The effect of adipose-derived mesenchymal stem cell transplantation on ovarian mitochondrial dysfunction in letrozole-induced polycystic ovary syndrome in rats: the role of PI3K-AKT signaling pathway.

OBJECTIVE: The present study aimed to elucidate how mesenchymal stem cells (MSCs) application could efficiently attenuate pathological changes of letrozole-induced poly cystic ovary syndrome (PCOS) by modulating mitochondrial dynamic via PI3K-AKT pathway. METHODS: Thirty-two female rats were randomly divided into four experimental groups: Sham, PCOS, PCOS + MSCs, and PCOS + MSCs + LY294002. The Sham group received 0.5% w/v carboxymethyl cellulose (CMC); the PCOS group received letrozole (1 mg/kg, daily) in 0.5% CMC for 21 days. Animals in the PCOS + MSCs group received 1 × 106 MSCs/rat (i.p,) on the 22th day of the study. In the PCOS + MSCs + LY294002 group, rats received LY294002 (PI3K-AKT inhibitor) 40 min before MSC transplantation. Mitochondrial dynamic gene expression, mitochondrial membrane potential (MMP), citrate synthase (CS) activity, oxidative stress, inflammation, ovarian histological parameters, serum hormone levels, homeostatic model assessment for insulin resistance (HOMA-IR), insulin and glucose concentrations, p-PI3K and p-AKT protein levels were evaluated at the end of the experiment. RESULTS: PCOS rats showed a significant disruption of mitochondrial dynamics and histological changes, lower MMP, CS, ovary super oxide dismutase (SOD) and estrogen level. They also had a notable rise in insulin and glucose concentrations, HOMA-IR, testosterone level, tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels, ovarian malondialdehyde (MDA) content as well as a notable decrease in p-PI3K and p-AKT protein levels compared to the Sham group. In the PCOS + MSCs group, the transplantation of MSCs could improve the above parameters. Administration of LY294002 (PI3K-AKT pathway inhibitor) deteriorated mitochondrial dynamic markers, oxidative stress status, inflammation markers, hormonal levels, glucose, and insulin levels and follicular development compared to the PCOS + MSCs group. CONCLUSIONS: This study demonstrated that the protective effects of MSC transplantation in regulating mitochondrial dynamics, promoting mitochondrial biogenesis, competing with redox status and inflammation response were mainly mediated through the PI3K-AKT pathway in the PCOS model.

Mesenchymal stem cells and their conditioned medium as potential therapeutic strategies in managing comorbid anxiety in rat sepsis induced by cecal ligation and puncture.

Objectives: Sepsis-associated encephalopathy (SAE) is a common brain dysfunction following sepsis. Due to the beneficial effects of mesenchymal stem cells (MSCs) therapy on anxiety, an extreme and early manifestation of SAE, we hypothesized that MSCs-derived conditioned medium (CM) may be able to attenuate anxiety in cecal ligation and puncture (CLP)-induced sepsis. Materials and Methods: Rats were assigned into 4 groups: sham, CLP, MSC, and CM. All animals, except in the sham group, underwent the CLP procedure to induce sepsis. Two hours after sepsis induction, the rats in MSC and CM groups, received 1×106 MSCs and CM derived from the same number of cells, respectively. 48 hr after the treatments, anxiety-related behaviors were assessed, and brain and right hippocampal tissues were collected. Results: MSCs and CM enhanced the percentages of open arm entries and time spent in the open arms of the elevated plus-maze and the time spent in the light side of the light-dark box. MSCs and CM decreased the Evans blue content and decreased the IL-6 and TNF-α levels in the brain tissue samples. Reductions in the expression of 5-HT2A receptors and phosphorylation of ERK1/2 and an increase in the expression of 5-HT1A receptors in the hippocampal tissue samples were observed in the MSC and CM groups. Conclusion: MSCs and MSCs-derived CM attenuated anxiety-related behaviors to an equal extent by reducing inflammation, modifying 5-HT receptor expression changes, and inhibiting the ERK pathway. Therefore, MSCs-derived CM may be considered a promising therapy for comorbid anxiety in septic patients.

Adipose-derived mesenchymal stem cells reduced transient cerebral ischemia injury by modulation of inflammatory factors and AMPK signaling.

