Effect of mesenchymal stromal cells-derived extracellular vesicles as a treatment to heal diabetic wounds: A meta-analysis.

A meta-analysis study to assess the influence of mesenchymal stromal cells-derived extracellular vesicles (MSC-EVs) as a treatment to heal the diabetic wound (DW). A comprehensive literature examination till February 2023 was implemented and 2975 linked studies were appraised. The picked studies contained 381 animals with diabetes mellitus in the picked studies' baseline, 217 of them were using MSC-EVs, and 173 were using control. Odds ratio in addition to 95% confidence intervals (CIs) were used to calculate the consequence of MSC-EVs as a therapy to heal DWs by the dichotomous and continuous styles and a fixed or random model. MSCs-EVs had a significantly higher rate of wound closure of DWs (Mean deviation [MD], 22.20; 95% CI, 19.16-25.24, P < .001), lower width of the scar (MD, -2.57; 95% CI, -3.35 to -1.79, P < .001), higher collagen deposition (MD, 30.82; 95% CI, 20.77-40.86, P < .001), and a higher rate of re-epithelialisation (MD, 34.36; 95% CI, 20.13-48.58, P < .001) compared with the control. MSCs-EVs had a significantly higher rate of wound closure of DWs, lower width of the scar, higher collagen deposition, and higher rate of re- epithelialisation compared with the control. Although precautions should be taken when commerce with the consequences because all of the picked studies for this meta-analysis was with low sample sizes.

Orexin A Suppresses the Expression of Exosomal PD-L1 in Colon Cancer and Promotes T Cell Activity by Inhibiting JAK2/STAT3 Signaling Pathway.

BACKGROUND: Colon cancer, ranked third in cancer related mortality, is the most common malignant cancer of digestive tract. Though immune checkpoint inhibitors show promising efficacy in colon cancer, a rather high unresponsive rate and recurrence rate requires further elucidation of the underlying regulatory mechanism of cancer-related immunity. AIMS: To study the regulatory function of Orexin A in the expression of exosomal PD-L1 and T cell activity. METHODS: Orthotopic colon cancer transplantation mice model were established to study the cancer growth and immune infiltration between Orexin A treated group and untreated group. In vitro studies using mouse CT-26 and human HCT-116 colon cancer cell model studied the effect of Orexin A on cellular and exosomal PD-L1 expression. Co-culturing Jurkat cells with exosomes delivered by cancer cells treated with Orexin A, PD-L1 knockdown and PBS studied different effects on T cell. Comparing Orexin A with WP1066, a JAK2/STAT3 inhibitor verified the mechanism of these changes. RESULTS: The growth rate of orthotopic transplanted colon cancer was slower in Orexin A treated group, with lower PD-L1 expression and higher immune infiltration. Orexin A could inhibit cellular and exosomal PD-L1 expression. The decreased expression of PD-L1 in exosomes could promote the activity of Jurkat cells secreting higher level of IFN-γ and IL-2. Orexin A showed a similar effect like WP1066 which proved JAK2/STAT3 signaling pathway was its downstream signaling pathway. CONCLUSIONS: Orexin A could suppress the expression of exosomal PD-L1 in colon cancer cells and promote T cells activity by inhibiting JAK2/STAT3 signaling pathway.

Decarboxylated osteocalcin, a possible drug for type 2 diabetes, triggers glucose uptake in MG63 cells.

