Schisandrin B inhibits inflammation and ferroptosis in S.aureus-induced mastitis through regulating SIRT1/p53/SLC7A11 signaling pathway

Sirtuins as modulators of infection outcomes in the battle of host-pathogen dynamics

Sirtuins's central role in governing metabolic processes has been known for decades. However, over the past two decades, sirtuin functions have been linked to immune regulation and immunity. Sirtuins are NAD+ dependent protein deacylases involved in the regulation of several important biological processes ranging from energy homeostasis, metabolism, aging, apoptosis, autophagy, immunity, adipocyte, and muscle differentiation. Here, in this review, we discuss the role of sirtuins in several infectious diseases including viral, bacterial, and protozoan infections with detailed emphasis on bacterial-host interactions. We have aimed to explore both host and bacterial sirtuin functions contributing to the infection progression, host responses and their influence on the everlasting host-pathogen tug-of-war. In order to manipulate host pathways, pathogens such as intracellular bacteria have evolved parallelly and harbor bacterial sirtuins. The recent discoveries of bacterial sirtuins influencing the host-pathogen interaction outcomes pave the way for the discovery of potential therapeutic targets.

Schisandrin B ameliorates Alzheimer's disease by suppressing neuronal ferroptosis and ensuing microglia M1 polarization

BACKGROUND

Alzheimer's disease (AD) is a neurodegenerative disorder characterized by neuronal damage, with poor prognosis and limited therapeutic options. Inhibition of neuronal ferroptosis has shown promise as a potential treatment for AD. Schisandrin B (Sch B), a major active component of Schisandra chinensis, exhibits potential neuroprotective effects. However, whether Sch B inhibits neuronal ferroptosis remains unclear.

PURPOSE

To investigate the mechanisms underlying the effects of Sch B on the GSK3β/Nrf2/GPX4 and FSP1 signaling pathways, which are the suppression of neuronal ferroptosis and the potential therapeutic intervention in AD.

METHODS

We employed the 3 × Tg mouse model in vivo, and utilized the erastin-induced ferroptosis model in SH-SY5Y/APP695swe cells in vitro. Nissl staining was conducted to facilitate histopathological assessment. Assessment of neuronal ferroptosis was performed utilizing a lipid peroxidation and ferroptosis marker assay kit. Furthermore, bioinformatic analysis was executed with the application of the GEO database. Immunofluorescence and Western blot analyses were performed to quantify protein expression levels within the cellular context. ELISA was utilized to determine cytokine concentrations within the supernatant of cell cultures. RT-PCR was executed to evaluate mRNA expression levels.

RESULTS

Sch B suppresses the activation of GSK3β, modulating the Nrf2/GPX4 signaling pathway and consequently inhibiting ferroptosis in neurons, which results in amelioration of cognitive impairment and pathological damage in 3 × Tg mice. Sch B also inhibits GSK3β activation, thereby modulating the Nrf2/GPX4 signaling pathway to prevent erastin-induced ferroptosis in SH-SY5Y695swe cells in vitro. Furthermore, Sch B modulates FSP1, enhancing its synergistic interaction with the GSK3β/Nrf2/GPX4 pathway to suppress neuronal ferroptosis. Sch B can also inhibit TNF-α release from neurons undergoing ferroptosis, thus impeding the activation of M1-type microglia, suggesting a multifaceted neuroprotective strategy against neuroinflammatory processes.

CONCLUSION

Sch B modulates the GSK3β/Nrf2/GPX4 pathway in conjunction with FSP1 to inhibit neuronal ferroptosis and the subsequent microglial M1 polarization mediated by neuronal ferroptosis, thereby improving cognitive impairment and pathological damage in AD.

