Human umbilical cord blood-derived mesenchymal stem cells restored hematopoiesis by improving radiation induced bone marrow niche remodeling in rats.

BACKGROUND: Functional hematopoiesis is governed by the bone marrow (BM) niche, which is compromised by radiotherapy, leading to radiation induced BM failure. The aim of this study was to demonstrate the radiation induced pathological remodeling of the niche and the efficacy of human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) in restoring hematopoiesis via improvement of the niche. METHODS: Thirty male Wistar rats were equally assigned to three groups: control (CON), irradiated (IR), and IR+hUCB-MSCs. Biochemical, histopathological and immunohistochemical analyses were performed to detect collagen type III and IV, Aquaporin 1+ sinusoidal endothelial cells and immature hematopoietic cells, CD11c+ dendritic cells, Iba1+ macrophages, CD9+ megakaryocytes, Sca-1+, cKit+, CD133 and N-cadherin+ hematopoietic stem and progenitor cells, CD20+, Gr1+ mature hematopoietic cells, in addition to ki67+ proliferation, Bcl-2+ anti-apoptotic, caspase-3+ apoptotic, TNF-α+ inflammatory cells. Histoplanimetry data were statistically analyzed using the one-way analysis of variance followed by the post hoc Duncan's test. Moreover, Pearson's correlation was used to assess the correlation between various parameters. RESULTS: In comparison to the IR group, the IR+hUCB-MSCs group showed restored cell populations and extracellular collagen components of the BM niche with significant increase in hematopoietic stem, progenitor, mature and proliferating cells, and a considerable decrease in apoptotic and inflammatory cells. Furthermore, highly significant correlations between BM niche and blood biochemical, histopathological, and immunohistochemical parameters were observed. CONCLUSION: hUCB-MSCs restored functional hematopoiesis through amelioration of the BM niche components via reduction of oxidative stress, DNA damage, inflammation, and apoptosis with upregulation of cellular proliferation.

Hypoxia pretreatment enhances the therapeutic potential of mesenchymal stem cells (BMSCs) on ozone-induced lung injury in rats.

Ozone (O3) gas is a double-sided weapon. It provides a shield that protects life on earth from the harmful ultraviolet (UV) rays, but ground-level O3 is considered an urban air pollutant. So, a rat model of chronic O3 inhalation was established to assess the biochemical and morphological alterations in the lung tissue and to investigate the ameliorative effects of bone marrow-derived mesenchymal stem cells (BMSCs) with or without hypoxia pre-treatment. Forty-two adult male albino rats were divided into four groups: control, ozone-exposed, normoxic BMSC-treated, and hypoxic BMSC-treated groups. Lung tissue sections were processed for light and electron microscope examination, immunohistochemical staining for caspase 3, and iNOS. Quantitative real-time PCR for IL-1α, IL-17, TNF-α, and Nrf2 mRNA gene expression were also performed. Chronic O3 exposure caused elevated inflammatory cytokines and decreased antioxidant Nrf2 mRNA expression. Marked morphological alterations with increased collagen deposition and elevated apoptotic markers and iNOS were evident. BMSC treatment showed immunomodulatory (decreased inflammatory cytokine gene expression), antioxidant (increased Nrf2 expression and decreased iNOS), and anti-apoptotic (decreased caspase3 expression) effects. Consequently, ameliorated lung morphology with diminished collagen deposition was observed. Hypoxia pretreatment enhanced BMSC survival by MTT assay. It also augmented the previously mentioned effects of BMSCs on the lung tissue as proved by statistical analysis. Lung morphology was similar to that of control group. In conclusion, hypoxia pretreatment represents a valuable intervention to enhance the effects of MSCs on chronic lung injury.

Bone marrow-derived mesenchymal stem cells combined with gonadotropin therapy restore postnatal oogenesis of chemo-ablated ovaries in rats via enhancing very small embryonic-like stem cells.

BACKGROUND: Very small embryonic-like stem cells (VSELs) are a rare population within the ovarian epithelial surface. They contribute to postnatal oogenesis as they have the ability to generate immature oocytes and resist the chemotherapy. These cells express markers of pluripotent embryonic and primordial germ cells. OBJECTIVE: We aimed to explore the capability of VSELs in restoring the postnatal oogenesis of chemo-ablated rat ovaries treated with bone marrow-derived mesenchymal stem cells (BM-MSCs) combined with pregnant mare serum gonadotropin (PMSG). METHODS: Female albino rats were randomly assigned across five groups: I (control), II (chemo-ablation), III (chemo-ablation + PMSG), IV (chemo-ablation + MSCs), and V (chemo-ablation + PMSG + MSCs). Postnatal oogenesis was assessed through measurement of OCT4, OCT4A, Scp3, Mvh, Nobox, Dazl4, Nanog, Sca-1, FSHr, STRA8, Bax, miR143, and miR376a transcript levels using qRT-PCR. Expression of selected key proteins were established as further confirmation of transcript expression changes. Histopathological examination and ovarian hormonal assessment were determined. RESULTS: Group V displayed significant upregulation of all measured genes when compared with group II, III or IV. Protein expression confirmed the changes in transcript levels as group V displayed the highest average density in all targeted proteins. These results were confirmed histologically by the presence of cuboidal germinal epithelium, numerous primordial, unilaminar, and mature Graafian follicles in group V. CONCLUSION: VSELs can restore the postnatal oogenesis in chemo-ablated ovaries treated by BM-MSCs combined with PMSG.

Adipose mesenchymal stem cells combined with platelet-rich plasma accelerate diabetic wound healing by modulating the Notch pathway.

