Melatonin protects mouse testes from palmitic acid-induced lipotoxicity by attenuating oxidative stress and DNA damage in a SIRT1-dependent manner

Astaxanthin prevents bone loss in osteoporotic rats with palmitic acid through suppressing oxidative stress

OBJECTIVES

The study aimed to assess the role of Astaxanthin (ATX) in palmitic acid(PA) -induced bone loss in Ovariectomized(OVX) rats.

METHODS

In the OVX rat model, we observed that PA affects bone metabolism and accelerates bone loss. Additionally, treatment with ATX was able to suppress the deleterious effects of PA and a simultaneous decrease in serum MDA levels and an increase in SOD was observed.

RESULTS

In addition, rats treated with ATX were observed to have significantly increased bone mass and elevated activity of SIRT1 and SOD2 in bone tissue. When MC3T3-E1 and RAW264.7 cells induced osteoblast and osteoclast differentiation, the ATX intervention was able to significantly restore the restriction of osteogenic differentiation and the up-regulation of osteoclast differentiation with PA therapy. Furthermore, we confirm that PA damage to cells is caused by increased oxidative stress, and that ATX can target and modulate the activity of SIRT1 to regulate the levels of oxidative stress in cells.

CONCLUSION

Summarizing, ATX may inhibit PA-induced bone loss through its antioxidant properties via the SIRT1 signaling pathway.

Melatonin regulates mitochondrial function to alleviate ferroptosis through the MT2/Akt signaling pathway in swine testicular cells

Increasing evidence has shown that many environmental and toxic factors can cause testicular damage, leading to testicular ferroptosis and subsequent male reproductive disorders. Melatonin is a major hormone and plays an vital role in regulating male reproduction. However, there is a lack of research on whether Mel can alleviate testicular cell ferroptosis and its specific mechanism. In this study, the results indicated that Mel could enhance the viability of swine testis cells undergoing ferroptosis, reduce LDH enzyme release, increase mitochondrial membrane potential, and affect the expression of ferroptosis biomarkers. Furthermore, we found that melatonin depended on melatonin receptor 1B to exert these functions. Detection of MMP and ferroptosis biomarker protein expression confirmed that MT2 acted through the downstream Akt signaling pathway. Moreover, inhibition of the Akt signaling pathway can eliminate the protective effect of melatonin on ferroptosis, inhibit AMPK phosphorylation, reduce the expression of mitochondrial gated channel (VDAC2/3), and affect mitochondrial DNA transcription and ATP content. These results suggest that melatonin exerts a beneficial effect on mitochondrial function to mitigate ferroptosis through the MT2/Akt signaling pathway in ST cells.

Targeting STAT3 potentiates CDK4/6 inhibitors therapy in head and neck squamous cell carcinoma

Anti-CDK4/6 therapy has been employed for the treatment for head and neck squamous cell carcinoma (HNSCC) with CDK4/6 hyperactivation, but the response rate is relatively low. In this study, we first showed that CDK4 and CDK6 was over-expressed and conferred poor prognosis in HNSCC. Moreover, in RB-positive HNSCC, STAT3 signaling was activated induced by CDK4/6 inhibition and STAT3 promotes RB deficiency by upregulation of MYC. Thirdly, the combination of Stattic and CDK4/6 inhibitor results in striking anti-tumor effect in vitro and in Cal27 derived animal models. Additionally, phospho-STAT3 level negatively correlates with RB expression and predicts poor prognosis in patients with HNSCC. Taken together, our findings suggest an unrecognized function of STAT3 confers to CDK4/6 inhibitors resistance and presenting a promising combination strategy for patients with HNSCC.

The effect of biological mechanisms of melatonin on the proliferation of spermatogonial stem cells: a systematic review

In the last decade, melatonin has gained recognition as a potent scavenger and an effective antioxidant capable of neutralizing free radicals, including reactive oxygen species. Additionally, it exhibits anti-apoptotic properties. In this review, we will examine a compilation of articles that explore the cellular signaling function of melatonin on spermatogonial stem cells (SSCs) and adjacent cells such as Sertoli and Leydig cells. These cells play a crucial role in the proliferation of SSCs both in vitro and in vivo. In this review, we analyze the function of melatonin in the proliferation of SSCs from other aspects. For this purpose, we examine the articles based on the presence of melatonin on SSCs in four groups: As a supplement in SSCs medium culture, SSCs three-dimensional culture system, SSCs freezing medium, and as a therapeutic factor in vivo. Mechanisms of growth and proliferation of SSCs were considered. The purpose of this study is to investigate the potential effects of melatonin as a powerful antioxidant or growth stimulant for SSCs, both in vivo and in vitro.

Nicotine induces senescence in spermatogonia stem cells by disrupting homeostasis between circadian oscillation and rhythmic mitochondrial dynamics via the SIRT6/Bmal1 pathway

Infertility is intricately linked with alterations in circadian rhythms along with physiological decline and stem cell senescence. Yet, the direct involvement of circadian mechanisms in nicotine-induced injury to the testes, especially the senescence of spermatogonia stem cells (SSCs), is not well comprehended. This study revealed that nicotine exposure induced testis injury by triggering SSCs senescence along with the upregulation of senescence marker genes and senescence-associated secretory phenotype components. Moreover, nicotine treatment caused mitochondrial hyper-fusion, increased oxidative stress, and DNA damage. Exposure to nicotine was found to suppress the expression of sirtuin 6 (SIRT6), which accelerated the senescence of spermatogonia stem cells (SSCs). This acceleration led to increased acetylation of brain and muscle ARNT-like protein (Bmal1), consequently reducing the expression of Bmal1 protein. Conversely, the overexpression of Bmal1 alleviated mitochondrial hyper-fusion and senescence phenotypes induced by nicotine. Overall, this study unveiled a novel molecular mechanism behind nicotine-induced disorders in spermatogenesis and highlighted the SIRT6/Bmal1 regulatory pathway as a potential therapeutic target for combating nicotine-associated infertility.

Notoginsenoside R1 decreases intraplaque neovascularization by governing pericyte-endothelial cell communication via Ang1/Tie2 axis in atherosclerosis

Atherosclerosis represents the major cause of mortality worldwide and triggers higher risk of acute cardiovascular events. Pericytes-endothelial cells (ECs) communication is orchestrated by ligand-receptor interaction generating a microenvironment which results in intraplaque neovascularization, that is closely associated with atherosclerotic plaque instability. Notoginsenoside R1 (R1) exhibits anti-atherosclerotic bioactivity, but its effect on angiogenesis in atherosclerotic plaque remains elusive. The aim of our study is to explore the therapeutic effect of R1 on vulnerable plaque and investigate its potential mechanism against intraplaque neovascularization. The impacts of R1 on plaque stability and intraplaque neovascularization were assessed in ApoE-/- mice induced by high-fat diet. Pericytes-ECs direct or non-direct contact co-cultured with VEGF-A stimulation were used as the in vitro angiogenesis models. Overexpressing Ang1 in pericytes was performed to investigate the underlying mechanism. In vivo experiments, R1 treatment reversed atherosclerotic plaque vulnerability and decreased the presence of neovessels in ApoE-/- mice. Additionally, R1 reduced the expression of Ang1 in pericytes. In vitro experiments demonstrated that R1 suppressed pro-angiogenic behavior of ECs induced by pericytes cultured with VEGF-A. Mechanistic studies revealed that the anti-angiogenic effect of R1 was dependent on the inhibition of Ang1 and Tie2 expression, as the effects were partially reversed after Ang1 overexpressing in pericytes. Our study demonstrated that R1 treatment inhibited intraplaque neovascularization by governing pericyte-EC association via suppressing Ang1-Tie2/PI3K-AKT paracrine signaling pathway. R1 represents a novel therapeutic strategy for atherosclerotic vulnerable plaques in clinical application.

Polystyrene nanoplastics exposure triggers spermatogenic cell senescence via the Sirt1/ROS axis

Polystyrene nanoplastics (PS-NPs) have been reported to accumulate in the testes and constitute a new threat to reproductive health. However, the exact effects of PS-NPs exposure on testicular cells and the underlying mechanisms remain largely unknown. The C57BL/6 male mice were orally administered with PS-NPs (80 nm) at different dosages (0, 10, and 40 mg/kg/day) for 60 days, and GC-1 cells were treated with PS-NPs in this study. Enlarged seminiferous tubule lumens and a loose and vacuolated layer of spermatogenic cells were observed in PS-NPs-exposed mice. Spermatogenic cells which may be one of the target cells for this reproductive damage, were decreased in the mice from PS-NPs group. PS-NPs caused spermatogenic cells to undergo senescence, manifested as elevated SA-β-galactosidase activity and activated senescence-related signaling p53-p21/Rb-p16 pathways, and induced cell cycle arrest. Mechanistically, Gene Ontology (GO) enrichment suggested the key role of reactive oxygen species (ROS) in PS-NPs-induced spermatogenic cell senescence, and this result was confirmed by measuring ROS levels. Moreover, ROS inhibition partially attenuated the senescence phenotype of spermatogenic cells and DNA damage. Using the male health atlas (MHA) database, Sirt1 was filtrated as the critical molecule in the regulation of testicular senescence. PS-NPs induced overexpression of the main ROS generator Nox2, downregulated Sirt1, increased p53 and acetylated p53 in vivo and in vitro, whereas these disturbances were partially restored by pterostilbene. In addition, pterostilbene intervention significantly alleviated the PS-NPs-induced spermatogenic cell senescence and attenuated ROS burst. Collectively, our study reveals that PS-NPs exposure can trigger spermatogenic cell senescence mediated by p53-p21/Rb-p16 signaling by regulating the Sirt1/ROS axis. Importantly, pterostilbene intervention may be a promising strategy to alleviate this damage.

