Exendin-4 enhances osteogenic differentiation of adipose tissue mesenchymal stem cells through the receptor activator of nuclear factor-kappa B and osteoprotegerin signaling pathway

A novel chitosan-peptide system for cartilage tissue engineering with adipose-derived stromal cells

The natural healing process of cartilage injuries often fails to fully restore the tissue's biological and mechanical functions. Cartilage grafts are costly and require surgical intervention, often associated with complications such as intraoperative infection and rejection by the recipient due to ischemia. Novel tissue engineering technologies aim to ideally fill the cartilage defect to prevent disease progression or regenerate damaged tissue. Despite many studies on designing biocompatible composites to stimulate chondrogenesis, only few focus on peptides and carriers that promote stem cell proliferation or differentiation to promote healing. Our research aimed to design a carbohydrate chitosan-based biomaterial to stimulate stem cells into the chondrogenesis pathway. Our strategy was to combine chitosan with a novel peptide (UG28) that sequence was based on the copin protein. The construct stimulated human adipose-derived stem cells (AD-SCs) cells to undergo chondrogenic differentiation. Chitosan 75/500 allows AD-SCs to grow and has no harmful effects on the cells. The combination of UG28 peptide with the chitosan composite offers promising properties for cell differentiation, indicating its potential for clinical applications in cartilage regeneration.

Adipose-Derived Mesenchymal Stem Cells and Their Derived Epidermal Progenitor Cells Conditioned Media Ameliorate Skin Aging in Rats

BACKGROUND

Skin alterations are among the most prominent signs of aging, and they arise from both intrinsic and extrinsic factors that interact and mutually influence one another. The use of D-galactose as an aging model in animals has been widely employed in anti-aging research. Adipose tissue-derived mesenchymal stem cells (Ad-MSCs) are particularly promising for skin anti-aging therapy due to their capacity for effective re-epithelization and secretion of various growth factors essential for skin regeneration. Accordingly, we aimed to examine the potential utility of Ad-MSCs as a therapy for skin anti-aging.

METHODS

In this study, we isolated and characterized adipose-derived mesenchymal stem cells (Ad-MSCs) from the epididymal fat of male Sprague Dawley rats. We assessed the in vitro differentiation of Ad-MSCs into epidermal progenitor cells (EPCs) using ascorbic acid and hydrocoritsone. Additionally, we induced skin aging in female Sprague Dawley rats via daily intradermal injection of D-galactose over a period of 8 weeks. Then we evaluated the therapeutic potential of intradermal transplantation of Ad-MSCs and conditioned media (CM) derived from differentiated EPCs in the D-galactose-induced aging rats. Morphological assessments, antioxidant assays, and histopathological examinations were performed to investigate the effects of the treatments.

RESULTS

Our findings revealed the significant capability of Ad-MSCs to differentiate into EPCs. Notably, compared to the group that received CM treatment, the Ad-MSCs-treated group exhibited a marked improvement in morphological appearance, antioxidant levels and histological features.

CONCLUSIONS

These results underscore the effectiveness of Ad-MSCs in restoring skin aging as a potential therapy for skin aging.

Semaglutide 6-months therapy of type 2 diabetes mellitus restores adipose progenitors potential to develop metabolically active adipocytes

BACKGROUND

Nowadays type 2 diabetes mellitus (T2DM) leads to population mortality growth. Today glucagon-like peptide type 1 receptor agonists (GLP-1 RA) are one of the most promising glucose-lowered drugs with anorexigenic and cardioprotective effects. The present study aims to determine the effects of GLP-1 RA semaglutide 6-month therapy on T2DM patient metabolic parameters and adipose progenitor cell health.

METHODS

T2DM patients (N = 8) underwent clinical characterization and subcutaneous fat biopsy at start point and after semaglutide 6-month therapy. Adipose-derived stem cells (ADSC) were isolated by enzymatic method. Cell proliferation analysis was performed by MTT and immunocytochemistry. White and beige adipogenesis was analyzed by BODIPY493/503 staining and confocal microscopy. Adipocyte's metabolic properties were estimated by 3H- and 14C-based metabolic assays. Thermogenesis analysis was performed by ERthermAC staining and confocal microscopy. Protein markers were assessed by Western blotting.

