Mitigation of honokiol on fluoride-induced mitochondrial oxidative stress, mitochondrial dysfunction, and cognitive deficits through activating AMPK/PGC-1α/Sirt3

Fluoride Induces Neurocytotoxicity by Disrupting Lysosomal Iron Metabolism and Membrane Permeability

The detrimental effects of fluoride on neurotoxicity have been widely recorded, yet the detailed mechanisms underlying these effects remain unclear. This study explores lysosomal iron metabolism in fluoride-related neurotoxicity, with a focus on the Steap3/TRPML1 axis. Utilizing sodium fluoride (NaF)-treated human neuroblastoma (SH-SY5Y) and mouse hippocampal neuron (HT22) cell lines, our research demonstrates that NaF enhances the accumulation of ferrous ions (Fe2+) in these cells, disrupting lysosomal iron metabolism through the Steap3/TRPML1 axis. Notably, NaF exposure upregulated ACSL4 and downregulated GPX4, accompanied by reduced glutathione (GSH) levels and superoxide dismutase (SOD) activity and increased malondialdehyde (MDA) levels. These changes indicate increased vulnerability to ferroptosis within neuronal cells. The iron chelator deferoxamine (DFO) mitigates this disruption. DFO binds to lysosomal Fe2+ and inhibits the Steap3/TRPML1 axis, restoring normal lysosomal iron metabolism, preventing lysosomal membrane permeabilization (LMP), and reducing neuronal cell ferroptosis. Our findings suggest that interference in lysosomal iron metabolism may mitigate fluoride-induced neurotoxicity, underscoring the critical role of the Steap3/TRPML1 axis in this pathological process.

Tirzepatide administration improves cognitive impairment in HFD mice by regulating the SIRT3-NLRP3 axis

PURPOSE

High-fat diet (HFD) currently is reported that in connection with cognitive impairment. Tirzepatide is a novel dual receptor agonist for glycemic control. But whether Tirzepatide exerts a protective effect in HFD-related cognitive impairment remains to be explore.

METHODS

During the study, the cognitive dysfunction mice model induced by HFD were established. The expressions synapse-associated protein and other target proteins were detected. The oxidative stress parameters, levels of inflammatory cytokine were also detected.

RESULTS

Our findings proved that Tirzepatide administration attenuates high fat diet-related cognitive impairment. Tirzepatide administration suppresses microglia activation, alleviates oxidative stress as well as suppressed the expression of NLRP3 in HFD mice by up-regulating SIRT3 expression. In conclusion, Tirzepatide attenuates HFD-induced cognitive impairment through reducing oxidative stress and neuroinflammation via SIRT3-NLRP3 signaling.

CONCLUSION

This study suggest that Tirzepatide has neuroprotective effects in HFD-related cognitive dysfunction mice model, which provides a promising treatment of HFD-related cognitive impairment.

Probiotic Limosilactobacillus reuteri DSM 17938 Alleviates Acute Liver Injury by Activating the AMPK Signaling via Gut Microbiota-Derived Propionate

Limosilactobacillus reuteri DSM 17938 (L. reuteri DSM 17938) was one of the most widely used probiotics in humans for gastrointestinal disorders, but few studies have investigated its role in drug-induced liver injury (DILI). Here, we evaluated the efficacy of L. reuteri DSM 17938 using a mouse model of DILI induced by triptolide. Pregavage of L. reuteri DSM 17938 for 1 week remarkably lowered hepatic inflammatory cytokines level and oxidative stress, with diminished serum alanine transaminase and aspartate aminotransferase levels. Metabolomics and RT-qPCR analysis confirmed its ability in ameliorating TP-disrupted hepatic fatty acid β oxidation. Genome annotation of L. reuteri showed its ability to modulate energy metabolism. Targeted metabolomics demonstrated that L. reuteri DSM 17938 modified the short fatty acid profiles in cecum, especially enhancing propionate levels. Further experiments found that L. reuteri DSM 17938 can activate AMPK signaling by upregulating gut microbiota-derived propionate level, thus restoring impaired mitochondrial biogenesis and energy supply processes to recover energy homeostasis, which leads to diminished ROS production and oxidative stress injury in hepatocytes. Besides, AMPK inhibitor dorsomorphin abolished all the effects on propionate protecting mitochondria and energy metabolism. This study established probiotic therapy of L. reuteri DSM 17938 as a preventive intervention for DILI in clinical. We also revealed that L. reuteri DSM 17938 can activate AMPK signaling by propionate, facilitating a deeper understanding of the action mechanism of L. reuteri DSM 17938 against acute liver injury and contributing to the development of its postbiotics and wider applications.

Honokiol ameliorates silica-induced lung fibrosis by inhibiting macrophage pyroptosis via modulating cGAS/STING signaling

Silicosis is a life-threatening occupational disease because of inhaling silica dust, leading to chronic inflammation, pyroptosis, and fibrosis. Unfortunately, it is still lacking effective pharmacological intervention currently. Honokiol (HKL), a natural extract with biological activity from Magnolia bark, is known for its antioxidant and anti-inflammatory biological effects. The current work aimed to investigate the therapeutic potential of HKL in mitigating silica-induced lung fibrosis and pyroptosis, particularly focusing on the cGAS/STING signaling pathway. The pulmonary pathological results shown in H&E and Masson's trichrome staining images confirmed the protective effects of HKL on lung tissue structure. In addition, HKL significantly reduced lung inflammation, collagen deposition, and oxidative stress compared to mice in the silicosis group. HKL treatment also alleviated silica-induced pyroptosis by suppressing the activation of the cGAS/STING signaling pathway in lung tissues. Moreover, the in vitro experiments using J774A.1 macrophages demonstrated that HKL reduced pyroptosis and improved cell viability under exposure to silica combined lipopolysaccharide (LPS). These were attributed to HKL downregulating the activation of the cGAS/STING signaling pathway in pyroptotic J774A.1 cells induced by silica combined with LPS. Meanwhile, inhibition of STING signaling induced by DNase I significantly enhanced the protective effects of HKL on the inflammatory and pyroptotic processes induced by silica. Overall, HKL could attenuate silica-induced pyroptosis by modulating the cGAS/STING signaling pathway against pulmonary fibrosis. The current study offers a promising approach for treating silicosis and related inflammatory responses.

Mitochondrial Dysfunction in HFpEF: Potential Interventions Through Exercise

HFpEF is a prevalent and complex type of heart failure. The concurrent presence of conditions such as obesity, hypertension, hyperglycemia, and hyperlipidemia significantly increase the risk of developing HFpEF. Mitochondria, often referred to as the powerhouses of the cell, are crucial in maintaining cellular functions, including ATP production, intracellular Ca2+ regulation, reactive oxygen species generation and clearance, and the regulation of apoptosis. Exercise plays a vital role in preserving mitochondrial homeostasis, thereby protecting the cardiovascular system from acute stress, and is a fundamental component in maintaining cardiovascular health. In this study, we review the mitochondrial dysfunction underlying the development and progression of HFpEF. Given the pivotal role of exercise in modulating cardiovascular diseases, we particularly focus on exercise as a potential therapeutic strategy for improving mitochondrial function. Graphical abstract Note: This picture was created with BioRender.com.

The lactate metabolism and protein lactylation in epilepsy

Protein lactylation is a new form of post-translational modification that has recently been proposed. Lactoyl groups, derived mainly from the glycolytic product lactate, have been linked to protein lactylation in brain tissue, which has been shown to correlate with increased neuronal excitability. Ischemic stroke may promote neuronal glycolysis, leading to lactate accumulation in brain tissue. This accumulation of lactate accumulation may heighten neuronal excitability by upregulating protein lactylation levels, potentially triggering post-stroke epilepsy. Although current clinical treatments for seizures have advanced significantly, approximately 30% of patients with epilepsy remain unresponsive to medication, and the prevalence of epilepsy continues to rise. This study explores the mechanisms of epilepsy-associated neuronal death mediated by lactate metabolism and protein lactylation. This study also examines the potential for histone deacetylase inhibitors to alleviate seizures by modifying lactylation levels, thereby offering fresh perspectives for future research into the pathogenesis and clinical treatment of epilepsy.

The SIRT-1/Nrf2/HO-1 axis: Guardians of neuronal health in neurological disorders

SIRT1 (Sirtuin 1) is a NAD+-dependent deacetylase that functions through nucleoplasmic transfer and is present in nearly all mammalian tissues. SIRT1 is believed to deacetylate its protein substrates, resulting in neuroprotective actions, including reduced oxidative stress and inflammation, increased autophagy, increased nerve growth factors, and preserved neuronal integrity in aging or neurological disease. Nrf2 is a transcription factor that regulates the genes responsible for oxidative stress response and substance detoxification. The activation of Nrf2 guards cells against oxidative damage, inflammation, and carcinogenic stimuli. Several neurological abnormalities and inflammatory disorders have been associated with variations in Nrf2 activation caused by either pharmacological or genetic factors. Recent evidence indicates that Nrf2 is at the center of a complex cellular regulatory network, establishing it as a transcription factor with genuine pleiotropy. HO-1 is most likely a component of a defense mechanism in cells under stress, as it provides negative feedback for cell activation and mediator synthesis. This mediator is upregulated by Nrf2, nitric oxide (NO), and other factors in various inflammatory states. HO-1 or its metabolites, such as CO, may mitigate inflammation by modulating signal transduction pathways. Neurological diseases may be effectively treated by modulating the activity of HO-1. Multiple studies have demonstrated that SIRT1 and Nrf2 share an important connection. SIRT1 enhances Nrf2, activates HO-1, protects against oxidative injury, and decreases neuronal death. This has been associated with numerous neurodegenerative and neuropsychiatric disorders. Therefore, activating the SIRT1/Nrf2/HO-1 pathway may help treat various neurological disorders. This review focuses on the current understanding of the SIRT1 and Nrf2/HO-1 neuroprotective processes and the potential therapeutic applications of their target activators in neurodegenerative and neuropsychiatric disorders.

