MiR-146a-5p targeting SMAD4 and TRAF6 inhibits adipogenensis through TGF-β and AKT/mTORC1 signal pathways in porcine intramuscular preadipocytes

Background: Intramuscular fat(IMF) content is a vital parameter for assessing pork quality. Increasing evidence has shown that microRNAs(miRNAs) play an important role in regulating porcine IMF deposition. Here, a novel miRNA implicated in porcine IMF adipogenesis was found, and its effect and regulatory mechanism were further explored with respect to intramuscular preadipocyte proliferation and differentiation.Results: By porcine adipose tissue miRNA sequencing analysis, we found that miR-146a-5p is a potential regulator of porcine IMF adipogenesis. Further studies showed that miR-146a-5p mimics inhibited porcine intramuscular preadipocyte proliferation and differentiation, while the miR-146a-5p inhibitor promoted cell proliferation and adipogenic differentiation. Mechanistically, miR-146a-5p suppressed cell proliferation by directly targeting SMAD family member 4(SMAD4) to attenuate TGF-β signaling. Moreover, miR-146a-5p inhibited the differentiation of intramuscular preadipocytes by targeting TNF receptor-associated factor 6(TRAF6) to weaken the AKT/mTORC1 signaling downstream of the TRAF6 pathway.Conclusions: MiR-146a-5p targets SMAD4 and TRAF6 to inhibit porcine intramuscular adipogenesis by attenuating TGF-β and AKT/mTORC1 signaling, respectively. These findings provide a novel miRNA biomarker for regulating intramuscular adipogenesis to promote pork quality.

Baicalin protects neonatal rat brains against hypoxicischemic injury by upregulating glutamate transporter 1 via the phosphoinositide 3-kinase/protein kinase B signaling pathway

Baicalin is a flavonoid compound extracted from Scutellaria baicalensis root.Recent evidence indicates that baicalin is neuroprotective in models of ischemic stroke.Here,we investigate the neuroprotective effect of baicalin in a neonatal rat model of hypoxic-ischemic encephalopathy.Seven-day-old pups underwent left common carotid artery ligation followed by hypoxia（8% oxygen at 37°C） for 2 hours,before being injected with baicalin（120 mg/kg intraperitoneally） and examined 24 hours later.Baicalin effectively reduced cerebral infarct volume and neuronal loss,inhibited apoptosis,and upregulated the expression of p-Akt and glutamate transporter 1.Intracerebroventricular injection of the phosphoinositide 3-kinase/protein kinase B（PI3 K/Akt） inhibitor LY294002 30 minutes before injury blocked the effect of baicalin on p-Akt and glutamate transporter 1,and weakened the associated neuroprotective effect.Our findings provide the first evidence,to our knowledge that baicalin can protect neonatal rat brains against hypoxic-ischemic injury by upregulating glutamate transporter 1 via the PI3 K/Akt signaling pathway.

Simiao Wan alleviates obesity-associated insulin resistance via PKCε/IRS-1/PI3K/Akt signaling pathway based on network pharmacology analysis and experimental validation

Background:The purpose of the study was to investigatethe active ingredients and potential biochemicalmechanisms of Simiao Wan(SMW)in obesity-associated insulin resistance.Methods:An integrated network pharmacology method to screen the active compoundsand candidate targets,construct the protein-protein-interaction network,and ingredients-targets-pathways network was constructed for topological analysis to identify core targets and main ingredients.To find the possible signaling pathways,enrichment analysis was performed.Further,a model of insulin resistance in HL-7702 cells was established to verify the impact of SMW and the regulatory processes.Results:An overall of 63 active components and 151 candidate targets were obtained,in which flavonoids were the main ingredients.Enrichment analysis indicated that the PI3K-Akt signaling pathway was the potential pathway regulated by SMW in obesity-associated insulin resistance treatment.The result showed that SMW could significantly ameliorate insulin sensitivity,increase glucose synthesis and glucose utilization and reduce intracellular lipids accumulation in hepatocytes.Also,SMW inhibited diacylglycerols accumulation-induced PKCεactivity and decreased its translocation to the membrane.Conclusion:SMW ameliorated obesity-associated insulin resistance through PKCε/IRS-1/PI3K/Akt signaling axis in hepatocytes,providing a new strategy for metabolic disease treatment.

Vascular endothelial growth factor: an attractive target in the treatment of hypoxic/ischemic brain injury

Cerebral hypoxia or ischemia results in cell death and cerebral edema, as well as other cellular reactions such as angiogenesis and the reestablishment of functional microvasculature to promote recovery from brain injury. Vascular endothelial growth factor is expressed in the central nervous system after hypoxic/ischemic brain injury, and is involved in the process of brain repair via the regulation of angiogenesis, neurogenesis, neurite outgrowth, and cerebral edema, which all require vascular endothelial growth factor signaling. In this review, we focus on the role of the vascular endothelial growth factor signaling pathway in the response to hypoxic/ischemic brain injury, and discuss potential therapeutic interventions.