Stem cell-based treatments have been recommended as a feasible therapy for stroke victims due to their potential for angiogenesis, neurogenesis, and synaptic plasticity. The intracellular mechanisms of stem cells against cerebral hypoperfusion are not well recognized. In this study, by releasing the clips, the reperfusion period was extended to 96 h, and two hours after cerebral ischemia, animals received adipose-derived MSCs. MSCs were isolated from the inguinal fat pads of rats and injected into two-vessel occlusion (2VO) rats 1 h after ischemia induction. Ninety-six hours after 2VO induction, behavioral and molecular tests were assessed. Adipose-derived MSCs treatment improves neurological scores, passive avoidance memory, and novel object recognition tests in the 2VO model compared to 2VO rats (P < 0.001). MSCs treatment decreased TNF-α (P < 0.01) and IL-6 (P < 0.01) and apoptotic factors (Bax/Bcl-2 ratio and caspase-3 level (P < 0.01)) compared with ischemic rats. MSCs treatment of ischemic rats could enhance Klotho-α and AMPK-α compared with ischemic rats (P < 0.001). The study disclosed that adipose-derived MSCs could improve neurological damage and memory deficits by reducing neuronal death in cerebral ischemia. Data proposed that adipose-derived MSCs inhibit pro-inflammatory factors such as IL-6 and TNF-α, consequently decreasing apoptosis in the hippocampus of CCAO rats. Besides, the Klotho-α and AMPK-α measurements found that MSCs might induce intracellular neuroprotective pathways via activation of Klotho-α/AMPK-α signaling.

Adipose-Derived Mesenchymal Stem Cells and Conditioned Medium Attenuate the Memory Retrieval Impairment During Sepsis in Rats.

In this study, we hypothesized that sepsis induction impairs memory retrieval in rats while transplanted mesenchymal stem cells (MSCs) and MSC-conditioned medium (MSC-CM) application are capable of attenuating those complications. MSCs were obtained from adipose tissue of rats and at the second culture passage; MSCs and MSC-CM were collected. Rats were randomly divided into four experimental groups: sham, CLP, MSC, and MSC-CM. Sepsis was induced by cecal ligation and puncture (CLP) model in the CLP, MSC, and MSC-CM groups. The MSC group received 1 × 106 MSCs/rat (i.p., 2 h after CLP surgery); the MSC-CM rats received the conditioned medium (CM) from 1 × 106 MSCs intraperitoneally 2 h after sepsis induction. Novel object recognition test, sepsis score, and blood pressure measurement were performed 24 h after the treatments. The right hippocampus was taken for western blot analysis. CLP rats showed a significantly higher sepsis score and systolic blood pressure. They also had a significant increase in the phosphorylated form of CAMKII-α, cleaved caspase 3 and Bax/Bcl2 ratio, and a reduction in c-fos protein in the hippocampus tissue samples compared with the sham group. MSC transplantation and MSC-CM administration significantly decreased the mean sepsis score and prevented sepsis-induced attenuation of blood pressure compared with the CLP rats. Animals in the MSC and MSC-CM groups showed a better memory retrieval, attenuation in phosphorylated form of CAMKII-α, cleaved caspase 3 and Bax/Bcl2 ratio, and an increase in c-fos protein expression compared with the CLP group. It seems that CAMKII and c-fos are inversely involved in regulating memory processes in hippocampus. Phosphorylated form of CaMKII-α overexpression may impair the ability of object recognition. Our findings confirmed that MSC-CM application has more advantages compared with transplanted MSCs and may be offered as a promising therapy for inflammatory diseases such as severe sepsis.

Resveratrol suppresses interleukin-6 expression through activation of sirtuin 1 in hypertrophied H9c2 cardiomyoblasts.

Inflammatory cytokine, interleukin-6 (IL-6), plays an important role in the pathogenesis of cardiac hypertrophy. Recent studies have documented that resveratrol exhibits cardioprotective effects. The present study attempts to explore whether resveratrol suppreses IL-6 in hypertrophied H9c2 cardiomyoblasts through histone deacetylase, sirtuin 1 (SIRT1). To induce hypertrophy, the cells were incubated with angiotensin II (Ang II). Treatment groups were treated with different doses (1, 10, 25, 50, 75, and 100 µM) of resveratrol (R). Cell viability was measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Cell size was determined using crystal violet staining. Gene expression was assessed by real-time polymerase chain reaction technique. Enzyme-linked immunosorbent assay was used to measure IL-6 concentration. The results showed that cell area and ANP messenger RNA (mRNA) levels decreased significantly in R25+Ang, R50+Ang, and R100+Ang groups, as compared with Ang group. Therefore, 10, 20, 30, 40, and 50 µM of resveratrol were used to to evaluate its anti-inflammatory effects. The results revealed that Ang II upregulated IL-6 at both mRNA and protein levels (p < .001 vs. normal) and resveratrol (50 µM) decreased IL-6 mRNA (p < .01) and protein (p < .05) significantly in comparison to Ang group. However, in groups in which the cells were pretreated with SIRT1 inhibitor, EX-527, the response of resveratrol was partially reversed. Transcription levels of IL-6 receptor components (gp130 and gp80) did not change significantly among the experimental groups. The current data suggests that resveratrol protects H9c2 cells against Ang II-induced hypertrophy by suppression of IL-6 through SIRT1 activation.