Nrf2 signaling pathway: Pivotal roles in inflammation

Cell polarization in ischemic stroke: molecular mechanisms and advances

Ischemic stroke is a cerebrovascular disease associated with high mortality and disability rates. Since the inflammation and immune response play a central role in driving ischemic damage, it becomes essential to modulate excessive inflammatory reactions to promote cell survival and facilitate tissue repair around the injury site. Various cell types are involved in the inflammatory response, including microglia, astrocytes, and neutrophils, each exhibiting distinct phenotypic profiles upon stimulation. They display either proinflammatory or anti-inflammatory states, a phenomenon known as 'cell polarization.' There are two cell polarization therapy strategies. The first involves inducing cells into a neuroprotective phenotype in vitro, then reintroducing them autologously. The second approach utilizes small molecular substances to directly affect cells in vivo. In this review, we elucidate the polarization dynamics of the three reactive cell populations (microglia, astrocytes, and neutrophils) in the context of ischemic stroke, and provide a comprehensive summary of the molecular mechanisms involved in their phenotypic switching. By unraveling the complexity of cell polarization, we hope to offer insights for future research on neuroinflammation and novel therapeutic strategies for ischemic stroke.

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.

GLP-1 analogue liraglutide attenuates CIH-induced cognitive deficits by inhibiting oxidative stress, neuroinflammation, and apoptosis via the Nrf2/HO-1 and MAPK/NF-κB signaling pathways

Obstructive sleep apnea (OSA) is a common clinical condition linked to cognitive impairment, mainly characterized by chronic intermittent hypoxia (CIH). GLP-1 receptor agonist, known for promoting insulin secretion and reducing glucose levels, has demonstrated neuroprotective effects in various experimental models such as stroke, Alzheimer's disease, and Parkinson's disease. This study aims to investigate the potential role and mechanisms of the GLP-1 receptor agonist liraglutide in ameliorating OSA-induced cognitive deficits. CIH exposure, a well-established and mature OSA pathological model, was used both in vitro and in vivo. In vitro, CIH significantly activated oxidative stress, inflammation, and apoptosis in SH-SY5Y cells. Liraglutide enhanced the nuclear translocation of Nrf2, activating its downstream pathways, thereby mitigating CIH-induced injury in SH-SY5Y cells. Additionally, liraglutide modulated the MAPK/NF-κB signaling pathway, reducing the expression of inflammatory factors and proteins. In vivo, we subjected mice to an intermittent hypoxia incubator to mimic the pathogenesis of human OSA. The Morris water maze test revealed that CIH exposure substantially impaired spatial memory. Subsequent western blot analyses and histopathological examinations indicated that liraglutide could activate the Nrf2/HO-1 axis and inhibit the MAPK/NF-κB signaling pathway, thereby alleviating OSA-associated cognitive dysfunction in mice. These findings suggest that GLP-1 receptor agonists may offer a promising preventive strategy for OSA-associated cognitive impairment. By refining these findings, we provide new insights into GLP-1's protective mechanisms in combating cognitive deficits associated with CIH, underscoring its potential as a therapeutic agent for conditions linked to OSA.

pH responsive fabrication of PVA-stabilized selenium nano formulation encapsulated with luteolin to reduce diabetic ureteral injury by decreasing NLRP3 inflammasome via Nrf2/ARE signaling

Diabetic ureteral injury (DUI) is a condition characterized by damage to the ureter, causing functional and morphological changes in the urinary system, which have a significant impact on a quality of life and requires appropriate medical treatment. The present study describes to novel design of luteolin (LT), a type of natural flavonoid, encapsulated selenium nanoparticles (Se NPs) to attain therapeutic potential for DUI. The physico-chemical characterizations of prepared Se NPs have benefitted zeta potential (-18 mV) and particle size (10-50 nm). In vitro assays were demonstrated the potential of LT-SeNPs by HEK 293 cells stimulated by STZ for DUI. Cytotoxicity assays on HEK 293 and NIH-3T3 showed >90% cell viability, which demonstrates the suitability of the nanoformulation for DUI treatment. The LT-SeNPs significantly inhibits the NLRP3 inflammasome through Nrf2/ARE pathway, which benefits for DUI treatment. The developed LT-SeNPs could be an effective formulation for the DUI therapy.

Anti-cancer activity and cellular uptake of 7,3',4'- and 7,8,4'-trihydroxyisoflavone in HepG2 cells under hypoxic conditions

Transarterial chemoembolisation (TACE) is used for unresectable hepatocellular carcinoma (HCC) treatment, but TACE-induced hypoxia leads to poor prognosis. The anti-cancer effects of soybean isoflavones daidzein derivatives 7,3',4'-trihydroxyisoflavone (734THIF) and 7,8,4'-trihydroxyisoflavone (784THIF) were evaluated under hypoxic microenvironments. Molecular docking of these isomers with cyclooxygenase-2 (COX-2) and vascular endothelial growth factor receptor 2 (VEGFR2) was assessed. About 40 μM of 734THIF and 784THIF have the best effect on inhibiting the proliferation of HepG2 cells under hypoxic conditions. At a concentration of 40 μM, 784THIF significantly inhibits COX-2 expression in pre-hypoxia conditions compared to 734THIF, with an inhibition rate of 67.73%. Additionally, 40 μM 784THIF downregulates the expression of hypoxic, inflammatory, and metastatic-related proteins, regulates oxidative stress, and inhibits the expression of anti-apoptotic proteins. The uptake by HepG2 confirmed higher 784THIF level and slower degradation characteristics under post- or pre-hypoxic conditions. In conclusion, our results showed that 784THIF had better anti-cancer effects and cellular uptake than 734THIF.

Phillyrin: A potential therapeutic agent for osteoarthritis via modulation of NF-κB and Nrf2 signaling pathways

Osteoarthritis (OA) is the predominant cause of disability among elderly people worldwide and is characterized by cartilage degeneration and excessive bone formation. Phillyrin, derived from forsythia, is a key extract renowned for its pronounced antibacterial and anti-inflammatory effects. Forsythia, deeply integrated into traditional Oriental medicine, has historically been utilized for its various pharmacological effects, including antibacterial, anti-inflammatory, and hepato-protective properties. Nevertheless, the anti-inflammatory impact of phillyrin on the progression of osteoarthritis remains enigmatic. The objective of this research was to assess the anti-inflammatory and anti-aging properties of phillyrin in mouse chondrocytes induced by IL-1β, as well as to elucidate the fundamental mechanisms underlying the phenomenon at play. Additionally, the investigation extends to observing the impact of phillyrin by establishing a murine osteoarthritic model. The ultimate goal was to identify phillyrin as a potential antiosteoarthritic agent. This investigation employs a multifaceted approach. Initially, key action targets of phillyrin, along with its probable action pathways, were identified by molecular docking and network pharmacological techniques. These findings were subsequently confirmed through both in vivo and in vitro studies. Network pharmacological analysis revealed NFE2L2 (NRF2), NFKB1, TLR4, and SERPING1 as pivotal candidate targets for the treatment of osteoarthritis with phillyrin. Molecular docking revealed hydrogen bond interactions between phillyrin and Arg415, Arg483, Ser508, and Asn387 on the Nrf2 receptor, while electrostatic interactions occurred with residues Arg415 and Arg380. Experiments conducted in vitro indicated that phillyrin preconditioning hindered the IL-1β-induced expression of proinflammatory factors which included TNF-α, COX-2, IL-6, and iNOS. Furthermore, phillyrin counteracts the IL-1β-induced degradation of aggrecan and collagen II within the extracellular matrix (ECM). This protective action is caused by the inhibition of the NF-κB pathway by phillyrin. Additionally, the mitigation of chondrocyte aging by phillyrin was observed. Our investigation revealed that phillyrin mitigates inflammation and counteracts cartilage degeneration in osteoarthritis (OA) patients by suppressing inflammation in chondrocytes and impeding aging through suppression of the NF-κB pathway.