RESULTS

Semaglutide 6-month therapy demonstrated significant anorexigenic and glucose-lowering effects. However, insulin sensitivity (HOMA-IR and M-index) was unchanged after therapy. Semaglutide 6-month therapy increased ADSC proliferation and white and beige adipogenesis. Moreover, lipid droplets fragmentation was observed in beige adipocytes. Both white and beige adipocytes after semaglutide therapy demonstrated 2-3 fold growth of glucose uptake without changes in insulin sensitivity. Newly formed white adipocytes demonstrated glucose utilization for active ATP synthesis, whereas beige adipocytes for canonical thermogenesis.

CONCLUSIONS

Our study has revealed that semaglutide 6-month therapy has not only systemic anorexigenic effects, but can markedly improve adipose tissue health. We have demonstrated critical restoration of ADSC renewal functions, which potentially can be involved in semaglutide based weight loss.

The effect of diabetes mellitus on differentiation of mesenchymal stem cells into insulin-producing cells

BACKGROUND

Diabetes mellitus (DM) is a global epidemic with increasing incidences. DM is a metabolic disease associated with chronic hyperglycemia. Aside from conventional treatments, there is no clinically approved cure for DM up till now. Differentiating mesenchymal stem cells (MSCs) into insulin-producing cells (IPCs) is a promising approach for curing DM. Our study was conducted to investigate the effect of DM on MSCs differentiation into IPCs in vivo and in vitro.

METHODS

We isolated adipose-derived mesenchymal stem cells (Ad-MSCs) from the epididymal fat of normal and STZ-induced diabetic Sprague-Dawley male rats. Afterwards, the in vitro differentiation of normal-Ad-MSCs (N-Ad-MSCs) and diabetic-Ad-MSCs (DM-Ad-MSCs) into IPCs was compared morphologically then through determining the gene expression of β-cell markers including neurogenin-3 (Ngn-3), homeobox protein (Nkx6.1), musculoaponeurotic fibrosarcoma oncogene homolog A (MafA), and insulin-1 (Ins-1) and eventually, through performing glucose-stimulated insulin secretion test (GSIS). Finally, the therapeutic potential of N-Ad-MSCs and DM-Ad-MSCs transplantation was compared in vivo in STZ-induced diabetic animals.

RESULTS

Our results showed no significant difference in the characteristics of N-Ad-MSCs and DM-Ad-MSCs. However, we demonstrated a significant difference in their abilities to differentiate into IPCs in vitro morphologically in addition to β-cell markers expression, and functional assessment via GSIS test. Furthermore, the abilities of both Ad-MSCs to control hyperglycemia in diabetic rats in vivo was assessed through measuring fasting blood glucose (FBGs), body weight (BW), histopathological examination of both pancreas and liver and immunoexpression of insulin in pancreata of study groups.

CONCLUSION

Our findings reveal the effectiveness of N-Ad-MSCs in differentiating into IPCs in vitro and controlling the hyperglycemia of STZ-induced diabetic rats in vivo compared to DM-Ad-MSCs.

Silencing of forkhead box protein O-1 (FOXO-1) enhances insulin-producing cell generation from adipose mesenchymal stem cells for diabetes therapy

AIMS

Generation of mature β-cells from MSCs has been a challenge in the field of stem cell therapy of diabetes. Adipose tissue-derived mesenchymal stem cells (Ad-MSCs) have made their mark in regenerative medicine, and provide several advantages compared to other MSCs sources. Forkhead box protein O-1 (FOXO-1) is an important transcription factor for normal development of β-cells, yet its over expression in β-cells may cause glucose intolerance. In this study, we isolated, characterized Ad-MSCs from rat epididymal fat pads, differentiated these MSCs into insulin producing cells (IPCs) and studied the role of FOXO-1 in such differentiation.

MATERIALS AND METHODS

We examined the expression of FOXO-1 and its nuclear cytoplasmic localization in the generated IPCs. Afterwards we knocked down FOXO-1 using siRNA targeting FOXO-1 (siFOXO-1). The differentiated siFOXO-1 IPCs were compared to non-targeting siRNA (siNT) IPCs regarding expression of β-cell markers by qRT-PCR and western blotting, dithizone (DTZ) staining and glucose stimulated insulin secretion (GSIS).

