the molecular and cellular mechanisms in tissues and organs during normal and pathological conditions opens up substantial prospects for the development of novel approaches to treatment of various diseases. For instance, lifelong replacement therapy is no longer mandatory for the management of some monogenic hereditary diseases. Genome editing techniques that have emerged in the last decade are being actively investigated as tools for correcting mutations in affected organs. Furthermore, new protocols for obtaining various types of human and animal cells and cellular systems are evolving, increasingly reflecting the real structures in vivo. These methods, together with the accompanying gene and cell therapy, are being actively developed and several approaches are already undergoing clinical trials. Adrenal insufficiency caused by a variety of factors can potentially be the target of such therapeutic strategies. The adrenal gland is a highly organized organ, with multiple structural components interacting with each other via a complex network of endocrine and paracrine signals. This review summarizes the findings of studies in the field of structural organization and functioning of the adrenal gland at the molecular level, as well as the modern approaches to the treatment of adrenal pathologies.

Advances in stem cell research for the treatment of primary hypogonadism

In Leydig cell dysfunction, cells respond weakly to stimulation by pituitary luteinizing hormone, and, therefore, produce less testosterone, leading to primary hypogonadism. The most widely used treatment for primary hypogonadism is testosterone replacement therapy (TRT). However, TRT causes infertility and has been associated with other adverse effects, such as causing erythrocytosis and gynaecomastia, worsening obstructive sleep apnoea and increasing cardiovascular morbidity and mortality risks. Stem-cell-based therapy that re-establishes testosterone-producing cell lineages in the body has, therefore, become a promising prospect for treating primary hypogonadism. Over the past two decades, substantial advances have been made in the identification of Leydig cell sources for use in transplantation surgery, including the artificial induction of Leydig-like cells from different types of stem cells, for example, stem Leydig cells, mesenchymal stem cells, and pluripotent stem cells (PSCs). PSC-derived Leydig-like cells have already provided a powerful in vitro model to study the molecular mechanisms underlying Leydig cell differentiation and could be used to treat men with primary hypogonadism in a more specific and personalized approach.

Towards novel treatments for adrenal diseases: Cell- and gene therapy-based approaches

Adrenal insufficiency, the inability to produce adequate levels of corticosteroids, is a multi-causal disease that requires lifelong daily hormone replacement. Nevertheless, this cannot replace the physiological demand for steroids which are secreted following a circadian rhythm and vary in periods of stress; the consequences of under- or over-replacement include adrenal crisis and metabolic disturbances, respectively. Although clinical research has focused on enhancing the effectiveness/reducing side effects of current treatment modalities, only small improvements are deemed possible; thus, alternative solutions are urgently needed. Gene and cell therapy strategies have opened new possibilities for the cure of many diseases in a way that has never been possible before and could offer a viable option for the cure of adrenal diseases. The current state of cell- and gene-based approaches to restore adrenocortical function is discussed in this review.

Hypoxia-Preconditioned Human Umbilical Cord Blood-Derived Mesenchymal Stem Cells Mitigate Hypoglycemic Testicular Injury Induced by Insulin in Rats

Hypoglycemia is a neglected metabolic disorder. Thus, we evaluated the protective effect of hypoxia-preconditioned human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) on hypoglycemic testicular injury. We examined 56 testes from 28 animals: 7 rats with insulin-induced hypoglycemia (HG group), 7 hypoglycemic rats which received an intratesticular injection of hUCB-MSCs (HG-MSC group), and 14 untreated control rats. Testosterone level, testicular catalase (CAT) activity, and malondialdehyde (MDA) level were analyzed. Immunostaining for specific testicular germ and somatic cell markers was performed. Proliferating and apoptotic cells were detected by anti-PCNA and anti-caspase-3, respectively. Morphometrical data were statistically analyzed. The hypoglycemic rats showed a significant decrease in testosterone level and CAT activity and a significant increase in MDA production. Examination of histological structure and protein expression of diverse germ cell markers revealed collapsed tubules that were lined by degenerated germ cells, decreased lactate dehydrogenase type C immune expression, as well as decreased proliferating and increased apoptotic cells number in hypoglycemic testes. Injection of MSCs improved testicular biochemical parameters, preserved germ cells and somatic cells, and decreased apoptosis. In conclusion, hypoxia-preconditioned hUCB-MSCs attenuate rat testicular injury caused by insulin-induced hypoglycemia. Avoidance and rapid management of hypoglycemia are necessary to avoid significant testicular injury.