Mitochondrial quality control: a pathophysiological mechanism and potential therapeutic target for chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a prevalent chronic respiratory disease worldwide. Mitochondrial quality control mechanisms encompass processes such as mitochondrial biogenesis, fusion, fission, and autophagy, which collectively maintain the quantity, morphology, and function of mitochondria, ensuring cellular energy supply and the progression of normal physiological activities. However, in COPD, due to the persistent stimulation of harmful factors such as smoking and air pollution, mitochondrial quality control mechanisms often become deregulated, leading to mitochondrial dysfunction. Mitochondrial dysfunction plays a pivotal role in the pathogenesis of COPD, contributing toinflammatory response, oxidative stress, cellular senescence. However, therapeutic strategies targeting mitochondria remain underexplored. This review highlights recent advances in mitochondrial dysfunction in COPD, focusing on the role of mitochondrial quality control mechanisms and their dysregulation in disease progression. We emphasize the significance of mitochondria in the pathophysiological processes of COPD and explore potential strategies to regulate mitochondrial quality and improve mitochondrial function through mitochondrial interventions, aiming to treat COPD effectively. Additionally, we analyze the limitations and challenges of existing therapeutic strategies, aiming to provide new insights and methods for COPD treatment.

Therapeutic Potential of Polyphenols in Cellular Reversal of Patho-Mechanisms of Alzheimer's Disease Using In Vitro and In Vivo Models: A Comprehensive Review

Alzheimer's disease (AD) is considered one of the most common neurological conditions associated with memory and cognitive impairment and mainly affects people aged 65 or above. Even with tremendous progress in modern neuroscience, a permanent remedy or cure for this crippling disease is still unattainable. Polyphenols are a group of naturally occurring potent compounds that can modulate the neurodegenerative processes typical of AD. The present comprehensive study has been conducted to find out the preclinical and clinical potential of polyphenols and elucidate their possible mechanisms in managing AD. Additionally, we have reviewed different clinical studies investigating polyphenols as single compounds or cotherapies, including those currently recruiting, completed, terminated, withdrawn, or suspended in AD treatment. Natural polyphenols were systematically screened and identified through electronic databases including Google Scholar, PubMed, and Scopus based on in vitro cell line studies and preclinical data demonstrating their potential for neuroprotection. A total of 63 significant polyphenols were identified. A multimechanistic pathway for polyphenol's mode of action has been proposed in the study. Out of 63, four potent polyphenols have been identified as promising potential candidates, based on their reported clinical efficacy. Polyphenols hold tremendous scope for the development of a future drug molecule as a phytopharmaceutical that may be incorporated as an adjuvant to the therapeutic regime. However, more high-quality studies with novel delivery methods and combinatorial approaches are required to overcome obstacles such as bioavailability and blood-brain barrier crossing to underscore the therapeutic potential of these compounds in AD management.

Mitophagy in ischemic heart disease: molecular mechanisms and clinical management

The influence of the mitochondrial control system on ischemic heart disease has become a major focus of current research. Mitophagy, as a very crucial part of the mitochondrial control system, plays a special role in ischemic heart disease, unlike mitochondrial dynamics. The published reviews have not explored in detail the unique function of mitophagy in ischemic heart disease, therefore, the aim of this paper is to summarize how mitophagy regulates the progression of ischemic heart disease. We conclude that mitophagy affects ischemic heart disease by promoting cardiomyocyte hypertrophy and fibrosis, the progression of oxidative stress, the development of inflammation, and cardiomyocyte death, and that the specific mechanisms of mitophagy are worthy of further investigation.

Synergistic effects of PS-NPs and Cd on ovarian toxicity in adolescent rats: Ferroptosis by induction of mitochondrial redox imbalance via the SIRT3-SOD2/Gpx4 pathway

Nanoplastics (NPs) are an emerging class of pollutants. They can act as a"Trojan horse" to change the bioavailability and toxicity of heavy metals in the environment. However, research on the combined toxicity of heavy metals and NPs is scarce, especially during the critical developmental period of adolescence. In this study, polystyrene nanoplastics (PS-NPs) and/or cadmium (Cd) were exposed to 4-week-old female rats for 28 days, with the aim of exploring the potential effects of combined exposure to PS-NPs and Cd on the ovaries of adolescence rats. Results showed that co-exposure to PS-NPs and Cd exacerbated ovarian toxicity in rats, primarily through increased atretic follicle numbers and endocrine disruption. Further studies revealed that PS-NPs and Cd synergistically repressed the SIRT3-SOD2/Gpx4 pathway, inducing mitochondrial oxidative stress and ferroptosis, resulting in damage to ovarian structure and function. However, the addition of the mitochondrion-targeted antioxidant SS-31 and the ferroptosis inhibitor Fer-1 reversed the harm to the ovaries from co-exposure to PS-NPs and Cd, the aberrant expression of genes related to the SIRT3-SOD2/Gpx4 pathway was also improved. Our results suggested that co-exposure to PS-NPs and Cd may trigger ferroptosis by inhibiting the SIRT3-SOD2/Gpx4 pathway, leading to mitochondrial redox imbalance, which provided novel insights into reproductive toxicity due to the interaction of PS-NPs and Cd during adolescence.

The ameliorative effects of melatonin against BDE-47-induced hippocampal neuronal ferroptosis and cognitive dysfunction through Nrf2-Chaperone-mediated autophagy of ACSL4 degradation

Recent studies demonstrate that lipid peroxidation-induced ferroptosis participates in 2,2',4,4'-tetrabromodiphenyl ether (BDE-47)-evoked neurotoxicity and cognitive dysfunction. Melatonin has been indicated to confer neuroprotection against brain diseases via its potent anti-ferroptotic effects. Therefore, this study aims to explore whether melatonin can mitigate BDE-47-elicited cognitive impairment via suppressing ferroptosis, and further delineate the underlying mechanisms. Our results found that melatonin administration effectively inhibited BDE-47-induced ferroptosis in mice hippocampi and murine hippocampal neuronal HT-22 cells. Acyl-CoA synthetase long-chain family member 4 (ACSL4), a key lipid metabolism enzyme dictating ferroptosis sensitivity, accompanied by higher MDA and lipid reactive oxygen species (ROS), was remarkably increased under BDE-47 stress, while melatonin supplementation could suppress the elevated ACSL4 in vivo and in vitro. Furthermore, melatonin facilitated lysosomal ACSL4 degradation through enhancing lysosome-associated membrane protein type 2a (LAMP2a) expression and chaperone-mediated autophagy (CMA) activity, while LAMP2a knockdown abrogated the positive effects of melatonin on ACSL4 elimination in BDE-47-treated HT-22 cells. Moreover, nuclear factor erythroid 2-related factor 2 (Nrf2) activation by melatonin contributed to LAMP2a upregulation and CMA of ACSL4 and subsequent neuronal ferroptosis. Importantly, melatonin, CMA activator CA77.1, and ACSL4 inhibitor rosiglitazone (RSG) administration substantially attenuated neuronal/synaptic injury and cognitive deficits following BDE-47 exposure. Taken together, these findings revealed that melatonin could prevent BDE-47-provoked ferroptosis in the hippocampal neurons and mitigate cognitive dysfunction by facilitating ACSL4 degradation via Nrf2-chaperone-mediated autophagy. Therefore, melatonin might be a potential candidate for treating BDE-47-elicited neurotoxicity and neurobehavioral disorder.

Naringin alleviates fluoride-induced neurological impairment: A focus on the regulation of energy metabolism mediated by mitochondrial permeability transition pore

The neurological impairment induced by fluoride is associated with mitochondrial dysfunction. Normal mitochondrial permeability transition pore (mPTP) opening plays a pivotal role in mitochondrial function. However, it remains unclear whether p53-dependent mPTP-related mitochondrial apoptosis is associated with fluoride-induced neurological impairment, and the alleviation of naringin on those. In vivo, NaF-treated rats had impaired learning and memory abilities, damaged hippocampal structure, and higher respiratory exchange rates (RER). In vitro, the increased apoptosis rates, excessive opening of mPTP, and decreased mitochondrial membrane potential (MMP) were observed in PC12 cells treated with NaF. The protein expressions of p53, CytoC, and cleaved caspase 3 were significantly increased in hippocampi of rats treated with 50 mg/L and 100 mg/L NaF and in 40 mg/L and 80 mg/L NaF-treated PC12 cells, while the protein expression of CypD remains stable. And the changes of p53 and CypD were also confirmed by the immunofluorescence staining in vivo. After inhibiting the expression of p53 with pifithrin-α and p53-siRNA, the decreased apoptosis rates and mPTP opening, increased MMP, and decreased protein expressions of p53, CytoC, and cleaved caspase 3 were observed in NaF-treated PC12 cells. Rats, treated with NaF and naringin, had alleviated impaired neurological function, and had lower RER than rats treated with NaF alone. And compared with those in the NaF group, the decreased apoptosis rates and mPTP opening, and increased MMP were also found in PC12 cells treated with NaF and naringin. Furthermore, hippocampi of rats and PC12 cells treated with NaF and naringin had decreased protein expressions of p53, CytoC, and cleaved caspase 3. Our results indicate that fluoride activates the p53-dependent mPTP-related mitochondrial apoptosis, which then affects energy metabolism, resulting in neurological impairment. Additionally, naringin can alleviate this damage, and further studies on the potential health benefits of naringin are needed.

THRA1/PGC-1α/SIRT3 pathway regulates oxidative stress and is implicated in hypertension of maternal hypothyroid rat offspring

Many epidemiologic and animal studies have shown that maternal hypothyroidism is associated with an increased risk of hypertension in offspring in later life. In this study, we established a maternal hypothyroidism rat model to explore the underlying mechanism that contributes to elevated blood pressure in adult male offspring of hypothyroid mothers. The levels of thyroid hormones (THs) in the offspring were measured using ELISA kits. Blood pressure (BP) and depressor response were recorded in conscious, freely moving rats. Vascular reactivity was conducted in isolated mesenteric arteries (MAs) using a myograph. We used real-time quantitative PCR (RT-qPCR) and Western blots to examine the mRNA and protein expression of relevant molecules in MAs. The A7r5 cells were transfected with small interfering RNA (siRNA) to further investigate the gene functions. The following findings were observed: Basal systolic BP and diastolic BP was significantly increased, accompanied by attenuated depressor response and decreased vascular sensitivity to sodium nitroprusside (SNP). Reactive Oxygen Species (ROS) levels in the MAs were enhanced, along with decreased expression of the THRA1/PGC-1α/SIRT3 pathway. In A7r5 cells, triiodothyronine (T3) pretreatment improved the PGC-1α/SIRT3 pathway and reduced ROS levels after H2O2-induced oxidative stress. In contrast, the knockdown of THRA1 or SIRT3 diminished the above effects of T3. Down-regulation of THRA1 contributed to a decline in the PGC-1α/SIRT3 pathway, which causes an increased production of ROS. This indicates that the T3-THRA1/PGC-1α/SIRT3 pathway plays a protective role in the regulation of BP and may be a potential therapeutic strategy against hypertension.