Metformin attenuates white matter injury in neonatal mice through activating NRF2/HO-1/NF-κB pathway

White matter injury (WMI) is a major form of brain injury that occurs in preterm infants and develops into lifelong disabilities, including cerebral palsy, impaired cognitive function, and psychiatric disorders. Metformin (MET) has been reported to have neuroprotective effects. However, whether MET is responsible for neuroprotection against WMI remains unclear. In this study, we established a WMI model in neonatal mice to explore the neuroprotective effects of MET and attempted to elucidate its potential mechanisms. Our results showed that MET increased the expression of myelin basic protein (MBP), oligodendrocyte transcription factor 2 (Olig2), and CC1, improved the thickness and density of the myelin sheath, and reduced oxidative stress and microglial infiltration after chronic hypoxia induction. Moreover, MET improved memory, learning, and motor abilities as well as relieved anxiety-like behaviors in mice with WMI. These protective effects of MET may involve the upregulation of the nuclear factor erythroid 2-related factor 2 (NRF2)/heme oxygenase-1(HO-1)/NF-κB pathway related protein expressions. In addition, the NRF2 inhibitor ML385 could significantly reverse the effects of MET. In conclusion, this study suggested that MET attenuated chronic hypoxia-induced WMI through activating the NRF2/HO-1/NF-κB pathway, indicating that MET might be a promising therapeutic option for WMI.

NRF2 in age-related musculoskeletal diseases: Role and treatment prospects

The NRF2 pathway is a metabolic- and redox-sensitive signaling axis in which the transcription factor controls the expression of a multitude of genes that enable cells to survive environmental stressors, such as oxidative stress, mainly by inducing the expression of cytoprotective genes. Basal NRF2 levels are maintained under normal physiological conditions, but when exposed to oxidative stress, cells activate the NRF2 pathway, which is crucial for supporting cell survival. Recently, the NRF2 pathway has been found to have novel functions in metabolic regulation and interplay with other signaling pathways, offering novel insights into the treatment of various diseases. Numerous studies have shown that targeting its pathway can effectively investigate the development and progression of age-related musculoskeletal diseases, such as sarcopenia, osteoporosis, osteoarthritis, and intervertebral disc degeneration. Appropriate regulation of the NRF2 pathway flux holds promise as a means to improve musculoskeletal function, thereby providing a new avenue for drug treatment of age-related musculoskeletal diseases in clinical settings. The review summarized an overview of the relationship between NRF2 and cellular processes such as oxidative stress, apoptosis, inflammation, mitochondrial dysfunction, ferroptosis, and autophagy, and explores the potential of targeted NRF2 regulation in the treatment of age-related musculoskeletal diseases.

Discovery of CYP2E1 as a novel target in rheumatoid arthritis and validation by a new specific CYP2E1 inhibitor

Considerable evidence indicates that CYP2E1 is associated with a variety of inflammatory diseases. Here we evaluated CYP2E1 as a potential therapeutic target for rheumatoid arthritis (RA) and established the protective effect of a new CYP2E1 inhibitor. Gene-expression datasets were used to analyze the change in expression of CYP2E1 in RA patients; CYP2E1 activity in collagen-induced arthritis (CIA) rats was determined by HPLC. We further evaluated the protective effects of Cyp2e1 knockout and a CYP2E1-specific inhibitor, Q11, synthesized by our group, in CIA and adjuvant-induced arthritis (AIA) rats. The expression of CYP2E1 in synovial tissue was elevated in RA patients and in CIA rats and the activity of CYP2E1 in vivo and in vitro in CIA rats was greater than that of controls. Cyp2e1 knockout significantly reduced the incidence of CIA and alleviated the severity of symptoms. Treatment with different doses of Q11 decreased paw thickness, volume and arthritis scores and reduced the serum levels of IL-6, TNF-α, IL-1β and MDA, and increased the level of GSH in CIA rats. A similar inhibitory effect was exhibited for Q11 in the AIA rats. Moreover, Q11 significantly impeded proliferation, migration, and invasion of human rheumatoid arthritis synovial fibroblasts cells. Q11 decreased the release of ROS and enhanced Nrf2 nuclear translocation and HO-1 expression in the cell nucleus. Overall, our results indicated that CYP2E1 may be a new target for RA and Q11 has potential protective effects against RA by reducing oxidative stress and opposing the inflammatory response via the ROS/Nrf2/HO-1 signaling pathway.

Anti-inflammatory properties of Bacillus pumilus TS1 in lipopolysaccharide-induced inflammatory damage in broilers

This study investigates whether Bacillus pumilus TS1 improves growth performance and alleviates inflammatory damage in broilers and explored its feasibility as an antibiotic alternative. We divided 240 one-day-old AA308 white-finned broilers into five groups (con, LPS, TS1L + LPS, TS1M + LPS and TS1H + LPS). The TS1L + LPS, TS1M + LPS and TS1H + LPS groups were fed TS1 for 15 days by gavage. The LPS, TS1L + LPS, TS1M + LPS and TS1H + LPS groups were injected intraperitoneally with 1 mg/kg LPS for three days. We investigated the probiotic and anti-inflammatory activities by measuring body weight, sequencing the intestinal flora and examining the structure of tissues by using pathological stain, real-time PCR, Western blotting and immunohistochemical detection. TS1 could improve growth performance and intestinal flora composition, also reduced different organ damage and inflammatory cytokine expression in serum and organs. The mechanism may involve upregulating HSP60 and HSP70 expression, targeting and regulating Nrf2 and P38 MAPK and modulating NF-κB and HO-1 expression at the transcriptional level in different organs. B. pumilus TS1 alleviated Inflammatory injury caused by LPS and attenuated the inflammatory response in broilers, and these effects were achieved through MAPK and Nrf2 regulation of HSPs/HO-1 in different organs. The above results suggested broilers fed with TS1 could release the LPS caused organ damage, and the most suggested dosage was 1.4 × 108 CFU/mL.

Ferulic Acid Protects Human Lens Epithelial Cells Against UVA-Induced Oxidative Damage by Downregulating the DNA Demethylation of the Keap1 Promoter

Ultraviolet (UV) radiation-triggered production of reactive oxygen species (ROS) is a primary contributor to apoptosis in human lens epithelial cells (HLECs), which can ultimately result in cataract formation. The nuclear factor erythroid-2-related factor 2 (Nrf2)-Kelch ECH associating protein 1 (Keap1) pathway, a fundamental oxidative stress regulation mechanism, plays a crucial role in the development of cataracts. Ferulic acid (FA), recognized for its potent antioxidant properties can activate the Nrf2 signaling pathway to mitigate oxidative damage and cell apoptosis. In this study, we have demonstrated the protective effects of FA in reducing UVA-induced oxidative damage and apoptosis in HLECs through the modulation of the Keap1/Nrf2 pathway, as evidenced by both cellular and animal experiments. HLECs and Lens were exposed to 10 J/cm2 UVA radiation with or without prior treatment with FA. We found that UVA radiation increased oxidative damage and cell apoptosis in HLECs, ultimately leading to opacification of rat lenses, while FA was able to attenuate both oxidative damage and cell apoptosis in HLECs and reduce the degree of lens opacification. FA upregulated the expression of antioxidant response factors of the Keap1/Nrf2 pathway and downregulated the expression of apoptosis-related genes in HLECs, as demonstrated by Western blot and RT-qPCR analyses. We also found that UVA radiation increased the degree of demethylation of the Keap1 promoter in HLECs, whereas FA reduced the level of Keap1 promoter demethylation as determined by DNA sequencing. Additionally, UVA upregulated the expression of DNA active demethylase of the Keap1 promoter in HLECs, Dnmt1, Dnmt3a, and Dnmt3b, as shown by immunofluorescence, Western blot, and RT-qPCR, however, FA attenuated the activity of the passive demethylase TET1 in addition to the active demethylases. These results demonstrated that UVA radiation can cause oxidative damage, cell apoptosis, and rat lens opacification by increasing the demethylation of the Keap1 promoter in lens epithelial cells. Conversely, FA was shown to reduce oxidative damage, inhibit cell apoptosis, and decrease rat lens opacification by increasing the methylation of the Keap1 promoter. These findings suggest that FA could be therapeutically beneficial in preventing and mitigating cataracts induced by UVA radiation.