Repairing and Analgesic Effects of Umbilical Cord Mesenchymal Stem Cell Transplantation in Mice with Spinal Cord Injury

Transplantation of human umbilical cord mesenchymal stem cells (hUC-MSCs) into spinal cord injury (SCI) may alleviate neuropathic pain and promote functional recovery. The underlying mechanism likely involves activation of glial cells and regulation of inflammatory factors but requires further validation. SCI was induced in 16 ICR mice using an SCI compression model, followed by injection of lentiviral vector-mediated green fluorescent protein- (GFP-) labeled hUC-MSCs 1 week later. Behavioral tests, histological evaluation, and inflammatory factor detection were performed in the treatment (SCI+hUC-MSCs) and model (SCI) groups. Histological evaluation revealed GFP expression in the spinal cord tissue of the treatment group, implying that the injected MSCs successfully migrated to the SCI. The Basso, Beattie, and Bresnahan (BBB) scores showed that motor function gradually recovered over time in both groups, but recovery speed was significantly higher in the treatment group than in the model group. The pain threshold in mice decreased after SCI but gradually increased over time owing to the self-repair function of the body. The corresponding pain threshold of the treatment group was significantly higher than that of the model group, indicating the therapeutic and analgesic effects of hUC-MSCs. Expression of IL-6 and TNF-α in the spinal cord tissue of the treated group decreased, whereas glial cell line-derived neurotrophic factor (GDNF) expression along with ED1 expression increased compared with those in the model group, suggesting that SCI activated ED1 inflammatory macrophages/microglia, which were subsequently reduced by hUC-MSC transplantation. hUC-MSCs are speculated to enhance the repair of the injured spinal cord tissue and exert an analgesic effect by reducing the secretion of inflammatory factors IL-6 and TNF-α and upregulating the expression of GDNF.

Allogeneic umbilical cord-derived mesenchymal stem cell transplantation for treating chronic obstructive pulmonary disease: a pilot clinical study

Introduction

Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide. COPD results from chronic inflammation of the lungs. Current treatments, including physical and chemical therapies, provide limited results. Stem cells, particularly mesenchymal stem cells (MSCs), are used to treat COPD. Here, we evaluated the safety and efficacy of umbilical cord-derived (UC)-MSCs for treating COPD.

Methods

Twenty patients were enrolled, 9 at stage C and 11 at stage D per the Global Initiative for Obstructive Lung Disease (GOLD) classification. Patients were infused with 10⁶ cells/kg of expanded allogeneic UC-MSCs. All patients were followed for 6 months after the first infusion. The treatment end-point included a comprehensive safety evaluation, pulmonary function testing (PFT), and quality-of-life indicators including questionnaires, the 6-min walk test (6MWT), and systemic inflammation assessments. All patients completed the full infusion and 6-month follow-up.

Results

No infusion-related toxicities, deaths, or severe adverse events occurred that were deemed related to UC-MSC administration. The UC-MSC-transplanted patients showed a significantly reduced Modified Medical Research Council score, COPD assessment test, and number of exacerbations. However, the forced expiratory volume in 1 s, C-reactive protein, and 6MWT values were nonsignificantly reduced after treatment (1, 3, and 6 months) compared with those before the treatment.

Conclusion

Systemic UC-MSC administration appears to be safe in patients with moderate-to-severe COPD, can significantly improve their quality of life, and provides a basis for subsequent cell therapy investigations.

Trial registration

ISRCTN, ISRCTN70443938. Registered 06 July 2019

Differentiation of human umbilical cord mesenchymal stem cells into Leydig-like cells with defined molecular compounds

95% of the body's testosterone is produced by the Leydig Cells (LCs) in adult testis, and LC functional degradation can cause testosterone deficiency ultimately leading towards hypogonadism. The transplantation of LCs derived from stem cells is a very promising therapy to overcome the testosterone deficiency. The isolated umbilical cord mesenchymal stem cells (UMSCs) were identified by flow cytometry and adipogenic and osteogenic differentiation. Western blotting and reverse transcription polymerase chain reaction (RT-PCR) were used for the differentiated Leydig-like cell identification. The comparisons of the testosterone levels, gene expression levels, and cyclic adenosine monophosphate (cAMP) productions were performed through radioimmunoassay, quantitative polymerase chain reaction (qPCR), and cAMP assay kit, respectively. Here, it is stated that our isolated human UMSCs, which could positively express CD29, CD44, CD59, CD90, CD105, and CD166 but negatively express CD34 as well as could be differentiated into adipocytes and osteocytes, could be differentiated into Leydig-like cells (UMSC-LCs) using a novel differentiation method based on molecular compounds. The enrichment UMSC-LCs could secrete testosterone into the medium supernatant and produce considerable cAMP at the stimulation of luteinizing hormone (LH), and positively expressed LC lineage-typical markers LHCGR, SCARB1, SATR, CYP11A1, CYP17A1, HSD3B1, HSD17B3, and SF-1 as well as negatively expressed mesenchymal stem cell typical markers CD29, CD44, and CD105. The expression levels of NR3C4, PDGFRA, and NR3A1 in UMSC-LCs were higher than those of UMSCs and were comparable with LCs. These results illuminated that UMSCs could be differentiated into Leydig-like cells using the defined molecular compounds, which might further support MSC-derived Leydig cell transplantation therapy for testosterone insufficiency.

