Methane Ameliorates Lipopolysaccharide-Induced Acute Orchitis by Anti-inflammatory, Antioxidative, and Antiapoptotic Effects via Regulation of the PK2/PKR1 Pathway

Abstract

Objective. The present study is aimed at investigating the anti-inflammatory, antioxidative, and antiapoptotic effects of methane on lipopolysaccharide- (LPS-) induced acute orchitis and its potential mechanisms. Methods. Adult male rats were intraperitoneally (i.p.) injected with methane-rich saline (MS, 20 mL/kg) following LPS (5 mg/kg, i.p.). The survival rate was assessed every 12 h until 72 h after LPS induction, and surviving rats were sacrificed for further detection. The wet/dry (W/D) ratio was determined, and testicular damage was histologically assessed. Inflammatory cytokines in the testes and serum, including interleukin-1β (IL-1β), IL-6, IL-10, and tumor necrosis factor-α (TNF-α), were measured using ELISA and RT-qPCR. Oxidative stress was evaluated by the level of superoxide dismutase (SOD) and malondialdehyde (MDA). Testicular apoptosis was detected via TUNEL staining. The expression of prokineticin 2 (PK2)/prokineticin receptor 1 (PKR1) was also analyzed using RT-qPCR, western blotting, and immunohistochemistry. Results. It was found that methane significantly prolonged rat survival, decreased the W/D ratio, alleviated LPS-induced histological changes, and reduced apoptotic cells in the testes. Additionally, methane suppressed and promoted the production of pro- and anti-inflammatory cytokines, respectively. Furthermore, methane significantly increased SOD levels, decreased MDA levels, and decreased testicular expression of PK2 and PKR1. Therefore, methane exerts therapeutic effects on acute orchitis and might be a new and convenient strategy for the treatment of inflammation-related testicular diseases.

OCT4 Represses Inflammation and Cell Injury During Orchitis by Regulating CIP2A Expression

“…The findings revealed that Bcl-2 expression was notably decreased whereas Bax expression was elevated due to LPS stimulation compared to that in untreated cells, while OCT4 overexpression reversed these alterations. In addition, TD-19 treatment in OCT4-overexpressed and LPS-stimulated cells recovered the Bax Because the reduced antioxidant response was a manifestation of testicular inflammation (Huang et al, 2020), we next determined the expression of antioxidant genes in testicular cells with various treatments using RT-qPCR. Data showed that the expression of antioxidant proteins, including GCLM, HMOX-1, and NQO1 (Wang et al, 2019), was downregulated in the LPS-treated Leydig, Sertoli, and germ cells compared with that in the control group.…”

Prokineticin 2/PROK2 and Male Infertility

“…It has been proven that the pathogenesis of orchitis mainly includes inflammatory cytokine imbalance, oxidative stress, apoptosis, and the PROK2 pathway. In lipopolysaccharide-induced acute orchitis, administration of methane, an interesting formulation with beneficial properties [ 52 ], decreased pro-inflammatory mediators, and over-expressed the anti-inflammatory interleukin IL-10 in the rat testes [ 53 ]. In particular, it was found that methane significantly prolonged rat survival, improved the testis condition, alleviated lipopolysaccharide-induced histological changes, and reduced apoptotic cells in the testes [ 53 ].…”

“…In lipopolysaccharide-induced acute orchitis, administration of methane, an interesting formulation with beneficial properties [ 52 ], decreased pro-inflammatory mediators, and over-expressed the anti-inflammatory interleukin IL-10 in the rat testes [ 53 ]. In particular, it was found that methane significantly prolonged rat survival, improved the testis condition, alleviated lipopolysaccharide-induced histological changes, and reduced apoptotic cells in the testes [ 53 ]. Furthermore, methane significantly increased superoxide dismutase, decreased malondialdehyde, and reduced testicular expression of PROK2 and PROKR1.…”

“…Therefore, methane exerts therapeutic effects on acute orchitis and might be a new and convenient strategy for the treatment of inflammation-related testicular diseases. [ 53 ]. Indeed, methane, the simplest organic compound, was deemed to have little physiological action for decades.…”

A narrative review of methane in treating neurological diseases

“…[ 1 2 3 4 5 6 ] Methane can significantly alleviate I/R injury of these organs. Moreover, the protective effects of methane on inflammatory diseases, such as endotoxic shock,[ 7 ] dextran sulfate sodium-induced colitis,[ 8 ] and bacteria-induced sepsis,[ 9 ] have also been confirmed. [ 6 ] Furthermore, methane can treat other diseases, such as diabetic retinopathy,[ 10 ] lung injury,[ 11 ] acute pancreatitis[ 12 ] and even chronic pain.…”