From Epimedium to Neuroprotection: Exploring the Potential of Wushanicaritin

Epimedium has been used for functional foods with many beneficial functions to human health. Wushanicaritin is one of the most important chemicals int Epimedium. This study investigated the neuroprotective effects of wushanicaritin and potential underlying mechanisms. The results demonstrated that wushanicaritin possessed superior intercellular antioxidant activity compared to icaritin. Wushanicaritin, with an EC50 value of 3.87 μM, showed better neuroprotective effect than quercetin, a promising neuroprotection agent. Wushanicaritin significantly reversed lactate dehydrogenase release, reactive oxygen species generation, cell apoptosis, and mRNA expression related to cell apoptosis and oxidative defense, in glutamate-induced PC-12 cells. Wushanicaritin could also maintain the enzymatic antioxidant defense system and mitochondrial function. The suppression of caspase-3 activation and amelioration of mitochondrial membrane potential loss and nucleus morphology changes were involved in the antiapoptotic effect of wushanicaritin. These findings suggested that wushanicaritin possesses excellent intercellular antioxidant and neuroprotective activities, showing potential promise in functional foods.

SIRT1: Harnessing multiple pathways to hinder NAFLD

Non-alcoholic fatty liver disease (NAFLD) encompasses hepatic steatosis, non-alcoholic steatohepatitis (NASH), fibrosis, cirrhosis, and hepatocellular carcinoma. It is the primary cause of chronic liver disorders, with a high prevalence but no approved treatment. Therefore, it is indispensable to find a trustworthy therapy for NAFLD. Recently, mounting evidence illustrates that Sirtuin 1 (SIRT1) is strongly associated with NAFLD. SIRT1 activation or overexpression attenuate NAFLD, while SIRT1 deficiency aggravates NAFLD. Besides, an array of therapeutic agents, including natural compounds, synthetic compounds, traditional Chinese medicine formula, and stem cell transplantation, alleviates NALFD via SIRT1 activation or upregulation. Mechanically, SIRT1 alleviates NAFLD by reestablishing autophagy, enhancing mitochondrial function, suppressing oxidative stress, and coordinating lipid metabolism, as well as reducing hepatocyte apoptosis and inflammation. In this review, we introduced the structure and function of SIRT1 briefly, and summarized the effect of SIRT1 on NAFLD and its mechanism, along with the application of SIRT1 agonists in treating NAFLD.

Melatonin attenuates dental pulp stem cells senescence due to vitro expansion via inhibiting MMP3

OBJECTIVE

We aimed to identify the crucial genes involved in dental pulp stem cell (DPSC) senescence and evaluate the impact of melatonin on DPSC senescence.

METHODS

Western blotting, SA-β-Gal staining and ALP staining were used to evaluate the senescence and differentiation potential of DPSCs. The optimal concentration of melatonin was determined using the CCK-8 assay. Differentially expressed genes (DEGs) involved in DPSC senescence were obtained via bioinformatics analysis, followed by RT-qPCR. Gain- and loss-of-function studies were conducted to explore the role of MMP3 in DPSC in vitro expansion and in response to melatonin. GSEA was employed to analyse MMP3-related pathways in cellular senescence.

RESULTS

Treatment with 0.1 μM melatonin attenuated cellular senescence and differentiation potential suppression in DPSCs due to long-term in vitro expansion. MMP3 was a crucial gene in senescence, as confirmed by bioinformatics analysis, RT-qPCR and Western blotting. Furthermore, gain- and loss-of-function studies revealed that MMP3 played a regulatory role in cellular senescence. Rescue assays showed that overexpression of MMP3 reversed the effect of melatonin on senescence. GSEA revealed that the MMP3-dependent anti-senescence effect of melatonin was associated with the IL6-JAK-STAT3, TNF-α-Signalling-VIA-NF-κB, COMPLEMENT, NOTCH Signalling and PI3K-AKT-mTOR pathways.

CONCLUSION

Melatonin attenuated DPSC senescence caused by long-term expansion by inhibiting MMP3.

Carboxymethyl Chitosan-Coated Cyanidin-3-O-Glucoside-Beared Nanonutriosomes Suppress Palmitic Acid-Induced Hepatocytes Injury

Cyanidin-3-O-glucoside (C3G) is classified as an anthocyanin (ACN) and is recognized for its remarkable antioxidant properties. Yet, the inadequate physicochemical stability of C3G restricts its potential for various biological applications. Thus, in this study, carboxymethyl chitosan (CMC)-coated nanonutriosomes (NS) were synthesized as a novel carrier for encapsulating C3G (CMC-C3G-NS) to improve C3G stability. CMC-C3G-NS exhibited a diameter of less than 200 nm along with an encouraging encapsulation efficiency exceeding 90%. Notably, the formulated CMC-C3G-NS possessed better stability under various pH, ionic, and oxygen conditions, improved controlled release properties, and higher hepatocellular uptake than uncoated particles (C3G-NS), indicating a longer retention time of C3G in a physiological environment. Of utmost significance, CMC-C3G-NS demonstrated superior alleviating effects against palmitic acid (PA)-induced oxidative hepatic damage compared to C3G-NS. Our study provided promising nanocarriers with the potential to deliver hydrophilic ACNs and controlled release properties for PA-induced hepatotoxicity alleviation.

Favorable osteogenic activity of vericiguat doped in β-tricalcium phosphate: In vitro and in vivo studies

Recently, more and more studies have shown that guanylate cyclase, an enzyme that synthesizes cyclic guanosine monophosphate (cGMP), plays an important role in bone metabolism. Vericiguat (VIT), a novel oral soluble guanylate cyclase stimulator, directly generates cyclic guanosine monophosphate and reduce the death incidence from cardio-vascular causes or hospitalization. Recent studies have shown beneficial effects of VIT in animal models of osteoporosis, but very little is currently known about the effects of VIT on bone defects in the osteoporotic states. Therefore, in this study, β-tricalcium phosphate (β-TCP) was used as a carrier to explore the effect of local VIT administration on the repair of femoral metaphyseal bone defects in ovariectomized (OVX) rats. When MC3T3-E1 was cultured in the presence of H2H2, VIT, similar to Melatonin (MT), therapy could increase the matrix mineralization and ALP, SOD2, SIRT1, and OPG expression, reduce ROS and Mito SOX production, RANKL expression, Promote the recovery of mitochondrial membrane potential. In the OVX rat model, VIT increases the osteogenic effect of β-TCP and better results were obtained at a dose of 5 mg. Local use of VIT can inhibit increased OC, BMP2 and RUNX2 expressions in bone tissue, while decreased SOST and TRAP expressions by RT-PCR and immunohistochemistry. Thereby, VIT stimulates bone regeneration and is a promising candidate for promoting bone repair in osteoporosis.

Melatonin improves salivary gland damage and hypofunction in pSS by inhibiting IL-6/STAT3 signaling through its receptor-dependent manner

OBJECTIVE

Primary Sjogren's syndrome (pSS) is an autoimmune disease of the exocrine glands with no specific or efficient treatments. Melatonin, a natural hormone, is revealed to show multiple biological functions, both receptor-dependent and independent effects, including anti-apoptotic, antioxidant, and anti-inflammatory activities. However, the potential mechanism by which melatonin protects salivary glands (SGs) of pSS from damage needs to be clarified. The purpose of current study was to explore the role and receptor-related mechanisms of melatonin in pSS-induced glandular damage.

METHODS AND RESULTS

NOD/Ltj mice were used to spontaneously mimic pSS-induced glandular hypofunction in vivo and primary human salivary gland epithelial (HSGE) cells were stimulated by interferon-γ (IFN-γ) to mimic pSS-induced inflammation in SGs cells in vitro. Melatonin-treated mice exhibited a significant reduction in SG injury of NOD/Ltj mice, which was accompanied by an increase in salivary flow rate, a decrease in inflammatory infiltration within the gland, and a suppression of oxidative stress indicators as well as cell apoptosis. Notably, both melatonin membrane receptors and nuclear receptors played an important role in the anti-apoptotic effects of melatonin on the SGs of NOD/Ltj mice. Furthermore, melatonin blocked the IL-6/STAT3 pathway through receptor-dependent manners in IFN-γ-stimulated HSGE cells. However, it was evident that the anti-oxidative and anti-apoptotic properties of melatonin on IFN-γ-stimulated HSGE cells were diminished by IL-6 treatment.

CONCLUSION

Melatonin had the potential to mitigate inflammation, oxidative stress, and apoptosis in SGs of pSS by inhibiting the IL-6/STAT3 pathway through receptor-dependent mechanisms. This intervention effectively prevented glandular damage and preserved functional integrity.

SIRT3: A potential therapeutic target for liver fibrosis

Sirtuin3 (SIRT3) is a nicotinamide adenine dinucleotide (NAD+)-dependent protein deacetylase located in the mitochondria, which mainly regulates the acetylation of mitochondrial proteins. In addition, SIRT3 is involved in critical biological processes, including oxidative stress, inflammation, DNA damage, and apoptosis, all of which are closely related to the progression of liver disease. Liver fibrosis characterized by the deposition of extracellular matrix is a result of long termed or repeated liver damage, frequently accompanied by damaged hepatocytes, the recruitment of inflammatory cells, and the activation of hepatic stellate cells. Based on the functions and pharmacology of SIRT3, we will review its roles in liver fibrosis from three aspects: First, the main functions and pharmacological effects of SIRT3 were investigated based on its structure. Second, the roles of SIRT3 in major cells in the liver were summarized to reveal its mechanism in developing liver fibrosis. Last, drugs that regulate SIRT3 to prevent and treat liver fibrosis were discussed. In conclusion, exploring the pharmacological effects of SIRT3, especially in the liver, may be a potential strategy for treating liver fibrosis.

RAMP1 Protects Hepatocytes against Ischemia-reperfusion Injury by Inhibiting the ERK/YAP Pathway

Background and Aims

Hepatic ischemia-reperfusion injury (HIRI) is a prevalent complication of liver transplantation, partial hepatectomy, and severe infection, necessitating the development of more effective clinical strategies. Receptor activity-modifying protein 1 (RAMP1), a member of the G protein-coupled receptor adapter family, has been implicated in numerous physiological and pathological processes. The study aimed to investigate the pathogenesis of RAMP1 in HIRI.

