Hydrogen alleviates hyperoxic acute lung injury related endoplasmic reticulum stress in rats through upregulation of SIRT1

SIRT1 regulates endoplasmic reticulum stress-related organ damage

Endoplasmic reticulum (ER) stress plays a key role in the pathogenesis of several organ damages. Studies show that excessive ER stress (ERS) can destroy cellular homeostasis, causing cell damage and physiological dysfunction in various organs. In recent years, Sirtuin1 (SIRT1) has become a research hotspot on ERS. Increasing evidence suggests that SIRT1 plays a positive role in various ERS-induced organ damage via multiple mechanisms, including inhibiting cellular apoptosis and promoting autophagy. SIRT1 can also alleviate liver, heart, lung, kidney, and intestinal damage by inhibiting ERS. We discuss the possible mechanism of SIRT1, explore potential therapeutic targets of diseases, and provide a theoretical basis for treating ERS-related diseases.

NAMPT inhibition relieves intestinal inflammation by regulating macrophage activation in experimental necrotizing enterocolitis

Nicotinamide phosphoribosyl transferase (NAMPT) is associated with various NAD+ -consuming enzymatic reactions. The precise role in intestinal mucosal immunity in necrotizing enterocolitis (NEC) is not well defined. Here, we examined whether NAMPT inhibition by the highly specific inhibitor FK866 could alleviate intestinal inflammation during the pathogenesis of NEC. In the present study, we showed that NAMPT expression was upregulated in the human terminal ileum of human infants with NEC. FK866 administration attenuated M1 macrophage polarization and relieved the symptoms of experimental NEC pups. FK866 inhibited intercellular NAD+ levels, macrophage M1 polarization, and the expression of NAD+ -dependent enzymes, such as poly (ADP ribose) polymerase 1 (PARP1) and Sirt6. Consistently, the capacity of macrophages to phagocytose zymosan particles, as well as antibacterial activity, were impaired by FK866, whereas NMN supplementation to restore NAD+ levels reversed the changes in phagocytosis and antibacterial activity. In conclusion, FK866 reduced intestinal macrophage infiltration and skewed macrophage polarization, which is implicated in intestinal mucosal immunity, thereby promoting the survival of NEC pups.

Nicotinamide riboside relieves the severity of experimental necrotizing enterocolitis by regulating endothelial function via eNOS deacetylation

BACKGROUND

Nicotinamide adenine dinucleotide (NAD+) is involved in regulating oxidative stress. Although NAD+ is associated with various health issues, its role in the intestinal microcirculation in necrotizing enterocolitis (NEC) remains to be confirmed. In the current study, we explored whether nicotinamide riboside (NR), a natural NAD + precursor, ameliorates the severity of NEC through endothelial nitric oxide synthase(eNOS) signaling.

METHODS

A mouse experimental NEC model was induced by formula gavage and hypoxia in full-term mouse pups. Intestinal endothelial cells (MIMECs) were isolated and subjected to stress using tumor necrosis factor (TNF)-α. NR was administered to assess the intestinal microcirculation and lipid peroxidation levels and to explore the involved signaling pathways.

RESULTS

NAD + levels were reduced after induction of NEC stress, which was associated with intestinal injury. NR administration promoted NAD + levels, attenuated oxidative stress and relieved the symptoms of experimental NEC, which were relevant to increased intestinal microcirculatory perfusion through the sirtuin (SIRT) 1 pathway in experimental NEC mice. However, this improvement was not found in eNOS-knockout mice. Consistently, MIMECs exposed to TNFα showed decreased SIRT1 activity associated with increased eNOS acetylation, which could bring about endothelial dysfunction due to limited nitric oxide production. NR administration increased the NAD + content and repressed the production of reactive oxygen species (ROS) in MIMECs under TNFα stress. NR also promoted SIRT1 activity and accordingly suppressed the eNOS acetylation levels under TNFα stress.

CONCLUSION

The current data indicate that NR administration improves the survival of experimental NEC mice via SIRT1-associated eNOS acetylation/deacetylation modulation, which is implicated in endothelial dysfunction. Although NR is commonly found in the human diet, it may also be a promising strategy for NEC treatment because of its pathogenic association with NEC.

