ROS-activated MAPK/ERK pathway regulates crosstalk between Nrf2 and Hif-1α to promote IL-17D expression protecting the intestinal epithelial barrier under hyperoxia

Neferine attenuates hypertensive cardiomyocyte apoptosis and modulates key signaling pathways: An in vivo and in vitro study

BACKGROUND

Although neferine exhibits obvious therapeutic effects against hypertension, its effects on cardiac protection remain unknown.

PURPOSE

This study aimed to investigate its potential cardioprotective effects and associated mechanisms.

METHODS

Spontaneously hypertensive rats (SHRs) were randomly divided into four groups, namely SHR, SHR + Neferine-L (2.5 mg/kg/day), SHR + Neferine-M (5 mg/kg/day), and SHR + Neferine-H (10 mg/kg/day). Wistar Kyoto rats were used as control. Various concentrations of neferine or double distilled water were then administered intragastrically for 10 weeks. Thereafter, cardiac function, pathological changes, cell apoptosis, and reactive oxygen species (ROS) accumulation, as well as their underlying mechanisms, were evaluated in SHRs and/or hypoxia-induced H9c2 cells.

RESULT

Neferine treatment significantly mitigated the decrease in left ventricular ejection fraction and fractional shortening and increase in left ventricular mass, end-systolic volume, and cardiac injury in SHRs. In SHR cardiac tissues, neferine treatment reversed 154 upregulated and 108 and downregulated transcripts. Pathway enrichment analysis found that multiple pathways were commonly enriched, including the apoptosis, PI3K-Akt, MAPK, and HIF-1 pathways. Consistently, neferine treatment significantly mitigated cardiomyocyte apoptosis, restored mitochondrial membrane depolarization, and reduced ROS accumulation. Mechanistically, neferine treatment significantly decreased the phosphorylation of ERK, p38 MAPK, and JNK; the Bax/Bcl-2 ratio; and the expression of HIF-1α, NADPH oxidase 4, and cleaved caspases-3 and -9 but increased the phosphorylation of PI3K and Akt and the expression of CD31.

CONCLUSION

Neferine treatment effectively mitigated hypertensive cardiomyocyte apoptosis and attenuated the abnormal activation of multiple signaling pathways, including the PI3K/Akt, MAPK, and HIF-1 pathways.

Deciphering the role of IL-17D, its newly identified receptor CD93, and IL-17D-CD93 axis in health and disease

This review explores interleukin (IL)-17D and its receptor CD93, highlighting their structural, functional, and clinical aspects. Identifying CD93 as the receptor for IL-17D has advanced understanding of the IL-17 family and its signaling pathways. IL-17D, with its unique glycoprotein structure, plays diverse roles in oxidative stress response and potential antitumor therapies. It is involved in autoimmune diseases, infections, and cancers, making it a promising therapeutic target. CD93 is crucial in various biological processes, from angiogenesis to inflammatory diseases. CD93's implications in cancers, neuroinflammation, and metabolism highlight its significance as a potential prognostic marker and therapeutic target. The review emphasizes IL-17D and CD93 as promising areas for future research, offering insights into their signaling pathways and potential applications in personalized medicine. Deciphering the relationship between IL-17D and CD93 is in its infancy and invites exploration for transformative advancements in immunology and beyond.

Understanding chronic inflammation: couplings between cytokines, ROS, NO, Cai 2+, HIF-1α, Nrf2 and autophagy

Chronic inflammation is an important component of many diseases, including autoimmune diseases, intracellular infections, dysbiosis and degenerative diseases. An important element of this state is the mainly positive feedback between inflammatory cytokines, reactive oxygen species (ROS), nitric oxide (NO), increased intracellular calcium, hypoxia-inducible factor 1-alpha (HIF-1α) stabilisation and mitochondrial oxidative stress, which, under normal conditions, enhance the response against pathogens. Autophagy and the nuclear factor erythroid 2-related factor 2 (Nrf2)-mediated antioxidant response are mainly negatively coupled with the above-mentioned elements to maintain the defence response at a level appropriate to the severity of the infection. The current review is the first attempt to build a multidimensional model of cellular self-regulation of chronic inflammation. It describes the feedbacks involved in the inflammatory response and explains the possible pathways by which inflammation becomes chronic. The multiplicity of positive feedbacks suggests that symptomatic treatment of chronic inflammation should focus on inhibiting multiple positive feedbacks to effectively suppress all dysregulated elements including inflammation, oxidative stress, calcium stress, mito-stress and other metabolic disturbances.