Methods

We established a 70% liver ischemia-reperfusion model in RAMP1 knockout (KO) and wild-type mice. Liver and blood samples were collected after 0, 6, and 24 h of hypoxia/reperfusion. Liver histological and serological analyses were performed to evaluate liver damage. We also conducted in-vitro and in-vivo experiments to explore the molecular mechanism underlying RAMP1 function.

Results

Liver injury was exacerbated in RAMP1-KO mice compared with the sham group, as evidenced by increased cell death and elevated serum transaminase and inflammation levels. HIRI was promoted in RAMP1-KO mice via the induction of hepatocyte apoptosis and inhibition of proliferation. The absence of RAMP1 led to increased activation of the extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) pathway and yes-associated protein (YAP) phosphorylation, ultimately promoting apoptosis. SCH772984, an ERK/MAPK phosphorylation inhibitor, and PY-60, a YAP phosphorylation inhibitor, reduced apoptosis in in-vitro and in-vivo experiments.

Conclusions

Our findings suggest that RAMP1 protects against HIRI by inhibiting ERK and YAP phosphorylation signal transduction, highlighting its potential as a therapeutic target for HIRI and providing a new avenue for intervention.

Melatonin improves influenza virus infection-induced acute exacerbation of COPD by suppressing macrophage M1 polarization and apoptosis

BACKGROUND

Influenza A viruses (IAV) are extremely common respiratory viruses for the acute exacerbation of chronic obstructive pulmonary disease (AECOPD), in which IAV infection may further evoke abnormal macrophage polarization, amplify cytokine storms. Melatonin exerts potential effects of anti-inflammation and anti-IAV infection, while its effects on IAV infection-induced AECOPD are poorly understood.

METHODS

COPD mice models were established through cigarette smoke exposure for consecutive 24 weeks, evaluated by the detection of lung function. AECOPD mice models were established through the intratracheal atomization of influenza A/H3N2 stocks in COPD mice, and were injected intraperitoneally with melatonin (Mel). Then, The polarization of alveolar macrophages (AMs) was assayed by flow cytometry of bronchoalveolar lavage (BAL) cells. In vitro, the effects of melatonin on macrophage polarization were analyzed in IAV-infected Cigarette smoking extract (CSE)-stimulated Raw264.7 macrophages. Moreover, the roles of the melatonin receptors (MTs) in regulating macrophage polarization and apoptosis were determined using MTs antagonist luzindole.

RESULTS

The present results demonstrated that IAV/H3N2 infection deteriorated lung function (reduced FEV20,50/FVC), exacerbated lung damages in COPD mice with higher dual polarization of AMs. Melatonin therapy improved airflow limitation and lung damages of AECOPD mice by decreasing IAV nucleoprotein (IAV-NP) protein levels and the M1 polarization of pulmonary macrophages. Furthermore, in CSE-stimulated Raw264.7 cells, IAV infection further promoted the dual polarization of macrophages accompanied with decreased MT1 expression. Melatonin decreased STAT1 phosphorylation, the levels of M1 markers and IAV-NP via MTs reflected by the addition of luzindole. Recombinant IL-1β attenuated the inhibitory effects of melatonin on IAV infection and STAT1-driven M1 polarization, while its converting enzyme inhibitor VX765 potentiated the inhibitory effects of melatonin on them. Moreover, melatonin inhibited IAV infection-induced apoptosis by suppressing IL-1β/STAT1 signaling via MTs.

CONCLUSIONS

These findings suggested that melatonin inhibited IAV infection, improved lung function and lung damages of AECOPD via suppressing IL-1β/STAT1-driven macrophage M1 polarization and apoptosis in a MTs-dependent manner. Melatonin may be considered as a potential therapeutic agent for influenza virus infection-induced AECOPD.

Roles of Sirt1 and its modulators in diabetic microangiopathy: A review

Diabetic vascular complications include diabetic macroangiopathy and diabetic microangiopathy. Diabetic microangiopathy is characterised by impaired microvascular endothelial function, basement membrane thickening, and microthrombosis, which may promote renal, ocular, cardiac, and peripheral system damage in diabetic patients. Therefore, new preventive and therapeutic strategies are urgently required. Sirt1, a member of the nicotinamide adenine dinucleotide-dependent histone deacetylase class III family, regulates different organ growth and development, oxidative stress, mitochondrial function, metabolism, inflammation, and aging. Sirt1 is downregulated in vascular injury and microangiopathy. Moreover, its expression and distribution in different organs correlate with age and play critical regulatory roles in oxidative stress and inflammation. This review introduces the background of diabetic microangiopathy and the main functions of Sirt1. Then, the relationship between Sirt1 and different diabetic microangiopathies and the regulatory roles mediated by different cells are described. Finally, we summarize the modulators that target Sirt1 to ameliorate diabetic microangiopathy as an essential preventive and therapeutic measure for diabetic microangiopathy. In conclusion, targeting Sirt1 may be a new therapeutic strategy for diabetic microangiopathy.

Trilobolide-6-O-isobutyrate exerts anti-tumor effects on cholangiocarcinoma cells through inhibiting JAK/STAT3 signaling pathway

Trilobolide-6-O-isobutyrate exhibits significant antitumor effects on cholangiocarcinoma (CCA) cells by effectively inhibiting the JAK/STAT3 signaling pathway. This study aims to investigate the mechanisms underlying the antitumor properties of trilobolide-6-O-isobutyrate, and to explore its potential as a therapeutic agent for CCA. This study illustrates that trilobolide-6-O-isobutyrate efficiently suppresses CCA cell proliferation in a dose- and time-dependent manner. Furthermore, trilobolide-6-O-isobutyrate stimulates the production of reactive oxygen species, leading to oxidative stress and initiation of apoptosis via the activation of the mitochondrial pathway. Data from xenograft tumor assays in nude mice confirms that TBB inhibits tumor growth, and that there are no obvious toxic effects or side effects in vivo. Mechanistically, trilobolide-6-O-isobutyrate exerts antitumor effects by inhibiting STAT3 transcriptional activation, reducing PCNA and Bcl-2 expression, and increasing P21 expression. These findings emphasizes the potential of trilobolide-6-O-isobutyrate as a promising therapeutic candidate for the treatment of CCA.

Cadmium as a male reproductive toxicant and natural and non-natural ways to tackle it: a review

Cadmium (Cd) is a naturally occurring environmental pollutant, a toxic substance that causes oxidative stress. According to epidemiological studies, the data suggested that environmental and occupational Cd exposure may be related to several diseases and severe testicular damage. However, studies are going on to explore the mechanism of Cd-induced male reproductive toxicity and its treatment strategies. Currently, researchers are focusing on naturally occurring bioactive compounds, plant extracts, and biochemical, which have better efficacy, less toxicity, and high bioavailability. This review focuses on the mechanistic effect of Cd on testicular toxicity and different categories of compounds having a beneficial impact on Cd-induced male reproductive toxicity. Some potent bioactive antioxidants are quercetin, caffeic acid phenethyl ester, cyanidin-3-O-glucoside, curcumin, and silymarin. In comparison, plant extracts are Costus afer leaf methanol extract, methanol root extract of Carpolobia lutea, red carrot methanolic extract, Panax ginseng extract, and biochemicals including melatonin, progesterone, glutamine, L-carnitine, and selenium. Advanced and more detailed studies are needed on these compounds to explore their mechanism in attenuating Cd-induced testicular toxicity and can be potential therapeutics in the future.

Melatonin ameliorates PM2.5-induced spermatogenesis disorder by preserving H3K9 methylation and SIRT3

There was a link between exposure to PM2.5 and male infertility. Melatonin has beneficial effects on the male reproductive processes. How PM2.5 caused spermatogenesis disturbance and whether melatonin could prevent PM2.5-induced reproductive toxicity have remained unclear. The results showed that PM2.5 could inhibit the Nrf2-mediated antioxidant pathway and distinctly increase the cell apoptosis in testes. Moreover, PM2.5 also perturbed the process of meiosis by modulating meiosis-associated proteins such as γ-H2AX and Stra8. Mechanistically, PM2.5 inhibited G9a-dependent H3K9 methylation and SIRT3-mediated p53 deacetylation, which consistent with decreased sperm count and motility rate in ApoE-/- mice. Further investigation revealed melatonin effectively alleviated PM2.5-induced meiosis inhibition by preserving H3K9 methylation. Melatonin also alleviated PM2.5-induced apoptosis by regulating SIRT3-mediated p53 deacetylation. Overall, our study revealed PM2.5 resulted in spermatogenesis disorder by perturbing meiosis via G9a-dependent H3K9 di-methylation and causing cell apoptosis via SIRT3/p53 deacetylation pathway and provided promising insights into the protective role of melatonin in air pollution associated with male infertility.

Sestrin2 maintains hepatic immune homeostasis and redox balance partially via inhibiting RIPK3-mediated necroptosis in metabolic dysfunction-associated steatohepatitis

BACKGROUND & AIMS

Necroptosis, a novel type of programmed cell death, is intricately associated with inflammatory response. Currently, most studies focus on the activation of necroptosis, while the mechanisms underlying the negative regulation of necroptosis remain poorly understood.

METHODS

The effects of sestrin2 (SESN2) overexpression or knockdown on the regulation of necroptosis were assessed in the TNFα/Smac-mimetic/Z-VAD-FMK (T/S/Z)-induced necroptosis model and palmitic acid (PA)-induced lipotoxicity model. Western-blot, co-Immunoprecipitation, Glutathione S-transferase pull-down, and confocal assays were employed to explore the regulatory mechanisms including protein-protein interactions and post-translational modification. Furthermore, we used GSK'872, a specific inhibitor of receptor-interacting serine/threonine-protein kinase (RIPK) 3, to evaluate the relationship between SESN2-related alterations and RIPK3-mediated necroptosis in T/S/Z-induced necroptosis model, PA-induced lipotoxicity model, and high-fat high-cholesterol diet (HFHCD)-induced non-alcoholic steatohepatitis model.