Molecular hydrogen is a potential protective agent in the management of acute lung injury

Acute lung injury (ALI) and acute respiratory distress syndrome, which is a more severe form of ALI, are life-threatening clinical syndromes observed in critically ill patients. Treatment methods to alleviate the pathogenesis of ALI have improved to a great extent at present. Although the efficacy of these therapies is limited, their relevance has increased remarkably with the ongoing pandemic caused by the novel coronavirus disease 2019 (COVID-19), which causes severe respiratory distress syndrome. Several studies have demonstrated the preventive and therapeutic effects of molecular hydrogen in the various diseases. The biological effects of molecular hydrogen mainly involve anti-inflammation, antioxidation, and autophagy and cell death modulation. This review focuses on the potential therapeutic effects of molecular hydrogen on ALI and its underlying mechanisms and aims to provide a theoretical basis for the clinical treatment of ALI and COVID-19.

Molecular hydrogen is a promising therapeutic agent for pulmonary disease

Molecular hydrogen exerts biological effects on nearly all organs. It has anti-oxidative, anti-inflammatory, and anti-aging effects and contributes to the regulation of autophagy and cell death. As the primary organ for gas exchange, the lungs are constantly exposed to various harmful environmental irritants. Short- or long-term exposure to these harmful substances often results in lung injury, causing respiratory and lung diseases. Acute and chronic respiratory diseases have high rates of morbidity and mortality and have become a major public health concern worldwide. For example, coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global pandemic. An increasing number of studies have revealed that hydrogen may protect the lungs from diverse diseases, including acute lung injury, chronic obstructive pulmonary disease, asthma, lung cancer, pulmonary arterial hypertension, and pulmonary fibrosis. In this review, we highlight the multiple functions of hydrogen and the mechanisms underlying its protective effects in various lung diseases, with a focus on its roles in disease pathogenesis and clinical significance.

Mechanism of Adipose-Derived Mesenchymal Stem Cell-Derived Extracellular Vesicles Carrying miR-21-5p in Hyperoxia-Induced Lung Injury

Hyperoxia-induced lung injury (HILI) tends to develop bronchopulmonary dysplasia. Adipose-derived mesenchymal stem cell (ADMSC)-derived extracellular vesicles (EVs) hold great promise in alleviating lung injury. This study explored the mechanism of ADMSC-EVs in HILI. ADMSC-EVs were isolated and identified. The murine and cell models of HILI were established. HILI mice and cells were pre-treated with ADMSC-EVs. The lung dry/wet ratio, pathological structure, apoptosis, and inflammation of HILI mice were measured. The viability, apoptosis, and oxidative stress of HILI cells were measured. The internalization of EVs in lung and cells was observed by fluorescence labeling. The binding relationships between miR-21-5p and SKP2, and Nr2f2 and C/EBPα were analyzed. The binding of SKP2 and Nr2f2 and the Nr2f2 ubiquitination level were detected. ADMSC-EVs exerted preventive effects on HILI mice, evidenced by reduced lung dry/wet ratio, inflammation, and apoptosis in HILI mice. In vitro, EVs enhanced HILI cell viability and reduced apoptosis, inflammation, and oxidative stress. EVs carried miR-21-5p into lung cells to upregulate miR-21-5p expression and thereby target SKP2. SKP2 bound to Nr2f2 and promoted its ubiquitination degradation. EVs inhibited the binding of Nr2f2 and C/EBPα and further suppressed C/EBPα transcription. Collectively, ADMSC-EVs carrying miR-21-5p alleviated HILI via the SKP2/Nr2f2/C/EBPα axis. Role and mechanism of adipose-derived mesenchymal stem cell-derived extracellular vesicles in hyperoxia-induced lung injury. ADMSC-EVs upregulated miR-21-5p expression in cells by carrying miR-21-5p into lung cells, thereby promoting the binding of miR-21-5p and SKP2 mRNA, inhibiting the expression of SKP2, reducing the ubiquitination level of Nr2f2, increasing the expression of Nr2f2, promoting the binding of Nr2f2 and the C/EBPα promoter, upregulating C/EBPα mRNA level, and eventually alleviating HILI.