Transcriptional Regulation of Ovarian Steroidogenic Genes: Recent Findings Obtained from Stem Cell-Derived Steroidogenic Cells

Ovaries represent one of the primary steroidogenic organs, producing estrogen and progesterone under the regulation of gonadotropins during the estrous cycle. Gonadotropins fluctuate the expression of various steroidogenesis-related genes, such as those encoding steroidogenic enzymes, cholesterol deliverer, and electronic transporter. Steroidogenic factor-1 (SF-1)/adrenal 4-binding protein (Ad4BP)/NR5A1 and liver receptor homolog-1 (LRH-1) play important roles in these phenomena via transcriptional regulation. With the aid of cAMP, SF-1/Ad4BP and LRH-1 can induce the differentiation of stem cells into steroidogenic cells. This model is a useful tool for studying the molecular mechanisms of steroidogenesis. In this article, we will provide insight into the transcriptional regulation of steroidogenesis-related genes in ovaries that are revealed from stem cell-derived steroidogenic cells. Using the cells derived from the model, novel SF-1/Ad4BP- and LRH-1-regulated genes were identified by combined DNA microarray and promoter tiling array analyses. The interaction of SF-1/Ad4BP and LRH-1 with transcriptional regulators in the regulation of ovarian steroidogenesis was also revealed.

SFMBT2 positively regulates SOX9 and chondrocyte proliferation

SRY‑box 9 (SOX9) is the master regulator of the chondrocyte phenotype, which is essential for differentiating chondrogenic mesenchymal condensations into chondrocytes, and is involved in regulating every stage of chondrocyte differentiation. SOX9 deletion in chondrocytes at the late stages of cartilage development results in decreased chondrocyte proliferation; inhibited expression of cartilage matrix genes, including Indian hedgehog and the downstream parathyroid hormone‑related protein; and premature conversion of proliferating chondrocytes into hypertrophic chondrocytes, which mineralize their matrix prematurely. Therefore, SOX9 is considered vital for the majority of phases of chondrocyte lineage, from early condensations to the differentiation of proliferating chondrocytes, leading to chondrocyte hypertrophy. It has been reported that SOX9 expression is decreased in osteoarthritis (OA) cartilage. Regeneration or repair of cartilage degradation in OA remains a challenge. Previous studies have indicated that overexpression of SOX9 can promote cartilage repair and can be used as a potential therapeutic agent at the early stages of human OA. The present study identified Scm‑like with four malignant brain tumor domains 2 (SFMBT2) as a novel regulator of SOX9 expression in human chondrocytes. Our previous study revealed that SFMBT2 is negatively regulated in OA cartilage, and decreased levels of SFMBT2 contribute to the catabolic phenotype of chondrocytes. The present study detected increased expression levels of SFMBT2 in early cartilage development and during the early phases of chondrogenesis. Overexpression of SFMBT2 in C28/I2 cells upregulated SOX9 expression in a dose‑dependent manner. Furthermore, SFMBT2 positively regulated C28/I2 cell proliferation and restored the decreased levels of SOX9 in chondrocytes following tumor necrosis factor‑α treatment. Additional studies may reveal novel insights into the molecular mechanism involved and the potential role of SFMBT2 in cartilage repair and OA management.

Mesenchymal stem cells from human umbilical cord ameliorate testicular dysfunction in a male rat hypogonadism model

Androgen deficiency is a physical disorder that not only affects adults but can also jeopardize children's health. Because there are many disadvantages to using traditional androgen replacement therapy, we have herein attempted to explore the use of human umbilical cord mesenchymal stem cells for the treatment of androgen deficiency. We transplanted CM-Dil-labeled human umbilical cord mesenchymal stem cells into the testes of an ethane dimethanesulfonate (EDS)-induced male rat hypogonadism model. Twenty-one days after transplantation, we found that blood testosterone levels in the therapy group were higher than that of the control group (P = 0.037), and using immunohistochemistry and flow cytometry, we observed that some of the CM-Dil-labeled cells expressed Leydig cell markers for cytochrome P450, family 11, subfamily A, polypeptide 1, and 3-β-hydroxysteroid dehydrogenase. We then recovered these cells and observed that they were still able to proliferate in vitro. The present study shows that mesenchymal stem cells from human umbilical cord may constitute a promising therapeutic modality for the treatment of male hypogonadism patients.

Neuroprotection of Transplanting Human Umbilical Cord Mesenchymal Stem Cells in a Microbead Induced Ocular Hypertension Rat Model

PURPOSE

The purpose of this study is to investigate the potential therapeutic benefits of intravitreally transplanted human umbilical cord mesenchymal stem cells (UC-MSCs) in an animal model of microbead-injection-induced ocular hypertension (OHT).