RESULTS

Our findings revealed that SESN2 was upregulated under conditions that induce necroptosis and functioned as a negative regulator of necroptosis. High levels of SESN2 could equipped hepatocytes with the ability to defend against necroptotic inflammation and oxidative stress. Mechanistically, SESN2 interacted with RIPK3 and tuned down necroptosis by inhibiting the phosphorylation of RIPK3, promoting the ubiquitination of RIPK3, and preventing the formation of the RIPK1/RIPK3 necrosome. The depletion of SESN2 resulted in excessive necroptosis, accompanied by increased fat accumulation, inflammation, and oxidative stress in the experimental steatohepatitis model. Blocking necroptosis by GSK'872 reduced the liberation of pro-inflammatory cytokines and reactive oxygen species generation, but not hepatocyte fat deposition, in both PA-treated SESN2 knockout cells and HFHCD-fed SESN2 knockout mice, suggesting that the activation of RIPK3-mediated necroptosis may partially account for the hyperinflammation and excessive oxidative stress induced by SESN2 deficiency.

CONCLUSION

Our results suggested that SESN2 inhibited RIPK3-mediated necroptosis; this regulation is an important for the immune homeostasis and the redox balance in the liver.

Natural isoflavone glabridin targets PI3Kγ as an adjuvant to increase the sensitivity of MDA-MB-231 to tamoxifen and DU145 to paclitaxel

Glabridin is a natural isoflavone with estrogen receptor agonism and significant anti-tumor activity. Additionally, glabridin has a regulation effect on PI3K/AKT/mTOR pathway, but its exact target remains unclear. In this study, we evaluated the antitumor activity of glabridin against breast cancer and prostate cancer cells, and further clarified its targeting to PI3K. We found that glabridin could significantly inhibit the cell viability of human breast cancer and prostate cancer cell lines. It induced caspase activation cascade and cell apoptosis through decreasing the mitochondrial transmembrane potential and increasing the intracellular reactive oxygen species (ROS). Moreover, glabridin could attenuate epithelial-mesenchymal transition (EMT) progression by inhibiting cell migration. PharmMapper calculation showed that PI3Kγ might be the most potential target protein because of the highest Normal Fit score (0.9735) and z'-score (0.9797). Molecular docking and bio-layer interferometry (BLI) analysis further demonstrated the PI3Kγ targeting of glabridin. In vivo experiments showed that glabridin can effectively inhibit the tumor growth of breast cancer xenograft model, and does not show obvious hepatorenal toxicity. Moreover, glabridin could effectively promote the anti-proliferation and pro-apoptotic effects of tamoxifen on MDA-MB-231 cell and taxol on DU145 cell. Elucidating the targeting of glabridin to PI3K may lay a theoretical foundation for the structural derivatization of glabridin, which is expected to greatly promote the application and development of glabridin in the field of cancer therapy.

Identification and validation of an H2AZ1-based index model: a novel prognostic tool for hepatocellular carcinoma

The H2A.Z variant histone 1 (H2AZ1) is aberrantly expressed in various tumors, correlating with an unfavorable prognosis. However, its role in hepatocellular carcinoma (HCC) remains unclear. We aimed to elucidate the pathways affected by H2AZ1 and identify promising therapeutic targets for HCC. Following bioinformatic analysis of gene expression and clinical data from The Cancer Genome Atlas and Gene Expression Omnibus database, we found 6,344 dysregulated genes related to H2AZ1 overexpression in HCC tissues (P < 0.05). We performed weighted gene co-expression network analysis to identify the gene module most related to H2AZ1. The H2AZ1-based index was further developed using Cox regression analysis, which revealed that the poor prognosis in the high H2AZ1-based index group could be attributed to elevated tumor stemness (P < 0.05). Moreover, the clinical model showed good prognostic potential (AUC > 0.7). We found that H2AZ1 knockdown led to reduced superoxide dismutase (SOD) activity, elevated malondialdehyde (MDA) levels, and increased apoptosis rate in tumor cells (P < 0.001). Thus, we developed an H2AZ1-based index model with the potential to predict the prognosis of patients with HCC. Our findings provide initial evidence that H2AZ1 overexpression plays a pivotal role in HCC initiation and progression.

SIRT1-Mediated HMGB1 Deacetylation Suppresses Neutrophil Extracellular Traps Related to Blood-Brain Barrier Impairment After Cerebral Venous Thrombosis

Cerebral venous thrombosis (CVT) is a neurovascular disease with recently increasing incidence. Aseptic inflammatory responses play an important role in the pathology of CVT. Recent studies report that neutrophil extracellular traps (NETs) are major triggers of thrombosis and inflammation in stroke, but their effect on brain injury in CVT requires further validation. In this study, two CVT animal models were used to simulate superior sagittal sinus thrombosis and cortical vein thrombosis. The effects of brain tissue infiltration of NETs and the molecular mechanisms associated with NET formation were deeply explored in combination with proteomics, histology, and serology. The results showed that the cortical vein thrombosis model could be combined with more severe blood-brain barrier (BBB) disruption and showed more severe cerebral hemorrhage. Decreased Sirtuin 1 (SIRT1) expression promotes high mobility group box 1 (HMGB1) acetylation, causing increased cytosolic translocation and extracellular release, and HMGB1 can promote NET formation and recruitment. In addition, corticocerebral accumulation of NETs contributes to BBB damage. This establishes a vicious cycle between BBB damage and NET accumulation. SIRT1 mediated-HMGB1 deacetylation may play a critical role in attenuating BBB damage following CVT. This study employed a combined validation using models of venous sinus thrombosis and cortical vein thrombosis to investigate the deacetylation role of SIRT1, aiming to offer new insights into the pathological mechanisms of brain injury following CVT.

Astaxanthin Inhibits H2O2-Induced Excessive Mitophagy and Apoptosis in SH-SY5Y Cells by Regulation of Akt/mTOR Activation

Oxidative stress, which damages cellular components and causes mitochondrial dysfunction, occurs in a variety of human diseases, including neurological disorders. The clearance of damaged mitochondria via mitophagy maintains the normal function of mitochondria and facilitates cell survival. Astaxanthin is an antioxidant known to have neuroprotective effects, but the underlying mechanisms remain unclear. This study demonstrated that astaxanthin inhibited H2O2-induced apoptosis in SH-SY5Y cells by ameliorating mitochondrial damage and enhancing cell survival. H2O2 treatment significantly reduced the levels of activated Akt and mTOR and induced mitophagy, while pretreatment with astaxanthin prevented H2O2-induced inhibition of Akt and mTOR and attenuated H2O2-induced mitophagy. Moreover, the inhibition of Akt attenuated the protective effect of astaxanthin against H2O2-induced cytotoxicity. Taken together, astaxanthin might inhibit H2O2-induced apoptosis by protecting mitochondrial function and reducing mitophagy. The results also indicate that the Akt/mTOR signaling pathway was critical for the protection of astaxanthin against H2O2-induced cytotoxicity. The results from the present study suggest that astaxanthin can reduce neuronal oxidative injury and may have the potential to be used for preventing neurotoxicity associated with neurodegenerative diseases.

Outdoor artificial light at night and male sperm quality: A retrospective cohort study in China

Due to the worldwide increased rate of infertility among reproductive-age couples, there is a growing interest in the relationship between environmental stimuli and human sperm quality. While animal studies have demonstrated the detrimental effects of outdoor artificial light at night (ALAN) on sperm quality, investigations based on human data are lacking. Therefore, we conducted a retrospective cohort study involving 1991 sperm donor candidates and employed multivariate linear regression and restricted cubic spline models to quantify the association between outdoor ALAN and sperm quality. The aim was to determine whether there exists an association between exposure to outdoor ALAN and sperm quality. The study included 1991 sperm donor candidates with the following characteristics: mean [SD] age, 24.98 [4.78] years; mean [SD] BMI, 22.13 [2.60] kg/m2; mean [SD] sleep duration, 7.66 [1.07] hours/day. Outdoor ALAN exposure of study participants ranged from 0 to 100 nW/cm2/sr. Multiple regression analysis on chronic exposure (0-90 days before sperm donation) and human sperm quality revealed the following associations: for CASA primary motion parameters, every 100-unit (nW/cm2/sr) increase in chronic outdoor ALAN was associated with a change of -0.043 [95%CI: 0.073, -0.014] in Linearity (LIN), and -5.523 [95%CI: 9.100, -1.946] in Curvilinear velocity (VCL). For CASA secondary motion parameters, every 100-unit (nW/cm2/sr) increase in chronic outdoor ALAN was associated with a change of -3.873 [95%CI: 4.926, -2.748] in non-progressive motility rate (NP). Furthermore, the primary sperm quality parameter exhibited a decline of -4.740 [95%CI: 8.853, -0.628] in sperm motility rate per 100-unit (nW/cm2/sr) increase in chronic outdoor ALAN. Similar associations were also observed for acute exposure (0-9 days before sperm donation). This retrospective study suggests that poorer sperm quality is more prevalent among adult males residing in areas with higher levels of outdoor ALAN, with a particularly pronounced impact observed in males below the age of 25 years.