Molecular and immunohistochemical alterations in fluoride-induced neurological impediment in adult rats

This study highlights the potential neurotoxic and impaired behavioral effects associated with high fluoride concentrations in drinking water.

PURPOSE

Fluoride is known to cause neurotoxicity, evinced by lower I.Q. levels in children from high-fluoride regions as compared to those in low-fluoride regions. Thus, the present study was designed to investigate the molecular mechanism behind the neurological and behavioural changes induced by sodium fluoride in Wistar rats.

MATERIAL AND METHODS

A total of 24 female Wistar rats, aged six weeks and weighing approximately 150-220 g, were randomly divided into three groups: Group I (control) received reverse osmosis (R.O.) water, Group II received Sodium Fluoride (NaF) at 10 ppm, and Group III received NaF at 50 ppm in their drinking water for 60 days. The animals underwent behavioural tests including the Forced Swim Test (F.S.T.), Open Field Test (OFT), and Novel Object Recognition Test (N.O.R.T.), to assess any alterations in behaviour. After 60 days, the animals were euthanized, and their blood and brain samples were analysed to evaluate biochemical changes by Western Blot/I.H.C. analysis of B.A.X., Bcl2, LC3B, TLR4, PARP1, p53, Caspase, α-Synuclein, PARKIN, NeuN, KI67, DNM-1, and M.F.N. for assessing molecular pathways for toxicity.

RESULTS

Impaired locomotion, memory impairment, and behaviour resembling depression in the animals were evinced by reduced mobility index in the F.S.T., discrimination index in the N.O.R.T., and reduced locomotor activity in the open field test results. Additionally, alterations in antioxidant levels and oxidative stress parameters were observed in the brain. The expression levels of various apoptotic and inflammatory biomarkers (B.A.X., Bcl2, TLR4, PARP1, p53, and Caspase) showed apoptosis in neurons. The confocal studies showed increased expression of inflammatory (α-Synuclein, PARKIN), apoptotic (LC3B, B.A.X., p53, KI67), and mitochondrial dysfunction (NeuN, DNM-1, M.F.N.) markers in fluoride-treated animals. Toxicity was more prominent in 50 ppm of fluoride-treated animals.

CONCLUSION

Fluoride showed potent neuronal toxicity as evidenced by alterations of various molecular markers.

Kaixinsan regulates neuronal mitochondrial homeostasis to improve the cognitive function of Alzheimer's disease by activating CaMKKβ-AMPK-PGC-1α signaling axis

BACKGROUND

Alzheimer's disease (AD) is a neurodegenerative disease primarily characterized by cognitive impairments. With the intensification of population aging, AD has become a major health concern affecting the elderly. Kaixinsan, a classical traditional Chinese formula, consists of Ginseng Panax et Rhizoma, Polygalae Radix, Poria and Acori Tatarinowii Rhizoma, and is commonly used in clinical for treating memory decline. However, its mechanism remains unclear, which hinders its popularization and application.

METHOD

Morris water maze (MWM) was performed to evaluate the effect of Kaixinsan on improving learning and memory ability in SAMP8 (senescence-accelerated mouse prone 8, an AD model mice) mice. Nissl staining, TdT-mediated dUTP Nick End Labeling (TUNEL) and western blotting (Bax and Bcl-2) were used to confirm the effect of Kaixinsan on the neuronal structure and apoptosis of SAMP8 mice. Ultra performance liquid chromatography coupled with quadrupole time of flight mass spectrometry (UPLC-Q-TOF/MS) was performed to identify the distribution components in brain tissue after administration of Kaixinsan extraction. Based on the identified brain distribution components, the mechanism of Kaixinsan improving the cognitive function was predicted by network pharmacology. Then, using HSP60 as a mitochondrial marker and RBFOX3 as a neuronal marker, immunofluorescence co-localization was used to confirm the effect of Kaixinsan on neuronal mitochondria quantity in SAMP8 mice. Western blotting was employed to access the expression of predicted proteins (AMPK, CaMKKβ, PGC-1α and HSP90) implicated in mitochondrial homeostasis. To further confirm the mechanism of Kaixinsan, SH-SY5Y cell injury model induced by amyloid β - protein fragment 25-35 (Aβ25-35) was replicated and the effect of Kaixinsan - containing serum on apoptosis in injured SH-SY5Y cells was investigated by flow cytometer. The expression level of apoptosis-associated proteins (Bax and Bcl-2) and mitochondrial homeostasis related proteins (AMPK, CaMKKβ, PGC-1α and HSP90) in the presence or absence of CaMKKβ inhibitor (STO-609) were compared.

RESULTS

The results indicate that Kaixinsan can improve the cognitive function of SAMP8 mice, alleviate the hippocampal tissue lesions and inhibit neuron apoptosis. Seventeen brain distribution components of Kaixinsan were identified. Based on the brain distribution components of Kaixinsan, the results of network pharmacology suggest that Kaixinsan may regulate mitochondrial homeostasis through the CaMKKβ-AMPK-PGC-1α signaling axis. In vivo experiments indicated that Kaixinsan could reverse neuronal mitochondrial loss in SAMP8 mice by upregulating CaMKKβ, AMPK, HSP90 and PGC-1α to promote mitochondrial biogenesis and increase the number of neuronal mitochondria. Additionally, the in vitro experiments demonstrated that Kaixinsan can inhibit apoptosis of Aβ25-35 injured SH-SY5Y cells and upregulate mitochondrial homeostasis-related proteins CaMKKβ, AMPK and PGC-1α. However, in addition to CaMKKβ inhibitors, the neuroprotective effect disappeared.

CONCLUSION

The results indicate that Kaixinsan can improve the cognitive function of SAMP8 mice by regulating CaMKKβ-AMPK-PGC-1α signaling axis to maintain mitochondrial homeostasis and inhibit neuronal apoptosis.

Fluoride induces immune-inflammatory disorder in the kidneys via histone lysine crotonylation in vivo

Fluoride is an essential trace element for human. Adequate levels of fluoride are crucial for maintaining skeletal growth, but excessive fluoride exposure entering the body can cause renal damage, including damaged renal tubules and impaired renal function. However, the mechanism on fluoride-induced kidney injury remains unclear. This study aimed to explore the immune-inflammatory imbalance induced by fluoride and its possible mechanism in the kidneys. Mice were exposed to sodium fluoride (NaF) (0, 25, 50 and 100 mg/L) for five months. The results showed that NaF increased the renal weight and renal index. The NaF-treated groups exhibited higher serum creatinine (Cre), blood urea nitrogen (BUN), albumin (ALB) total protein (TP) levels. Further, NaF increased reactive oxygen species (ROS) levels, lipid peroxidation (LPO) levels and malondialdehyde (MDA) level. Superoxide dismutase (SOD) activity was reduced and glutathione (GSH) activities were reduced in fluoride-treated group. NaF treatment also downregulated the nuclear factor E2-related factor (Nrf2) protein and its downstream enzymes heme oxygenase-1 (HO-1) and NAD(P)H: Quinone Oxidoreductase 1(NQO1) in the kidneys. Further, NaF shifted Th1/Th2 balance toward Th1 bias. Similarly, NaF exhibited increased macrophages and augmented M1 differentiation but suppressed M2 differentiation. The renal inflammatory response was also induced by fluoride via activation of the NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome and increase of the pro-inflammatory factors tumour necrosis factor-α (TNF-α), transforming growth factor-β (TGF-β), interleukin-6 (IL-6) and interleukin-18 (IL-18). In addition, NaF treatment reduced the expression of the histone 2B lysine 12 crotonylation (H2BK12cr) and H4K8cr proteins as well as decreased the histone acetyltransferase P300 protein. NaF incresed the protein expression of histone decrotonylation enzyme sirtuin1 (sirt1) and histone deacetylase 3 (HDAC3) and upregulated HDAC2 protein. These findings demonstrate that fluoride exposure induces renal dysfunction and oxidative injury, affects M1/M2 polarization and Th1/Th2 differentiation, and promotes the inflammatory response via histone lysine crotonylation, ultimately resulting in nephrotoxicity.

Mitochondrial DNA (mtDNA) accelerates oxygen-glucose deprivation-induced injury of proximal tubule epithelia cell via inhibiting NLRC5

The high morbidity and mortality associated with acute kidney injury (AKI) are global health concerns. AKI is commonly attributed to ischemia/reperfusion injury (IRI), a condition characterized by activation of inflammatory responses and mitochondrial dysfunction. Nonetheless, mitochondrial DNA (mtDNA) has the potential to induce renal IRI. This study aimed to elucidate the mechanism and function of mtDNA in HK-2 cells that had been exposed to oxygen-glucose deprivation/reperfusion (OGD/R) and in renal IRI mice. OGD/R was discovered to induce an increase in the amount of mtDNA in HK-2 cells. Moreover, our study demonstrated that mtDNA facilitated cellular apoptosis and inflammation in vivo and in vitro. Given the potential role of inflammation in OGD/R, we investigated the effect of mtDNA on various signaling pathways associated with inflammation. Western blot analysis demonstrated that mtDNA significantly upregulated NLRC5/TAP1 signaling. Furthermore, the upregulation of NLRC5 and TAP1 expression induced by mtDNA was reversed when NLRC5 was inhibited. It is worth mentioning that the loss of NLRC5 effectively nullified the beneficial effects of mtDNA on inflammation and cell apoptosis induced by OGD/R. In addition, in renal IRI mice, mtDNA treatment also aggravated inflammation and kidney damage, and increased the NLRC5 levels in kidney tissues. These results suggested that NLRC5 acts as an intermediary between mtDNA and the pathogenicity of renal IRI. In summary, this study provides evidence that mtDNA promotes apoptosis and inflammation in OGD/R treated HK-2 cells and renal IRI mice through upregulating NLRC5 levels.