High concentration of hydrogen ameliorates lipopolysaccharide-induced acute lung injury in a sirt1-dependent manner

The aim of this study was to investigate the efficacy and underlying mechanism of high concentration of hydrogen on lipopolysaccharide (LPS)-induced acute lung injury (ALI). We have established a corresponding mouse model and examined the function of hydrogen inhalation on lung pathology and pulmonary edema induced by LPS, as well as contents of IL-1β, TNF-α and IL-8. The pulmonary microvascular permeability and 66.7 % hydrogen on the expression of sirt1 and its downstream signaling molecules were tested. Results showed that 66.7 % hydrogen alleviated lung pathological changes and pulmonary edema caused by LPS, and reduced the degree of ALI by inhibiting pro-inflammatory cytokine release and oxidative stress response, thereby decreasing the expression of molecules related to intercellular adhesion. sirt1 contributed to the repair of LPS-induced ALI by hydrogen through the regulation of NF-κB and catalase expression. In conclusion, 66.7 % hydrogen protected against LPS-induced ALI by suppressing inflammatory response and oxidative stress mediated by NF-κB and catalase in a sirt1-dependent manner.

Protective effects of molecular hydrogen on lung injury from lung transplantation

Lung grafts may experience multiple injuries during lung transplantation, such as warm ischaemia, cold ischaemia, and reperfusion injury. These injuries all contribute to primary graft dysfunction, which is a major cause of morbidity and mortality after lung transplantation. As a potential selective antioxidant, hydrogen molecule (H₂) protects against post-transplant complications in animal models of multiple organ transplantation. Herein, the authors review the current literature regarding the effects of H₂ on lung injury from lung transplantation. The reviewed studies showed that H₂ improved the outcomes of lung transplantation by decreasing oxidative stress and inflammation at the donor and recipient phases. H₂ is primarily administered via inhalation, drinking hydrogen-rich water, hydrogen-rich saline injection, or a hydrogen-rich water bath. H₂ favorably modulates signal transduction and gene expression, resulting in the suppression of pro-inflammatory cytokines and excess reactive oxygen species production. Although H₂ appears to be a physiological regulatory molecule with antioxidant, anti-inflammatory and anti-apoptotic properties, its exact mechanisms of action remain elusive. Taken together, accumulating experimental evidence indicates that H₂ can significantly alleviate transplantation-related lung injury, mainly via inhibition of inflammatory cytokine secretion and reduction in oxidative stress through several underlying mechanisms. Further animal experiments and preliminary human clinical trials will lay the foundation for the use of H₂ as a treatment in the clinic.

Hydrogen-rich water protects against liver injury in nonalcoholic steatohepatitis through HO-1 enhancement via IL-10 and Sirt 1 signaling

Nonalcoholic steatohepatitis (NASH) could progress to hepatic fibrosis in the absence of effective control. The purpose of our experiment was to investigate the protective effect of drinking water with a high concentration of hydrogen, namely, hydrogen-rich water (HRW), on mice with nonalcoholic fatty liver disease to elucidate the mechanism underlying the therapeutic action of molecular hydrogen. The choline-supplemented, l-amino acid-defined (CSAA) or the choline-deficient, l-amino acid-defined (CDAA) diet for 20 wk was used to induce NASH and fibrosis in the mice model and simultaneously treated with the high-concentration 7-ppm HRW for different periods (4 wk, 8  wk, and 20 wk). Primary hepatocytes were stimulated by palmitate to mimic liver lipid metabolism during fatty liver formation. Primary hepatocytes were cultured in a closed vessel filled with 21% O₂ + 5% CO₂ + 3.8% H₂ and N₂ as the base gas to verify the response of primary hepatocytes in a high concentration of hydrogen gas in vitro. Mice in the CSAA + HRW group had lower serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and milder histological damage. The inflammatory cytokines were expressed at lower levels in the HRW group than in the CSAA group. Importantly, HRW reversed hepatocyte fatty acid oxidation and lipogenesis as well as hepatic inflammation and fibrosis in preexisting hepatic fibrosis specimens. Molecular hydrogen inhibits the lipopolysaccharide-induced production of inflammation cytokines through increasing heme oxygenase-1 (HO-1) expression. Furthermore, HRW improved hepatic steatosis in the CSAA + HRW group. Sirtuin 1 (Sirt1) induction by molecular hydrogen via the HO-1/adenosine monophosphate activated protein kinase (AMPK)/peroxisome proliferator-activated receptor α (PPARα)/peroxisome proliferator-activated receptor γ (PPAR-γ) pathway suppresses palmitate-mediated abnormal fat metabolism. Orally administered HRW suppressed steatosis induced by CSAA and attenuated fibrosis induced by CDAA, possibly by reducing oxidative stress and the inflammation response.NEW & NOTEWORTHY The mRNA expression of inflammatory cytokines in the HRW group was lower than in the CSAA group. HRW reversed hepatocyte apoptosis as well as hepatic inflammation and fibrosis in NASH specimens. Molecular hydrogen inhibits LPS-induced inflammation via an HO-1/interleukin 10 (IL-10)-independent pathway. HRW improved hepatic steatosis in the CSAA + HRW group. Sirt1 induction by molecular hydrogen via the HO-1/AMPK/PPARα/PPARγ pathway suppresses palmitate-mediated abnormal fat metabolism.