Octahydroindolizine alkaloid Homocrepidine A from Dendrobium crepidatum attenuate P. acnes-induced inflammatory in vitro and in vivo

ETHNOPHARMACOLOGICAL RELEVANCE

Dendrobium crepidatum Lindl. ex Paxton is a perennial epiphyte of Dendrobium genus, distributed in southern China, and utilized as the traditional Chinese medicine "Shihu" in Yunnan Province. Due to its heat-clearing and detoxicating properties, it is formulated as the "XiaoCuoWan" as recorded in the China Pharmacopoeia, and specially used to treat chronic skin inflammatory diseases, such as acne.

AIM OF THE STUDY

This research aimed to estimate impact of the octahydroindoline alkaloid Homocrepidine A (HCA), isolated from D. crepidatum, on acne inflammation using both human THP-1 cells and mouse models. Furthermore, the potential anti-inflammatory mechanism of HCA has been analyzed through molecular biology methods and computer simulation.

MATERIALS AND METHODS

THP-1 cells and mouse models induced by live Propionibacterium acnes (P. acnes) were employed to evaluate the anti-inflammatory properties of crude extract of D. crepidatum (DCE) and HCA. ELISA was utilized to detect the release of inflammatory cytokines in both cellular and murine ear tissues. RNAseq was used to screen the pathways associated with HCA-mediated inflammatory inhibition, while Western blot, RT-qPCR, and immunofluorescence were utilized to detect the expression of relevant proteins. Additionally, molecular docking simulations and cellular thermal shift assays were employed to confirm the target of HCA.

RESULTS

Our research shows that DCE and HCA can effectively alleviate acne inflammation. HCA inhibits TLR2 expression by interacting with amino acid residues in the TIR domain of hTLR2, including Pro-681, Asn-688, Trp-684, and Ile-685. Moreover, HCA disrupts inflammatory signal transduction mediated by MAPK and NF-κB pathways through MyD88-dependent pathway. Additionally, HCA treatment facilitates Nrf2 nuclear translocation and upregulates HO-1 expression, thereby inhibiting NLRP3 inflammasomes activation. In vivo experiments further revealed that HCA markedly attenuated erythema and swelling caused by P. acnes in mice ears, while also decreasing the expression of pro-inflammatory cytokines IL-1β and IL-8.

CONCLUSIONS

Our research highlights the protective effects of D. crepidatum and its bioactive compound HCA against acne inflammation, marking the first exploration of its potential in this context. The discoveries indicate that HCA treatment may represent a promising functional approach for acne therapy.

Non-electrophilic NRF2 activators promote wound healing in human keratinocytes and diabetic mice and demonstrate selective downstream gene targeting

The transcription factor NRF2 plays an important role in many biological processes and is a promising therapeutic target for many disease states. NRF2 is highly expressed in the skin and is known to play a critical role in diabetic wound healing, a serious disease process for which treatment options are limited. However, many existing NRF2 activators display off-target effects due to their electrophilic mechanism, underscoring the need for alternative approaches. In this work, we investigated two recently described non-electrophilic NRF2 activators, ADJ-310 and PRL-295, and demonstrated their efficacy in vitro and in vivo in human keratinocytes and Leprdb/db diabetic mice. We also compared the downstream targets of PRL-295 to those of the widely used electrophilic NRF2 activator CDDO-Me by RNA sequencing. Both ADJ-310 and PRL-295 maintained human keratinocyte cell viability at increasing concentrations and maintained or improved cell proliferation over time. Both compounds also increased cell migration, improving in vitro wound closure. ADJ-310 and PRL-295 enhanced the oxidative stress response in vitro, and RNA-sequencing data showed that PRL-295 activated NRF2 with a narrower transcriptomic effect than CDDO-Me. In vivo, both ADJ-310 and PRL-295 improved wound healing in Leprdb/db diabetic mice and upregulated known downstream NRF2 target genes in treated tissue. These results highlight the non-electrophilic compounds ADJ-310 and PRL-295 as effective, innovative tools for investigating the function of NRF2. These compounds directly address the need for alternative NRF2 activators and offer a new approach to studying the role of NRF2 in human disease and its potential as a therapeutic across multiple disease states.

Mangiferin Represses Inflammation in Macrophages Under a Hyperglycemic Environment Through Nrf2 Signaling

Inflammation in macrophages is exacerbated under hyperglycemic conditions, contributing to chronic inflammation and impaired wound healing in diabetes. This study investigates the potential of mangiferin, a natural polyphenol, to alleviate this inflammatory response by targeting a redox-sensitive transcription factor, nuclear factor erythroid 2-related factor 2 (Nrf2). Mangiferin, a known Nrf2 activator, was evaluated for its ability to counteract the hyperglycemia-induced inhibition of Nrf2 and enhance antioxidant defenses. The protective effects of mangiferin on macrophages in a hyperglycemic environment were assessed by examining the expression of Nrf2, NF-κB, NLRP3, HO-1, CAT, COX-2, IL-6, and IL-10 through gene and protein expression analyses using qPCR and immunoblotting, respectively. The mangiferin-mediated nuclear translocation of Nrf2 was evidenced, leading to a robust antioxidant response in macrophages exposed to a hyperglycemic microenvironment. This activation suppressed NF-κB signaling, reducing the expression of pro-inflammatory mediators such as COX-2 and IL-6. Additionally, mangiferin decreased NLRP3 inflammasome activation and reactive oxygen species accumulation in hyperglycemia exposed macrophages. Our findings revealed that mangiferin alleviated hyperglycemia-induced reductions in AKT phosphorylation, highlighting its potential role in modulating key signaling pathways. Furthermore, mangiferin significantly enhanced the invasiveness and migration of macrophages in a hyperglycemic environment, indicating its potential to improve wound healing. In conclusion, this study suggests that mangiferin may offer a promising therapeutic approach for managing inflammation and promoting wound healing in diabetic patients by regulating Nrf2 activity in hyperglycemia-induced macrophages.

Promising tools into oxidative stress: A review of non-rodent model organisms

Oxidative stress is a crucial concept in redox biology, and significant progress has been made in recent years. Excessive levels of reactive oxygen species (ROS) can lead to oxidative damage, heightening vulnerability to various diseases. By contrast, ROS maintained within a moderate range plays a role in regulating normal physiological metabolism. Choosing suitable animal models in a complex research context is critical for enhancing research efficacy. While rodents are frequently utilized in medical experiments, they pose challenges such as high costs and ethical considerations. Alternatively, non-rodent model organisms like zebrafish, Drosophila, and C. elegans offer promising avenues into oxidative stress research. These organisms boast advantages such as their small size, high reproduction rate, availability for live imaging, and ease of gene manipulation. This review highlights advancements in the detection of oxidative stress using non-rodent models. The oxidative homeostasis regulatory pathway, Kelch-like ECH-associated protein 1-Nuclear factor erythroid 2-related factor 2 (Keap1-Nrf2), is systematically reviewed alongside multiple regulation of Nrf2-centered pathways in different organisms. Ultimately, this review conducts a comprehensive comparative analysis of different model organisms and further explores the combination of novel techniques with non-rodents. This review aims to summarize state-of-the-art findings in oxidative stress research using non-rodents and to delineate future directions.