USP14 modulates cell pyroptosis and ameliorates doxorubicin-induced cardiotoxicity by deubiquitinating and stabilizing SIRT3

This study investigates the role of the deubiquitinating enzyme USP14 in alleviating doxorubicin (DOX)-induced cardiotoxicity (DIC), particularly concerning its mechanism of regulating pyroptosis through the stabilization of the mitochondrial protein SIRT3. Using in vivo and in vitro models, the research demonstrated that USP14 overexpression protects against DOX-induced cardiac damage by modulating pyroptosis. Silencing SIRT3 via siRNA revealed that SIRT3 is a key intermediary molecule in USP14-mediated regulation of pyroptosis. Notably, DOX exposure resulted in decreased USP14 expression, while its overexpression preserved mitochondrial function and reduced oxidative stress by stabilizing SIRT3. Immunoprecipitation confirmed that USP14 stabilizes SIRT3 through deubiquitination. These findings position USP14 as a promising therapeutic target for mitigating DOX-induced cardiotoxicity by stabilizing SIRT3 and maintaining mitochondrial integrity, suggesting potential novel strategies for cardio-protection in chemotherapy.

Mitochondrial HKDC1 suppresses oxidative stress and apoptosis by regulating mitochondrial function in goose fatty liver

Different from human non-alcoholic fatty liver disease (NAFLD), goose fatty liver is physiological with no inflammation. Consistently, mitochondrial dysfunction, oxidative stress and apoptosis are rarely seen in goose fatty liver. Hexokinase domain-containing protein 1 (HKDC1) is involved in maintaining systemic glucose homeostasis, and its absence causes mitochondrial dysfunction. Here, we demonstrated that mitochondrial outer membrane-bound HKDC1 (mHKDC1) had an expression pattern different from that of whole-cell HKDC1 (wHKDC1). Data indicated that the protein level of whole-cell HKDC1 (wHKDC1) was increased but mHKDC1 was decreased in mouse fatty liver. Interestingly, both the protein levels of wHKDC1 and mHKDC1 were significantly increased in goose fatty liver. Treatment of goose or mouse hepatocytes with fatty liver-related factors could influence the expression of wHKDC1 and mHKDC1, but the influence on wHKDC1 was not identical to mHKDC1. HKDC1 overexpression in goose hepatocytes increased wHKDC1 and mHKDC1 expression, mitochondrial membrane potential (MMP), mitochondrial respiratory chain activity, and suppressed reactive oxygen species (ROS) generation, apoptosis and cytokine-cytokine receptor signaling pathway. In addition, mutations in mitochondrial signal peptide or activation domain of HKDC1 altered MMP or ROS levels. In conclusion, HKDC1, particularly mHKDC1, may protect goose fatty liver by regulating mitochondrial function, ROS generation, apoptosis, and inflammation-related pathways.

Unraveling the mechanism of quercetin alleviating BHPF-induced apoptosis in epithelioma papulosum cyprini cells: SIRT3-mediated mitophagy

Fluorene-9-bisphenol (BHPF), as an alternative to bisphenol A, is now increasingly used in plastic products. The accumulation of BHPF in the water environment has posed potential safety risks to aquatic organisms. Unfortunately, the toxicity of BHPF on the physiological metabolism of aquatic animals remains unclear, especially on the molecular mechanisms of BHPF kidney toxicity and antagonizing BHPF toxicity. Quercetin (QCT), a naturally occurring flavonoid, has been reported to mitigate the toxic effects on aquatic organisms induced by a variety of environmental contaminants. It is unclear whether QCT can be a candidate for mitigating BHPF toxicity. In this study, we investigated the protective effect of QCT on BHPF-induced apoptosis and elucidated the possible mechanism of the protective effect mediated by QCT. We treated epithelioma papulosum cyprini cells (EPCs) with 20 μM of BHPF and/or 20 μM of QCT, and the results showed that BHPF significantly increased the release of reactive oxygen species (ROS) from EPCs, decreased the expression of SIRT3, and initiated endogenous apoptosis. Molecular docking provides evidence for the interaction of QCT and SIRT3. Our intervention with Honokiol (HKL) showed that QCT or HKL treatment significantly attenuated BHPF-induced mitochondrial dysfunction and mitochondrial apoptosis (mtApoptosis) in EPCs, and activated mitophagy, restoring autophagy flux. To further investigate the specific mechanism of the protective effect of QCT, we intervened with Cyclosporin A (CsA), and our results suggest that QCT activation of SIRT3-promoted regulation of mitophagy may be a therapeutic strategy to attenuate the toxic effects of BHPF on EPCs. In conclusion, our findings suggest that BHPF induces oxidative damage and mtApoptosis in EPCs and that QCT activates mitophagy and improves autophagic flux through activation of SIRT3, thereby alleviating apoptosis mediated by mitochondrial dysfunction in EPCs. Our study provides a theoretical basis for reassessing the safety of BHPF for aquatic organisms and reveals a novel detoxification mechanism against the toxic effects of BHPF.

Protective effect of honokiol on cadmium-induced liver injury in chickens

Cadmium (Cd), a highly toxic heavy metal in the environment, poses a significant threat to livestock and poultry farming. Honokiol (HNK), a Chinese herbal extract with potent antioxidant activity, acts through oxidative damage and inflammation. Cd induces oxidative stress and causes liver damage in animals. However, whether HNK can alleviate Cd-induced liver injury in chickens and its mechanism remains unclear. In this study, the 48 chickens were randomly allocated into 4 groups, control group, Cd group (70 mg/kg Cd), HNK group (200 mg/kg HNK) and Cd + HNK group (70 mg/kg Cd+200 mg/kg HNK). Results showed that HNK improved the Cd induced reduction in chicken body weight, liver weight, and liver coefficient. HNK recovered the Cd induced liver damaged through increased serum liver biochemical indexes, impaired liver oxidase activity and the disordered the expression level of antioxidant genes. HNK alleviated Cd induced pathological and ultrastructure damage of liver tissue and liver cell that leads apoptosis. HNK decreased Cd contents in the liver, Cd induced disturbances in the levels of trace elements such as iron, copper, zinc, manganese, and selenium. HNK attenuated the damage to the gap junction structure of chicken liver cells caused by Cd and reduced the impairment of oxidase activity and the expression level of antioxidant genes induced by Cd. In conclusion, HNK presents essential preventive measures and a novel pharmacological potential therapy against Cd induced liver injury. Our experiments show that HNK can be used as a new green feed additive in the poultry industry, which provides a theoretical basis for HNK to deal with the pollution caused by Cd in the poultry industry.

Cynaroside regulates the AMPK/SIRT3/Nrf2 pathway to inhibit doxorubicin-induced cardiomyocyte pyroptosis

Doxorubicin (DOX) is a commonly administered chemotherapy drug for treating hematological malignancies and solid tumors; however, its clinical application is limited by significant cardiotoxicity. Cynaroside (Cyn) is a flavonoid glycoside distributed in honeysuckle, with confirmed potential biological functions in regulating inflammation, pyroptosis, and oxidative stress. Herein, the effects of Cyn were evaluated in a DOX-induced cardiotoxicity (DIC) mouse model, which was established by intraperitoneal injections of DOX (5 mg/kg) once a week for three weeks. The mice in the treatment group received dexrazoxane, MCC950, and Cyn every two days. Blood biochemistry, histopathology, immunohistochemistry, reverse transcription-quantitative polymerase chain reaction (RT-qPCR), and western blotting were conducted to investigate the cardioprotective effects and potential mechanisms of Cyn treatment. The results demonstrated the significant benefits of Cyn treatment in mitigating DIC; it could effectively alleviate oxidative stress to a certain extent, maintain the equilibrium of cell apoptosis, and enhance the cardiac function of mice. These effects were realized via regulating the transcription levels of pyroptosis-related genes, such as nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3), caspase-1, and gasdermin D (GSDMD). Mechanistically, for DOX-induced myocardial injury, Cyn could significantly modulate the expression of pivotal genes, including adenosine monophosphate-activated protein kinase (AMPK), peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α), sirtuin 3 (SIRT3), and nuclear factor erythroid 2-related factor 2 (Nrf2). We attribute it to the mediation of AMPK/SIRT3/Nrf2 pathway, which plays a central role in preventing DOX-induced cardiomyocyte injury. In conclusion, the present study confirms the therapeutic potential of Cyn in DIC by regulating the AMPK/SIRT3/Nrf2 pathway.

New insights into the role of mitochondrial dynamics in oxidative stress-induced diseases

The accumulation of excess reactive oxygen species (ROS) can lead to oxidative stress (OS), which can induce gene mutations, protein denaturation, and lipid peroxidation directly or indirectly. The expression is reduced ATP level in cells, increased cytoplasmic Ca2+, inflammation, and so on. Consequently, ROS are recognized as significant risk factors for human aging and various diseases, including diabetes, cardiovascular diseases, and neurodegenerative diseases. Mitochondria are involved in the production of ROS through the respiratory chain. Abnormal mitochondrial characteristics, including mitochondrial OS, mitochondrial fission, mitochondrial fusion, and mitophagy, play an important role in various tissues. However, previous excellent reviews focused on OS-induced diseases. In this review, we focus on the latest progress of OS-induced mitochondrial dynamics, discuss OS-induced mitochondrial damage-related diseases, and summarize the OS-induced mitochondrial dynamics-related signaling pathways. Additionally, it elaborates on potential therapeutic methods aimed at preventing oxidative stress from further exacerbating mitochondrial disorders.

GLT-1 downregulation in hippocampal astrocytes induced by type 2 diabetes contributes to postoperative cognitive dysfunction in adult mice

AIMS

Type 2 diabetes mellitus (T2DM) is related to an increased risk of postoperative cognitive dysfunction (POCD), which may be caused by neuronal hyperexcitability. Astrocyte glutamate transporter 1 (GLT-1) plays a crucial role in regulating neuron excitability. We investigated if T2DM would magnify the increased neuronal excitability induced by anesthesia/surgery (A/S) and lead to POCD in young adult mice, and if so, determined whether these effects were associated with GLT-1 expression.