METHODS

UC-MSCs were isolated from human umbilical cords and then cultured. The OHT model was induced via intracameral injection of polystyrene microbeads in Sprague-Dawley adult rat eyes. Fifty-four healthy adult rats were randomly divided into three groups: normal control, OHT model treated with intravitreal transplantation of UC-MSCs, or phosphate-buffered saline (PBS). Two days after OHT was induced, either 5 µl 10⁵ UC-MSCs suspension or PBS was injected into the vitreous cavity of rats. UC-MSCs localization and integration were examined via immunohistochemistry. Neuroprotection was quantified by counting retinal ganglion cells (RGCs) and axons 2 weeks following transplantation. The expression levels of glial-derived neurotrophic factor (GDNF), brain-derived neurotrophic factor (BDNF), and glial fibrillary acidic protein (GFAP) were assessed via immunohistochemistry and Western blot. Functional recovery was assessed 2 weeks after transplantation via scotopic threshold response (STR) electroretinography.

RESULTS

Elevated IOP levels were sustained at least 3 weeks after intracameral microbead injection and the number of β-III-tubulin⁺ RGCs significantly declined compared to PBS-injected eyes. UC-MSCs survived for at least 2 weeks after intravitreal transplantation and predominantly located in the vitreous cavity. A fraction of cells migrated into the ganglion cell layer of host retina, but without differentiation. Intravitreal UC-MSC transplantation resulted in increased number of RGCs, axons, and increased expression of GDNF and BDNF but decreased expression of GFAP. Intravitreal delivery of UC-MSCs significantly improved the recovery of the positive STR.

CONCLUSIONS

Intravitreal transplantation of UC-MSCs revealed the neuroprotection in the microbead-injection induced OHT. The effects could be related to the secretion of tropic factors (BDNF and GDNF) and the modulation of glial cell activation.

Modeling Congenital Adrenal Hyperplasia and Testing Interventions for Adrenal Insufficiency Using Donor-Specific Reprogrammed Cells

Adrenal insufficiency is managed by hormone replacement therapy, which is far from optimal; the ability to generate functional steroidogenic cells would offer a unique opportunity for a curative approach to restoring the complex feedback regulation of the hypothalamic-pituitary-adrenal axis. Here, we generated human induced steroidogenic cells (hiSCs) from fibroblasts, blood-, and urine-derived cells through forced expression of steroidogenic factor-1 and activation of the PKA and LHRH pathways. hiSCs had ultrastructural features resembling steroid-secreting cells, expressed steroidogenic enzymes, and secreted steroid hormones in response to stimuli. hiSCs were viable when transplanted into the mouse kidney capsule and intra-adrenal. Importantly, the hypocortisolism of hiSCs derived from patients with adrenal insufficiency due to congenital adrenal hyperplasia was rescued by expressing the wild-type version of the defective disease-causing enzymes. Our study provides an effective tool with many potential applications for studying adrenal pathobiology in a personalized manner and opens venues for the development of precision therapies.

Umbilical cord: an unlimited source of cells differentiable towards dopaminergic neurons

Cell replacement therapy utilizing mesenchymal stem cells as its main resource holds great promise for ultimate treatment of human neurological disorders. Parkinson's disease (PD) is a common, chronic neurodegenerative disorder hallmarked by localized degeneration of a specific set of dopaminergic neurons within a midbrain sub-region. The specific cell type and confined location of degenerating neurons make cell replacement therapy ideal for PD treatment since it mainly requires replenishment of lost dopaminergic neurons with fresh and functional ones. Endogenous as well as exogenous cell sources have been identified as candidate targets for cell replacement therapy in PD. In this review, umbilical cord mesenchymal stem cells (UCMSCs) are discussed as they provide an inexpensive unlimited reservoir differentiable towards functional dopaminergic neurons that potentially lead to long-lasting behavioral recovery in PD patients. We also present miRNAs-mediated neuronal differentiation of UCMSCs. The UCMSCs bear a number of outstanding characteristics including their non-tumorigenic, low-immunogenic properties that make them ideal for cell replacement therapy purposes. Nevertheless, more investigations as well as controlled clinical trials are required to thoroughly confirm the efficacy of UCMSCs for therapeutic medical-grade applications in PD.

Decrease of miR-195 Promotes Chondrocytes Proliferation and Maintenance of Chondrogenic Phenotype via Targeting FGF-18 Pathway