Curcumenol inhibits malignant progression and promotes ferroptosis via the SLC7A11/NF‑κB/TGF‑β pathway in triple‑negative breast cancer

Triple‑negative breast cancer (TNBC) exhibits a high degree of malignancy and a propensity for metastasis, ultimately resulting in unfavorable patient outcomes. Curcuma phaeocaulis Valeton is a common herb used in traditional Chinese medicine to treat TNBC. Curcumenol (Cur) is a natural compound derived from C. phaeocaulis Valeton, the effects of which on breast cancer remain under‑reported. The present study elucidated that Cur could effectively inhibit the survival ability of TNBC cells and enhance their sensitivity to paclitaxel. Western blotting (WB) further revealed that Cur modulated apoptosis and epithelial‑mesenchymal transition (EMT) in TNBC. Findings from animal experiments further validated these observations. In the established TNBC mouse model, Cur was shown to exert an inhibitory effect on tumor growth, effectively attenuate EMT and substantially reduce the incidence of lung metastasis. Integrated analyses using RNA sequencing, WB and reverse transcription‑quantitative polymerase chain reaction demonstrated that Cur markedly downregulated the expression levels of solute carrier family 7 member 11 (SLC7A11), phosphorylated‑NF‑κB and TGF‑β. Molecular docking studies further validated that Cur can establish stable interactions with SLC7A11. In‑depth bioinformatics analysis revealed a positive association between high SLC7A11 expression and reduced disease‑free survival in patients with breast cancer. Additionally, in TNBC cells, Cur was revealed to reduce the mitochondrial membrane potential and promote the accumulation of lipid reactive oxygen species. Subsequent experimental investigations demonstrated that Cur can counteract the inhibitory influence of ferrostatin‑1 on ferroptosis. These findings strongly implied a potential underlying mechanism, suggesting that Cur may impede the malignant progression of TNBC via the modulation of ferroptosis. In conclusion, the findings of the present study underscore the marked efficacy of Cur in hampering the progression of TNBC by suppressing the SLC7A11/NF‑κB/TGF‑β signaling pathway.

Schisandra total lignans ameliorate neuronal ferroptosis in 3xTg-AD mice via regulating NADK/NADPH/GSH pathway

BACKGROUND

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with limited treatments. Schisandra total lignans (STL), the primary active component of Schisandra chinensis, shows potential in alleviating AD-related symptoms, though the mechanisms remain unclear.

PURPOSE

Considering the promoting effect of neuronal ferroptosis on AD and the neuroprotective activity of STL, this study aimed to investigate the impact of STL on AD neuronal ferroptosis and elucidate its underlying mechanisms.

METHODS

This study used 3xTg-AD mice and SH-SY5Y cells overexpressing APPswe as models. UHPLC/Q-TOF-MS was applied for identifying components in STL extract and the plasma of 3xTg-AD mice, as well as to detect cellular endogenous metabolites for one-carbon metabolism analysis. Behavioral tests, including the Y maze, novel object recognition, Morris water maze, and open field, were conducted to assess the cognitive function and emotional state. Histopathological examinations were performed using immunofluorescence, immunohistochemistry, Nissl staining, and transmission electron microscopy. The GSH, GSSG, NAD(H), NADP(H), and MDA levels, as well as GPX and GR activity were measured using assay kits. ROS, Fe2+, and lipid peroxidation levels were detected with probes. Protein expression was evaluated by Western blot. Molecular docking, molecular dynamics simulations and cellular thermal shift assay were performed to analyze the STL-NADK interactions.

RESULTS

Behavioral tests indicated that STL alleviated cognitive impairments and anxiety in 3xTg-AD mice. Histological analysis showed that STL decreased hippocampal Aβ levels, inhibited hippocampal neuronal ferroptosis, and mitigated synaptic damage. Cellular assays demonstrated that STL alleviated APPswe overexpression-induced ferroptosis and synaptic damage by activating the NADK/NADPH/GSH pathway, with NADK knockdown abolishing this neuroprotective effect of STL. Computational analysis and cellular thermal shift assay identified Gomisin D as the key STL component with strong affinity for NADK, driving its neuroprotective effects.

CONCLUSION

NADK emerges as a novel potential therapeutic target for AD, with STL activating NADK, promoting NADPH and GSH production, thereby mitigating neuronal ferroptosis in AD.