Depleting microRNA-146a-3p attenuates lipopolysaccharide-induced acute lung injury via up-regulating SIRT1 and mediating NF-κB pathway

OBJECTIVE

The role of microRNAs (miRs) in acute lung injury (ALI) has been discussed. This study is to uncover the effects of miR-146a-3p/Sirtuin-1 (SIRT1)/Nuclear factor-kappa B (NF-κB) axis on ALI.

METHODS

Human normal lung epithelial cell line BEAS-2B was exposed to lipopolysaccharide (LPS) to establish an in vitro model of ALI. NF-κB expression, cell activity, apoptosis, inflammatory factors, oxidative stress indices were detected in LPS-induced BEAS-2B cells after miR-146a-3p was down-regulated or SIRT1 was up-regulated. ALI rat model was established and the NF-κB expression, wet/dry weight (W/D) ratio, pathological changes, pneumonocyte apoptosis, inflammatory factors, oxidative stress indices were detected in ALI rats after miR-146a-3p was down-regulated or SIRT1 was up-regulated. The target relationship between miR-146a-3p and SIRT1 was confirmed.

RESULTS

Reduced SIRT1 and raised miR-146a-3p  were found in LPS-induced BEAS-2B cells and ALI rats. SIRT1-overexpressing or  miR-146a-3p-underexpressing up-regulated NF-κB expression, promoted viability and inhibited apoptosis of LPS-induced BEAS-2B cells in vitro, and increased NF-κB expression, down-regulated the W/D ratio, attenuated pathological changes, suppressed apoptosis, and alleviated inflammatory response and oxidative stress in the lung of ALI rats. MiR-146a-3p directly binds to the 3'UTR of SIRT1 mRNA.

CONCLUSION

Depleting miR-146a-3p improves ALI through up-regulating SIRT1 and mediating NF-κB pathway.

Hydrogen-rich saline protects intestinal epithelial tight junction barrier in rats with intestinal ischemia-reperfusion injury by inhibiting endoplasmic reticulum stress-induced apoptosis pathway

AIM

To investigate the effects of hydrogen-rich saline (HRS) on intestinal epithelial tight junction (TJ) barrier in rats with intestinal ischemia-reperfusion injury (IIRI).

MATERIALS AND METHODS

Thirty-two healthy male Sprague-Dawley (SD) rats were randomly divided into four groups (n = 8 each): Sham group, I/R group, HRS group and 4-PBA group. After 45 min of ischemia and 6 h of reperfusion, the rats were sacrificed to collect serum and ileum for detection. Hematoxylin and eosin (H&E) staining was used to observe the morphology of small intestine. The serum expression levels of intestinal fatty acid binding protein (IFABP), tumor necrosis factor-α (TNF-α), and interleukin-1β (IL-1β) were determined by enzyme linked immunosorbent assay (ELISA). Imunohistochemistry, immunofluorescence and Western blot were used to detect key proteins in intestinal epithelial TJs, ERS, and ERS-induced apoptosis, including occludin, zonula occludens-1 (ZO-1), glucose-regulated protein 78 (GRP78), X-box binding protein-1 (XBP1), C/EBP-homologous protein (CHOP) and caspase-3. Data was presented as mean ± SEM and compared using one-way ANOVA. A p-value <0.05 was considered significant.