Methionine and vitamin E supplementation improve production performance, antioxidant potential, and liver health in aged laying hens

Sulfur metabolites of methionine (Met) and vitamin E (VE) have antioxidant potential and can maintain liver health in chickens. This study explored the underlying mechanisms of Met sources, the ratio of total sulfur amino acids to lysine (TSAA: Lys), and VE levels on production performances, antioxidant potential, and hepatic oxidation in aged laying hens. Eight hundred and sixty-four, Hy-Line Brown laying hens (70-week age) were divided into 12 treatment groups, each having 6 repeats and 12 birds/each repeat. The dietary treatments consisted of DL-Met (DL-Met), DL-2-hydroxy-4-(methylthio)-butanoic acid (OH-Met), 3 ratios of TSAA: Lys (0.90, 0.95, and 1.00), and 2 levels of VE (20 and 40 g/ton). Albumen height and Haugh unit significantly increased at a lower level of VE (P < 0.05). Triglycerides (TG), total cholesterol (TC), low-density lipoprotein (LDL), and very low-density lipoprotein (VLDL) in serum and superoxide dismutase (SOD) and catalase activities (CAT) in the liver significantly reduced at 0.95 TSAA: Lys ratio (P < 0.05). Fatty acid synthase (FAS), lipoprotein lipase (LPL), nuclear factor erythroid 2-related factor 2 (Nrf2), and carnitine palmitoyltransferase-1 alpha (CPT-1α) also upregulated at this TSAA: Lys ratio (P < 0.05). Compared with the DL-Met group, the OH-Met group had lower Dipeptidyl Peptidase 4 (DPP4) and higher TC, LDL, and VLDL concentrations (P < 0.05).The expression of FAS,CPT-1α), glutathione (GSH), glutathione disulfide (GSSG), glutathione synthetase (GSS), and Nrf2 were significantly higher in OH-Met compared with the DL-Met group (P < 0.05). OH-Met at 0.95 and DL-Met at 0.90 TSAA: Lys ratio showed higher CAT and lower aspartate aminotransferase (AST) activities. Moreover, OH-Met at 0.90 and DL-Met at 0.95 of the TSAA: Lys ratio had a significant reduction of malondialdehyde (MDA) (P < 0.05). Overall, these results suggest that OH-Met source with a lower level of VE positively influenced production performance and improved liver health in aged laying hens through improved lipid metabolism and hepatic antioxidant function.

Licochalcone A Ameliorates Aspergillus fumigatus Keratitis by Reducing Fungal Load and Activating the Nrf2/HO-1 Signaling Pathway

Fungal keratitis (FK) is a blinding corneal infectious disease. The prognosis is frequently unfavorable due to fungal invasion and an excessive host inflammatory response. Licochalcone A (Lico A) exhibits a broad spectrum of pharmacological activities, encompassing antifungal, anti-inflammatory, antioxidation, and antitumor properties. However, the role of Lico A has not yet been studied in FK. In this study, we discovered that Lico A could disrupt Aspergillus fumigatus (A. fumigatus) biofilms, inhibit fungal growth and adhesion to host cells, induce alterations of hyphal morphology, and impair the cell membrane and cell wall integrity and mitochondrial structure of A. fumigatus. Lico A can alleviate the severity of FK in mice, reduce neutrophil infiltration and fungal load, and significantly decrease the pro-inflammatory cytokines in mouse corneas infected with A. fumigatus. In vitro, we also demonstrated that Lico A increased the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) around the nucleus in human corneal epithelial cells (HCECs) stimulated with A. fumigatus. We verified that the anti-inflammatory effect of Lico A is associated with the activation of the Nrf2/HO-1 axis. These results indicated that Lico A could provide a protective role in A. fumigatus keratitis through its anti-inflammatory and antifungal activities.

Inhibitory Effects of Decursin Derivative against Lipopolysaccharide-Induced Inflammation

BACKGROUND

This study aims to explore the protective role of JB-V-60-a novel synthetic derivative of decur-sin-against lipopolysaccharide (LPS)-induced inflammation.

METHODS

We examined the effects of JB-V-60 on heme oxygenase (HO)-1, cyclooxygenase (COX)-2, and inducible nitric oxide synthase (iNOS) in LPS-activated human pulmonary artery endothelial cells (HPAECs). Additionally, we assessed its effects on iNOS, tumor necrosis factor (TNF)-α, and interleukin (IL)-1β in LPS-exposed mice.

RESULTS

JB-V-60 enhanced HO-1 levels, inhibited NF-κB activation, reduced COX-2/PGE2 and iNOS/NO concentra-tions, and lowered phosphorylation of signal transducer and activator of transcription 1. It also promoted the translocation of Nrf2 into the nucleus, allowing its binding to antioxidant response elements and resulting in reduced IL-1β in LPS-stimulated HPAECs. The reduction in iNOS/NO levels by JB-V-60 was reversed when HO-1 was inhibited via RNAi. In the animal model, JB-V-60 sig-nificantly decreased iNOS expression in lung tissues and TNF-α levels in bronchoalveolar lavage fluid.

CONCLUSIONS

These findings highlight the anti-inflammatory effects of JB-V-60 and its potential as a treat-ment for inflammatory disorders.

A quantitative proteomic approach to evaluate the efficacy of carnosine in a murine model of chronic obstructive pulmonary disease (COPD)

The aim of the work was to study a dose-dependent effect of inhaled carnosine (10, 50 or 100 mg/kg/day) in mice exposed to cigarette smoke as a model of chronic obstructive pulmonary disease (COPD). A dose-dependent loading of the dipeptide in lung tissue and bronchoalveolar lavage (BAL) was firstly demonstrated by LC-ESI-MS analysis. Cigarette smoke exposure induced a significant lung inflammation and oxidative stress in mice which was dose-dependently reduced by carnosine. Inflammation was firstly evaluated by measuring the cytokines content in the BAL. All the measured cytokines were found significantly higher in the smoke group in respect to control, although the data are affected by a significant variability. Carnosine was found effective only at the highest dose tested and significantly only for keratinocyte-derived cytokine (KC). Due to the high variability of cytokines, a quantitative proteomic approach to better understand the functional effect of carnosine and its molecular mechanisms was used. Proteomic data clearly indicate that smoke exposure had a great impact on lung tissue with 692 proteins differentially expressed above a threshold of 1.5-fold. Protein network analysis identified the activation of some pathways characteristic of COPD, including inflammatory response, fibrosis, induction of immune system by infiltration and migration of leukocyte pathways, altered pathway of calcium metabolism and oxidative stress. Carnosine at the tested dose of 100 mg/kg was found effective in reverting all the pathways evoked by smoke. Only a partial reverse of the dysregulated proteins was evident at low- and mid-tested doses, although, for some specific proteins, indicating an overall dose-dependent effect. Regarding the molecular mechanisms involved, we found that carnosine upregulated some key enzymes related to Nrf2 activation and in particular glutathione peroxidase, reductase, transferase, SOD, thioredoxins, and carbonyl reductase. Such mechanism would explain the antioxidant and anti-inflammatory effects of the dipeptide.

Forsythoside A mitigates osteoarthritis and inhibits chondrocyte senescence by promoting mitophagy and suppressing NLRP3 inflammasome via the Nrf2 pathway

BACKGROUND

Chondrocyte senescence and inflammation are hallmarks of osteoarthritis (OA). Forsythiaside A (FTA), a phenylethanol glycoside isolated from air-dried fruits of Forsythia, has been reported to have significant anti-inflammatory and antioxidant properties. However, its protective effects against OA have not been elucidated.

PURPOSE

We explored the therapeutic efficacy of FTA in inhibiting chondrocyte senescence and inflammation during OA, as well as the potential underlying mechanisms.

STUDY DESIGN

This study aimed to investigate the novel mechanism of FTA in alleviating OA in both cell and animal models.