BACKGROUND: Uncarboxylated osteocalcin (GluOC) has been reported to improve glucose metabolism, prevent type 2 diabetes, and decrease the severity of obesity in mice with type 2 diabetes. GluOC can increase glucose uptake in a variety of cells. Glucose metabolism is the main source of energy for osteoblast proliferation and differentiation. We hypothesized that decarboxylated osteocalcin (dcOC), a kind of GluOC, can increase glucose uptake in MG63 cells (osteoblast-like osteosarcoma cells) and influence their proliferation and differentiation. AIM: To investigate the effects of dcOC on glucose uptake in human osteoblast-like osteosarcoma cells and the possible signaling pathways involved. METHODS: MG63 cells (human osteoblast-like osteosarcoma cells) were treated with dcOC (0, 0.3, 3, 10, or 30 ng/mL) for 1 and 72 h, and glucose uptake was measured by flow cytometry. The effect of dcOC on cell proliferation was measured with a CCK-8 assay, and alkaline phosphatase (ALP) enzyme activity was measured. PI3K was inhibited with LY294002, and hypoxia-inducible factor 1 alpha (HIF-1α) was silenced with siRNA. Then, GPRC6A (G protein-coupled receptor family C group 6 subtype A), total Akt, phosphorylated Akt, HIF-1α, and glucose transporter 1 (GLUT1) levels were measured by Western blot to elucidate the possible pathways by which dcOC modulates glucose uptake. RESULTS: The glucose uptake of MG63 cells was significantly increased compared with that of the paired control cells after short-term (1 h) treatment with dcOC at different concentrations (0.3, 3, and 10 ng/mL groups, P < 0.01; 30 ng/mL group, P < 0.05). Glucose uptake of MG63 cells was significantly increased compared with that of the paired control cells after long-term (72 h) treatment with dcOC at different concentrations (0.3, 3, and 10 ng/mL groups, P < 0.01; 30 ng/mL group, P < 0.05). DcOC triggered Akt phosphorylation in a dose-dependent manner, and the most effective stimulatory concentration of dcOC for short-term (1 h) was 3 ng/mL (P < 0.01). LY294002 abolished the dcOC-mediated (1 h) promotion of Akt phosphorylation and glucose uptake without affecting GLUT1 protein expression. Long-term dcOC stimulation triggered Akt phosphorylation and increased the protein levels of HIF-1α, GLUT1, and Runx2 in a dose-dependent manner. Inhibition of HIF-1α with siRNA abolished the dcOC-mediated glucose uptake and substantially decreased GLUT1 protein expression. DcOC intervention promoted cell proliferation in a time- and dose-dependent manner as determined by the CCK-8 assay. Treatment with both 3 ng/mL and 10 ng/mL dcOC affected the ALP activity in MG63 cells after 72 h (P < 0.01). CONCLUSION: Short- and long-term dcOC treatment can increase glucose uptake and affect proliferation and ALP activity in MG63 cells. This effect may occur through the PI3K/Akt, HIF-1α, and GLUT1 signaling factors.

The Anti-proliferative Activity of GnRH Through Downregulation of the Akt/ERK Pathways in Pancreatic Cancer.

Gonadotropin-releasing hormone (GnRH) has been demonstrated to exert anti-proliferative functions on various tumor cells in endometrial, ovarian, bladder, or prostate cancer as a part of the autocrine system. In addition, the expression levels of GnRH and its receptor had been identified in breast cancer or non-reproductive cancers, such as glioblastoma and pancreatic cancer. Previous studies have reported abnormal GnRH expression in several malignant tumors, suggesting that GnRH and its receptor might be essential for tumourigenesis. In the present study, we attempted to clarify the mechanisms underlying GnRH function in cell proliferation in pancreatic cancer. Our results indicated that GnRH expression might be essential for the malignancy of pancreatic cancer. We then found that GnRH overexpression can induce cell apoptosis through activating the Bcl-2/Bax pathway and autophagy might be involved in the GnRH-mediated apoptosis in Panc1 cells. Further investigation showed that the inhibition of GnRH may promote tumor invasion and migration through upregulation of MMP2 expression in pancreatic cancer cells. Moreover, our results indicated that GnRH can regulate the Akt/ERK1/2 pathways to promote cell proliferation by inhibiting cell apoptosis in Panc1 cells. Therefore, our finding exhibited that the regulation of GnRH expression may be essential for tumourigenesis in pancreatic cancer, and might be a potential target for the treatment of the patients with pancreatic cancer.

Orexin-A Stimulates Insulin Secretion Through the Activation of the OX1 Receptor and Mammalian Target of Rapamycin in Rat Insulinoma Cells.

OBJECTIVES: The study aimed to investigate the involvement of the mammalian target of rapamycin (mTOR) signaling pathway in orexin-A/OX1 receptor-induced insulin secretion in rat insulinoma INS-1 cells. METHODS: Rat insulinoma INS-1 cells were grown and treated with various concentrations of orexin-A, with or without OX1 receptor-selective antagonist SB674042 or the phosphatidylinositol 3-kinase/mTOR antagonist PF-04691502. Insulin release experiments, Western blot analysis, and statistical analysis were conducted using INS-1 cells. RESULTS: Our results showed that treating cells with orexin-A increased the expression of the OX1 receptor and the phosphorylation of mTOR in a concentration-dependent manner. An increase in insulin secretion was also observed for cells treated with orexin-A. We further demonstrated that the increase in insulin secretion was dependent on the activation of the OX1 receptor and mTOR signaling pathway by using the OX1 receptor-selective antagonist SB674042 or the phosphatidylinositol 3-kinase/mTOR antagonist PF-04691502, which abolished the effects of orexin-A treatment. CONCLUSIONS: Our results concluded that orexin-A/OX1 receptor stimulates insulin secretion by activating AKT and its downstream target, mTOR. Therefore, orexins may regulate the energy balance for cell survival with the involvement of mTOR in this process.