RESULTS

Compared with rats in the I/R group, the Chiu score of ileum damage in the HRS group and 4-PBA group were lower. The levels of serum IFABP, TNF-α, and IL-1β were statistically significant among the groups. Increased expression of TJ proteins occludin and ZO-1 by reducing various parameters of ERS and ERS-induced apoptosis evidenced by down-regulation of the protein levels of GRP78, XBP1, CHOP and caspase-3 were shown in the HRS and 4-PBA groups.

CONCLUSION

HRS had potential protective effects on intestinal barrier in IIRI rats. This study suggested that inhibition of excessive ERS and ERS-induced apoptosis by HRS may reduce intestinal epithelial cells damage and maintain the integrity of intestinal epithelial TJ barrier in rats with IIRI.

Fengbaisan suppresses endoplasmic reticulum stress by up-regulating SIRT1 expression to protect rats with chronic obstructive pulmonary diseases

CONTEXT

Our previous study found that Fengbaisan improved chronic obstructive pulmonary diseases (COPD).

OBJECTIVE

To elucidate the mechanism of Fengbaisan in COPD.

MATERIALS AND METHODS

Rats in Model, FBS, FBS + DMSO and FBS + EX527 groups received cigarette smoke extract (CSE) inhalation and intratracheal instillation of lipopolysaccharide to establish COPD model. Normal group received room air and normal saline. The COPD rats were given Fengbaisan (1 mL/d) or combined with EX527 (5 mg/kg/2 d) by intraperitoneal injection. Human lung carcinoma (A549) cells were treated with 10% CSE, 10% serum-containing Fengbaisan or EX527. We observed lung percentage of forced expiratory volume in first 0.3 sec to forced vital capacity (FEV0.3/FVC), inspiratory resistance (RI) and lung dynamic compliance (Cdyn) of rats. The lung pathological changes, the number of inflammatory cells and neutrophils, inflammatory factor, apoptosis, gene and protein expression were examined.

RESULTS

SIRT1 was downregulated in lung tissues of COPD rats and CSE-induced A549 cells. Fengbaisan enhanced FEV0.3/FVC (74.28%) and Cdyn (0.28 cm H₂O/mL/s), and reduced RI (0.48 mL/cm H₂O) of COPD rats. Moreover, Fengbaisan promoted SIRT1 expression, and repressed TIMP-1/MMP-9 expression. Fengbaisan enhanced apoptosis and the expression of GRP78, caspase-12 and caspase-3. The inflammatory factor levels, the number of inflammatory cells and neutrophils, and lung lesions were inhibited by Fengbaisan in COPD rats. The influence conferred by Fengbaisan was abolished by EX527.

DISCUSSION AND CONCLUSIONS

Fengbaisan inhibits endoplasmic reticulum stress and inflammation reaction by up-regulating SIRT1 expression to improve COPD. Therefore, Fengbaisan may be an effective Chinese medicine for treating COPD.

SIRT1 is a key regulatory target for the treatment of the endoplasmic reticulum stress-related organ damage

Endoplasmic reticulum (ER) stress is an evolutionarily conserved adaptive response that contributes to deal with the misfolded or unfolded protein in the lumen of the ER and restore the ER homeostasis. However, excessive and prolonged ER stress can trigger the cell-death signaling pathway which causes cell death, usually in the form of apoptosis. It is generally accepted that inappropriate cellular apoptosis and a series of the subsequent inflammatory response and oxidative stress can cause disturbance of normal physiological functions and organ damage. A lot of evidence shows that the excessive activation of the ER stress contributes to the pathogenesis of many kinds of diseases and inhibiting the inappropriate stress is of great significance for maintaining the normal physiological function. In recent years, Sirtuin1 (SIRT1) has become a research hotspot on ER stress. As a master regulator of ER stress, increasing evidence suggests that SIRT1 plays a positive role in a variety of ER stress-induced organ damage via multiple mechanisms, including inhibiting cellular apoptosis and promoting autophagy. Furthermore, a lot of factors have shown effective regulation of SIRT1, which indicates the feasibility of treating SIRT1 as a target for the treatment of ER stress-related diseases. We summarize and reveal the molecular mechanisms underlying the protective effect of SIRT1 in multiple ER stress-mediated organ damage in this review. We also summed up the possible adjustment mechanism of SIRT1, which provides a theoretical basis for the treatment of ER stress-related diseases.