FBXO5-mediated RNF183 degradation prevents endoplasmic reticulum stress-induced apoptosis and promotes colon cancer progression

Endoplasmic reticulum (ER) stress induces the unfolded protein response (UPR), and prolonged ER stress leads to cell apoptosis. Despite increasing research in this area, the underlying molecular mechanisms remain unclear. Here, we discover that ER stress upregulates the UPR signaling pathway while downregulating E2F target gene expression and inhibiting the G2/M phase transition. Prolonged ER stress decreases the mRNA levels of E2F2, which specifically regulates the expression of F-Box Protein 5(FBXO5), an F-box protein that functions as an inhibitor of the anaphase-promoting complex/cyclosome (APC/C) ubiquitin ligase complex. Depletion of FBXO5 results in increased ER stress-induced apoptosis and decreased expression of proteins related to PERK/IRE1α/ATF6 signaling. Overexpression of FBXO5 wild-type (not its ΔF-box mutant) alleviates apoptosis and the expression of the C/EBP Homologous Protein (CHOP)/ATF. Mechanistically, we find that FBXO5 directly binds to and promotes the ubiquitin-dependent degradation of RNF183, which acts as a ubiquitin E3 ligase in regulating ER stress-induced apoptosis. Reversal of the apoptosis defects caused by FBXO5 deficiency in colorectal cancer cells can be achieved by knocking down RNF183 in FBXO5-deficient cells. Functionally, we observed significant upregulation of FBXO5 in colon cancer tissues, and its silencing suppresses tumor occurrence in vivo. Therefore, our study highlights the critical role of the FBXO5/RNF183 axis in ER stress regulation and identifies a potential therapeutic target for colon cancer treatment.

Menaquinone-4 attenuates ferroptosis by upregulating DHODH through activation of SIRT1 after subarachnoid hemorrhage

BACKGROUND

Menaquinone-4(MK-4), the isoform of vitamin K2 in the brain, exerts neuroprotective effects against a variety of central nervous system disorders. This study aimed to demonstrate the anti-ferroptosis effects of MK-4 in neurons after SAH.

METHODS

A subarachnoid hemorrhage (SAH) model was prepared by endovascular perforation in mice. In vitro hemoglobin stimulation of primary cortical neurons mimicked SAH. MK-4, Brequinar (BQR, DHODH inhibitor), and Selisistat (SEL, SIRT1 inhibitor) were administered, respectively. Subsequently, WB, immunofluorescence was used to determine protein expression and localization, and transmission electron microscopy was used to observe neuronal mitochondrial structure while other indicators of ferroptosis were measured.

RESULTS

MK-4 treatment significantly upregulated the protein levels of DHODH; decreased GSH, PTGS2, NOX1, ROS, and restored mitochondrial membrane potential. Meanwhile, MK-4 upregulated the expression of SIRT1 and promoted its entry into the nucleus. BQR or SEL partially abolished the protective effect of MK-4 on, neurologic function, and ferroptosis.

CONCLUSIONS

Taken together, our results suggest that MK-4 attenuates ferroptosis after SAH by upregulating DHODH through the activation of SIRT1.

Melatonin rescues the mitochondrial function of bone marrow-derived mesenchymal stem cells and improves the repair of osteoporotic bone defect in ovariectomized rats

Osteoporotic bone defects, a severe complication of osteoporosis, are distinguished by a delayed bone healing process and poor repair quality. While bone marrow-derived mesenchymal stem cells (BMMSCs) are the primary origin of bone-forming osteoblasts, their mitochondrial function is impaired, leading to inadequate bone regeneration in osteoporotic patients. Melatonin is well-known for its antioxidant properties and regulation on bone metabolism. The present study postulated that melatonin has the potential to enhance the repair of osteoporotic bone defects by restoring the mitochondrial function of BMMSCs. In vitro administration of melatonin at varying concentrations (0.01, 1, and 100 μM) demonstrated a significant dose-dependent improvement in the mitochondrial function of BMMSCs obtained from ovariectomized rats (OVX-BMMSCs), as indicated by an elevation in mitochondrial membrane potential, adenosine triphosphate synthesis and expression of mitochondrial respiratory chain factors. Melatonin reduced the level of mitochondrial superoxide by activating the silent information regulator type 1 (SIRT1) and its downstream antioxidant enzymes, particularly superoxide dismutase 2 (SOD2). The protective effects of melatonin were found to be nullified upon silencing of Sirt1 or Sod2, underscoring the crucial role of the SIRT1-SOD2 axis in the melatonin-induced enhancement of mitochondrial energy metabolism in OVX-BMMSCs. To achieve a sustained and localized release of melatonin, silk fibroin scaffolds loaded with melatonin (SF@MT) were fabricated. The study involved the surgical creation of bilateral femur defects in OVX rats, followed by the implantation of SF@MT scaffolds. The results indicated that the application of melatonin partially restored the mitochondrial energy metabolism and osteogenic differentiation of OVX-BMMSCs by reinstating mitochondrial redox homeostasis. These findings suggest that the localized administration of melatonin through bone implants holds potential as a therapeutic approach for addressing osteoporotic bone defects.

Mechanisms of multi-omics and network pharmacology to explain traditional chinese medicine for vascular cognitive impairment: A narrative review

BACKGROUND

The term "vascular cognitive impairment" (VCI) describes various cognitive conditions that include vascular elements. It increases the risk of morbidity and mortality in the elderly population and is the most common cognitive impairment associated with cerebrovascular disease. Understanding the etiology of VCI may aid in identifying approaches to target its possible therapy for the condition. Treatment of VCI has focused on vascular risk factors. There are no authorized conventional therapies available right now. The medications used to treat VCI are solely approved for symptomatic relief and are not intended to prevent or slow the development of VCI.

PURPOSE

The function of Chinese medicine in treating VCI has not yet been thoroughly examined. This review evaluates the preclinical and limited clinical evidence to comprehend the "multi-component, multi-target, multi-pathway" mechanism of Traditional Chinese medicine (TCM). It investigates the various multi-omics approaches in the search for the pathological mechanisms of VCI, as well as the new research strategies, in the hopes of supplying supportive evidence for the clinical treatment of VCI.

METHODS

This review used the Preferred Reporting Items for Preferred reporting items for systematic reviews and meta-analyses (PRISMA) statements. Using integrated bioinformatics and network pharmacology approaches, a thorough evaluation and analysis of 25 preclinical studies published up to July 1, 2023, were conducted to shed light on the mechanisms of TCM for vascular cognitive impairment. The studies for the systematic review were located using the following databases: PubMed, Web of Science, Scopus, Cochrane, and ScienceDirect.

RESULTS

We discovered that the multi-omics analysis approach would hasten the discovery of the role of TCM in the treatment of VCI. It will explore components, compounds, targets, and pathways, slowing the progression of VCI from the perspective of inhibiting oxidative stress, stifling neuroinflammation, increasing cerebral blood flow, and inhibiting iron deposition by a variety of molecular mechanisms, which have significant implications for the treatment of VCI.

CONCLUSION

TCM is a valuable tool for developing dementia therapies, and further research is needed to determine how TCM components may affect the operation of the neurovascular unit. There are still some limitations, although several research have offered invaluable resources for searching for possible anti-dementia medicines and treatments. To gain new insights into the molecular mechanisms that precisely modulate the key molecules at different levels during pharmacological interventions-a prerequisite for comprehending the mechanism of action and determining the potential therapeutic value of the drugs-further research should employ more standardized experimental methods as well as more sophisticated science and technology. Given the results of this review, we advocate integrating chemical and biological component analysis approaches in future research on VCI to provide a more full and objective assessment of the standard of TCM. With the help of bioinformatics, a multi-omics analysis approach will hasten the discovery of the role of TCM in the treatment of VCI, which has significant implications for the treatment of VCI.

Utility of vitamin C in ameliorating citalopram-induced testicular toxicity via modulating nitro-oxidative stress and apoptosis in mice

There is a growing concern that antidepressant drugs impair sexual function and adversely impact spermatogenesis and male fertility. Vitamin C is a natural antioxidant that plays a vital role in the male reproductive system. The present study investigated the ameliorating potential of vitamin C against citalopram (CTL)-evoked testicular toxicity and spermatogenesis impairment in mice. Mice were randomly divided into six groups: control, CTL, vitamin C 100, vitamin C 200, CTL plus vitamin C 100, and CTL plus vitamin C 200. Adult male mice were intraperitoneally (ip) injected with 10 mg/kg of CTL for 35 days with or without vitamin C. At the end of the study, body and testes weight, sperm parameters, histopathology of testes, testosterone level, testicular levels of malondialdehyde (MDA), nitric oxide (NO), total antioxidant capacity (TAC), and apoptosis (TUNEL assay) were evaluated. Our findings revealed that vitamin C restored spermatogenesis by improving sperm count, motility, viability, morphology, and chromatin integrity. Testosterone levels and testes histopathology were significantly improved in the vitamin C-administrated groups. Furthermore, vitamin C administration markedly alleviated CTL-induced nitro-oxidative damage, enhancing TAC levels, and reducing NO and MDA levels. Whilst CTL therapy induced a significant increase in the number of TUNEL-positive cells compared to the control, the administration of vitamin C significantly prevented the apoptotic effects of CTL. Together, vitamin C therapy protects against CTL-induced testicular damage via mitigating nitro-oxidative stress and apoptosis, which provides evidence for vitamin C as a beneficial therapy against antidepressant drug-associated reproductive toxicity and male sub/infertility.

Gss deficiency causes age-related fertility impairment via ROS-triggered ferroptosis in the testes of mice

Glutathione synthetase (GSS) catalyzes the final step in the synthesis of glutathione (GSH), a well-established antioxidant. Research on the specific roles of the Gss gene during spermatogenesis remains limited due to the intricate structure of testis. In this study, we identified pachytene spermatocytes as the primary site of GSS expression and generated a mouse model with postnatal deletion of Gss using Stra8-Cre (S8) to investigate the role of GSS in germ cells. The impact of Gss knockout on reducing male fertility is age-dependent and caused by ferroptosis in the testis. The 2-month-old S8/Gss-/- male mice exhibited normal fertility, due to a compensatory increase in GPX4, which prevented the accumulation of ROS. With aging, there was a decline in GPX4 and an increase in ALOX15 levels observed in 8-month-old S8/Gss-/- mice, resulting in the accumulation of ROS, lipid peroxidation, and ultimately testicular ferroptosis. We found that testicular ferroptosis did not affect spermatogonia, but caused meiosis disruption and acrosome heterotopia. Then the resulting aberrant sperm showed lower concentration and abnormal morphology, leading to reduced fertility. Furthermore, these injuries could be functionally rescued by inhibiting ferroptosis through intraperitoneal injection of GSH or Fer-1. In summary, Gss in germ cells play a crucial role in the resistance to oxidative stress injury in aged mice. Our findings deepen the understanding of ferroptosis during spermatogenesis and suggest that inhibiting ferroptosis may be a potential strategy for the treatment of male infertility.