The Orexin-A-Regulated Akt/mTOR Pathway Promotes Cell Proliferation Through Inhibiting Apoptosis in Pancreatic Cancer Cells.

The orexin-A and its receptors are associated with many physiological processes in peripheral organs and the central nervous system and play important roles in a series of human diseases, including narcolepsy, obesity, and drug addiction. Increasing evidence has indicated high expression of orexin-A and OX1 receptor (OX1R) in malignant tumors, suggesting that the stimulation of OX1R might be essential for tumorigenesis. Here, we attempted to clarify the correlation between orexin-A expression and malignancy in pancreatic cancer. Our results indicated that the stimulation of OX1R promotes cell proliferation in pancreatic cancer PANC1 cells. Additionally, orexin-A treatment can protect PANC1 cells from apoptosis, whereas inhibition of the stimulation of OX1R results in apoptosis through regulating pancreatic cancer cell expression levels of Bcl-2, caspase-9, and c-myc, which are key apoptotic factors. Further investigation revealed that orexin-A treatment activates theAkt/mTOR signaling pathway to promote cell proliferation byinhibiting Bcl-2/caspase-9/c-myc-mediated apoptosis in pancreatic cancer cells. Our findings revealed that the stimulation of OX1R might be important for tumorigenesis in pancreatic cancer and is a potential target for the treatment of patients with pancreatic cancer.

Orexin-A regulates cell apoptosis in human H295R adrenocortical cells via orexin receptor type 1 through the AKT signaling pathway.

Numerous studies have demonstrated the ability of orexin-A to regulate adrenocortical cells through the mitogen-activated protein kinase signaling pathway. In the present study, human H295R adrenocortical cells were exposed to orexin­A (10­10-10­6 M), with orexin receptor type 1 (OX1 receptor) antagonist SB334867 or AKT antagonist PF­04691502. It was found that orexin­A stimulated H295R cell proliferation, reduced the pro­apoptotic activity of caspase­3 to protect against apoptotic cell death and increased cortisol secretion. Furthermore, phospho­AKT protein was increased by orexin­A. SB334867 (10­6 M) and PF­04691502 (10­6 M) abolished the effects of orexin­A (10­6 M). These results suggested that the orexin­A/OX1 receptor axis has a significant pro-survival function in adrenal cells, which is mediated by AKT activation. Further studies investigating the effects of orexin-A-upregulation may further elucidate the diverse biological effects of orexin-A in adrenal cells.

Effect of Orexin-A on Cortisol Secretion in H295R Cells via p70S6K/4EBP1 Signaling Pathway.

Orexin-A is a neuropeptide that orchestrates diverse central and peripheral processes. It is now clear that orexin system plays a central role in the regulation of endocrine, paracrine, and neurocrine. It is involved in the regulation of growth hormone, adrenocorticotropic hormone, thyroid, mineralocorticoid, and cortisol secretion. These hormones may also serve as a kind of signal linking energy balance regulation, reproduction, stress response, and cardiovascular regulation. Many studies have demonstrated the ability of orexin-A to regulate adrenocortical cells through the MAPK (mitogen-activated protein kinases) pathway. The aim of our study is to investigate the effect of orexin-A on cortisol secretion via the protein 70 ribosomal protein S6 kinase-1 (p70S6K) and eukaryotic translation initiation factor 4E binding proteins (4EBP1) signaling pathway in adrenocortical cells. We reported the first evidence that orexin-A stimulated p70S6K and 4EBP1 in human H295R adrenocortical cells in a concentration and time-dependent manner. 10(-6) M orexin-A treatment for 1 hour was the most potent. Our results also indicated that p70S6K and 4EBP1 kinases participated in controlling cortisol secretion via OX1 receptor in H295R cells, which implied important role of p70S6K and 4EBP1 kinases in regulating adrenal function induced by orexin-A.

Orexin-A stimulates 3ß-hydroxysteroid dehydrogenase expression and cortisol production in H295R human adrenocortical cells through the AKT pathway.