METHODS

The protective effect of FTA against tert‑butyl hydroperoxide-induced chondrocyte damage was assessed, and the effects of FTA on cartilage aging and OA progression were evaluated using a medial meniscus (DMM)-induced knee OA mouse model. The regulatory effects of FTA on the NLRP3 Inflammasome, mitophagy, and the PKC/Nrf2 pathway were also explored.

RESULTS

In vitro, FTA improved mitochondrial function, enhanced mitophagy, suppressed NLRP3 inflammasome activation, and inhibited chondrocyte senescence; however, these chondroprotective effects were partially reversed after mitophagy inhibition, NLRP3 inflammasome activation, and Nrf2 pathway inhibition. Furthermore, we found that FTA directly interacts with Nrf2 and enhances its phosphorylation by protein kinase C (PKC). In vivo, FTA attenuated the pathological signs of knee OA in a DMM-model mouse model, which was partially reversed by ML385.

CONCLUSION

FTA inhibited chondrocyte senescence and OA progression by activating the PKC-Nrf2 pathway. Thus, FTA is a potential novel therapeutic agent for OA.

Pathophysiological role and potential drug target of NLRP3 inflammasome in the metabolic disorders

NLRP3 plays a role in the development of autoinflammatory diseases. NLRP3, ASC, and Caspases 1 or 8 make up the NLRP3 inflammasome, which is an important part of innate immune system. The NLRP3 inflammasome-mediated inflammatory cytokines may also participate in metabolic disorders, such as diabetes, hyperlipidemia, atherosclerosis, non-alcoholic fatty liver disease, and gout. Hence, an overview of the NLRP3 regulation in these metabolic diseases and the potential drugs targeting NLRP3 is the focus of this review.

Apo-12'-capsorubinal exhibits anti-inflammatory effects and activates nuclear factor erythroid 2-related factor 2 in RAW264.7 macrophages

Apocarotenoids have short carbon chain structures cleaved at a polyene-conjugated double bond. They can be biosynthesized in plants and microorganisms. Animals ingest carotenoids through food and then metabolize them into apocarotenoids. Although several apocarotenoids have been identified in the body, their precise health functions are still poorly understood. This study investigated the anti-inflammatory activities of apo-12'-capsorubinal in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. It was confirmed that apo-12'-capsorubinal was not cytotoxic to the macrophages at the concentrations tested. Apo-12'-capsorubinal treatment led to a marked downregulation of interleukin (IL)-6 protein and Il6 mRNA levels. This apocarotenoid exhibited more potent inhibitory effects than its parent carotenoids, capsanthin and capsorubin. Furthermore, apo-12'-capsorubinal, but not its parent carotenoids, promoted the nuclear accumulation of nuclear factor erythroid 2-related factor 2 (Nrf2) and upregulated the expression of Nrf2-target genes, such as heme oxygenase 1 (HO-1) and NAD(P)H:quinone oxidoreductase 1 (NQO-1), in a dose-dependent manner. Furthermore, a comparison using apo-12'-zeaxanthinal and 7,8-dihydro-8-oxo-apo-12'-zeaxanthinal revealed that the α, β-unsaturated carbonyl group on the polyene linear chain mediated the enhanced nuclear Nrf2 translocation, HO-1 expression, and inhibition of IL-6 production. In contrast, apo-12'-mytiloxanthinal, which harbored a hydroxyl group at C-8 of apo-12'-capsorubinal, did not exhibit any of these activities. These results indicated that the β carbon of the α, β-unsaturated carbonyl group in the linear part of the polyene chain is crucial to the Nrf2-activating and anti-inflammatory effects of apo-12'-capsorubinal. This study will advance our knowledge of the physiological significance of xanthophyll-derived apocarotenoids and their potential use as nutraceuticals and pharmaceuticals.

Mechanistic Insights and Potential Therapeutic Implications of NRF2 in Diabetic Encephalopathy

Diabetic encephalopathy (DE) is a complication of diabetes, especially type 2 diabetes (T2D), characterized by damage in the central nervous system and cognitive impairment, which has gained global attention. Despite the extensive research aimed at enhancing our understanding of DE, the underlying mechanism of occurrence and development of DE has not been established. Mounting evidence has demonstrated a close correlation between DE and various factors, such as Alzheimer's disease-like pathological changes, insulin resistance, inflammation, and oxidative stress. Of interest, nuclear factor erythroid 2-related factor 2 (NRF2) is a transcription factor with antioxidant properties that is crucial in maintaining redox homeostasis and regulating inflammatory responses. The activation and regulatory mechanisms of NRF2 are a relatively complex process. NRF2 is involved in the regulation of multiple metabolic pathways and confers neuroprotective functions. Multiple studies have provided evidence demonstrating the significant involvement of NRF2 as a critical transcription factor in the progression of DE. Additionally, various molecules capable of activating NRF2 expression have shown potential in ameliorating DE. Therefore, it is intriguing to consider NRF2 as a potential target for the treatment of DE. In this review, we aim to shed light on the role and the possible underlying mechanism of NRF2 in DE. Furthermore, we provide an overview of the current research landscape and address the challenges associated with using NRF2 activators as potential treatment options for DE.

Exploring the correlation between innate immune activation of inflammasome and regulation of pyroptosis after intracerebral hemorrhage: From mechanism to treatment

Stroke has emerged as the primary cause of disability and death globally in recent years. Intracerebral hemorrhage (ICH), a particularly severe kind of stroke, is occurring in an increasing number of people. The two main clinical treatments for ICH now in use are conservative pharmaceutical therapy and surgical intervention, both of which have risks and drawbacks. Consequently, it is crucial to look into the pathophysiology of ICH and consider cutting-edge therapeutic approaches. Recent research has revealed that pyroptosis is a newly identified type of cell death distinguished by the break of the cell membrane and the discharge of pro-inflammatory substances through different routes. Following ICH, glial cells experience pyroptosis, which worsens neuroinflammation. Hence, the onset and progression of ICH are strongly linked to pyroptosis, which is facilitated by different inflammasomes. It is essential to conduct a comprehensive investigation of ICH damage processes and uncover new targets for treatment. The impact and function of pyroptosis in ICH, as well as the activation and regulation of inflammasomes and their mediated pyroptosis pathways will be fully discussed in this review.

Nrf2-mediated ferroptosis inhibition: a novel approach for managing inflammatory diseases

Inflammatory diseases, including psoriasis, atherosclerosis, rheumatoid arthritis, and ulcerative colitis, are characterized by persistent inflammation. Moreover, the existing treatments for inflammatory diseases only provide temporary relief by controlling symptoms, and treatments of unstable and expensive. Therefore, new therapeutic solutions are urgently needed to address the underlying causes or symptoms of inflammatory diseases. Inflammation frequently coincides with a high level of (reactive oxygen species) ROS activation, serving as a fundamental element in numerous physiological and pathological phenotypes that can result in serious harm to the organism. Given its pivotal role in inflammation, oxidative stress, and ferroptosis, ROS represents a focal node for investigating the (nuclear factor E2-related factor 2) Nrf2 pathway and ferroptosis, both of which are intricately linked to ROS. Ferroptosis is mainly triggered by oxidative stress and involves iron-dependent lipid peroxidation. The transcription factor Nrf2 targets several genes within the ferroptosis pathway. Recent studies have shown that Nrf2 plays a significant role in three key ferroptosis-related routes, including the synthesis and metabolism of glutathione/glutathione peroxidase 4, iron metabolism, and lipid processes. As a result, ferroptosis-related treatments for inflammatory diseases have attracted much attention. Moreover, drugs targeting Nrf2 can be used to manage inflammatory conditions. This review aimed to assess ferroptosis regulation mechanism and the role of Nrf2 in ferroptosis inhibition. Therefore, this review article may provide the basis for more research regarding the treatment of inflammatory diseases through Nrf2-inhibited ferroptosis.