Melatonin-pretreated human umbilical cord mesenchymal stem cells improved endometrium regeneration and fertility recovery through macrophage immunomodulation in rats with intrauterine adhesions†

Intrauterine adhesions (IUA) are a common gynecological problem. Stem cell therapy has been widely used in the treatment of IUA. However, due to the complex and harsh microenvironment of the uterine cavity, the effectiveness of such therapy is greatly inhibited. This study aimed to investigate whether melatonin pretreatment enhances the efficacy of human umbilical cord mesenchymal stem cells (HucMSCs) in IUA treatment in rats. First, we explored the effect of melatonin on the biological activity of HucMSCs in vitro through a macrophage co-culture system, Cell Counting Kit 8 (CCK-8), 5-Ethynyl-2'-deoxyuridine (EdU), flow cytometry, immunofluorescence staining, and qRT-PCR. Subsequently, we established the IUA rat model and tracked the distribution of HucMSCs in this model. In addition, we observed the number of M1 and M2 macrophages through immunofluorescence staining and detected the levels of inflammatory cytokines. Four weeks after cell transplantation, HE, Masson, and immunohistochemical staining were performed. In vitro experiments showed that melatonin pretreatment of HucMSCs promoted proliferation, reduced apoptosis, up-regulated the stemness gene, and regulated macrophage polarization. In vivo, melatonin pretreatment caused more HucMSCs to remain in the uterine cavity. Melatonin-pretreated HucMSCs recruited more macrophages, regulated macrophage polarization, and reduced inflammation. Melatonin-pretreated HucMSCs relieved fibrosis, increased endometrium thickness, and up-regulated CD34, vimentin, proliferating cell nuclear antigen (PCNA), and alpha small muscle antigen (α-SMA) expression. Fertility tests showed that melatonin-pretreated HucMSCs increased the number of embryos. In summary, pretreatment with melatonin was beneficial for HucMSC treatment because it enhanced the cell's ability to recruit macrophages and regulate macrophage polarization, which led to the regeneration of the endometrium and improved pregnancy outcomes.

Effects and possible mechanisms of combined exposure to noise and carbon monoxide on male reproductive system in rats

Environmental hazards are an increasing concern due to the rapid pace of industrialization. Among these hazards, noise and carbon monoxide (CO) are common risk factors and have been shown to cause serious health problems. However, existing studies focused on the individual effects of noise and CO exposure and the combined effects of these two factors remain poorly understood. Our study aimed to examine the combined effects of noise and CO exposure on testicular function by constructing individual and combined exposure models. Our findings indicated that combined exposure to noise and CO was associated with a higher risk of testicular damage and male reproductive damage when compared to exposure alone. This was evidenced by poorer semen quality and more severe pathological damage to the testis. This combined exposure led to higher levels of oxidative stress and apoptosis in the testes, with bioinformatics analyses suggesting the signaling pathways involved in these responses. Specifically, activation of the P53 signaling pathway was found to contribute to the testicular damage caused by the combined exposure. Encouragingly, pterostilbene (PTE), a novel phytochemical, alleviated combined exposure-induced testicular damage by reducing oxidative stress and germ cell apoptosis. Overall, we identified joint reproductive toxicity resulting from the exposure to noise and CO, and found that PTE is a promising potential treatment for injuries caused by these factors. The cover image is based on the Research Article Effects and possible mechanisms of combined exposure to noise and carbon monoxide on male reproductive system in rats by Yingqing Li et al., https://doi.org/10.1002/tox.23927.

Melatonin Alleviates Acute Respiratory Distress Syndrome by Inhibiting Alveolar Macrophage NLRP3 Inflammasomes Through the ROS/HIF-1α/GLUT1 Pathway

Sepsis-induced acute respiratory distress syndrome (ARDS) is a devastating clinically severe respiratory disorder, and no effective therapy is available. Melatonin (MEL), an endogenous neurohormone, has shown great promise in alleviating sepsis-induced ARDS, but the underlying molecular mechanism remains unclear. Using a lipopolysaccharide (LPS)-treated mouse alveolar macrophage cell line (MH-S) model, we found that MEL significantly inhibited NOD-like receptor protein 3 (NLRP3) inflammasome activation in LPS-treated macrophages, whereas this inhibitory effect of MEL was weakened in MH-S cells transfected with glucose transporter 1 (GLUT1) overexpressing lentivirus. Further experiments showed that MEL downregulated GLUT1 via inhibition of hypoxia-inducible factor 1 (HIF-1α). Notably, hydrogen peroxide (H2O2), a donor of reactive oxygen species (ROS), significantly increased the level of intracellular ROS and inhibited the regulatory effect of MEL on the HIF-1α/GLUT1 pathway. Interestingly, the protective effect of MEL was attenuated after the knockdown of melatonin receptor 1A (MT1) in MH-S cells. We also confirmed in vivo that MEL effectively downregulated the HIF-1α/GLUT1/NLRP3 pathway in the lung tissue of LPS-treated mice, as well as significantly ameliorated LPS-induced lung injury and improved survival in mice. Collectively, these findings revealed that MEL regulates the activation of the ROS/HIF-1α/GLUT1/NLRP3 pathway in alveolar macrophages via the MT1 receptor, further alleviating sepsis-induced ARDS.

PP2Ac knockdown attenuates lipotoxicity‑induced pancreatic β‑cell dysfunction and apoptosis

Protein phosphatase 2A (PP2A) is one of the most common serine/threonine phosphatases in mammalian cells, and it primarily functions to regulate cell signaling, glycolipid metabolism and apoptosis. The catalytic subunit of PP2A (PP2Ac) plays an important role in the functions of the protein. However, there are few reports on the regulatory role of PP2Ac in pancreatic β-cells under lipotoxic conditions. In the present study, mouse insulinoma 6 (MIN6) pancreatic cells were transfected with short hairpin RNAs to generate PP2Ac knockdown cells and incubated with palmitate (PA) to establish a lipotoxicity model. Serine/threonine phosphatase assay system, Cell Counting Kit-8, flow cytometry, enzyme-linked immunosorbent assay and western blotting were used to measure PP2A activity, cell viability, apoptosis, oxidative stress and insulin secretion in the cells. In addition, a mouse model of lipotoxicity was established with a high-fat diet (HFD) and the knockdown of PP2Ac using adeno-associated viruses to interfere with PP2Ac expression in the pancreatic tissues. The activity of PP2A in the mouse pancreatic tissue and the serum insulin level were measured. Furthermore, the proliferation of mouse pancreatic β-cells was assessed using pancreatic tissue immunofluorescence. PP2Ac knockdown inhibited lipotoxicity-induced PP2A hyperactivation, increased the resistance of pancreatic β-cells to lipotoxicity and attenuated PA-induced apoptosis in MIN6 cells. It also protected the endoplasmic reticulum and mitochondria, and ameliorated insulin secretion. The results of mRNA sequencing and western blotting analysis suggested that the protective effects of PP2Ac knockdown in MIN6 cells may be mediated via the MAPK pathway. Moreover, the results of the animal experiments suggested that specific knockdown of pancreatic PP2Ac effectively attenuated HFD-induced insulin resistance and reduced the compensatory proliferation of pancreatic β-cells in mice. In summary, the present study revealed the effects of interfering with PP2Ac gene expression on pancreatic β-cells in vivo and in vitro and the underlying mechanisms, which may provide insights for the treatment of type 2 diabetes mellitus in the clinic.

Vitamin D Receptor Activation Attenuates Olanzapine-Induced Dyslipidemia in Mice Through Alleviating Hepatic Endoplasmic Reticulum Stress

The involvement of vitamin D (VD) signaling in atypical antipsychotics (AAPs)-induced metabolic disturbances has been previously established. This study aims to elucidate the role of VD in maintaining endoplasmic reticulum (ER) homeostasis and its impact on AAPs-induced metabolic adverse effects. Female C57BL/6 mice receive either calcitriol or vehicle one week prior to co-treatment with olanzapine (OLZ) for an additional four weeks. Metabolic parameters, hepatic ER homeostasis, and the SREBPs pathway are assessed through biochemical assays and protein expression profiling. HepG2 cells are transfected with vitamin D receptor (VDR) siRNA for VDR knockdown. OLZ-treated HepG2 cells are exposed to calcitriol to examine its effects on SREBPs and the unfolded protein response (UPR) pathways. VDR activation by calcitriol reduces OLZ-induced hepatic ER stress, leading to decreased SREBPs activity and lipid accumulation. Conversely, the knockdown of VDR in HepG2 cells diminishes the protective effects of calcitriol against OLZ-induced ER stress and SREBPs activation. This resulted in sustained UPR activation, elevated cleaved SREBPs levels, and increased lipid accumulation. These findings highlight an essential role of VDR signaling in the beneficial effects of VD on OLZ-induced metabolic side effects. Targeting VDR to resolve ER stress is likely an applicable therapeutic strategy for AAPs-induced metabolic disturbances.