Giardia duodenalis triggered neutrophil extracellular traps in goats

Giardia duodenalis is a globally distributed zoonotic parasite primarily transmitted through the fecal-oral route, infecting various vertebrates, and the infection of which is prevalent in goats. Immune cells play a crucial role in pathogens invasion, and neutrophil extracellular traps (NETs) released by neutrophils serve as a non-specific defense mechanism against pathogens including parasites. In this study, we investigated the characteristics, components, and molecular mechanisms of goat NETs upon stimulation with G. duodenalis trophozoites. This study demonstrates that G. duodenalis trigger dose-dependent NETs formation in goat neutrophils, composed of DNA, citrullinated histone H3 (CitH3), and neutrophil elastase (NE). Reactive oxygen species (ROS) accumulation synchronizes with NETosis during G. duodenalis infection. Inhibitor experiments confirmed that G. duodenalis-induced NETs and ROS production depend on TLR2/4 signaling and require NADPH oxidase (NOX), ERK1/2, and p38 MAPK activation. This work identifies TLR2/4, NOX, ERK1/2, and p38 MAPK pathways as key regulators of NETs/ROS coordination during G. duodenalis infection, providing the first evidence of G. duodenalis-triggered NETs in goats. The findings highlight NETs as critical components of anti-G. duodenalis immunity and suggest potential for NETs-targeted therapeutic strategies.

Cucurbitacin IIb mitigates concanavalin A-induced acute liver injury by suppressing M1 macrophage polarization

Cucurbitacins are a class of triterpenoid compounds extracted from plants and possess various pharmacological applications. Cucurbitacin IIb (CuIIb), extracted from the medicinal plant Hemsleya amabilis (Cucurbitaceae), has served as a traditional Chinese medicine for the treatment of bacterial dysentery and intestinal inflammation. CuIIb has been shown to exhibit anti-inflammatory activity; however, the protective effect of CuIIb against concanavalin A (Con A)-induced acute liver injury (ALI) and the fundamental mechanism remain unelucidated. In this study, we established an acute liver injury mouse model using Con A to investigate the effects of CuIIb on ALI. The results revealed that CuIIb significantly reduced serum aminotransferase levels and increased the survival rate of mice. Additionally, CuIIb effectively attenuated hepatocyte apoptosis, hepatic histopathological damage, and oxidative stress. Notably, CuIIb inhibited the polarization of M1 macrophages in vivo and in vitro. Moreover, the expression levels of pro-inflammatory cytokines related to M1 macrophages, such as interleukin (IL)-12, IL-1β, IL-6 and tumor necrosis factor-α (TNF-α), were reduced. CuIIb regulated M1 macrophage activation by modulating the nuclear factor (NF)-κB and mitogen-activated protein kinase (MAPK) signaling pathways. Conclusively, these results demonstrated that CuIIb significantly prevented Con A-induced ALI by suppressing M1 macrophage polarization via the MAPK and NF-κB signaling pathways, demonstrating the potential use of CuIIb for ALI treatment.

SPRY4 regulates ERK1/2 phosphorylation to affect oxidative stress and steroidogenesis in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a prevalent endocrine disorder in women of childbearing age. The role of Sprouty RTK Signaling Antagonist 4 (SPRY4) in ovarian function in PCOS was investigated herein, focusing on its regulation of ERK1/2 phosphorylation. PCOS models were established in mice using dehydroepiandrosterone (DHEA). The expression levels of SPRY4 in ovarian tissues were analyzed through RT-qPCR and immunohistochemistry. SPRY4 knockdown was achieved via lentivirus, and its effects on endocrine function, ovarian morphology, oxidative stress, and ERK1/2 phosphorylation were evaluated. Afterwards, granulosa cells were isolated and treated with DHEA and ERK2 agonist tert-Butylhydroquinone. The impacts of ERK2 activation on the regulation of SPRY4 knockdown were assessed using ELISA, fluorescent probes, western blotting, and biochemical assays. SPRY4 knockdown normalized the estrous cycle, reduced serum levels of testosterone, anti-Müllerian hormone, and luteinizing hormone/follicle-stimulating hormone ratio, and improved ovarian morphology. Additionally, SPRY4 knockdown alleviated oxidative stress by decreasing reactive oxygen species and malondialdehyde levels while increasing superoxide dismutase activity. It also restored steroidogenic enzyme expression, which were disrupted by DHEA induction. In vitro, SPRY4 knockdown enhanced granulosa cell viability and reduced ERK1/2 phosphorylation, with tert-Butylhydroquinone reversing these effects and restoring oxidative stress and steroidogenesis disruptions. Together, SPRY4 modulates ERK1/2 phosphorylation to influence oxidative stress and steroidogenesis in PCOS. Targeting SPRY4 may provide novel therapeutic avenues for improving ovarian function and managing PCOS.