Tectorigenin mitigates homocysteine-induced inflammation and ferroptosis in BV-2 microglial cells through promoting the SIRT1/SLC7A11 pathway

Ferroptosis and inflammation are central to the pathophysiology of hyperhomocysteinemia (HHcy)-associated neurological disorders. Tectorigenin, a natural flavonoid aglycone extracted from numerous plants, possesses antioxidant, anti-inflammatory, and neuroprotective properties. This study aimed to investigate whether tectorigenin mitigates elevated homocysteine (Hcy)-induced toxicity in BV-2 microglial cells, focusing on its effects on inflammation and ferroptosis. Cell viability, lactate dehydrogenase (LDH) release, and proliferation assays were employed to evaluate cell injury. Inflammatory cytokines levels were determined by ELISA. Ferroptosis markers, including reactive oxygen species (ROS), lipid ROS, malondialdehyde (MDA), 4-hydroxy-nonenal (4-HNE), mitochondrial membrane potential (MMP), ATP, Fe2 + content, antioxidant enzymes (superoxide dismutase [SOD] and catalase [CAT]) activities were evaluated. mRNA and protein expressions were analyzed by qRT-PCR and western blotting, respectively. Our findings revealed that tectorigenin pretreatment significantly alleviated Hcy-induced cell injury and inflammatory response in BV-2 microglial cells. Furthermore, tectorigenin pretreatment reduced lipid peroxidation, enhanced antioxidant capacity, and alleviated ferroptotic cell death in Hcy-treated cells. Importantly, ferroptosis inhibitor Fer-1 also alleviated Hcy-induced cell injury and inflammation. Mechanistically, tectorigenin pretreatment activated the SIRT1/SLC7A11 pathway, and silencing SIRT1 reversed its protective effects. Collectively, these results indicate that tectorigenin attenuates Hcy-induced microglial injury by inhibiting inflammation and ferroptosis through the activation of the SIRT1/SLC7A11 pathway.

Protocatechualdehyde improves cyclophosphamide-induced premature ovarian insufficiency by inhibiting granulosa cell apoptosis and senescence through the SIRT1/p53 axis

Premature ovarian insufficiency (POI) is a prevalent gynecological disorder. Cyclophosphamide (CP), as a chemotherapeutic drug, particularly plays an important role in inducing POI. Protocatechualdehyde (PCA) is a major phenolic acid in Chinese herb Danshen, and has been reported to have beneficial effects on anti-inflammatory, anti-apoptotic, and anti-oxidant functions. We aimed to investigate the effect of different doses of PCA on ovarian function and the underlying molecular mechanisms. PCA administration reduced estrous cycle disorders, increased ovarian weight, promoted the secretion of serum hormone levels, and improved the CP-damaged ovarian microenvironment. Importantly, the administration of PCA contributed to the recovery of ovarian function with POI by inhibiting the senescence and apoptosis of granulosa cells. In vitro assay further confirmed the protective effect of PCA on CP-induced senescence and apoptosis of granulosa cells. Mechanistically, both in vivo and in vitro experiments proved that PCA administration promoted activation of the Sirt1/p53 signaling cascade, ultimately improving ovarian function. In conclusion, PCA might protect against ovarian damage in CP-induced POI that might be related to its activity on senescence and apoptosis of granulosa cells by the Sirt1/p53 pathway.

Potential role of SIRT1 in cell ferroptosis

Ferroptosis is a novel form of cell death that uniquely requires iron and is characterized by iron accumulation, the generation of free radicals leading to oxidative stress, and the formation of lipid peroxides, which distinguish it from other forms of cell death. The regulation of ferroptosis is extremely complex and is closely associated with a spectrum of diseases. Sirtuin 1 (SIRT1), a NAD + -dependent histone deacetylase, has emerged as a pivotal epigenetic regulator with the potential to regulate ferroptosis through a wide array of genes intricately associated with lipid metabolism, iron homeostasis, glutathione biosynthesis, and redox homeostasis. This review provides a comprehensive overview of the specific mechanisms by which SIRT1 regulates ferroptosis and explores its potential therapeutic value in the context of multiple disease pathologies, highlighting the significance of SIRT1-mediated ferroptosis in treatment strategies.

Stigmasterol from Prunella vulgaris L. Alleviates LPS-induced mammary gland injury by inhibiting inflammation and ferroptosis

BACKGROUND

Dairy mastitis, a prevalent condition affecting dairy cattle, represents a significant challenge to both animal welfare and the quality of dairy products. However, current treatment options remain limited. Stigmasterol (ST) is a bioactive component of Prunella vulgaris L. (PV) with various pharmacological functions such as anti-inflammatory and anti-oxidation. At present, the specific effects and underlying mechanisms of PV and ST on dairy mastitis are still not fully understood.