METHODS

T2DM model was induced by high fat diet (HFD) and injecting STZ. Then, we evaluated the spatial learning and memory of T2DM mice after A/S with the novel object recognition test (NORT) and object location test (OLT). Western blotting and immunofluorescence were used to analyze the expression levels of GLT-1 and neuronal excitability. Oxidative stress reaction and neuronal apoptosis were detected with SOD2 expression, MMP level, and Tunel staining. Hippocampal functional synaptic plasticity was assessed with long-term potentiation (LTP). In the intervention study, we overexpressed hippocampal astrocyte GLT-1 in GFAP-Cre mice. Besides, AAV-Camkllα-hM4Di-mCherry was injected to inhibit neuronal hyperexcitability in CA1 region.

RESULTS

Our study found T2DM but not A/S reduced GLT-1 expression in hippocampal astrocytes. Interestingly, GLT-1 deficiency alone couldn't lead to cognitive decline, but the downregulation of GLT-1 in T2DM mice obviously enhanced increased hippocampal glutamatergic neuron excitability induced by A/S. The hyperexcitability caused neuronal apoptosis and cognitive impairment. Overexpression of GLT-1 rescued postoperative cognitive dysfunction, glutamatergic neuron hyperexcitability, oxidative stress reaction, and apoptosis in hippocampus. Moreover, chemogenetic inhibition of hippocampal glutamatergic neurons reduced oxidative stress and apoptosis and alleviated postoperative cognitive dysfunction.

CONCLUSIONS

These findings suggest that the adult mice with type 2 diabetes are at an increased risk of developing POCD, perhaps due to the downregulation of GLT-1 in hippocampal astrocytes, which enhances increased glutamatergic neuron excitability induced by A/S and leads to oxidative stress reaction, and neuronal apoptosis.

ZLN005, a PGC-1α Activator, Protects the Liver against Ischemia-Reperfusion Injury and the Progression of Hepatic Metastases

BACKGROUND

Exercise can promote sustainable protection against cold and warm liver ischemia-reperfusion injury (IRI) and tumor metastases. We have shown that this protection is by the induction of hepatic mitochondrial biogenesis pathway. In this study, we hypothesize that ZLN005, a PGC-1α activator, can be utilized as an alternative therapeutic strategy.

METHODS

Eight-week-old mice were pretreated with ZLN005 and subjected to liver warm IRI. To establish a liver metastatic model, MC38 cancer cells (1 × 106) were injected into the spleen, followed by splenectomy and liver IRI.

RESULTS

ZLN005-pretreated mice showed a significant decrease in IRI-induced tissue injury as measured by serum ALT/AST/LDH levels and tissue necrosis. ZLN005 pretreatment decreased ROS generation and cell apoptosis at the site of injury, with a significant decrease in serum pro-inflammatory cytokines, innate immune cells infiltration, and intrahepatic neutrophil extracellular trap (NET) formation. Moreover, mitochondrial mass was significantly upregulated in hepatocytes and maintained after IRI. This was confirmed in murine and human hepatocytes treated with ZLN005 in vitro under normoxic and hypoxic conditions. Additionally, ZLN005 preconditioning significantly attenuated tumor burden and increased the percentage of intratumoral cytotoxic T cells.

CONCLUSIONS

Our study highlights the effective protection of ZLN005 pretreatment as a therapeutic alternative in terms of acute liver injury and tumor metastases.

Adiponectin receptor agonist AdipoRon alleviates memory impairment in the hippocampus of septic mice

Sepsis-associated encephalopathy (SAE) is a common and severe clinical feature of sepsis; however, therapeutic approaches are limited because of the unclear pathogenesis. Adiponectin receptor agonist (AdipoRon) is a small-molecule agonist of the adiponectin receptor that exhibits anti-inflammatory and memory-improving effects in various diseases. In the present study, we established lipopolysaccharide (LPS)-induced mice models of SAE and found that Adiponectin receptor 1 (AdipoR1) was significantly decreased in the hippocampus. Administration of AdipoRon improves memory impairment, mitigates synaptic damage, and alleviates neuronal death. Furthermore, AdipoRon reduces the number of microglia. More importantly, AdipoRon promotes the phosphorylation of adenosine 5 '-monophosphate activated protein kinase (pAMPK). In conclusion, AdipoRon is protective against SAE-induced memory decline and brain injury in the SAE models via activating the hippocampal adenosine 5 '-monophosphate activated protein kinase (AMPK).

Extracellular vesicles: opening up a new perspective for the diagnosis and treatment of mitochondrial dysfunction

Mitochondria are crucial organelles responsible for energy generation in eukaryotic cells. Oxidative stress, calcium disorders, and mitochondrial DNA abnormalities can all cause mitochondrial dysfunction. It is now well documented that mitochondrial dysfunction significantly contributes to the pathogenesis of numerous illnesses. Hence, it is vital to investigate innovative treatment methods targeting mitochondrial dysfunction. Extracellular vesicles (EVs) are cell-derived nanovesicles that serve as intercellular messengers and are classified into small EVs (sEVs, < 200 nm) and large EVs (lEVs, > 200 nm) based on their sizes. It is worth noting that certain subtypes of EVs are rich in mitochondrial components (even structurally intact mitochondria) and possess the ability to transfer them or other contents including proteins and nucleic acids to recipient cells to modulate their mitochondrial function. Specifically, EVs can modulate target cell mitochondrial homeostasis as well as mitochondria-controlled apoptosis and ROS generation by delivering relevant substances. In addition, the artificial modification of EVs as delivery carriers for therapeutic goods targeting mitochondria is also a current research hotspot. In this article, we will focus on the ability of EVs to modulate the mitochondrial function of target cells, aiming to offer novel perspectives on therapeutic approaches for diverse conditions linked to mitochondrial dysfunction.

Lactucopicrin promotes fatty acid β-oxidation and attenuates lipid accumulation through adenosine monophosphate-activated protein kinase activation in free fatty acid-induced human hepatoblastoma cancer cells

With its annually increasing prevalence, non-alcoholic fatty liver disease (NAFLD) has become a serious threat to people's life and health. After a preliminary research, we found that Lactucopicrin has pharmacological effects, such as lowering blood lipids and protecting the liver. Further research showed its significant activation for fatty acid β-oxidase hydroxyacyl-coenzyme A (CoA) dehydrogenase trifunctional multienzyme complex subunit alpha (HADHA), so we hypothesized that Lactucopicrin could ameliorate lipid accumulation in hepatocytes by promoting fatty acid β-oxidation. In this study, free fatty acid (FFA)-induced human hepatoblastoma cancer cells (HepG2) were used to establish an in vitro NAFLD model to investigate the molecular basis of Lactucopicrin in regulating lipid metabolism. Staining with Oil red O and measurements of triglyceride (TG) content, fatty acid β-oxidase (FaβO) activity, reactive oxygen species (ROS) content, mitochondrial membrane potential, and adenosine triphosphate (ATP) content were used to assess the extent to which Lactucopicrin ameliorates lipid accumulation and promotes fatty acid β-oxidation. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot methods were used to explore the regulatory effects of Lactucopicrin on factors related to fatty acid β-oxidation. Results showed that Lactucopicrin downregulated phosphorylated mammalian target of rapamycin (P-mTOR) by activating the adenosine monophosphate-activated protein kinase (AMPK) pathway and upregulated the messenger RNA (mRNA) and protein expression levels of coactivators (peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α)), transcription factors (peroxisome proliferator-activated receptor α (PPARα) and peroxisome proliferator-activated receptor γ (PPARγ)), and oxidative factors (carnitine palmitoyltransferase 1A (CPT1A) and HADHA). This phenomenon resulted in a significant increase in FaβO activity, ATP content, and JC-1 and a significant decrease in ROS level, TG content, and intracellular lipid droplets. With the addition of Dorsomorphin, all the effects of Lactucopicrin intervention were suppressed. In summary, Lactucopicrin promotes fatty acid β-oxidation by activating the AMPK pathway, thereby ameliorating FFA-induced intracellular lipid accumulation in HepG2 cells.

Activation of Sirtuin3 by honokiol ameliorates alveolar epithelial cell senescence in experimental silicosis via the cGAS-STING pathway

BACKGROUND

Silicosis, characterized by interstitial lung inflammation and fibrosis, poses a significant health threat. ATII cells play a crucial role in alveolar epithelial repair and structural integrity maintenance. Inhibiting ATII cell senescence has shown promise in silicosis treatment. However, the mechanism behind silica-induced senescence remains elusive.

METHODS

The study employed male C57BL/6 N mice and A549 human alveolar epithelial cells to investigate silicosis and its potential treatment. Silicosis was induced in mice via intratracheal instillation of crystalline silica particles, with honokiol administered intraperitoneally for 14 days. Silica-induced senescence in A549 cells was confirmed, and SIRT3 knockout and overexpression cell lines were generated. Various analyses were conducted, including immunoblotting, qRT-PCR, histology, and transmission electron microscopy. Statistical significance was determined using one-way ANOVA with Tukey's post-hoc test.

RESULTS

This study elucidates how silica induces ATII cell senescence, emphasizing mtDNA damage. Notably, honokiol (HKL) emerges as a promising anti-senescence and anti-fibrosis agent, acting through sirt3. honokiol effectively attenuated senescence in ATII cells, dependent on sirt3 expression, while mitigating mtDNA damage. Sirt3, a class III histone deacetylase, regulates senescence and mitochondrial stress. HKL activates sirt3, protecting against pulmonary fibrosis and mitochondrial damage. Additionally, HKL downregulated cGAS expression in senescent ATII cells induced by silica, suggesting sirt3's role as an upstream regulator of the cGAS/STING signaling pathway. Moreover, honokiol treatment inhibited the activation of the NF-κB signaling pathway, associated with reduced oxidative stress and mtDNA damage. Notably, HKL enhanced the activity of SOD2, crucial for mitochondrial function, through sirt3-mediated deacetylation. Additionally, HKL promoted the deacetylation activity of sirt3, further safeguarding mtDNA integrity.

CONCLUSIONS

This study uncovers a natural compound, HKL, with significant anti-fibrotic properties through activating sirt3, shedding light on silicosis pathogenesis and treatment avenues.