BACKGROUND: Diabetic foot ulceration is a serious chronic complication of diabetes mellitus characterized by high disability, mortality, and morbidity. Platelet-rich plasma (PRP) has been widely used for diabetic wound healing due to its high content of growth factors. However, its application is limited due to the rapid degradation of growth factors. The present study aimed to evaluate the efficacy of combined adipose-derived mesenchymal stem cells (ADSCs) and PRP therapy in promoting diabetic wound healing in relation to the Notch signaling pathway. METHODS: Albino rats were allocated into 6 groups [control (unwounded), sham (wounded but non-diabetic), diabetic, PRP-treated, ADSC-treated, and PRP+ADSCs-treated groups]. The effect of individual and combined therapy was evaluated by assessing wound closure rate, epidermal thickness, dermal collagen, and angiogenesis. Moreover, gene and protein expression of key elements of the Notch signaling pathway (Notch1, Delta-like canonical Notch ligand 4 (DLL4), Hairy Enhancer of Split-1 (Hes1), Hey1, Jagged-1), gene expression of angiogenic marker (vascular endothelial growth factor and stromal cell-derived factor 1) and epidermal stem cells (EPSCs) related gene (ß1 Integrin) were assessed. RESULTS: Our data showed better wound healing of PRP+ADSCs compared to their individual use after 7 and 14 days as the combined therapy caused reepithelialization and granulation tissue formation with a marked increase in area percentage of collagen, epidermal thickness, and angiogenesis. Moreover, Notch signaling was significantly downregulated, and EPSC proliferation and recruitment were enhanced compared to other treated groups and diabetic groups. CONCLUSIONS: These data demonstrated that PRP and ADSCs combined therapy significantly accelerated healing of diabetic wounds induced experimentally in rats via modulating the Notch pathway, promoting angiogenesis and EPSC proliferation.

Mesenchymal stem cells enhance AQP1 expression in the sublingual salivary gland of ovariectomized menopausal rat model.

BACKGROUND: Ovariectomized menopausal rat model was used to investigate the effects of menopause on the sublingual salivary gland (SSG) and the potential therapeutic effect of human umbilical cord blood mesenchymal stem cells (hUCB-MSCs). METHODS: Thirty rats were equally divided into three groups: sham-operated (SHAM), ovariectomized (OVX), and ovariectomized stem cells injected (OVX+ hUCB-MSCs). Expressions of α-SMA, AQP1, Sca-1, PCNA, ssDNA, and caspase-3 were determined. Homing of hUCB-MSCs was detected by fluorescence microscopy and examination of immunostained sections for human CD105 and CD34 was performed. Morphometric data were statistically analyzed using the Kruskal-Wallis test followed by Scheffé's method. Correlation of AQP1 with Sca-1-positive sublingual stem cells was also analyzed. RESULTS: In the SSGs of the OVX group, ballooned mucus acinar cells, atrophied serous cells, and a decreased number and height of duct lining cells were observed. The interstitial spaces were edematous, and the blood vessels were congested. The significant decrease in the positive area % of α-SMA and AQP1, the number of Sca-1-positive sublingual stem cells, and proliferating cells was associated with a significant increase in apoptotic cells. The OVX+hUCB-MSCs group showed significant structural improvement, manifested by the normal appearance of mucus and serous acini, as well as the number and height of striated duct cells. A significant increase in the positive area % of α-SMA and AQP1 and the number of proliferating and Sca-1-positive sublingual stem cells was observed. Interestingly, a significantly positive Pearson's correlation between the area % of AQP1 and the number of Sca-1-positive sublingual stem cells was also recorded. CONCLUSION: Our results indicated a positive effect of hUCB-MSCs therapy for SSG pathology in a post ovariectomy rat model as evidenced by an improvement in the histologic architecture, upregulation of the immunostained area % of α-SMA and AQP1, increase in the number of Sca-1-positive sublingual stem cells and proliferating cells, and downregulation of apoptotic cells.

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.

Mesenchymal Stem Cell-Derived Exosomes Ameliorated Diabetic Nephropathy by Autophagy Induction through the mTOR Signaling Pathway.

BACKGROUND: Diabetic nephropathy (DN) is a serious complication of diabetes mellitus and a common cause of end-stage renal disease. Autophagy has a defensive role against kidney damage caused by hyperglycemia. Mesenchymal stem cell (MSC)-derived exosomes are currently considered as a new promising therapy for chronic renal injury. However, the renal-protective mechanism of exosomes on DN is not completely understood. We examined the potential role of MSC-derived exosomes for enhancement of autophagy activity and their effect on DN. In our study, we used five groups of rats: control; DN; DN treated with exosomes; DN treated with 3-methyladenine (3-MA) and chloroquine (inhibitors of autophagy); and DN treated with 3-methyladenine (3-MA), chloroquine, and exosome groups. We assessed renal function, morphology, and fibrosis. Moreover, ratios of the autophagy markers mechanistic target of rapamycin (mTOR), Beclin-1, light chain-3 (LC3-II), and LC3-II/LC3-I were detected. Additionally, electron microscopy was used for detection of autophagosomes. RESULTS: Exosomes markedly improved renal function and showed histological restoration of renal tissues, with significant increase of LC3 and Beclin-1, and significant decrease of mTOR and fibrotic marker expression in renal tissue. All previous effects were partially abolished by the autophagy inhibitors chloroquine and 3-MA. CONCLUSION: We conclude that autophagy induction by exosomes could attenuate DN in a rat model of streptozotocin-induced diabetes mellitus.