Escherichia coli triggers α-synuclein pathology in the LRRK2 transgenic mouse model of PD

Alpha-synuclein (α-syn) pathology is the hallmark of Parkinson's disease (PD). The leucine-rich repeat kinase 2 (LRRK2) gene is a major-effect risk gene for sporadic PD (sPD). However, what environmental factors may trigger the formation of α-syn pathology in carriers of LRRK2 risk variants are still unknown. Here, we report that a markedly increased abundance of Escherichia coli (E. coli) in the intestinal microbiota was detected in LRRK2 risk variant(R1628P or G2385R) carriers with sPD compared with carriers without sPD. Animal experiments showed that E. coli administration triggered pathological α-syn accumulation in the colon and spread to the brain via the gut-brain axis in Lrrk2 R1628P mice, due to the co-occurrence of Lrrk2 variant-induced inhibition of α-syn autophagic degradation and increased phosphorylation of α-syn caused by curli in E. coli-derived extracellular vesicles. Fecal microbiota transplantation (FMT) effectively ameliorated motor deficits and α-syn pathology in Lrrk2 R1628P mice. Our findings elaborate on the mechanism that E. coli triggers α-syn pathology in Lrrk2 R1628P mice, and highlight a novel gene-environment interaction pattern in LRRK2 risk variants. Even more importantly, the findings reveal the interplay between the specific risk gene and the matched environmental factors triggers the initiation of α-syn pathology in sPD.

Pyrroloquinoline quinone inhibits PCSK9-NLRP3 mediated pyroptosis of Leydig cells in obese mice

Abnormal lipid metabolism and chronic low-grade inflammation are the main traits of obesity. Especially, the molecular mechanism of concomitant deficiency in steroidogenesis-associated enzymes related to testosterone (T) synthesis of obesity dominated a decline in male fertility is still poorly understood. Here, we found that in vivo, supplementation of pyrroloquinoline quinone (PQQ) efficaciously ameliorated the abnormal lipid metabolism and testicular spermatogenic function from high-fat-diet (HFD)-induced obese mice. Moreover, the transcriptome analysis of the liver and testicular showed that PQQ supplementation not only inhibited the high expression of proprotein convertase subtilisin/Kexin type 9 (PCSK9) but also weakened the NOD-like receptor family pyrin domain containing 3 (NLRP3)-mediated pyroptosis, which both played a negative role in T synthesis of Leydig Cells (LCs). Eventually, the function and the pyroptosis of LCs cultured with palmitic acid in vitro were simultaneously benefited by suppressing the expression of NLRP3 or PCSK9 respectively, as well the parallel effects of PQQ were affirmed. Collectively, our data revealed that PQQ supplementation is a feasible approach to protect T synthesis from PCSK9-NLRP3 crosstalk-induced LCs' pyroptosis in obese men.

Melatonin supplementation protects against traumatic colon injury by regulating SERPINA3N protein expression

Traumatic colon injury (TCI) is a typical injury with high mortality. Prolongation of the intervention time window is a potentially useful approach to improving the outcomes of TCI casualties. This study aimed to identify the pathological mechanisms of TCI and to develop effective strategies to extend the survival time. A semicircular incision was made to prepare a TCI model using C57BL/6 mice. An overview of microbiota dysregulation was achieved by metagenome sequencing. Protein expression reprogramming in the intestinal epithelium was investigated using proteomics profiling. The mice that were subjected to TCI died within a short period of time when not treated. Gut symbiosis showed abrupt turbulence, and specific pathogenic bacteria rapidly proliferated. The protein expression in the intestinal epithelium was also reprogrammed. Among the differentially expressed proteins, SERPINA3N was overexpressed after TCI modeling. Deletion of Serpina3n prolonged the posttraumatic survival time of mice with TCI by improving gut homeostasis in vivo. To promote the translational application of this research, the effects of melatonin (MLT), an oral inhibitor of the SERPINA3N protein, were further investigated. MLT effectively downregulated SERPINA3N expression and mitigated TCI-induced death by suppressing the NF-κB signaling pathway. Our findings prove that preventive administration of MLT serves as an effective regimen to prolong the posttraumatic survival time by restoring gut homeostasis perturbed by TCI. It may become a novel strategy for improving the prognosis of patients suffering from TCI.

Melatonin protects HT-22 cells against palmitic acid-induced glucolipid metabolic dysfunction and cell injuries: Involved in the regulation of synaptic plasticity and circadian rhythms

Melatonin (MLT) is ahormonal substance reported with various pharmacological activities.Based on its effects of neuroprotection and metabolic regulation, the aim of the present study is to investigate its potential effect on palmitic acid (PA)-induced cell injuries and glucolipid metabolic dysfunction and explore the possible mechanism. Briefly, HT-22 cells were challenged with PA (0.1 mM, 24 h) and treated with MLT (10-6-10-8 mol/L). Cell proliferation, lipid accumulation and glucose consumption were detected. The protein expression of key molecular involved with the function of synaptic plasticity and circadian rhythms were measured via western blotting, and the expression of Map-2, MT1A, MT1B and Bmal1 were measured via immunofluorescence staining. The results showed that MLT could alleviate the neurotoxicity induced by PA, as indicated by the increased cell proliferation, enhanced fluorescence intensity of Map-2, and decreased lipid deposition and insulin resistance. Moreover, treatment of MLT could reverse the imbalanced expression of p-Akt, p-ERK, Synapsin I, Synaptotagmin I, BDNF, MT1B, Bmal1, and Clock in PA-induced HT-22 cells. These results suggested a remarkably neuroprotective effect of MLT against PA-induced cell injury and glucolipid metabolic dysfunction, the mechanism of which might be involved in the regulation of synaptic plasticity and circadian rhythms.

Post-translational modifications of histone and non-histone proteins in epigenetic regulation and translational applications in alcohol-associated liver disease: Challenges and research opportunities

Epigenetic regulation is a process that takes place through adaptive cellular pathways influenced by environmental factors and metabolic changes to modulate gene activity with heritable phenotypic variations without altering the DNA sequences of many target genes. Epigenetic regulation can be facilitated by diverse mechanisms: many different types of post-translational modifications (PTMs) of histone and non-histone nuclear proteins, DNA methylation, altered levels of noncoding RNAs, incorporation of histone variants, nucleosomal positioning, chromatin remodeling, etc. These factors modulate chromatin structure and stability with or without the involvement of metabolic products, depending on the cellular context of target cells or environmental stimuli, such as intake of alcohol (ethanol) or Western-style high-fat diets. Alterations of epigenetics have been actively studied, since they are frequently associated with multiple disease states. Consequently, explorations of epigenetic regulation have recently shed light on the pathogenesis and progression of alcohol-associated disorders. In this review, we highlight the roles of various types of PTMs, including less-characterized modifications of nuclear histone and non-histone proteins, in the epigenetic regulation of alcohol-associated liver disease (ALD) and other disorders. We also describe challenges in characterizing specific PTMs and suggest future opportunities for basic and translational research to prevent or treat ALD and many other disease states.

Sirtuin1 Mediates the Protective Effects of Echinacoside against Sepsis-Induced Acute Lung Injury via Regulating the NOX4-Nrf2 Axis

Currently, the treatment for sepsis-induced acute lung injury mainly involves mechanical ventilation with limited use of drugs, highlighting the urgent need for new therapeutic options. As a pivotal aspect of acute lung injury, the pathologic activation and apoptosis of endothelial cells related to oxidative stress play a crucial role in disease progression, with NOX4 and Nrf2 being important targets in regulating ROS production and clearance. Echinacoside, extracted from the traditional Chinese herbal plant Cistanche deserticola, possesses diverse biological activities. However, its role in sepsis-induced acute lung injury remains unexplored. Moreover, although some studies have demonstrated the regulation of NOX4 expression by SIRT1, the specific mechanisms are yet to be elucidated. Therefore, this study aimed to investigate the effects of echinacoside on sepsis-induced acute lung injury and oxidative stress in mice and to explore the intricate regulatory mechanism of SIRT1 on NOX4. We found that echinacoside inhibited sepsis-induced acute lung injury and oxidative stress while preserving endothelial function. In vitro experiments demonstrated that echinacoside activated SIRT1 and promoted its expression. The activated SIRT1 was competitively bound to p22 phox, inhibiting the activation of NOX4 and facilitating the ubiquitination and degradation of NOX4. Additionally, SIRT1 deacetylated Nrf2, promoting the downstream expression of antioxidant enzymes, thus enhancing the NOX4-Nrf2 axis and mitigating oxidative stress-induced endothelial cell pathologic activation and mitochondrial pathway apoptosis. The SIRT1-mediated anti-inflammatory and antioxidant effects of echinacoside were validated in vivo. Consequently, the SIRT1-regulated NOX4-Nrf2 axis may represent a crucial target for echinacoside in the treatment of sepsis-induced acute lung injury.

A short-term high-fat diet alters rat testicular activity and blood-testis barrier integrity through the SIRT1/NRF2/MAPKs signaling pathways

Background

Overweight/obesity are metabolic disorder resulting from behavioral, environmental, and heritable causes. WHO estimates that 50% of adults and 30% of children and adolescents are overweight or obese, and, in parallel, an ongoing decline in sperm quality and male fertility has been described. Numerous studies demonstrated the intimate association between overweight/obesity and reproductive dysfunction due to a highly intricate network of causes not yet completely understood. This study expands the knowledge on the impact of a short-term high-fat diet (st-HFD) on rat testicular activity, specifically on steroidogenesis and spermatogenesis, focusing on the involved molecular mechanisms related to mitochondrial dynamics, blood-testis barrier (BTB) integrity, and SIRT1/NRF2/MAPKs pathways.

Methods

Ten adult Male Wistar rats were divided into two groups of five and treated with a standard diet or an HFD for five weeks. At the end of the treatment, rats were anesthetized and sacrificed by decapitation. Blood was collected for serum sex hormone assay; one testis was stored at -80ÅãC for western blot analysis, and the other, was fixed for histological and immunofluorescence analysis.

Results

Five weeks of HFD results in reduced steroidogenesis, increased apoptosis of spermatogenic cells, and altered spermatogenesis, as highlighted by reduced protein levels ofmeiotic and post-meiotic markers. Further, we evidenced the compromission of the BTB integrity, as revealed by the downregulation of structural proteins (N-Cadherin, ZO-1, occludin, connexin 43, and VANGL2) other than the phosphorylation of regulative kinases (Src and FAK). At the molecular level, the impairment of mitochondrial dynamics (fission, fusion, andbiogenesis), and the dysregulation of the SIRT1/NRF2/MAPKs signaling pathways, were evidenced. Interestingly, no change was observed in the levels of pro-inflammatory markers (TNFα, NF-kB, and IL-6).

