Quercetin relieved diabetic neuropathic pain by inhibiting upregulated P2X4 receptor in dorsal root ganglia

The upregulation of nociceptive ion channels expressed in dorsal root ganglia (DRG) contributes to the development and retaining of diabetic pain symptoms. The flavonoid quercetin (3,3′,4′,5,7-pentahydroxyflavone) is a component extracted from various fruits and vegetables and exerts anti-inflammatory, analgesic, anticarcinogenic, antiulcer, and antihypertensive effects. However, the exact mechanism underlying quercetin's analgesic action remains poorly understood. The aim of this study was to investigate the effects of quercetin on diabetic neuropathic pain related to the P2X₄ receptor in the DRG of type 2 diabetic rat model. Our data showed that both mechanical withdrawal threshold and thermal withdrawal latency in diabetic rats treated with quercetin were higher compared with those in untreated diabetic rats. The expression levels of P2X₄ messenger RNA and protein in the DRG of diabetic rats were increased compared with the control rats, while quercetin treatment significantly inhibited such enhanced P2X₄ expression in diabetic rats. The satellite glial cells (SGCs) enwrap the neuronal soma in the DRG. Quercetin treatment also lowered the elevated coexpression of P2X₄ and glial fibrillary acidic protein (a marker of SGCs) and decreased the upregulation of phosphorylated p38 mitogen-activated protein kinase (p38MAPK) in the DRG of diabetic rats. Quercetin significantly reduced the P2X₄ agonist adenosine triphosphate-activated currents in HEK293 cells transfected with P2X₄ receptors. Thus, our data demonstrate that quercetin may decrease the upregulation of the P2X₄ receptor in DRG SGCs, and consequently inhibit P2X₄ receptor-mediated p38MAPK activation to relieve the mechanical and thermal hyperalgesia in diabetic rats.     

Downregulation of lysyl oxidase-like 4 LOXL4 by miR-135a-5p promotes lung cancer progression in vitro and in vivo

Aberrant microRNAs are widely identified in multiple cancers, including lung cancer. miR-135a-5p can function as a significant tumor regulator in diverse cancers via impacting multiple genes in oncogenic pathways. Nevertheless, the biological role of miR-135a-5p in lung cancer is poorly known. Here, we investigated its function in lung cancer. As exhibited, miR-135a-5p was elevated in lung cancer cells in contrast to BEAS-2B cells. Then, we inhibited miR-135a-5p expression by transfecting LV-anti-miR-135a-5p into lung cancer cells. As displayed, miR-135a-5p was obviously reduced in A549 and H1299 cells. Knockdown of miR-135a-5p repressed lung cancer cell growth and cell proliferation. Meanwhile, cell colony formation capacity was depressed, cell apoptosis was enhanced and cell cycle progression was blocked in G1 phase by inhibition of miR-135a-5p in vitro. Additionally, the migration and invasion of A549 and H1299 cells was strongly depressed by LV-anti-miR-135a-5p. For another, by using informatics analysis, lysyl oxidase-like 4 (LOXL4) was speculated as the downstream target of miR-135a-5p. We validated their direct correlation and moreover, overexpression of miR-135a-5p restrained LOXL4 levels in lung cancer cells. Subsequently, we proved that miR-135a-5p promoted lung cancer development via targeting LOXL4 by carrying out the in vivo assays. Taken these together, our study revealed miR-135a-5p might be indicated as a perspective for lung cancer via targeting LOXL4.     

Fibroblast growth factor 21 protects against pathological cardiac remodeling by modulating galectin-3 expression

Background/Aims: Fibroblast growth factor 21 (FGF21) plays a protective role in ischemia/reperfusion induced cardiac injury. However, the exact molecular mechanism of FGF21 action remains unclear. This study was designed the protective effect of FGF21 on the heart and its mechanism. Method: Adenovirus vector expressing FGF21 or control β-galactosidase was injected into the myocardium of mice. Myocardial injury was observed by tissue staining and immunohistochemical staining. The expression level of caspases-3 and galectin-3 in myocardial cells were observed by immunoblotting. Then, hypoxia-induced cell model was established. Small interfering RNA (SiRNA) and plasmid were transfected into H9c2 using Lipofectamine 2000 reagent (Invitrogen). The expression levels of galectin-3, ECM and cystatin-3 in cells were observed by immunoblotting, and the relationship between fibroblast growth factor 21 and galectin-3 was analyzed. Result: Cell test in vitro showed that FGF21 could inhibit apoptosis and decrease the expression of ECM (ColIaI, fibronectin, and alpha-SMA) under hypoxia. Western blot data showed that hypoxia-induced cell damage increased galectin-3 levels, while FGF21 decreased galactose lectin-3 levels. In addition, inhibition of galactose agglutinin-3 expression by siRNA enhanced the cardioprotective effect of FGF21, while overexpression of galectin-3 reduced the cardioprotective effect of fibroblast growth factor 21. Conclusion: FGF21 may be a novel therapy for hypoxia-induced cardiac injury by regulating the expression of galectin-3.     

The effect of GNAQ methylation on GnRH secretion in sheep hypothalamic neurons

Kazakh sheep are seasonal estrous animals, and gonadotropin-releasing hormone (GnRH) is the key to fertility regulation. The nutritional level has a certain regulatory effect on estrous, and vitamin B folate plays a role in DNA methylation, directly participating in the process. The goal of this study was to determine whether folate is involved in GnAQ methylation and its effect on GnRH secretion. The hypothalamic neurons of Kazakh fetal sheep were treated with folate at concentrations of 0 mg/mL, 4 mg/mL, 40 mg/mL, and 80 mg/mL. GnAQ promoter methylation, DNMT1, GnAQ expression, and GnRH secretion following treatment with different concentrations of folate were analyzed. One CpG site was methylated in the GNAQ promoter with 40 mg/mL folic acid, and no CpG methylation was found in the other groups. GnAQ expression was related to folate concentration and showed a trend of increasing first and then decreasing. The GnRH expression level in the 40 mg/mL folate group was significantly higher than in the other three groups ( P < .05). These results demonstrate that the appropriate folate concentration promoted GANQ promoter methylation, which in turn affected GnRH secretion.