PURPOSE

The aim of this research was to evaluate the pharmacological effects of PV and its active component ST on lipopolysaccharide (LPS) -stimulated bovine mammary epithelial cells (BMECs) and a mouse mastitis model, and to elucidate the possible mechanisms of action.

METHODS

UPLC-Q-TOF-MS/MS was employed to identify the constituents of PV. BMECs and mice were used to establish in vitro and in vivo models of mastitis. Western Blotting, RT-qPCR, immunofluorescence and other techniques were used to explore the effects of PV and ST on inflammatory factors, blood-milk barrier integrity, ferroptosis related indicators and their potential molecular mechanisms.

RESULTS

PV significantly attenuated the production of inflammatory mediators by LPS-stimulated BMECs. Subsequently, ST was found to be a potent anti-inflammatory agent in PV by inhibiting TLR4/NF-κB signaling pathway. This inhibition inhibits the myosin light chain (MLC)/MLC kinase signaling cascade and alleviates blood-milk barrier (BMB) disruption in BMECs. In addition, ferroptosis occurred in BMECs after LPS stimulation, and ST inhibited ferroptosis by stimulating Nrf2/GPX4 signaling pathway. Treatment of BMECs with the Nrf2 inhibitor ML385 significantly attenuated the therapeutic effect of ST. In vivo experiments further confirmed that both PV and ST attenuated LPS-induced breast tissue damage while reducing ferroptosis levels and restoring BMB.

CONCLUSION

ST from PV exhibits substantial anti-inflammatory properties and is a promising candidate for the treatment of dairy mastitis.

Modulatory Effects of Regulated Cell Death: An Innovative Preventive Approach for the Control of Mastitis

Mastitis is a common disease worldwide that affects the development of the dairy industry due to its high incidence and complex etiology. Precise regulation of cell death and survival plays a critical role in maintaining internal homeostasis, organ development, and immune function in organisms, and regulatory abnormalities are a common mechanism of various pathological changes. Recent research has shown that regulated cell death (RCD) plays a crucial role in mastitis. The development of drugs to treat cell death and survival abnormalities that can be widely used in mastitis treatment has important clinical significance. This paper will review the molecular mechanisms of apoptosis, autophagy, pyroptosis, ferroptosis, and necroptosis and their regulatory roles in mastitis to provide a new perspective for the targeted treatment of mastitis.

Cerebroprotein hydrolysate-I ameliorates cognitive dysfunction in APP/PS1 mice by inhibiting ferroptosis via the p53/SAT1/ALOX15 signalling pathway

Ferroptosis, an iron-dependent lipid peroxidation-driven cell death pathway, has been linked to the development of Alzheimer's disease (AD). However, the role of ferroptosis in the pathogenesis of AD remains unclear. Cerebroprotein hydrolysate-I (CH-I) is a mixture of peptides with neurotrophic effects that improves cognitive deficits and reduces amyloid burden. The present study investigated the ferroptosis-induced signalling pathways and the neuroprotective effects of CH-I in the brains of AD transgenic mice. Seven-month-old male APPswe/PS1dE9 (APP/PS1) transgenic mice were treated with intraperitoneal injections of CH-I and saline for 28 days. The Morris water maze test was used to assess cognitive function. CH-I significantly improved cognitive deficits and attenuated beta-amyloid (Aβ) aggregation and tau phosphorylation in the hippocampus of APP/PS1 mice. RNA sequencing revealed that multiple genes and pathways, including ferroptosis-related pathways, were involved in the neuroprotective effects of CH-I. The increased levels of lipid peroxidation, ferrous ions, reactive oxygen species (ROS), and altered expression of ferroptosis-related genes (recombinant solute carrier family 7, member 11 (SLC7A11), spermidine/spermine N1-acetyltransferase 1 (SAT1) and glutathione peroxidase 4 (GPX4)) were significantly alleviated after CH-I treatment. Quantitative real-time PCR and western blotting were performed to investigate the expression of key ferroptosis-related genes and the p53/SAT1/arachidonic acid 15-lipoxygenase (ALOX15) signalling pathway. The p53/SAT1/ALOX15 signalling pathway was found to be involved in mediating ferroptosis, and the activation of this pathway was significantly suppressed in AD by CH-I. CH-I demonstrated neuroprotective effects against AD by attenuating ferroptosis and the p53/SAT1/ALOX15 signalling pathway, thus providing new targets for AD treatment.