Honokiol alleviates monosodium urate-induced gouty pain by inhibiting voltage-gated proton channels in mice

OBJECTIVE

To investigate whether honokiol (HNK) acted as an analgesic in connection with inhibiting the voltage-gated proton channel (Hv1).

METHODS

The model of gouty arthritis was induced by injecting monosodium urate (MSU) crystals into the hind ankle joint of mice. HNK was given by intragastric administration. Ankle swelling degree and mechanical allodynia were evaluated using ankle joint circumference measurement and von Frey filaments, respectively. Hv1 current, tail current, and action potential in dorsal root ganglion (DRG) neurons were recorded with patch-clamp techniques.

RESULTS

HNK (10, 20, 40 mg/kg) alleviated inflammatory response and mechanical allodynia in a dose-dependent manner. In normal DRG neurons, 50 µM Zn2+ or 2-GBI significantly inhibited the Hv1 current and the current density of Hv1 increased with increasing pH gradient. The amplitude of Hv1 current significantly increased on the 3rd after MSU treatment, and HNK dose-dependently reversed the upregulation of Hv1 current. Compared with MSU group, 40 mg/kg HNK shifted the activation curve to the direction of more positive voltage and increased reversal potential to the normal level. In addition, 40 mg/kg HNK reversed the down-regulation of tail current deactivation time constant (τtail) but did not alter the neuronal excitability of DRG neurons in gouty mice.

CONCLUSION

HNK may be a potential analgesic by inhibiting Hv1 current.

Serum SIRT3 levels in epilepsy patients and its association with clinical outcomes and severity: A prospective observational study

Objective

In this prospective observational study, we aimed to investigate the serum levels of sirtuin (SIRT)3 in epilepsy patients and its association with the severity of the disease.

Methods

This prospective observational study included 203 patients with symptomatic epilepsy and 100 healthy controls who visited our hospital from November 2019 to November 2022. The severity of the disease in epilepsy patients was assessed using the National Hospital Seizure Severity Scale (NHS3). We used enzyme-linked immunosorbent assay to measure the serum levels of SIRT3, interleukin (IL)-6, IL-1β, tumor necrosis factor-alpha, and C-reactive protein in all patients. In addition, the cognitive function of all study participants was evaluated using the Mini-Mental State Examination and the Montreal Cognitive Assessment (MOCA). All data were analyzed using SPSS 25.0 software.

Results

The MOCA scores of the epilepsy patients were significantly lower compared to the healthy volunteers (P < 0.05). The serum SIRT3 levels were decreased significantly in patients with refractory epilepsy (183.16 ± 17.22 pg/mL) compared to non-refractory epilepsy patients (199.00 ± 18.68 pg/mL). In addition, serum SIRT3 levels were negatively correlated with the inflammatory factors IL-6 (Pearson's correlation -0.221, P = 0.002) and NHS score (Pearson's correlation -0.272, P < 0.001) of epilepsy patients, while positively correlated with MOCA scores (Pearson's correlation 0.166, P = 0.018). Furthermore, the receiver operating characteristic curve demonstrated that serum SIRT3 could be used to diagnose epilepsy, as well as refractory epilepsy. Finally, logistic regression analysis showed that SIRT3 (OR = 1.028, 95%CI: 1.003-1.054, P = 0.028), IL-6 (OR = 0.666, 95%CI: 0.554-0.800, P < 0.001), IL-1β (OR = 0.750, 95%CI: 0.630-0.894, P = 0.001), and NHS3 (OR = 0.555, 95%CI: 0.435-0.706, P < 0.001) were risk factors for refractory epilepsy.

Conclusion

In conclusion, our findings demonstrated that serum SIRT3 levels were significantly decreased in epilepsy patients and further decreased in patients with refractory epilepsy. This study might provide new therapeutic targets and comprehensive treatment strategies for epilepsy patients.

Polyphenols targeting multiple molecular targets and pathways for the treatment of vitiligo

Vitiligo, a pigmentary autoimmune disorder, is marked by the selective loss of melanocytes in the skin, leading to the appearance of depigmented patches. The principal pathological mechanism is the melanocyte destruction mediated by CD8+ T cells, modulated by oxidative stress and immune dysregulation. Vitiligo affects both physical health and psychological well-being, diminishing the quality of life. Polyphenols, naturally occurring compounds with diverse pharmacological properties, including antioxidant and anti-inflammatory activities, have demonstrated efficacy in managing various dermatological conditions through multiple pathways. This review provides a comprehensive analysis of vitiligo and the therapeutic potential of natural polyphenolic compounds. We examine the roles of various polyphenols in vitiligo management through antioxidant and immunomodulatory effects, melanogenesis promotion, and apoptosis reduction. The review underscores the need for further investigation into the precise molecular mechanisms of these compounds in vitiligo treatment and the exploration of their combination with current therapies to augment therapeutic outcomes.

The study of honokiol as a natural product-based antimicrobial agent and its potential interaction with FtsZ protein

Multidrug resistant bacteria have been a global health threat currently and frontline clinical treatments for these infections are very limited. To develop potent antibacterial agents with new bactericidal mechanisms is thus needed urgently to address this critical antibiotic resistance challenge. Natural products are a treasure of small molecules with high bioactive and low toxicity. In the present study, we demonstrated that a natural compound, honokiol, showed potent antibacterial activity against a number of Gram-positive bacteria including MRSA and VRE. Moreover, honokiol in combination with clinically used β-lactam antibiotics exhibits strong synergistic antimicrobial effects against drug-resistant S. aureus strains. Biochemical studies further reveal that honokiol may disrupt the GTPase activity, FtsZ polymerization, cell division. These biological impacts induced by honokiol may ultimately cause bacterial cell death. The in vivo antibacterial activity of honokiol against S. aureus infection was also verified with a biological model of G. mellonella larvae. The in vivo results support that honokiol is low toxic against the larvae and effectively increases the survival rate of the larvae infected with S. aureus. These findings demonstrate the potential of honokiol for further structural advancement as a new class of antibacterial agents with high potency against multidrug-resistant bacteria.

Melatonin attenuates scopolamine-induced cognitive dysfunction through SIRT1/IRE1α/XBP1 pathway

BACKGROUND

The prevalence of dementia around the world is increasing, and these patients are more likely to have cognitive impairments, mood and anxiety disorders (depression, anxiety, and panic disorder), and attention deficit disorders over their lifetime. Previous studies have proven that melatonin could improve memory loss, but its specific mechanism is still confused.

METHODS

In this study, we used in vivo and in vitro models to examine the neuroprotective effect of melatonin on scopolamine (SCOP)-induced cognitive dysfunction. The behavioral tests were performed. 18F-FDG PET imaging was used to assess the metabolism of the brain. Protein expressions were determined through kit detection, Western blot, and immunofluorescence. Nissl staining was conducted to reflect neurodegeneration. MTT assay and RNAi transfection were applied to perform the in vitro experiments.

RESULTS

We found that melatonin could ameliorate SCOP-induced cognitive dysfunction and relieve anxious-like behaviors or HT22 cell damage. 18F-FDG PET-CT results showed that melatonin could improve cerebral glucose uptake in SCOP-treated mice. Melatonin restored the cholinergic function, increased the expressions of neurotrophic factors, and ameliorated oxidative stress in the brain of SCOP-treated mice. In addition, melatonin upregulated the expression of silent information regulator 1 (SIRT1), which further relieved endoplasmic reticulum (ER) stress by decreasing the expression of phosphorylate inositol-requiring enzyme (p-IRE1α) and its downstream, X-box binding protein 1 (XBP1).

CONCLUSIONS

These results indicated that melatonin could ameliorate SCOP-induced cognitive dysfunction through the SIRT1/IRE1α/XBP1 pathway. SIRT1 might be the critical target of melatonin in the treatment of dementia.

Gut microbial metabolites in MASLD: Implications of mitochondrial dysfunction in the pathogenesis and treatment

With an increasing prevalence, metabolic dysfunction-associated steatotic liver disease (MASLD) has become a major global health problem. MASLD is well-known as a multifactorial disease. Mitochondrial dysfunction and alterations in the gut bacteria are 2 vital events in MASLD. Recent studies have highlighted the cross-talk between microbiota and mitochondria, and mitochondria are recognized as pivotal targets of the gut microbiota to modulate the host's physiological state. Mitochondrial dysfunction plays a vital role in MASLD and is associated with multiple pathological changes, including hepatocyte steatosis, oxidative stress, inflammation, and fibrosis. Metabolites are crucial mediators of the gut microbiota that influence extraintestinal organs. Additionally, regulation of the composition of gut bacteria may serve as a promising therapeutic strategy for MASLD. This study reviewed the potential roles of several common metabolites in MASLD, emphasizing their impact on mitochondrial function. Finally, we discuss the current treatments for MASLD, including probiotics, prebiotics, antibiotics, and fecal microbiota transplantation. These methods concentrate on restoring the gut microbiota to promote host health.

Research progress on the role of mitochondria in the process of hepatic ischemia-reperfusion injury

During liver ischemia-reperfusion injury, existing mechanisms involved oxidative stress, calcium overload, and the activation of inflammatory responses involve mitochondrial injury. Mitochondrial autophagy, a process that maintains the normal physiological activity of mitochondria, promotes cellular metabolism, improves cellular function, and facilitates organelle renewal. Mitochondrial autophagy is involved in oxidative stress and apoptosis, of which the PINK1-Parkin pathway is a major regulatory pathway, and the deletion of PINK1 and Parkin increases mitochondrial damage, reactive oxygen species production, and inflammatory response, playing an important role in mitochondrial quality regulation. In addition, proper mitochondrial permeability translational cycle regulation can help maintain mitochondrial stability and mitigate hepatocyte death during ischemia-reperfusion injury. This mechanism is also closely related to oxidative stress, calcium overload, and the aforementioned autophagy pathway, all of which leads to the augmentation of the mitochondrial membrane permeability transition pore opening and cause apoptosis. Moreover, the release of mitochondrial DNA (mtDNA) due to oxidative stress further aggravates mitochondrial function impairment. Mitochondrial fission and fusion are non-negligible processes required to maintain the dynamic renewal of mitochondria and are essential to the dynamic stability of these organelles. The Bcl-2 protein family also plays an important regulatory role in the mitochondrial apoptosis signaling pathway. A series of complex mechanisms work together to cause hepatic ischemia-reperfusion injury (HIRI). This article reviews the role of mitochondria in HIRI, hoping to provide new therapeutic clues for alleviating HIRI in clinical practice.