Slow growth and rapid loss of chondrogenic phenotypes are the major problems affecting chronic cartilage lesions. The role of microRNA-195 (miR-195) and its detailed working mechanism in the fore-mentioned process remains unknown. Fibroblastic growth factor 18 (FGF-18) plays a key role in cartilage homeostasis; whether miR-195 could regulate FGF-18 and its downstream signal pathway in chondrocyte proliferation and maintenance of chondrogenic phenotypes still remains unclear. The present research shows elevated miR-195 but depressed FGF-18 expressed in joint fluid specimens of 20 patients with chronic cartilage lesions and in CH1M and CH3M chondrocytes when compared with that in joint fluid specimens without cartilage lesions and in CH1W and CH2W chondrocytes, respectively. The following loss of function test revealed that downregulation of miR-195 by transfection of miR-195 inhibitors promoted chondrocyte proliferation and expression of a type II collagen α I chain (Col2a1)/aggrecan. Through the online informatics analysis we theoretically predicted that miR-195 could bind to a FGF-18 3' untranslated region (3'UTR), also, we verified that a miR-195 could regulate the FGF-18 and its downstream pathway. The constructed dual luciferase assay further confirmed that FGF-18 was a direct target of miR-195. The executed anti-sense experiment displayed that miR-195 could regulate chondrocyte proliferation and Col2a1/aggrecan expression via the FGF-18 pathway. Finally, through an in vivo anterior cruciate ligament transection (ACLT) model, downregulation of miR-195 presented a significantly protective effect on chronic cartilage lesions. Evaluating all of the outcomes of the current research revealed that a decrease of miR-195 protected chronic cartilage lesions by promoting chondrocyte proliferation and maintenance of chondrogenic phenotypes via the targeting of the FGF-18 pathway and that the miR-195/FGF-18 axis could be a potential target in the treatment of cartilage lesions.

MANAGEMENT OF ENDOCRINE DISEASE: Regenerative therapies in autoimmune Addison's disease

The treatment for autoimmune Addison's disease (AAD) has remained virtually unchanged in the last 60 years. Most patients have symptoms that are relatively well controlled with exogenous steroid replacement, but there may be persistent symptoms, recurrent adrenal crisis and poor quality of life, despite good compliance with optimal current treatments. Treatment with conventional exogenous steroid therapy is also associated with premature mortality, increased cardiovascular risk and complications related to excessive steroid replacement. Hence, novel therapeutic approaches have emerged in the last decade attempting to improve the long-term outcome and quality of life of patients with AAD. This review discusses the recent developments in treatment innovations for AAD, including the novel exogenous steroid formulations with the intention of mimicking the physiological biorhythm of cortisol secretion. Our group has also carried out a few studies attempting to restore endogenous glucocorticoid production via immunomodulatory and regenerative medicine approaches. The recent advances in the understanding of adrenocortical stem cell biology, and adrenal plasticity will also be discussed to help comprehend the science behind the therapeutic approaches adopted.

External factors influencing mesenchymal stem cell fate in vitro

Mesenchymal stem cells (MSCs) have extensive potentials, which make them attractive candidates for the developmental biology, drug discovery and regenerative medicine. However, the use of MSCs is limited by their scarceness in tissues and in culture conditions. They also exhibit various degrees of potency which subsequently influencing their applications. Nowadays, questions remain about how self-renewal and differentiation of MSCs can be controlled in vitro and in vivo, how they will behave and migrate to the right place and how they modulate the immune system. Therefore, identification of factors and culture conditions to affect the fate and function of MSCs may be effective to enhance their applications in clinical situations. Studies have indicated that the fate of MSCs in culture is influenced by various external factors, including the specific cell source, donor age, plating density, passage number and plastic surface quality. Some other factors such as cell culture media and their supplementary factors, O₂ concentration, mechano-/electro-stimuli and three-dimensional scaffolds are also shown to be influential. This review addresses the current state of MSC research for describing and discussing the findings about external factors that influence the fate and function of MSCs. Additionally, the new discoveries and suggestions regarding their molecular mechanisms will be explained.

Stem cell therapy for the treatment of Leydig cell dysfunction in primary hypogonadism

The production of testosterone occurs within the Leydig cells of the testes. When production fails at this level from either congenital, acquired, or systemic disorders, the result is primary hypogonadism. While numerous testosterone formulations have been developed, none are yet fully capable of replicating the physiological patterns of testosterone secretion. Multiple stem cell therapies to restore androgenic function of the testes are under investigation. Leydig cells derived from bone marrow, adipose tissue, umbilical cord, and the testes have shown promise for future therapy for primary hypogonadism. In particular, the discovery and utilization of a group of progenitor stem cells within the testes, known as stem Leydig cells (SLCs), has led not only to a better understanding of testicular development, but of treatment as well. When combining this with an understanding of the mechanisms that lead to Leydig cell dysfunction, researchers and physicians will be able to develop stem cell therapies that target the specific step in the steroidogenic process that is deficient. The current preclinical studies highlight the complex nature of regenerating this steroidogenic process and the problems remain unresolved. In summary, there appears to be two current directions for stem cell therapy in male primary hypogonadism. The first method involves differentiating adult Leydig cells from stem cells of various origins from bone marrow, adipose, or embryonic sources. The second method involves isolating, identifying, and transplanting stem Leydig cells into testicular tissue. Theoretically, in-vivo re-activation of SLCs in men with primary hypogonadism due to age would be another alternative method to treat hypogonadism while eliminating the need for transplantation.