Hydrogen Sulfide Ameliorates Lung Ischemia-Reperfusion Injury Through SIRT1 Signaling Pathway in Type 2 Diabetic Rats

Lung ischemia-reperfusion (IR) injury remains a significant factor for the early mortality of lung transplantations. Diabetes mellitus (DM) is an independent risk factor for 5-year mortality following lung transplantation. Our previous study showed that DM aggravated lung IR injury and that oxidative stress played a key role in this process. Previously, we demonstrated that hydrogen sulfide (H₂S) protected against diabetic lung IR injury by suppressing oxidative damage. This study aimed to examine the mechanism by which H₂S affects diabetic lung IR injury. High-fat-diet-fed streptozotocin-induced type 2 diabetic rats were exposed to GYY4137, a slow-releasing H₂S donor with or without administration of EX527 (a SIRT1 inhibitor), and then subjected to a surgical model of IR injury of the lung. Lung function, oxidative stress, cell apoptosis, and inflammation were assessed. We found that impairment of lung SIRT1 signaling under type 2 diabetic conditions was further exacerbated by IR injury. GYY4137 treatment markedly activated SIRT1 signaling and ameliorated lung IR injury in type 2 DM animals by improving lung functional recovery, diminishing oxidative damage, reducing inflammation, and suppressing cell apoptosis. However, these effects were largely compromised by EX527. Additionally, treatment with GYY4137 significantly activated the Nrf2/HO-1 antioxidant signaling pathway and increased eNOS phosphorylation. However, these effects were largely abolished by EX527. Together, our results indicate that GYY4137 treatment effectively attenuated lung IR injury under type 2 diabetic conditions via activation of lung SIRT1 signaling. SIRT1 activation upregulated Nrf2/HO-1 and activated the eNOS-mediated antioxidant signaling pathway, thus reducing cell apoptosis and inflammation and eventually preserving lung function.

Brain Metastases Completely Disappear in Non-Small Cell Lung Cancer Using Hydrogen Gas Inhalation: A Case Report

Lung cancer is the most common type of tumor, prone to contralateral lung, bone and brain metastasis. We report a 44-year-old woman diagnosed with lung cancer with multiple metastases in November 2015. Oral targeted drugs were initiated after the removal of brain metastases, and most lesions remained stable for 28 months. In March 2018, intracranial multiple metastases, as well as hydrocephalus accumulation in the third ventricle and lateral ventricles, and metastases in bone, adrenal gland, liver were noted. Hydrogen-gas monotherapy was started to control the tumor a month later. After 4 months, the size of multiple brain tumors was reduced significantly, and the amount of hydrocephalus in the third ventricle and lateral ventricles reduced significantly. After 1 year, all brain tumors had disappeared, and there were no significant changes in metastases in the liver and lung. These data show that, after standard treatments had failed, hydrogen-gas monotherapy elicited significant effective control of tumors (especially those in the brain), and survival time was lengthened.

Protective effects of resveratrol on hyperoxia-induced lung injury in neonatal rats by alleviating apoptosis and ROS production