Orexin-A is a regulatory peptide involved in the regulation of food intake, sleep-wakefulness, and it has various endocrine and metabolic functions. It orchestrates diverse central and peripheral processes through the stimulation of two G-protein coupled receptors, orexin receptor type 1 (OX1 receptor) and orexin receptor type 2 (OX2 receptor). In this study, human adrenocortical cells (NCI-H295R cells) were incubated with various concentrations of orexin-A (10-10 to 10-6 M) in vitro, and the mRNA and protein expression of OX1 receptor was determined in the cells. In addition, NCI-H295R cells treated with 10-6 M orexin-A were then treated with or without OX1 receptor specific antagonist (SB334867), AKT antagonist (PF-04691502), or a combination of both. Subsequently, cell proliferation, the cortisol content in the medium and the mRNA and protein expression expression of 3ß-hydroxysteroid dehydrogenase (3ß-HSD) were analyzed. The activity of the AKT signaling pathway was also determined in the NCI-H295R cells. We observed that the increase in the mRNA and protein expression of OX1 receptor was orexin-A concentration-dependent, with 10-6 M orexin-A exerting the most potent effect. Orexin-A enhanced cell proliferation and cortisol production, and increased the mRNA and protein expression of 3ß-HSD in the NCI-H295R cells; however, these effects were partly blocked by the OX1 receptor antagonist, the AKT antagonist and the combination of both. Furthermore, orexin-A significantly increased the phosphorylation of AKT, with the levels of total AKT protein remaining unaltered. This effect was blocked in the presence of PF-04691502 (10-6 M), SB334867 (10-6 M) and the combination of both. On the whole, our data demonstrate that the effects of orexin-A on the survival and function of human adrenocortical cells are mediated through the AKT signaling pathway.

Orexin A protects cells from apoptosis by regulating FoxO1 and mTORC1 through the OX1R/PI3K/AKT signaling pathway in hepatocytes.

Orexin A and B are multifunctional neuropeptides that are involved in the regulation of food intake, energy metabolism, glucose regulation and wakefulness. They signal through two G-protein­coupled receptors (GPCR): orexin receptor 1 (OX1R) and orexin receptor 2 (OX2R). Previous studies have shown that orexins interact with PI3K/AKT signaling pathways through OX1R-coupling in other cell types, but are seldom involved in hepatocytes. In the present study, reverse transcription (RT)-PCR and western blot analysis revealed that OX1R mRNA expression and activation in rat hepatocytes in vitro were upregulated by exogenous orexin A (10(-10) to 10(-6) M) in a dose-dependent manner. The result showed that orexin A affects increasing cell proliferation and protects cells from apoptosis. Additionally, inhibition studies showed that orexin A induced forkhead box O1 (FoxO1) and mammalian target of rapamycin 1 (mTORC1) phosphorylation, while OX1R antagonist (SB334867, 10(-6) M), AKT antagonist (PF-04691502, 10(-6) M), Foxo1 inhibitor (AS1842856, 10(-6) M) or mTORC1 inhibitor (everolimus, 10(-5) M) blocked these effects of orexin A. The results of the present study showed a possible effect of orexin A on cell apoptosis in regulating Foxo1 and mTORC1 through the OX1R/PI3K/AKT signaling pathway in rat hepatocytes.

Effects of orexin A on GLUT4 expression and lipid content via MAPK signaling in 3T3-L1 adipocytes.

Orexin A regulates food intake, energy metabolism and gastrointestinal function; it also increases glucose uptake and inhibits lipolysis, suggesting a role for orexin A in glucose and lipid metabolism. In this study, the effects of orexin A on glucose transporter 4 (GLUT4) mRNA level and lipid content were explored in 3T3-L1 preadipocytes and adipocytes. Orexin receptor 1 (OX1R) protein expression was determined in the adipose tissue of normal and obese rats. In addition, 3T3-L1 preadipocytes and differentiated 3T3-L1 adipocytes were incubated with different concentrations of orexin A (10(-9) to 10(-7)M), without or with OX1R specific antagonist, then the peroxisome proliferator-activated receptor-γ2 (PPARγ2) mRNA expression was analyzed. Differentiated 3T3-L1 adipocytes were exposed to orexin A, without or with MAPK and OX1R antagonist, after which the GLUT4 and ERK1/2, JNK, and p38 MAPK activation, and triglyceride (TG) content were measured. We observed that OX1R protein expression was decreased in obese rats, and OX1R protein level was negatively correlated with body fat, Lee's index, TG, total cholesterol, and fasting insulin levels. Orexin A enhanced PPARγ2 mRNA expression in a dose-dependent manner in 3T3-L1 preadipocytes through OX1R. In differentiated 3T3-L1 adipocytes, orexin A significantly increased GLUT4 mRNA levels, which was blocked by the ERK1/2, JNK, and p38 MAPK inhibitors as well as OX1R antagonist. Furthermore, orexin A increased cellular TG content via ERK1/2, JNK, and p38 MAPK as well as OX1R. Thus, orexin A increases GLUT4 mRNA expression and lipid accumulation in differentiated 3T3-L1 adipocytes via ERK1/2, JNK, and p38 MAPK signaling. In addition, orexin A increases PPARγ2 mRNA expression in 3T3-L1 preadipocytes. Further studies are necessary to elucidate the impact of orexin A in metabolic disorders and adipocyte differentiation.