Differentiation of human umbilical cord mesenchymal stem cells into steroidogenic cells in vitro

Although previous studies have shown that stem cells can be differentiated into Leydig cells by gene transfection, a simple, safe and effective induction method has not yet been reported. Therefore, the present study investigated novel methods for the induction of human umbilical cord mesenchymal stem cell (HUMSC) differentiation into Leydig-like, steroidogenic cells. HUMSCs were acquired using the tissue block culture attachment method, and the expression of MSC surface markers was evaluated by flow cytometry. Leydig cells were obtained by enzymatic digestion and identified by lineage-specific markers via immunofluorescence. Third-passage HUMSCs were cultured with differentiation-inducing medium (DIM) or Leydig cell-conditioned medium (LC-CM), and HUMSCs before induction were used as the control group. Following the induction of HUMSCs, Leydig cell lineage-specific markers (CYP11A1, CYP17A1 and 3β-HSD) were positively identified using immunofluorescence analysis. Additionally, reverse transcription-quantitative polymerase chain reaction and western blot analysis were performed to evaluate the expression levels of these genes and enzymes. In contrast, the control group cells did not show the characteristics of Leydig cells. Collectively, these results indicate that, under in vitro conditions, LC-CM can achieve a comparable effect to that of DIM on inducing HUMSCs differentiation into steroidogenic cells.

Genetic Comparison of Stemness of Human Umbilical Cord and Dental Pulp

This study focuses on gene expression patterns and functions in human umbilical cord (UC) and dental pulp (DP) containing mesenchymal stem cells (MSCs). DP tissues were collected from 25 permanent premolars. UC tissue samples were obtained from three newborns. Comparative gene profiles were obtained using cDNA microarray analysis and the expression of tooth development-associated and MSC-related genes was assessed by the quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR). Genes related to cell proliferation, angiogenesis, and immune responses were expressed at higher levels in UC, whereas genes related to growth factor and receptor activity and signal transduction were more highly expressed in DP. Although UC and DP tissues exhibited similar expression of surface markers for MSCs, UC showed higher expression of CD29, CD34, CD44, CD73, CD105, CD146, and CD166. qRT-PCR analysis showed that CD146, CD166, and MYC were expressed 18.3, 8.24, and 1.63 times more highly in UC, whereas the expression of CD34 was 2.15 times higher in DP. Immunohistochemical staining revealed significant differences in the expression of genes (DSPP, DMP1, and CALB1) related to odontogenesis and angiogenesis in DP. DP and UC tissue showed similar gene expression, with the usual MSC markers, while they clearly diverged in their differentiation capacity.

Umbilical Cord as Prospective Source for Mesenchymal Stem Cell-Based Therapy

The paper presents current evidence on the properties of human umbilical cord-derived mesenchymal stem cells, including origin, proliferative potential, plasticity, stability of karyotype and phenotype, transcriptome, secretome, and immunomodulatory activity. A review of preclinical studies and clinical trials using this cell type is performed. Prospects for the use of mesenchymal stem cells, derived from the umbilical cord, in cell transplantation are associated with the need for specialized biobanking and transplant standardization criteria.

Regulation of Steroidogenesis, Development, and Cell Differentiation by Steroidogenic Factor-1 and Liver Receptor Homolog-1

Steroidogenic factor-1 (SF-1) and liver receptor homolog-1 (LRH-1) belong to the nuclear receptor superfamily and are categorized as orphan receptors. In addition to other nuclear receptors, these play roles in various physiological phenomena by regulating the transcription of target genes. Both factors share very similar structures and exhibit common functions. Of these, the roles of SF-1 and LRH-1 in steroidogenesis are the most important, especially that of SF-1, which was originally discovered and named to reflect such roles. SF-1 and LRH-1 are essential for steroid hormone production in gonads and adrenal glands through the regulation of various steroidogenesis-related genes. As SF-1 is also necessary for the development of gonads and adrenal glands, it is also considered a master regulator of steroidogenesis. Recent studies have clearly demonstrated that LRH-1 also represents another master regulator of steroidogenesis, which similarly to SF-1, can induce differentiation of non-steroidogenic stem cells into steroidogenic cells. Here, we review the functions of both factors in these steroidogenesis-related phenomena.

New directions for the treatment of adrenal insufficiency

Adrenal disease, whether primary, caused by defects in the hypothalamic-pituitary-adrenal (HPA) axis, or secondary, caused by defects outside the HPA axis, usually results in adrenal insufficiency, which requires lifelong daily replacement of corticosteroids. However, this kind of therapy is far from ideal as physiological demand for steroids varies considerably throughout the day and increases during periods of stress. The development of alternative curative strategies is therefore needed. In this review, we describe the latest technologies aimed at either isolating or generating de novo cells that could be used for novel, regenerative medicine application in the adrenocortical field.