Background: Bronchopulmonary dysplasia (BPD) is one of the most common long-term lung complications of prematurely born infants caused by prolonged injury and repair during immature lung development. Resveratrol has reported to exert anti-inflammatory, antioxidation, and antiapoptosis effects. This study aimed to investigate the effect of resveratrol in BPD.Methods: Neonate rats were delivered spontaneously and randomized divided into four groups on postnatal day (PN) 0.5: room air (21% O₂)+dimethyl sulfoxide (DMSO), room air + resveratrol, hyperoxia (80%)+DMSO, hyperoxia + resveratrol. Lung tissues were collected on PN1, PN7, and PN14. Protective effects of resveratrol on hyperoxia-induced lung injury were evaluated by hematoxylin and eosin (HE) staining, TUNEL staining, reactive oxygen species (ROS) detection, qRT-PCR, and western blotting.Results: Hyperoxia-induced alveolar simplification and apoptosis were alleviated by resveratrol; resveratrol reduced ROS production, up-regulated SIRT1, decreased the expressing of p53, and acetyl-p53 in the lung of hyperoxia-exposed neonatal rats.Conclusions: This study showed that resveratrol alleviated hyperoxia-induced apoptosis in neonatal rats lung tissue via reducing ROS and p53. Resveratrol-induced SIRT1 upregulation and acetyl-p53 reduction may also be involved in lung protection.

Molecular hydrogen protects against ischemia-reperfusion injury in a mouse fatty liver model via regulating HO-1 and Sirt1 expression

Fatty liver has lower tolerance against ischemia-reperfusion (I/R) injury in liver operations, including liver transplantation. Seeking to ameliorate liver injury following I/R in fatty liver, we examined the protective effect of hydrogen (H₂) saline on I/R liver injury in a methionine and choline-deficient plus high fat (MCDHF) diet-induced fatty liver mouse model. Saline containing 7 ppm H₂ was administrated during the process of I/R. Livers were obtained and analyzed. Primary hepatocytes and Kupffer cells (KCs) were obtained from fatty liver and subjected to hypoxia/reoxygenation. Apoptosis-related proteins and components of the signaling pathway were analyzed after treatment with hydrogen gas. The MCDHF I/R group showed higher levels of AST and ALT in serum, TUNEL-positive apoptotic cells, F4/80 immunopositive cells, mRNA levels of inflammatory cytokines, constituents of the signaling pathway, pro-apoptotic molecules in liver, and KCs and/or primary hepatocytes, compared to the control group. In contrast, H₂ treatment significantly suppressed the signs of I/R injury in fatty liver. Moreover, the expression of Bcl-2, HO-1, and Sirt1 in liver, KCs, and hepatocytes by hydrogen gas were increased, whereas caspase activation, Bax, and acetylation of p53 were suppressed by hydrogen gas. These results demonstrated that H₂ treatment ameliorated I/R liver injury in a fatty liver model by reducing hepatocyte apoptosis, inhibiting macrophage activation and inflammatory cytokines, and inducing HO-1 and Sirt1 expression. Taken togather, treatment with H₂ saline may have a protective effect and safe therapeutic activity during I/R events, such as in liver transplantation with fatty liver.

CTRP3 attenuates high-fat diet-induced male reproductive dysfunction in mice

Recent studies have suggested a role for abdominal obesity in male infertility. Previous studies have found that cell apoptosis exerts an important role in obesity-related male infertility. C1q/TNF-related protein 3 (CTRP3), a paralog of adiponectin, has been proposed to exert anti-apoptotic effects and to attenuate diabetes-related cardiac injuries. However, the role of CTRP3 in high-fat diet (HFD)-induced spermatogenic impairment remains unclear. In the present study, we fed male mice an HFD for 24 weeks to induce obesity. The expression of CTRP3 was decreased by HFD feeding. Supplementation with the recombinant human globular domain of CTRP3 (0.25 μg/g/day) for 4 weeks beginning at 20 weeks of the HFD improved spermatogenic function in the HFD-fed mice, which were characterized by improved testis morphology, increased testis weight/body weight ratio, and increased sperm count, sperm viability, and sperm motility. We also found that CTRP3 infusion resulted in the attenuation of endoplasmic reticulum (ER) stress and the activation of silence information regulator 1 (SIRT1) in the testes of obese mice. Our in vitro study also suggested that CTRP3 attenuated the palmitic acid (PA)-induced reductions in sperm viability and motility via the inhibition of ER stress. Moreover, germ cell-specific Sirtuin1 knockout abolished the protective effects of CTRP3 in vivo and in vitro. In vitro studies of human sperm showed that the protective effects of CTRP3 on sperm viability and motility were abrogated by a specific inhibitor of SIRT1. Thus, our results demonstrated that CTRP3 expression protected against HFD-induced spermatogenic deficiency through the SIRT1/ER stress pathway.