NRF2 signaling pathway and telomere length in aging and age-related diseases

The transcription factor nuclear factor erythroid 2-related factor 2 (NRF2) is well recognized as a critical regulator of redox, metabolic, and protein homeostasis, as well as the regulation of inflammation. An age-associated decline in NRF2 activity may allow oxidative stress to remain unmitigated and affect key features associated with the aging phenotype, including telomere shortening. Telomeres, the protective caps of eukaryotic chromosomes, are highly susceptible to oxidative DNA damage, which can accelerate telomere shortening and, consequently, lead to premature senescence and genomic instability. In this review, we explore how the dysregulation of NRF2, coupled with an increase in oxidative stress, might be a major determinant of telomere shortening and age-related diseases. We discuss the relevance of the connection between NRF2 deficiency in aging and telomere attrition, emphasizing the importance of studying this functional link to enhance our understanding of aging pathologies. Finally, we present a number of compounds that possess the ability to restore NRF2 function, maintain a proper redox balance, and preserve telomere length during aging.

p-Hydroxy benzaldehyde, a phenolic compound from Nostoc commune, ameliorates DSS-induced colitis against oxidative stress via the Nrf2/HO-1/NQO-1/NF-κB/AP-1 pathway

BACKGROUND

Ulcerative colitis (UC), a chronic idiopathic inflammatory bowel disease (IBD), presents with limited current drug treatment options. Consequently, the search for safe and effective drug for UC prevention and treatment is imperative. Our prior studies have demonstrated that the phenolic compound p-Hydroxybenzaldehyde (HD) from Nostoc commune, effectively mitigates intestinal inflammation. However, the mechanisms underlying HD's anti-inflammatory effects remain unclear.

PURPOSE

This study delved into the pharmacodynamics of HD and its underlying anti-inflammation mechanisms.

METHODS

For in vivo experiments, dextran sodium sulfate (DSS)-induced colitis mouse model was established. In vitro inflammation model was established using lipopolysaccharide (LPS)-induced RAW264.7 and bone marrow-derived macrophages (BMDMs). The protective effect of HD against colitis was determined by monitoring clinical symptoms and histological morphology in mice. The levels of inflammatory factors and oxidative stress markers were subsequently analyzed with enzyme-linked immunosorbent assay (ELISA) and biochemical kits. Furthermore, western blotting (WB), immunofluorescence (IF), luciferase reporter gene, drug affinity reaction target stability (DARTS) assay, molecular docking, and molecular dynamics (MD) simulation were used to determine the potential target and molecular mechanism of HD.

RESULTS

Our findings indicate that HD significantly alleviated the clinical symptoms and histological morphology of colitis in mice, and curtailed the production of pro-inflammatory cytokines, including TNF-α, IL-6, IFN-γ, COX-2, and iNOS. Furthermore, HD stimulated the production of SOD, CAT, and GSH-px, enhanced total antioxidant capacity (T-AOC), and reduced MDA levels. Mechanically, HD augmented the expression of Nrf2, HO-1, and NQO-1, while concurrently downregulating the phosphorylation of p65, IκBα, c-Jun, and c-Fos. ML385 and siNrf2 largely attenuated the protective effect of HD in enteritis mice and RAW 264.7 cells, as well as the promotion of HO-1 expression levels. ZnPP-mediated HO-1 knockdown reversed HD-induced inhibition of colonic inflammation. Luciferase reporter assay and IF assay confirmed the transcriptional activation of Nrf2 by HD. DARTS analysis, molecular docking, and MD results showed high binding strength, interaction efficiency and remarkable stability between Nrf2 and HD.

CONCLUSION

These outcomes extend our previous research results that HD can combat oxidative stress through the Nrf2/HO-1/NQO-1/NF-κB/AP-1 pathways, effectively alleviating colitis, and propose new targets for HD to protect against intestinal barrier damage.

Thiols-rich peptide from water buffalo horn keratin alleviates oxidative stress and inflammation through co-regulating Nrf2/Hmox-1 and NF-κB signaling pathway

Water buffalo horn (WBH), a traditional Chinese medicine, is known for its antipyretic, anti-inflammatory and antioxidant properties. This study aims to investigate the therapeutic potential of WBH keratin (WBHK) and its derived thiol-rich peptide fractions (SHPF) for oxidative stress and inflammation. WBHK and SHPF were prepared and tested using various models including LPS-induced fever in rabbits, H2O2-induced oxidative damage in bEnd.3 cells, TNF-α-induced inflammation in bEnd.3 cells and LPS-induced inflammation in RAW 264.7 cells. Expression of key markers, such as Nrf2, Hmox-1 and NF-κB, were analyzed using qRT-PCR, ELISA and Western blotting. Label-free quantitative proteomic analysis was used to identify key differential proteins associated with the efficacy of SHPF. Our results demonstrated that treatment with WBHK significantly reduced body temperature after 0.5 h of administration in the fever rabbit model. SHPF could alleviate cellular inflammatory injury and oxidative damage by activating the key transcription factor Nrf2 and increasing the expression level of Hmox-1. SHPF could inhibit the NF-κB pathway by reducing IκB phosphorylation. It was also found that SHPF could reduce pro-inflammatory cytokine (IL-6, COX-2 and PGE2) and inhibit the expression of VCAM-1, ICAM-1, IL-6 and MCP-1. Proteomics analysis showed that SHPF could inhibit HMGB1 expression and release. The results indicated that SHPF could significantly reduce inflammation and oxidative stress by regulating the Nrf2/Hmox-1 and NF-κB pathways. These findings suggest the potential therapeutic applications of WBH components in the treatment of oxidative stress and inflammation-related diseases.

The role of Keap1-Nrf2 signaling pathway in the treatment of respiratory diseases and the research progress on targeted drugs

Lungs are exposed to external oxidants from the environment as in harmful particles and smog, causing oxidative stress in the lungs and consequently respiratory ailment. The NF-E2-related factor 2 (Nrf2) is the one with transcriptional regulatory function, while its related protein Kelch-like ECH-associated protein 1 (Keap1) inhibits Nrf2 activity. Together, they form the Keap1-Nrf2 pathway, which regulates the body's defense against oxidative stress. This pathway has been shown to maintain cellular homeostasis during oxidative stressing, inflammation, oncogenesis, and apoptosis by coordinating the expression of cytoprotective genes and making it a potential therapeutic target for respiratory diseases. This paper summarizes this point in detail in Chapter 2. In addition, this article summarizes the current drug development and clinical research progress related to the Keap1-Nrf2 signaling pathway, with a focus on the potential of Nrf2 agonists in treating respiratory diseases. Overall, the article reviews the regulatory mechanisms of the Keap1-Nrf2 signaling pathway in respiratory diseases and the progress of targeted drug research, aiming to provide new insights for treatment.

Nuclear factor erythroid 2-related factor 2 (Nrf2) signaling in heavy metals-induced oxidative stress

Organisms encounter reactive oxidants through intrinsic metabolism and environmental exposure to toxicants. Reactive oxygen and nitrogen species (ROS, RNS) are generally considered detrimental because they induce oxidative stress. In order to combat oxidative stress, a potential modulator of cellular defense nuclear factor erythroid 2-related factor 2 (Nrf2) and its endogenous inhibitor Kelch-like ECH-associated protein 1 (Keap1) operate as a common, genetically preserved intrinsic defense system. There has been a significant increase in the amount of harmful metalloids and metals that individuals are exposed to through their food, water, and air, primarily due to human activities. Many studies have looked at the connection between the emergence of different ailments in humans and ecological exposure to metalloids, i.e., arsenic (As) and metals viz., chromium (Cr), mercury (Hg), cadmium (Cd), cobalt (Co), and lead (Pb). It is known that they can produce ROS in several organs by both direct and indirect means. Studies suggest that Nrf2 signaling is a crucial mechanism in maintaining antioxidant balance and can have two roles, depending on the particular biological setting. From one perspective, Nrf2 is an essential defense mechanism against metal-induced toxicity. Still, it may also operate as a catalyst for metal-induced carcinogenesis in situations involving protracted exposure and persistent activation. Therefore, this review aims to provide an overview of the antioxidant defense mechanism of Nrf2-Keap1 signaling and the interrelation between Nrf2 signaling and the toxic elements.