Protective Effects of Beta-3 Adrenoceptor Agonism on Mucosal Integrity in Hyperoxia-Induced Ileal Alterations

Organogenesis occurs in the uterus under low oxygen levels (4%). Preterm birth exposes immature newborns to a hyperoxic environment, which can induce a massive production of reactive oxygen species and potentially affect organ development, leading to diseases such as necrotizing enterocolitis. The β3-adrenoreceptor (β3-AR) has an oxygen-dependent regulatory mechanism, and its activation exerts an antioxidant effect. To test the hypothesis that β3-AR could protect postnatal ileal development from the negative impact of high oxygen levels, Sprague-Dawley rat pups were raised under normoxia (21%) or hyperoxia (85%) for the first 2 weeks after birth and treated or not with BRL37344, a selective β3-AR agonist, at 1, 3, or 6 mg/kg. Hyperoxia alters ileal mucosal morphology, leading to increased cell lipid oxidation byproducts, reduced presence of β3-AR-positive resident cells, decreased junctional protein expression, disrupted brush border, mucin over-production, and impaired vascularization. Treatment with 3 mg/kg of BRL37344 prevented these alterations, although not completely, while the lower 1 mg/kg dose was ineffective, and the higher 6 mg/kg dose was toxic. Our findings indicate the potential of β3-AR agonism as a new therapeutic approach to counteract the hyperoxia-induced ileal alterations and, more generally, the disorders of prematurity related to supra-physiologic oxygen exposure.

Unveiling the role of IL-17: Therapeutic insights and cardiovascular implications

Interleukin-17 (IL-17), a pivotal cytokine in immune regulation, has attracted significant attention in recent years due to its roles in various physiological and pathological processes. This review explores IL-17 in immunological context, emphasizing its structure, production, and signaling pathways. Specifically, we explore its involvement in inflammatory diseases and autoimmune diseases, with a notable focus on its emerging implications in cardiovascular system. Through an array of research insights, IL-17 displays multifaceted functions yet awaiting comprehensive discovery. Highlighting therapeutic avenues, we scrutinize the efficacy and clinical application of four marketed IL-17 mAbs along other targeted therapies, emphasizing their potential in immune-mediated disease management. Additionally, we discussed the novel IL-17D-CD93 axis, elucidating recent breakthroughs in their biological function and clinical implications, inviting prospects for transformative advancements in immunology and beyond.

Beneficial effect of heat-killed Lactiplantibacillus plantarum L-137 on intestinal barrier function of rat small intestinal epithelial cells

Heat-killed Lactiplantibacillus plantarum L-137 (HK L-137) has been suggested to enhance the intestinal barrier in obese mice, leading to improvement of metabolic abnormalities and adipose tissue inflammation, and in healthy humans with overweight, leading to improvement of systemic inflammation. However, its detailed mechanism of action has not been clarified. Therefore, this study investigated the effects of HK L-137 on the permeability of rat small intestinal epithelial IEC-6 cells, tight junction-related gene and protein expression and localization, and intracellular signaling pathways involved in barrier function. Treatment of IEC-6 cells with HK L-137 for 26 h significantly reduced the permeability to fluorescein isothiocyanate-dextran (FD-4). HK L-137 also increased gene and protein expression of zonula occludens-1 (ZO-1), an important tight junction protein, without affecting the localization. Furthermore, inhibition of the extracellular signal-regulated kinase (ERK)1/2 pathway in IEC-6 cells canceled the HK L-137-related reduction in permeability to FD-4. Phosphorylation of ERK in IEC-6 cells was induced 15 min after the addition of HK L-137. These results suggest that HK L-137 reduces intestinal permeability partly through activating the ERK pathway and increasing expression of the ZO-1 gene and protein. Enhancement of intestinal barrier function with HK L-137 might be effective in preventing and treating leaky gut, for which no specific therapeutic tool has been established.