Advances in SIRT3 involvement in regulating autophagy-related mechanisms

The silencing regulatory factor 2-like protein 3 (SIRT3) is a nicotinamide adenine dinucleotide (NAD+) dependent deacetylase located primarily in the mitochondria. This protein plays an important role in oxidative stress, energy metabolism, and autophagy in multicellular organisms. Autophagy (macroautophagy) is primarily a cytoprotective mechanism necessary for intracellular homeostasis and the synthesis, degradation, and recycling of cellular products. Autophagy can influence the progression of several neural, cardiac, hepatic, and renal diseases and can also contribute to the development of fibrosis, diabetes, and many types of cancer. Recent studies have shown that SIRT3 has an important role in regulating autophagy. Therefore in this study, we aimed to perform a literature review to summarize the role of SIRT3 in the regulation of cellular autophagy. The findings of this study could be used to identify new drug targets for SIRT3-related diseases. Methods: A comprehensive literature review of the mechanism involved behind SIRT3 and autophagy-related diseases was performed. Relevant literature published in Pubmed and Web of Science up to July 2023 was identified using the keywords "silencing regulatory factor 2-like protein 3", "SIRT3" and "autophagy".

Mechanisms Underlying Memory Impairment Induced by Fructose

Fructose consumption has increased over the years, especially in adolescents living in urban areas. Growing evidence indicates that daily fructose consumption leads to some pathological conditions, including memory impairment. This review summarizes relevant data describing cognitive deficits after fructose intake and analyzes the underlying neurobiological mechanisms. Preclinical experiments show sex-related deficits in spatial memory; that is, while males exhibit significant imbalances in spatial processing, females seem unaffected by dietary supplementation with fructose. Recognition memory has also been evaluated; however, only female rodents show a significant decline in the novel object recognition test performance. According to mechanistic evidence, fructose intake induces neuroinflammation, mitochondrial dysfunction, and oxidative stress in the short term. Subsequently, these mechanisms can trigger other long-term effects, such as inhibition of neurogenesis, downregulation of trophic factors and receptors, weakening of synaptic plasticity, and long-term potentiation decay. Integrating all these neurobiological mechanisms will help us understand the cellular and molecular processes that trigger the memory impairment induced by fructose.

Recent advances of honokiol：pharmacological activities, manmade derivatives and structure-activity relationship

Honokiol (HNK) is a typical natural biphenyl polyphenol compound. It has been proven to have a wide range of biological activities, including pharmacological effects such as anti-cancer, anti-inflammatory, neuroprotective, and antimicrobial. However, due to the poor stability, water solubility, and bioavailability of HNK, HNK has not been used in clinical treatment. This article reviews the latest research on the pharmacological activity of HNK and summarizes the HNK derivatives designed and improved by several researchers. Reviewing these contents could promote the research process of HNK and guide the design of better HNK derivatives for clinical application in the future.

GPX4 degradation contributes to fluoride-induced neuronal ferroptosis and cognitive impairment via mtROS-chaperone-mediated autophagy

Ferroptosis is a newly recognized type of programmed cell death that is implicated in the pathophysiological process of neurological disorders. Our previous studies have revealed that exposure to high concentrations of fluoride for long periods of time induces hippocampal neural injury and cognitive deficits. However, whether ferroptosis is involved in fluoride-induced neuronal death and the underlying mechanism remain unknown. In this study, the results indicated that exposure to high fluoride triggered ferroptosis in SH-SY5Y cells and in the hippocampus of mice. Fluoride exposure accelerated the lysosomal degradation of GPX4 and led to neuronal ferroptosis, while GPX4 overexpression protected SH-SY5Y cells against fluoride-induced neurotoxicity. Intriguingly, the enhanced chaperone-mediated autophagy (CMA) induced by fluoride stimulation was responsible for GPX4 degradation because the inhibition of CMA activity by LAMP2A knockdown effectively prevented fluoride-induced GPX4 loss. Furthermore, mitochondrial ROS (mtROS) accumulation caused by fluoride contributed to CMA activation-mediated GPX4 degradation and subsequent neuronal ferroptosis. Notably, the ferroptosis-specific inhibitor ferrostatin-1 (Fer-1) or the ROS scavenger N-acetyl-L-cysteine (NAC) alleviated fluoride-evoked hippocampal neuronal death and synaptic injury as well as cognitive deficits in mice. The present studies indicates that ferroptosis is a novel mechanism of fluoride-induced neurotoxicity and that chronic fluoride exposure facilitates GPX4 degradation via mtROS chaperone-mediated autophagy, leading to neuronal ferroptosis and cognitive impairment.

New insight into molecular mechanisms of different polyphenols affecting Sirtuin 3 deacetylation activity

Multiple phenolic substances have been shown to promote SIRT3 expression, however, few studies have focused on the effects of these phenolics on SIRT3 enzyme activity. This study constructed a variety of reaction systems to elucidate the mechanisms by which different polyphenols affect SIRT3 enzyme activity. The results showed that acP53317-320 was the most suitable substrate among the five acetylated peptide substrates (Kcat/Km = 74.85 ± 1.86 M-1•s-1). All the phenolic compounds involved in the experiment inhibited the enzymatic activity of SIRT3, and the lowest IC50 among them was quercetin (0.12 ± 0.01 mM) and the highest was piceatannol (1.29 ± 0.08 mM). Their inhibition types were mainly competitive and mixed. In addition, piceatannol was found to be a natural SIRT3 agonist by enzyme kinetic analysis and validation of deacetylation efficiency. This study will provide a useful reference for polyphenol modulation of SIRT3 dosage, as well as the development and application of polyphenol-based SIRT3 activators and agonists.

Gastrodin alleviates mitochondrial dysfunction by regulating SIRT3-mediated TFAM acetylation in vascular dementia

BACKGROUND

Mitochondrial dysfunction is key to the pathogenesis of vascular dementia (VaD). Sirtuin-3 (SIRT3), an essential member of the sirtuins family, has been proven to be a critical sirtuin in regulating mitochondrial function. The phenolic glucoside gastrodin (GAS), a bioactive ingredient from Gastrodiae Rhizome (known in Chinese as Tian ma) demonstrates significant neuroprotective properties against central nervous system disorders; however, the precise mechanisms through which GAS modulates VaD remain elusive.

PURPOSE

This study aims to investigate whether GAS confers a protective role against VaD, and to figure out the underlying molecular mechanisms.

METHODS

A bilateral common carotid artery occlusion (BCCAO)-mediated chronic cerebral hypoperfusion (CCH) VaD rat model and a hypoxia model using HT22 cells were employed to investigate pharmacological properties of GAS in mitigating mitochondrial dysfunction. A SIRT3 agonist resveratrol (RES), a SIRT3 inhibitor 3-TYP and SIRT3-knockdown in vitro were used to explore the mechanism of GAS in association with SIRT3. The ability of SIRT3 to bind and deacetylate mitochondrial transcription factor A (TFAM) was detected by immunoprecipitation assay, and TFAM acetylation sites were further validated using mass spectrometry.

RESULTS

GAS increased SIRT3 expression and ameliorated mitochondrial structure, mitochondrial respiration, mitochondrial dynamics along with upregulated TFAM, mitigating oxidative stress and senescence. Comparable results were noted with the SIRT3 agonist RES, indicating an impactful neuroprotection played by SIRT3. Specifically, the attenuation of SIRT3 expression through knockdown techniques or exposure to the SIRT3 inhibitor 3-TYP in HT22 cells markedly abrogated GAS-mediated mitochondrial rescuing function. Furthermore, our findings elucidate a novel facet: SIRT3 interacted with and deacetylated TFAM at the K5, K7, and K8 sites. Decreased SIRT3 is accompanied by hyper-acetylated TFAM.

CONCLUSION

The present results were the first to demonstrate that the SIRT3/TFAM pathway is a protective target for reversing mitochondrial dysfunction in VaD. The findings suggest that GAS-mediated modulation of the SIRT3/TFAM pathway, a novel mechanism, could ameliorate CCH-induced VaD, offering a potentially beneficial therapeutic strategy for VaD.

Honokiol suppress the PD-L1 expression to improve anti-tumor immunity in lung cancer

Lung cancer is a serious health issue globally, and current treatments have proven to be inadequate. Therefore, immune checkpoint inhibitors (ICIs) that target the PD-1/PD-L1 pathway have become a viable treatment option in lun cancer. Honokiol, a lignan derived from Magnolia officinalis, has been found to possess anti-inflammatory, antioxidant, and antitumor properties. Our research found that honokiol can effectively regulate PD-L1 through network pharmacology and transcriptome analysis. Cell experiments showed that honokiol can significantly reduce PD-L1 expression in cells with high PD-L1 expression. Molecular docking, cellular thermal shift assay (CETSA) and Bio-Layer Interferometry (BLI)indicated that Honokiol can bind to PD-L1. Co-culture experiments on lung cancer cells and T cells demonstrated that honokiol mediates PD-L1 degradation, stimulates T cell activation, and facilitates T cell killing of tumor cells. Moreover, honokiol activates CD4 + and CD8 + T cell infiltration in vivo, thus suppressing tumor growth in C57BL/6 mice. In conclusion, this study has demonstrated that honokiol can inhibit the growth of lung cancer by targeting tumor cell PD-L1, suppressing PD-L1 expression, blocking the PD-1/PD-L1 pathway, and enhancing anti-tumor immunity.