Anti-Inflammatory Effects of Lupeol as a Candidate for New Drug Development

This study explores the anti-inflammatory properties of lupeol, a notable phytosterol found in various medicinal plants, highlighting its potential as a candidate for new drug development. We examined the effects of lupeol on heme oxygenase (HO)-1, cyclooxygenase (COX)-2, and inducible nitric oxide synthase (iNOS) in lipopolysaccharide (LPS)-stimulated human umbilical vein endothelial cells (HUVECs), as well as its impact on inflammatory markers in the lung tissues of LPS-challenged mice. Lupeol treatment enhanced HO-1 production, inhibited nuclear factor (NF)-κB activity, and reduced levels of COX-2/prostaglandin E2 (PGE2) and iNOS/nitric oxide (NO). In addition, lupeol decreased the phosphorylation of signal transducer and activator of transcription 1 (STAT-1) and promoted the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2), enhancing its binding to the anti-oxidant response element (ARE) and subsequently reducing interleukin (IL)-1β expression. In vivo, lupeol significantly lowered iNOS expression and tumor necrosis factor (TNF)-α levels in bronchoalveolar lavage fluid from LPS-treated mice. These findings suggest that lupeol exerts its anti-inflammatory effects by modulating key signaling pathways, positioning it as a promising candidate for the development of novel therapeutics targeting pathological inflammation.

Molecular Therapeutics for Diabetic Kidney Disease: An Update

Diabetic kidney disease (DKD) is a common microvascular complication of diabetes mellitus (DM). With the increasing prevalence of DM worldwide, the incidence of DKD remains high. If DKD is not well controlled, it can develop into chronic kidney disease or end-stage renal disease (ESRD), which places considerable economic pressure on society. Traditional therapies, including glycemic control, blood pressure control, blood lipid control, the use of renin-angiotensin system blockers and novel drugs, such as sodium-glucose cotransporter 2 inhibitors, mineralocorticoid receptor inhibitors and glucagon-like peptide-1 receptor agonists, have been used in DKD patients. Although the above treatment strategies can delay the progression of DKD, most DKD patients still ultimately progress to ESRD. Therefore, new and multimodal treatment methods need to be explored. In recent years, researchers have continuously developed new treatment methods and targets to delay the progression of DKD, including miRNA therapy, stem cell therapy, gene therapy, gut microbiota-targeted therapy and lifestyle intervention. These new molecular therapy methods constitute opportunities to better understand and treat DKD. In this review, we summarize the progress of molecular therapeutics for DKD, leading to new treatment strategies.

Dysregulated BCL9 Controls Tumorigenicity and Ferroptosis Susceptibility by Binding With Nrf2 in Thyroid Carcinoma

Thyroid carcinoma (TC) is the most common malignant tumor of the endocrine system with increasing incidence. In this study, we found that BCL9 is markedly upregulated in human TC tumors and its expression is positively corrected with the process of TC. Functionally, we found that overexpression of BCL9 promoted the proliferation and migration of TC cells, while reduced the sensitivity of TC cells to ferroptosis, a form of cell death driven by iron-dependent lipid peroxidation and implicated as a novel cancer therapeutic strategy. Mechanistically, the co-immunoprecipitation assay determined that BCL9 could bind to Nrf2 which has been confirmed to play an important role in ferroptosis. Furthermore, we demonstrated that silence of BCL9 could decrease Nrf2 expression, and then affect the expression of the downstream genes of Nrf2, ultimately induce ferroptosis. Importantly, we confirmed the effects of BCL9 on TC tumors in vivo. Overall, this study unveils the functional role and clinical significance of BCL9 in TC progression, and highlights the potential of targeting BCL9/Nrf2 ferroptosis axis as a novel therapeutic strategy for TC treatment.

Bioactivated Glucoraphanin Modulates Genes Involved in Necroptosis on Motor-Neuron-like Nsc-34: A Transcriptomic Study

Research on bioactive compounds has grown recently due to their health benefits and limited adverse effects, particularly in reducing the risk of chronic diseases, including neurodegenerative conditions. According to these observations, this study investigates the activity of sulforaphane (RS-GRA) on an in vitro model of differentiated NSC-34 cells. We performed a transcriptomic analysis at various time points (24 h, 48 h, and 72 h) and RS-GRA concentrations (1 µM, 5 µM, and 10 µM) to identify molecular pathways influenced by this compound and the effects of dosage and prolonged exposure. We found 39 differentially expressed genes consistently up- or downregulated across all conditions. Notably, Nfe2l2, Slc1a5, Slc7a11, Slc6a9, Slc6a5, Sod1, and Sod2 genes were consistently upregulated, while Ripk1, Glul, Ripk3, and Mlkl genes were downregulated. Pathway perturbation analysis showed that the overall dysregulation of these genes results in a significant increase in redox pathway activity (adjusted p-value 1.11 × 10-3) and a significant inhibition of the necroptosis pathway (adjusted p-value 4.64 × 10-3). These findings suggest RS-GRA's potential as an adjuvant in neurodegenerative disease treatment, as both increased redox activity and necroptosis inhibition may be beneficial in this context. Furthermore, our data suggest two possible administration strategies, namely an acute approach with higher dosages and a chronic approach with lower dosages.

Qian Yang Yu Yin Granule prevents hypertensive cardiac remodeling by inhibiting NLRP3 inflammasome activation via Nrf2

ETHNOPHARMACOLOGICAL RELEVANCE

Qian Yang Yu Yin Granule (QYYYG), a traditional Chinese poly-herbal formulation, has been validated in clinical trials to mitigate cardiac remodeling (CR), and cardiac damage in patients with hypertension. However, the specific mechanism remains unclear.

AIM OF THE STUDY

This study explored the potential effects and potential mechanisms of QYYYG on hypertensive CR by combining various experimental approaches.

MATERIALS AND METHODS

Spontaneously hypertensive rats (SHRs) were used as a model of hypertensive CR, followed by QYYYG interventions. Blood pressure, cardiac function and structure, histopathological changes, and myocardial inflammation and oxidative stress were tested to assess the efficacy of QYYYG in SHRs. For in vitro experiments, a cell model of myocardial hypertrophy and injury was constructed with isoprenaline. Cardiomyocyte hypertrophy, oxidative stress, and death were examined after treatment with different concentrations of QYYYG, and transcriptomics analyses were performed to explore the underlying mechanism. Nrf2 and the ROS/NF-κB/NLRP3 inflammasome pathway were detected. Thereafter, ML385 and siRNAs were used to inhibit Nrf2 in cardiomyocytes, so as to verify whether QYYYG negatively regulates the NLRP3 inflammasome by targeting Nrf2, thereby ameliorating the associated phenotypes. Finally, high performance liquid chromatography (HPLC) was conducted to analyze the active ingredients in QYYYG, and molecular docking was utilized to preliminarily screen the compounds with modulatory effects on Nrf2 activities.