Short-chain fatty acids in nonalcoholic fatty liver disease: New prospects for short-chain fatty acids as therapeutic targets

Nonalcoholic fatty liver disease (NAFLD) is a stress-induced liver injury related to heredity, environmental exposure and the gut microbiome metabolism. Short-chain fatty acids (SCFAs), the metabolites of gut microbiota (GM), participate in the regulation of hepatic steatosis and inflammation through the gut-liver axis, which play an important role in the alleviation of NAFLD. However, little progress has been made in systematically elucidating the mechanism of how SCFAs improve NAFLD, especially the epigenetic mechanisms and the potential therapeutic application as clinical treatment for NAFLD. Herein, we adopted PubMed and Medline to search relevant keywords such as 'SCFAs', 'NAFLD', 'gut microbiota', 'Epigenetic', 'diet', and 'prebiotic effect' to review the latest research on SCFAs in NAFLD up to November 2023. In this review, firstly, we specifically discussed the production and function of SCFAs, as well as their crosstalk coordination in the gut liver axis. Secondly, we provided an updated summary and intensive discussion of how SCFAs affect hepatic steatosis to alleviate NAFLD from the perspective of genetic and epigenetic. Thirdly, we paid attention to the pharmacological and physiological characteristics of SCFAs, and proposed a promising future direction to adopt SCFAs alone or in combination with prebiotics and related clinical drugs to prevent and treat NAFLD. Together, this review aimed to elucidate the function of SCFAs and provide new insights to the prospects of SCFAs as a therapeutic target for NAFLD.

Recent progress and applications of small molecule inhibitors of Keap1-Nrf2 axis for neurodegenerative diseases

The Kelch-like ECH-associated protein 1 (Keap1)-nuclear factor erythroid 2-related factor 2 (Nrf2) pathway serves as a crucial regulator against oxidative stress (OS) damage in various cells and organs. It has garnered significant attention as a potential therapeutic target for neurodegenerative diseases (NDD). Although progress has been achieved in strategies to regulate the Keap1-Nrf2 pathway, the availability of Nrf2 activators applicable to NDD is currently limited. Currently, the FDA has approved the Nrf2 activators dimethyl fumarate (DMF) and Omaveloxolone (Omav) as novel first-line oral drugs for the treatment of patients with relapsing forms of multiple sclerosis and Friedreich's ataxia. A promising alternative approach involves the direct inhibition of Keap1-Nrf2 protein-protein interactions (PPI), which offers numerous advantages over the use of electrophilic Nrf2 activators, primarily in avoiding off-target effects. This review examines the compelling evidence supporting the beneficial role of Nrf2 in NDD and explores the potential of Keap1 inhibitors and Keap1-Nrf2 PPI inhibitors as therapeutic agents, with the aim to provide further insights into the development of inhibitors targeting this pathway for the treatment of NDD.

Suppression of the SLC7A11/glutathione axis causes ferroptosis and apoptosis and alters the mitogen-activated protein kinase pathway in nasopharyngeal carcinoma

SLC7A11 is a unit of the glutamate cystine antiporter Xc- system. It functions to import cystine for glutathione biosynthesis and maintains the redox balance in cells. Sorafenib inhibits the transporter activity of SLC7A11. The use of sorafenib has been approved in the treatment of multiple cancers. However, at present, our understanding of the mechanism of SLC7A11 and sorafenib in nasopharyngeal carcinoma (NPC) remains limited. We found that the expression of SLC7A11 was upregulated in NPC. A high SLC7A11 expression was associated with poor prognosis, metastasis, and an advanced T stage, which can be used as an independent prognostic indicator of NPC. In vitro, we observed that NPC cells relied on cystine for survival. Targeting SLC7A11 resulted in glutathione biosynthesis limitation, intracellular reactive oxygen species accumulation, lipid peroxides, ferroptosis, and apoptosis. Meanwhile, it altered mitogen activated protein kinase pathway, including p38 activation but ERK inhibition in NPC. This limited the proliferation of NPC cells. Sorafenib inhibited the proliferation and induced the death of NPC cells in vivo. In conclusion, SLC7A11 plays an important role in the occurrence and progression of NPC and may be a novel target for NPC treatment.