Hepatocyte Growth Factor Gene-Modified Mesenchymal Stem Cells Augment Sinonasal Wound Healing

This study was designed to investigate the effects of hepatocyte growth factor (HGF) transgenic mesenchymal stem cells (HGF-MSCs) on wound healing in the sinonasal mucosa and nasal epithelial cells (NECs). We also sought to determine whether HGF-MSCs and MSCs can migrate into the injured mucosa and differentiate into ciliated cells. Human HGF-overexpressing umbilical cord MSCs (hHGF-UCMSCs) were established, and upregulation of hHGF expression was confirmed by real-time PCR (RT-PCR) and enzyme-linked immunosorbant assay (ELISA). To investigate the paracrine effect of human MSCs (hMSCs) on nasal epithelial repair, hMSC- and HGF-MSC-conditioned media (CM) were used in NEC proliferation assays and in an in vitro scratch-wound repair model. The in vivo sinonasal wound-healing model was established, and all enrolled rabbits were randomly assigned to four groups: the GFP-MSC group, the HGF-MSC group, the Ad-HGF group, and the surgery control group. The average decreased diameter was recorded, and the medial wall of the maxillary sinus was removed for histological analysis and scanning electron microscopy. Collagen deposition in the wound tissue was detected via Masson trichrome (M&T) staining. The distribution of MSCs and HGF-MSCs was observed by immunofluorescence. MSCs improved nasal wound healing both in vivo and in vitro. HGF overexpression in MSCs augmented the curative effects. Reduced collagen deposition and transforming growth factor beta1 (TGF-β1) expression were detected in the HGF-MSC group compared with the MSC-, Ad-HGF-, and phosphate-buffered saline-treated groups based on M&T staining and ELISA. The enhanced therapeutic effects of HGF-MSCs were accompanied by decreased level of the fibrogenic cytokine TGF-β1. In addition, both HGF-MSCs and MSCs can migrate to the injured mucosa and epithelial layer.

All the Tested Human Somatic Cells Express Both Oct4A and Its Pseudogenes but Express Oct4A at Much Lower Levels Compared with Its Pseudogenes and Human Embryonic Stem Cells

Oct4 pseudogenes and isoforms seriously confuse the detection of the pluripotency-associated Oct4A expression in somatic cells, which in many cases was not accurately determined. This confusion has recently been discussed, but the wrong conclusions have continuously been made. Most studies failed to detect the expression of Oct4 pseudogenes and isoforms in somatic cells but detected only Oct4A, for which the detection signals incorrectly came from its pseudogenes and isoforms. Some studies detected the expression of only Oct4 pseudogenes in somatic cells but failed to detect Oct4A. The other studies failed to detect the expression of any Oct4 genes. Oct4A is more homologous to its pseudogenes than its isoforms, and it is much more difficult to distinguish Oct4A from its pseudogenes, so this study focused on them. In this study, the strict experimental procedures were followed. Three pairs of Oct4A-specific polymerase chain reaction (PCR) primers were carefully designed and tested by sequencing reverse transcription-polymerase chain reaction (RT-PCR) clones, which showed that only one of them was truly specific to Oct4A. RT-PCR was also performed with the primers amplifying both Oct4A and its pseudogenes, and several hundreds of PCR clones from each cell type were sequenced to reliably distinguish the low-abundant Oct4A from its high-abundant pseudogenes. Western blot, immunocytochemistry, and flow cytometric analyses were performed with three Oct4 antibodies to confirm the results of Oct4 mRNA expression. This study undoubtedly made the correct conclusions about Oct4 expression in human somatic cells and showed that all the tested human somatic cells expressed both Oct4A and its pseudogenes but expressed Oct4A at much lower levels compared with its pseudogenes.

Human Umbilical Cord Mesenchymal Stem Cells Inhibit the Function of Allogeneic Activated Vγ9Vδ2 T Lymphocytes In Vitro

Background. Human umbilical cord mesenchymal stem cells (UC-MSCs) can regulate the function of immune cells. However, whether and how UC-MSCs can modulate the function of Vγ9Vδ2 T cells has not been fully understood. Methods. The PBMCs or Vγ9Vδ2 T cells were activated and expanded with pamidronate (PAM) and interleukin-2 (IL-2) with or without the presence UC-MSCs. The effects of UC-MSCs on the proliferation, cytokine expression, and cytotoxicity of Vγ9Vδ2 T cells were determined by flow cytometry. The effects of UC-MSCs on Fas-L, TRAIL-expressing Vγ9Vδ2 T cells, and Vγ9Vδ2 T cell apoptosis were determined by flow cytometry. Results. UC-MSCs inhibited Vγ9Vδ2 T cell proliferation in a dose-dependent but cell-contact independent manner. Coculture with UC-MSCs reduced the frequency of IFNγ+ but increased granzyme B+ Vγ9Vδ2 T cells. UC-MSCs inhibited the cytotoxicity of Vγ9Vδ2 T cells against influenza virus H1N1 infected A549 cells and also reduced the frequency of Fas-L+, TRAIL+ Vγ9Vδ2 T cells but failed to modulate the apoptosis of Vγ9Vδ2 T cells. Conclusions. These results indicated that UC-MSCs efficiently suppressed the proliferation and cytotoxicity of Vγ9Vδ2 T cells and modulated their cytokine production. Fas-L and TRAIL were involved in the regulation. Cell contact and apoptosis of Vγ9Vδ2 T cells were not necessary for the inhibition.