Conclusions

The combined data led us to confirm that overweight is a less severe state than obesity. Furthermore, understanding the molecular mechanisms behind the association between metabolic disorders and male fertility could improve the possibility of identifying novel targets to prevent and treat fertility disorders related to overweight/obesity.

The Coumarin-Derivative Esculetin Protects against Lipotoxicity in Primary Rat Hepatocytes via Attenuating JNK-Mediated Oxidative Stress and Attenuates Free Fatty Acid-Induced Lipid Accumulation

Coumarin derivates have been proposed as a potential treatment for metabolic-dysfunction-associated fatty liver disease (MAFLD). However, the mechanisms underlying their beneficial effects remain unclear. In the present study, we explored the potential of the coumarin derivate esculetin in MAFLD, focusing on hepatocyte lipotoxicity and lipid accumulation. Primary cultures of rat hepatocytes were exposed to palmitic acid (PA) and palmitic acid plus oleic acid (OA/PA) as models of lipotoxicity and lipid accumulation, respectively. Esculetin significantly reduced oxidative stress in PA-treated hepatocytes, as shown by decreased total reactive oxygen species (ROS) and mitochondrial superoxide production and elevated expression of antioxidant genes, including Nrf2 and Gpx1. In addition, esculetin protects against PA-induced necrosis. Esculetin also improved lipid metabolism in primary hepatocytes exposed to nonlipotoxic OA/PA by decreasing the expression of the lipogenesis-related gene Srebp1c and increasing the expression of the fatty acid β-oxidation-related gene Ppar-α. Moreover, esculetin attenuated lipid accumulation in OA/PA-treated hepatocytes. The protective effects of esculetin against lipotoxicity and lipid accumulation were shown to be dependent on the inhibition of JNK and the activation of AMPK, respectively. We conclude that esculetin is a promising compound to target lipotoxicity and lipid accumulation in the treatment of MAFLD.

Detection of Simulated In Vitro Digestion Products of Fucoxanthin and Their Photodamage Alleviation Effect in Retinal Müller Cells Induced by Ultraviolet B Irradiation: A Proteomics Analysis

Our previous study reported that the marine dietary bioactive compound fucoxanthin (FX) has the potential to reduce the level of oxidation in retinal Müller cells (RMCs) induced by ultraviolet B (UVB) irradiation. However, the gastrointestinal environment can inhibit the bioavailability and absorption of FX in the cell systems. In the current study, FX was initially digested in a simulated in vitro gastrointestinal fluid. Nine main digestive products were identified, and the photoprotective activities of FX simulated in vitro gastrointestinal digestion products (FX-ID) were assessed in the same RMC model. FX-ID significantly reduced intracellular ROS and alleviated apoptosis. Western blot assays showed that FX-ID inhibited phosphorylated proteins in the MAPK and NF-κB signaling pathways. Our proteomics analysis revealed that the differentially expressed proteins were linked to biological networks associated with antioxidation and metabolic processes. The data may provide insight into the photoprotective mechanisms of FX-ID and promote the development of various functional foods to prevent retinal disorders.

Non-Excitatory Amino Acids, Melatonin, and Free Radicals: Examining the Role in Stroke and Aging

The aim of this review is to explore the relationship between melatonin, free radicals, and non-excitatory amino acids, and their role in stroke and aging. Melatonin has garnered significant attention in recent years due to its diverse physiological functions and potential therapeutic benefits by reducing oxidative stress, inflammation, and apoptosis. Melatonin has been found to mitigate ischemic brain damage caused by stroke. By scavenging free radicals and reducing oxidative damage, melatonin may help slow down the aging process and protect against age-related cognitive decline. Additionally, non-excitatory amino acids have been shown to possess neuroprotective properties, including antioxidant and anti-inflammatory in stroke and aging-related conditions. They can attenuate oxidative stress, modulate calcium homeostasis, and inhibit apoptosis, thereby safeguarding neurons against damage induced by stroke and aging processes. The intracellular accumulation of certain non-excitatory amino acids could promote harmful effects during hypoxia-ischemia episodes and thus, the blockade of the amino acid transporters involved in the process could be an alternative therapeutic strategy to reduce ischemic damage. On the other hand, the accumulation of free radicals, specifically mitochondrial reactive oxygen and nitrogen species, accelerates cellular senescence and contributes to age-related decline. Recent research suggests a complex interplay between melatonin, free radicals, and non-excitatory amino acids in stroke and aging. The neuroprotective actions of melatonin and non-excitatory amino acids converge on multiple pathways, including the regulation of calcium homeostasis, modulation of apoptosis, and reduction of inflammation. These mechanisms collectively contribute to the preservation of neuronal integrity and functions, making them promising targets for therapeutic interventions in stroke and age-related disorders.

Particle-induced osteolysis is mediated by endoplasmic reticulum stress-associated osteoblast apoptosis

Osteoblast dysfunction plays a crucial role in periprosthetic osteolysis and aseptic loosening, and endoplasmic reticulum (ER) stress is recognized as an important causal factor of wear particle-induced osteolysis. However, the influence of ER stress on osteoblast activity during osteolysis and its underlying mechanisms remain elusive. This study aims to investigate whether ER stress is involved in the detrimental effects of wear particles on osteoblasts. Through our investigation, we observed elevated expression levels of ER stress and apoptosis markers in particle-stimulated bone specimens and osteoblasts. To probe further, we employed the ER stress inhibitor, 4-PBA, to treat particle-stimulated osteoblasts. The results revealed that 4-PBA effectively alleviated particle-induced osteoblast apoptosis and mitigated osteogenic reduction. Furthermore, our study revealed that wear particle-induced ER stress in osteoblasts coincided with mitochondrial damage, calcium overload, and oxidative stress, all of which were effectively alleviated by 4-PBA treatment. Encouragingly, 4-PBA administration also improved bone formation and attenuated osteolysis in a mouse calvarial model. In conclusion, our results demonstrate that ER stress plays a crucial role in mediating wear particle-induced osteoblast apoptosis and impaired osteogenic function. These findings underscore the critical involvement of ER stress in wear particle-induced osteolysis and highlight ER stress as a potential therapeutic target for ameliorating wear particle-induced osteogenic reduction and bone destruction.

SIRT1 activation promotes energy homeostasis and reprograms liver cancer metabolism

BACKGROUND

Cancer cells are characterized by uncontrolled cell proliferation and impaired bioenergetics. Sirtuins are a family of highly conserved enzymes that play a fundamental role in energy metabolism regulation. SIRT1, in particular, drives many physiological stress responses and metabolic pathways following nutrient deprivation. We previously showed that SIRT1 activation using SCIC2.1 was able to attenuate genotoxic response and senescence. Here, we report that in hepatocellular carcinoma (HCC) cells under glucose-deprived conditions, SCIC2.1 treatment induced overexpression of SIRT1, SIRT3, and SIRT6, modulating metabolic response.

METHODS

Flow cytometry was used to analyze the cell cycle. The MTT assay and xCELLigence system were used to measure cell viability and proliferation. In vitro enzymatic assays were carried out as directed by the manufacturer, and the absorbance was measured with an automated Infinite M1000 reader. Western blotting and immunoprecipitation were used to evaluate the expression of various proteins described in this study. The relative expression of genes was studied using real-time PCR. We employed a Seahorse XF24 Analyzer to determine the metabolic state of the cells. Oil Red O staining was used to measure lipid accumulation.

RESULTS

SCIC2.1 significantly promoted mitochondrial biogenesis via the AMPK-p53-PGC1α pathway and enhanced mitochondrial ATP production under glucose deprivation. SIRT1 inhibition by Ex-527 further supported our hypothesis that metabolic effects are dependent on SIRT1 activation. Interestingly, SCIC2.1 reprogrammed glucose metabolism and fatty acid oxidation for bioenergetic circuits by repressing de novo lipogenesis. In addition, SCIC2.1-mediated SIRT1 activation strongly modulated antioxidant response through SIRT3 activation, and p53-dependent stress response via indirect recruitment of SIRT6.

CONCLUSION

Our results show that SCIC2.1 is able to promote energy homeostasis, attenuating metabolic stress under glucose deprivation via activation of SIRT1. These findings shed light on the metabolic action of SIRT1 in the pathogenesis of HCC and may help determine future therapies for this and, possibly, other metabolic diseases.

Retinal cell-targeted liposomal ginsenoside Rg3 attenuates retinal ischemia-reperfusion injury via alleviating oxidative stress and promoting microglia/macrophage M2 polarization

Retinal ischemia-reperfusion (RIR) injury remains a major challenge that is detrimental to retinal cell survival in a variety of ocular diseases. However, current clinical treatments focus on a single pathological mechanism, making them unable to provide comprehensive retinal protection. A variety of natural products including ginsenoside Rg3 (Rg3) exhibit potent antioxidant and anti-inflammatory activities. Unfortunately, the hydrophobicity of Rg3 and the presence of various intraocular barriers limit its effective application in clinical settings. Hyaluronic acid (HA)- specifically binds to cell surface receptors, CD44, which is widely expressed in retinal pigment epithelial cells and M1-type macrophage. Here, we developed HA-decorated liposomes loaded with Rg3, termed Rg3@HA-Lips, to protect against retinal damage caused by RIR injury. Treatment with Rg3@HA-Lips significantly inhibited the oxidative stress induced by RIR injury. In addition, Rg3@HA-Lips promoted the transition of M1-type macrophage to the M2 type, ultimately reversing the pro-inflammatory microenvironment. The mechanism of Rg3@HA-Lips was further investigated and found that they can regulateSIRT/FOXO3a, NF-κB and STAT3 signaling pathways. Together with as well demonstrated good safety profiles, this CD44-targeted platform loaded with a natural product alleviates RIR injury by modulating the retinal microenvironment and present a potential clinical treatment strategy.