Electroacupuncture inhibits annulus fibrosis cell apoptosis in vivo via TNF-α-TNFR1-caspase-8 and integrin β1/Akt signaling pathways

OBJECTIVE: To examine whether electroacupuncture(EA) treatment inhibited cell apoptosis of intervertebral annulus fibrosis(AF) via tumor necrosis factor-α(TNF-α)-tumor necrosis factor receptor 1(TNFR1)-caspase-8 and integrin β1/Akt signaling pathways in a rat model of cervical intervertebral disc degeneration caused by unbalanced dynamic and static forces.METHODS: Thirty-two Sprague-Dawley rats were included in this study, of which 24 rats underwent surgery to induce cervical intervertebral disc degeneration, while eight rats received EA treatment at Dazhui(GV 14). Immunohistochemical staining was used to detect TNF-α, TNFR1, and caspase-8Apoptosis of AF cells was examined with terminal deoxynucleotidyl transferase-mediated d UTP-biotin nick end labeling(TUNEL) staining. The m RNA and protein expression levels of integrin β1 andAkt were evaluated with real-time polymerase chain reaction and western blot analysis, respectively.RESULTS: Treatment with EA decreased TUNEL-positive AF cells and lowered TNF-α, TNFR1 and caspase-8 positive cells compared with control groups. EA treatment also increased integrin β1and Akt m RNA and protein levels compared with controls.CONCLUSION: Treatment with EA inhibits AF cell apoptosis through suppression of the TNF-α-TNFR1-caspase-8 signal pathway and increases the expression of integrin β1 and Akt. EA may be a good alternative therapy for treating cervical spondylosis.

PI3K signaling pathway targeting by using different molecular approaches to treat cancer

Recent evidence of research has been proposed that the phosphoinositide 3-kinase(PI3K) pathway is noticeable target for searching novel anticancer agents. The phosphoinositide 3-kinase(PI3K) is accountable for harmonizing a diverse range of cell functions, such as transcription, proliferation, cell survival, cell growth, degranulation, vesicular trafficking and cell migration, which are mostly involved in carcinogenesis. Particularly, PI3K-mediated signaling molecules and its effects on gene expression contribute to tumorigenesis. PI3Ks generally are grouped into three distinct classes: Ⅰ, Ⅱ and Ⅲ according to their structure and function. The class IA of PI3K includes an alpha, beta or delta p110 catalytic subunit(p110α, p110β, or p110γ), which are associated with the activation of RTKs. Mutations in PIK3CA, the gene encoding the p110α catalytic subunit of PI3K, have just been recognized as novel mechanisms of inducing oncogenic PI3K signaling. Therefore, the class IA PI3K is the only one of most evidently implicated in cancer. The PI3K pathway is mostly mutated in more cancer patients compared with normal person, making it an eyecatching molecular target for analyses based on inhibitor molecule. In this article, we highlighted the signaling effects and regulation pathway of PI3K involved in the development and survival of tumor cells. The consequence and intricacy of PI3K pathway made it an essential beneficial target for cancer treatment.

Wide Pulse Width Electroacupuncture Ameliorates Denervation-Induced Skeletal Muscle Atrophy in Rats via IGF-1/PI3K/Akt Pathway

Objective:To evaluate the effect of the pulse width of electroacupuncture(EA)in the treatment of denervation-induced skeletal muscle atrophy in rats and examine the role of insulin-like growth factor 1(IGF-1)/phosphatidylinositol 3-kinase(PI3 K)/Akt signaling pathway during EA.Methods:Sciatic nerve functional index(SFI),muscle wet weight and the cross-sectional area(CSA)of the gastrocnemius muscle were analyzed after treatment in model rats with EA of various pulse widths(0.5,50,100 and 200 ms).The apoptosis index(AI)and paired box(PAX)3 and PAX7 protein expression were also determined.Further,the mRNA and protein expressions of components of IGF-1/PI3 K/Akt pathway and their downstream targets were determined,along with the inhibiting effect of the pathway with a PI3-specific inhibitor.Results:EA with a pulse width of 200 ms was found to have the best effect with regard to increasing SFI,CSA and muscle weight,decreasing AI,and increasing the expression of PAX3 and PAX7.The IGF-1/PI3 K/Akt pathway was found to be activated by denervation,although the downstream forkhead box O(FoxO)pathway was not suppressed by its activation.The PI3 K/Akt pathway and its downstream molecule mammalian target of rapamycin(mTOR)were up-regulated further by EA to promote muscle protein synthesis.Meanwhile,the expressions of downstream FoxO and F-box protein 32(ATROGIN-1)were down-regulated to reduce protein degradation.Conclusions:EA with 200-ms pulse width was found to have a more significant effect than 0.5-ms EA.The positive effects of EA disappeared after inhibition of the PI3 K/Akt pathway.

FOXO1 Alleviates Liver Ischemia-reperfusion Injury by Regulating the Th17/Treg Ratio through the AKT/Stat3/FOXO1 Pathway

Background and Aims:Hepatic ischemic reperfusion in-jury(IRI)occurring during surgery seriously affects patient prognosis.The specific mechanism of IRI has not been fully elucidated.The study aim was to explore the changes of in-flammatory environment,and the relationship of the Th17/Treg cell ratio and FOXO1 expression in hepatic IRI.Methods:Liver samples at different ischemic times were collected from patients and mice.The expression of inflammatory markers and FOXO1 in the liver was detected by western blotting and qPCR.Phenotypic changes of liver lymphocytes were analyzed by flow cytometry.The AKT/Stat3/FOXO1 pathway was veri-fied by targeting AKT with GSK2141795.The role of FOXO1 in liver inflammation and changes in lymphocyte phenotype was confirmed by upregulating FOXO1 with resveratrol.Re-sults:Prolonged ischemic time aggravates liver injury in both humans and mouse models of hepatic IRI.IR-stress caused Th17/Treg imbalance and FOXO1 down-regulation by activat-ing the AKT/Stat3/FOXO1 signaling pathway.Upregulation of FOXO1 reversed the Th17/Treg cytokine imbalance and altered the inflammation environment in the liver.Conclusions:Liver IRI induced Th17/Treg imbalance.Upregulation of FOXO1 re-versed the imbalance and alleviated liver inflammation.