KEY FINDINGS

Isolated Ad-MSCs exhibited all characteristics of MSCs and can generate IPCs. FOXO-1 was initially elevated during differentiation followed by a decline towards end of differentiation. FOXO-1 was dephosphorylated and localized to the nucleus upon differentiation into IPCs. Knock down of FOXO-1 improved the expression of β-cell markers in final differentiated IPCs, improved DTZ uptake and showed increased insulin secretion upon challenging with increased glucose concentration.

SIGNIFICANCE

These results portray FOXO-1 as a hindering factor of generation of IPCs whose down-regulation can generate more mature IPCs for MSCs therapy of diabetes mellitus.

Adipose tissue-derived mesenchymal stem cells ameliorate cognitive impairment in Alzheimer's disease rat model: Emerging role of SIRT1

Alzheimer's disease (AD) is a complex form of neurodegenerative dementia. Growing body of evidence supports the cardinal role of sirtuin1 (SIRT1) in neurodegeneration and AD development. Recently, adipose tissue-derived mesenchymal stem cells (Ad-MSCs) have made their mark for a wide array of regenerative medicine applications, including neurodegenerative disorders. Therefore, the present study aimed to investigate the therapeutic potential of Ad-MSCs in AD rat model, and to explore the possible implication of SIRT1. Ad-MSCs were isolated from rat epididymal fat pads and properly characterized. Aluminum chloride was used to induce AD in rats, and afterward, a group of AD-induced rats received a single dose of Ad-MSCs (2 × 106 cell, I.V per rat). One month after Ad-MSCs transplantation, behavioral tests were done, brain tissues were collected, then histopathological and biochemical assessments were performed. Amyloid beta and SIRT1 levels were determined by enzyme-linked immunosorbent assay. Whereas expression levels of neprilysin, BCL2 associated X protein, B-cell lymphoma-2, interleukin-1β, interleukin-6, and nerve growth factor in hippocampus and frontal cortex brain tissues were assessed using reverse transcriptase quantitative polymerase chain reaction. Our data demonstrated that transplantation of Ad-MSCs alleviated cognitive impairment in AD rats. Additionally, they exhibited anti-amyloidogenic, antiapoptotic, anti-inflammatory, as well as neurogenic effects. Furthermore, Ad-MSCs were found to possibly mediate their therapeutic effects, at least partially, via modulating both central and systemic SIRT1 levels. Hence, the current study portrays Ad-MSCs as an effective therapeutic approach for AD management and opens the door for future investigations to further elucidate the role of SIRT1 and its interrelated molecular mediators in AD.

Impact of Adipose Tissue Depot Harvesting Site on the Multilineage Induction Capacity of Male Rat Adipose-Derived Mesenchymal Stem Cells: An In Vitro Study

Recently, substantial attention has been paid toward adipose-derived mesenchymal stem cells (AdMSCs) as a potential therapy in tissue engineering and regenerative medicine applications. Rat AdMSCs (r-AdMSCs) are frequently utilized. However, the influence of the adipose depot site on the multilineage differentiation potential of the r-AdMSCs is still ambiguous. Hence, the main objective of this study was to explore the influence of the adipose tissue harvesting location on the ability of r-AdMSCs to express the stem-cell-related markers and pluripotency genes, as well as their differentiation capacity, for the first time. Herein, we have isolated r-AdMSCs from the inguinal, epididymal, peri-renal, and back subcutaneous fats. Cells were compared in terms of their phenotype, immunophenotype, and expression of pluripotency genes using RT-PCR. Additionally, we investigated their potential for multilineage (adipogenic, osteogenic, and chondrogenic) induction using special stains confirmed by the expression of the related genes using RT-qPCR. All cells could positively express stem cell marker CD 90 and CD 105 with no significant in-between differences. However, they did not express the hematopoietic markers as CD 34 and CD 45. All cells could be induced successfully. However, epididymal and inguinal cells presented the highest capacity for adipogenic and osteogenic differentiation (21.36-fold and 11.63-fold for OPN, 29.69-fold and 26.68-fold for BMP2, and 37.67-fold and 22.35-fold for BSP, respectively, in epididymal and inguinal cells (p < 0.0001)). On the contrary, the subcutaneous cells exhibited a superior potential for chondrogenesis over the other sites (8.9-fold for CHM1 and 5.93-fold for ACAN, (p < 0.0001)). In conclusion, the adipose tissue harvesting site could influence the differentiation capacity of the isolated AdMSCs. To enhance the results of their employment in various regenerative cell-based therapies, it is thus vital to take the collection site selection into consideration.