Promise(s) of using mesenchymal stem cells in reproductive disorders

In recent times, infertility among both man and woman has become a major concern affecting about 20 per cent of the population worldwide and has been attributed in part to several aetiological factors such as changes in lifestyle, which includes sedentary life, dietary habits, sleep anomalies, environmental pollution, etc. Assisted reproductive technologies (ART) have come to the rescue of many such couples, but presence of metabolic disorders such as obesity, diabetes with insulin resistance (IR) and its secondary complications (micro- and macro-vascular complications), become confounders to the outcome of ART. Cell therapies are arising as a new hope in the management of reproductive disorders and currently, the efficacy of mesenchymal stem cells (MSCs) harvested from the adult sources finds wide application in the management of diseases like stroke, neuropathy, nephropathy, myopathy, wounds in diabetes, etc. Given the capacity of MSCs to preferentially home to damaged tissue and modulate the cellular niche/microenvironment to augment tissue repairs and regeneration, the present review outlines the applications of MSCs in the management of infertility/reproductive disorders.

PHBVHHx scaffolds loaded with umbilical cord-derived mesenchymal stem cells or hepatocyte-like cells differentiated from these cells for liver tissue engineering

More attention has recently been focused on the treatment of various kinds of hepatic diseases based on cell-based therapies. In this study, mesenchymal stem cells were isolated from umbilical cord (UC-MSCs). Results confirmed that UC-MSCs could differentiate into adipocytes, osteoblasts and hepatocytes. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate) (PHBVHHx), a new member of polyhydroxyalkanoate (PHA) family, was produced by bacteria. Liver-injured mouse model was established by CCl4 injection. PHBVHHx scaffolds were transplanted into the liver-injured mice. Liver morphology on day 28 post-transplantation of scaffolds loaded with UC-MSCs or hepatocyte-like cells differentiated from UC-MSCs significantly improved and looked similar to the normal liver. Concentrations of albumin (ALB) significantly increased, and total bilirubin (TB) and alanine axminotransferase (ALT) significantly decreased on days 14 and 28 post-transplantation of scaffolds loaded with UC-MSCs or differentiated UC-MSCs. HE staining showed that on day 28 post-transplantation of scaffolds loaded with UC-MSCs or differentiated UC-MSCs, livers had similar tissue structure of normal livers. Masson staining showed that on day 28 post-transplantation of scaffolds loaded with UC-MSCs or differentiated UC-MSCs, livers had less blue staining for collagen deposition compared with the others. These results demonstrated that PHBVHHx scaffolds loaded with UC-MSCs or differentiated UC-MSCs had the similar effect on injured livers and significantly promoted the recovery of injured livers.

Differentiation of mesenchymal stem cells into gonad and adrenal steroidogenic cells

Hormone replacement therapy is necessary for patients with adrenal and gonadal failure. Steroid hormone treatment is also employed in aging people for sex hormone deficiency. These patients undergo such therapies, which have associated risks, for their entire life. Stem cells represent an innovative tool for tissue regeneration and the possibility of solving these problems. Among various stem cell types, mesenchymal stem cells have the potential to differentiate into steroidogenic cells both in vivo and in vitro. In particular, they can effectively be differentiated into steroidogenic cells by expressing nuclear receptor 5A subfamily proteins (steroidogenic factor-1 and liver receptor homolog-1) with the aid of cAMP. This approach will provide a source of cells for future regenerative medicine for the treatment of diseases caused by steroidogenesis deficiencies. It can also represent a useful tool for studying the molecular mechanisms of steroidogenesis and its related diseases.

Co-culture with Sertoli cells promotes proliferation and migration of umbilical cord mesenchymal stem cells

Human umbilical cord mesenchymal stem cells (hUCMSCs) have been recently used in transplant therapy. The proliferation and migration of MSCs are the determinants of the efficiency of MSC transplant therapy. Sertoli cells are a kind of "nurse" cells that support the development of sperm cells. Recent studies show that Sertoli cells promote proliferation of endothelial cells and neural stem cells in co-culture. We hypothesized that co-culture of UCMSCs with Sertoli cells may also promote proliferation and migration of UCMSCs. To examine this hypothesis, we isolated UCMSCs from human cords and Sertoli cells from mouse testes, and co-cultured them using a Transwell system. We found that UCMSCs exhibited strong proliferation ability and potential to differentiate to other cell lineages such as osteocytes and adipocytes. The presence of Sertoli cells in co-culture significantly enhanced the proliferation and migration potential of UCMSCs (P<0.01). Moreover, these phenotypic changes were accompanied with upregulation of multiple genes involved in cell proliferation and migration including phospho-Akt, Mdm2, phospho-CDC2, Cyclin D1, Cyclin D3 as well as CXCR4, phospho-p44 MAPK and phospho-p38 MAPK. These findings indicate that Sertoli cells boost UCMSC proliferation and migration potential.