Cadmium exposure induced neuronal ferroptosis and cognitive deficits via the mtROS-ferritinophagy pathway

Exposure to environmental cadmium (Cd) is known to cause neuronal death and cognitive decline in humans. Ferroptosis, a novel iron-dependent type of regulated cell death, is involved in various neurological disorders. In the present study, Cd exposure triggered ferroptosis in the mouse hippocampus and in the HT22 murine hippocampal neuronal cell line, as indicated by significant increases in ferroptotic marker expression, intracellular iron levels, and lipid peroxidation. Interestingly, ferroptosis of hippocampal neurons in response to Cd exposure relied on the induction of autophagy since the suppression of autophagy by 3-methyladenine (3-MA) and chloroquine (CQ) substantially ameliorated Cd-induced ferroptosis. Furthermore, nuclear receptor coactivator 4 (NCOA4)-mediated degradation of ferritin was required for the Cd-induced ferroptosis of hippocampal neurons, demonstrating that NCOA4 knockdown decreased intracellular iron levels and lipid peroxidation and increased cell survival, following Cd exposure. Moreover, Cd-induced mitochondrial reactive oxygen species (mtROS) generation was essential for the ferritinophagy-mediated ferroptosis of hippocampal neurons. Importantly, pretreatment with the ferroptosis inhibitor ferrostatin-1 (Fer-1) effectively attenuated Cd-induced hippocampal neuronal death and cognitive impairment in mice. Taken together, these findings indicate that ferroptosis is a novel mechanism underlying Cd-induced neurotoxicity and cognitive impairment and that the mtROS-ferritinophagy axis modulates Cd-induced neuronal ferroptosis.

Mangiferin alleviates diabetic pulmonary fibrosis in mice via inhibiting endothelial-mesenchymal transition through AMPK/FoxO3/SIRT3 axis

Diabetes mellitus results in numerous complications. Diabetic pulmonary fibrosis (DPF), a late pulmonary complication of diabetes, has not attracted as much attention as diabetic nephropathy and cardiomyopathy. Mangiferin (MF) is a natural small molecular compound that exhibits a variety of pharmacological effects including anti-inflammatory, anti-cancer, anti-diabetes, and anti-fibrosis effects. In this study, we investigated whether long-term diabetes shock induces DPF, and explored whether MF had a protective effect against DPF. We first examined the lung tissues and sections of 20 diabetic patients obtained from discarded lung surgical resection specimens and found that pulmonary fibrosis mainly accumulated around the pulmonary vessels, accompanied by significantly enhanced endothelial-mesenchymal transition (EndMT). We established a mouse model of DPF by STZ injections. Ten days after the final STZ injection, the mice were administered MF (20, 60 mg/kg, i.g.) every 3 days for 4 weeks, and kept feeding until 16 weeks and euthanized. We showed that pulmonary fibrotic lesions were developed in the diabetic mice, which began around the pulmonary vessels, while MF administration did not affect long-term blood glucose levels, but dose-dependently alleviated diabetes-induced pulmonary fibrosis. In human umbilical vein endothelial cells (HUVECs), exposure to high glucose (33.3 mM) induced EndMT, which was dose-dependently inhibited by treatment with MF (10, 50 μM). Furthermore, MF treatment promoted SIRT3 expression in high glucose-exposed HUVECs by directly binding to AMPK to enhance the activity of FoxO3, which finally reversed diabetes-induced EndMT. We conclude that MF attenuates DPF by inhibiting EndMT through the AMPK/FoxO3/SIRT3 axis. MF could be a potential candidate for the early prevention and treatment of DPF.

The role and therapeutic potential of SIRTs in sepsis

Sepsis is a life-threatening organ dysfunction caused by the host's dysfunctional response to infection. Abnormal activation of the immune system and disturbance of energy metabolism play a key role in the development of sepsis. In recent years, the Sirtuins (SIRTs) family has been found to play an important role in the pathogenesis of sepsis. SIRTs, as a class of histone deacetylases (HDACs), are widely involved in cellular inflammation regulation, energy metabolism and oxidative stress. The effects of SIRTs on immune cells are mainly reflected in the regulation of inflammatory pathways. This regulation helps balance the inflammatory response and may lessen cell damage and organ dysfunction in sepsis. In terms of energy metabolism, SIRTs can play a role in immunophenotypic transformation by regulating cell metabolism, improve mitochondrial function, increase energy production, and maintain cell energy balance. SIRTs also regulate the production of reactive oxygen species (ROS), protecting cells from oxidative stress damage by activating antioxidant defense pathways and maintaining a balance between oxidants and reducing agents. Current studies have shown that several potential drugs, such as Resveratrol and melatonin, can enhance the activity of SIRT. It can help to reduce inflammatory response, improve energy metabolism and reduce oxidative stress, showing potential clinical application prospects for the treatment of sepsis. This review focuses on the regulation of SIRT on inflammatory response, energy metabolism and oxidative stress of immune cells, as well as its important influence on multiple organ dysfunction in sepsis, and discusses and summarizes the effects of related drugs and compounds on reducing multiple organ damage in sepsis through the pathway involving SIRTs. SIRTs may become a new target for the treatment of sepsis and its resulting organ dysfunction, providing new ideas and possibilities for the treatment of this life-threatening disease.

Lentinan-loaded GelMA hydrogel accelerates diabetic wound healing through enhanced angiogenesis and immune microenvironment modulation

Diabetic wound healing is a substantial clinical challenge, characterized by delayed angiogenesis and unresolved inflammation. Lentinan, a polysaccharide extracted from shiitake mushrooms, has the potential to regulate both macrophage polarization and angiogenesis, though this aspect remains inadequately explored. To facilitate lentinan's clinical utility, we have developed a GelMA hydrogel encapsulated with lentinan (10 μM), offering a controlled release mechanism for sustained lentinan delivery at the wound site. Application of the lentinan-encapsulated delivery system topically significantly expedites wound closure compared to control groups. Furthermore, histological examination demonstrates enhanced neovascularization and reduced inflammation in lentinan-treated wounds, as evidenced by increased M2 macrophage infiltration. Moreover, our results indicated that lentinan-induced AMPK activation promotes DAF16 expression, enhancing the resistance of macrophages and HUVECs to oxidative stress in high-glucose environments, thereby promoting M2 macrophage polarization and angiogenesis. All these findings underscore lentinan's capacity to modulate macrophage polarization and angiogenesis via the AMPK/DAF16 pathway, ultimately facilitating the healing of diabetic wounds.

PGC-1α activation ameliorates cancer-induced bone pain via inhibiting apoptosis of GABAergic interneurons

Cancer-induced bone pain (CIBP) stands out as one of the most challenging issues in clinical practice due to its intricate and not fully elucidated pathophysiological mechanisms. Existing evidence has pointed toward the significance of peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) down-regulation in contributing to pain behaviors in various rodent models of neuropathic pain. In our current study, we aimed to investigate the role of PGC-1α in CIBP. Our results unveiled a reduction in PGC-1α expression within the spinal cord of CIBP rats, particularly in GABAergic interneurons. Notably, intrathecal administration of the PGC-1α activator ZLN005 suppressed the loss of spinal GABAergic interneurons. This suppression was achieved by inhibiting caspase-3-mediated apoptosis, ultimately leading to the alleviation of mechanical allodynia in CIBP rats. Further exploration into the mechanism revealed that PGC-1α activation played a pivotal role in mitigating ATP depletion and reactive oxygen species accumulation linked to mitochondrial dysfunction. This was achieved through the restoration of mitochondrial biogenesis and the activation of the SIRT3-SOD2 pathway. Impressively, the observed effects were prominently reversed upon the application of SR18292, a specific PGC-1α inhibitor. In conclusion, our findings strongly suggest that PGC-1α activation acts as a potent inhibitor of apoptosis in spinal GABAergic interneurons. This inhibition is mediated by the improvement of mitochondrial function, facilitated in part through the enhancement of mitochondrial biogenesis and the activation of the SIRT3-SOD2 pathway. The results of our study shed light on potential therapeutic avenues for addressing CIBP.

Inhibition of Sirt3 activates the cGAS-STING pathway to aggravate hepatocyte damage in hepatic ischemia-reperfusion injury mice

Hepatic ischemia-reperfusion injury (IRI) typically manifests during subtotal hepatectomy and inflicts substantial damage to liver function in the perioperative period. Although the central role of cGAS-STING-mediated immune inflammation in hepatocyte damage during hepatic IRI is acknowledged, the precise regulatory mechanisms remain elusive. The current study aims to elucidate how Sirt3 inhibition activates the cGAS-STING pathway and exacerbates hepatocyte damage in hepatic IRI. We established both in vivo and in vitro models by creating hepatic IRI mice model and subjecting AML-12 hepatocyte cell lines to oxygen-glucose deprivation/reperfusion (OGD/R). Hepatic IRI compromised liver and mitochondrial function while elevating cytosolic mitochondrial DNA (mtDNA) levels in hepatocytes. Additionally, both in vivo hepatic IRI and in vitro OGD/R induced increased phosphorylation and activation of cGAS, STING, and IRF3, accompanied by heightened levels of pro-inflammatory factors, including TNF-α, IL-1β, and type I interferon (IFN-β). Importantly, knockdown of cGAS or STING through siRNA effectively attenuated hepatic IRI-induced inflammation and ameliorated liver function in both experimental settings, underscoring the dynamic involvement of the cGAS-STING pathway in hepatic IRI-induced inflammation. Furthermore, we observed a significant reduction in Sirt3 expression following hepatic IRI, both in vivo and in vitro. Then we generated Sirt3-deficient mice and applied Sirt3 knockdown in AML-12 hepatocytes. Notably, Sirt3 deficiency led to increased phosphorylation and activation of cGAS, STING, and IRF3, coupled with elevated TNF-α, IL-1β, and IFN-β levels in both in vivo and in vitro conditions. Moreover, upon silencing various downstream targets of Sirt3, such as transcription factors Sp1, Pu1, and p65, we observed that specifically knocking down p65 in AML-12 hepatocytes reduced cGAS mRNA levels. Co-immunoprecipitation assays confirmed a direct interaction between Sirt3 and p65. The absence of Sirt3 significantly increased nuclear translocation of p65 in mice, whereas Sirt3 knockdown in AML-12 hepatocytes heightened nuclear translocation of p65. ChIP-PCR assays demonstrated that Sirt3 deficiency notably enhanced the binding of p65 to two cGAS promoters, ultimately promoting cGAS transcription. Collectively, our results underscored that inhibition of Sirt3 activates the cGAS-STING pathway to aggravate hepatocyte damage by increasing cytosolic mtDNA and promoting nuclear translocation of p65 to promote cGAS transcription in hepatic IRI. These findings hold promise for potential therapeutic interventions in hepatic IRI by targeting the Sirt3-cGAS-STING axis, offering new avenues for the development of clinical strategies to mitigate liver damage during the perioperative period.