RESULTS

QYYYG improved blood pressure, cardiac function, and structural remodeling and attenuated myocardial inflammation, oxidative stress, and cell death in SHRs. The transcriptomics results showed that the inflammatory response might be crucial in pathological CR and that Nrf2, which potentially negatively regulates the process, was upregulated by QYYYG treatment. Furthermore, QYYYG indeed facilitated Nrf2 activation and negatively regulated the ROS/NF-κB/NLRP3 inflammasome pathway, therefore ameliorating the associated phenotypes. In vitro inhibition or knockdown of Nrf2 weakened or even reversed the repressive effect of QYYYG on ISO-induced inflammation, oxidative stress, pyroptosis, and the NLRP3 inflammasome activation. Based on the results of HPLC and molecular docking, 30 compounds, including cafestol, genistein, hesperetin, and formononetin, have binding sites to Keap1-Nrf2 protein and might affect the activity or stability of Nrf2.

CONCLUSION

In conclusion, the alleviatory effect of QYYYG on hypertensive CR is related to its regulation of Nrf2 activation. Specifically, QYYYG blocks the activation of the NLRP3 inflammasome by boosting Nrf2 signaling and depressing myocardial inflammation, oxidative stress, and pyroptosis, thereby effectively ameliorating hypertensive CR.

Supramolecular nanoparticle loaded with bilirubin enhances cartilage protection and alleviates osteoarthritis via modulating oxidative stress and inflammatory responses

Osteoarthritis (OA) is a chronic inflammation that gradually leads to cartilage degradation. Prolonged chondrocyte oxidative stress contributes to the development of diseases, including chondrocyte apoptosis, cartilage matrix degradation, and aggravation of articular cartilage damage. Bilirubin (BR) possesses strong antioxidant properties by scavenging reactive oxygen species (ROS) and potent protection effects against inflammation. However, its insolubility and short half-life limit its clinical use. Therefore, we developed a supramolecular system of ε-polylysine (EPL) conjugated by β-cyclodextrin (β-CD) on the side chain, and bilirubin was loaded via host-guest interactions, which resulted in the self-assemble of this system into bilirubin-loaded polylysine-β-cyclodextrin nanoparticle (PB) with improving solubility while reducing toxicity and prolonging medication action time. To explore PB's potential pharmacological mechanisms on OA, we established in vitro and in vivo OA models. PB exerted ROS-scavenging proficiency and anti-apoptotic effects on rat chondrocytes by activating the Nrf2-HO-1/GPX4 signaling pathway. Additionally, PB reprogrammed the cartilage microenvironment by regulating the NF-κB signaling pathway to maintain chondrocyte function. Animal experiments further confirmed that PB had excellent scavenging ability for ROS and inflammatory factors related to charge adsorption with cartilage as well as long retention ability. Together, this work suggests that PB has superior protective abilities with beneficial effects on OA, indicating its great potential for intervention therapy targeting chondrocytes.

Neuroprotection of isoorientin against microglia activation induced by lipopolysaccharide via regulating GSK3β, NF-κb and Nrf2/HO-1 pathways

Background: Isoorientin (ISO), a flavone C-glycoside, is a glycogen synthase kinase 3β (GSK3β) substrate-competitive inhibitor. ISO has potential in treatment of Alzheimer's disease (AD). An excessive activation of GSK3β can lead to neuroinflammation causing neuronal damage. Microglia cells, as resident immune cells of the central nervous system, mediate neuroinflammation. Here, we studied the effects of ISO on microglial activation to alleviate neuroinflammation.

Methods: Effects of ISO were observed upon the stimulation of mouse microglia BV2 or SIM-A9 cells by lipopolysaccharide (LPS). Lithium chloride (LiCl) was the positive control as a GSK3β inhibitor. The release of TNF-α and NO were analyzed by ELISA and Griess assays, while expressions of COX-2, Iba-1, BDNF, GSK3β, NF-κB p65, IκB, Nrf2 and HO-1 were detected by Western blotting. In the co-culture model of SIM-A9 cells and differentiated SH-SY5Y human neuroblastoma cells, effects of ISO on microglia-mediated neuronal damage were evaluated with the MTS assay.

Results: ISO significantly inhibited the production of TNF-α (p < 0.01), NO (p < 0.001) and the expression of COX-2 (p < 0.01) and Iba-1 (p < 0.05) induced by LPS, and increased BDNF. The cell viability of SH-SY5Y was inhibited by LPS in the co-culture, which was prevented by ISO pretreatment. ISO increased the expression of p-GSK3β (Ser9), IκB and HO-1 in the cytoplasm, decreased NF-κB p65 and increased Nrf2 in the nucleus compared with the LPS group.

Conclusion: ISO attenuated the activation of microglia through regulating the GSK3β, NF-κB and Nrf2/HO-1 signaling pathways to exert neuroprotection.

Asiatic acid reduces lipopolysaccharides-induced pulp inflammation through activation of nuclear factor erythroid 2-related factor 2 in rats

Background

Dental pulp inflammation, often initiated by Gram-negative microorganisms and lipopolysaccharides (LPS), can lead to pulpitis and, subsequently, dental pulp necrosis, compromising tooth structure and increasing susceptibility to fracture. Asiatic acid, derived from Centella asiatica, has demonstrated pharmacological properties, including anti-inflammatory and antioxidant effects, making it a potential candidate for mitigating LPS-induced pulp inflammation. This in vivo study aims to investigate the impact of Asiatic acid on the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway in Rattus norvegicus with LPS-induced pulp inflammation.

Methods

This quasi-laboratory experimental in vivo study employed a post-test-only control group design to investigate the effects of Asiatic acid on LPS-induced pulp inflammation in Wistar rats. Thirty rats were randomly divided into six groups subjected to various interventions. LPS was administered to all groups for 6 h except the standard control group (CG, n = 5). The negative control group (NCG, n = 5) received only glass ionomer cement. The positive control group (PCG, n = 5) received Eugenol with glass ionomer cement. Intervention groups 1, 2, and 3 (IG1, IG2, IG3; n = 5 each) received Asiatic acid at concentrations of 0.5%, 1%, and 2%, respectively, with glass ionomer cement. Dental pulp inflammation was confirmed through immunological (tumor necrosis factor alpha (TNF-α) levels), histopathological (inflammatory parameters), and physiological (pain assessment using the rat grimace scale) analyses. Additionally, Nrf2 levels were examined using enzyme-linked immunosorbent assay (ELISA).

Results

Asiatic acid administration significantly influenced Nrf2 levels in rats with LPS-induced pulp inflammation. Nrf2 levels were significantly higher in groups treated with 0.5% (IG1) (8.810 ± 1.092 ng/mL; p = 0.047), 1.0% (IG2) (9.132 ± 1.285 ng/mL; p = 0.020), and 2.0% (IG3) (11.972 ± 1.888 ng/mL; p = 0.000) Asiatic acid compared to NCG (7.146 ± 0.706). Notably, Nrf2 levels were also significantly higher in the 2.0% Asiatic acid group (IG3) compared to the PCG treated with Eugenol (8.846 ± 0.888 ng/mL; p = 0.001), as well as IG1 (p = 0.001) and IG2 (p = 0.002). However, no significant difference was observed between administering 0.5% Asiatic acid (IG1), 1.0% Asiatic acid (IG2), and Eugenol (PCG).

Conclusion

This research showed that Asiatic acid significantly impacted the Nrf2 levels in rats with LPS-induced pulp inflammation. This suggests that it has the potential to be used as a therapeutic agent for reducing dental pulp inflammation. These findings support the need to further explore Asiatic acid as a promising intervention for maintaining dental pulp health.

Zinc: a potential star for regulating peritoneal fibrosis

Peritoneal dialysis (PD) is a commonly used renal replacement therapy for patients with end-stage renal disease (ESRD). During PD, the peritoneum (PM), a semi-permeable membrane, is exposed to nonbiocompatible PD solutions. Peritonitis can occur, leading to structural and functional PM disorders, resulting in peritoneal fibrosis and ultrafiltration failure, which are important reasons for patients with ESRD to discontinue PD. Increasing evidence suggests that oxidative stress (OS) plays a key role in the pathogenesis of peritoneal fibrosis. Furthermore, zinc deficiency is often present to a certain extent in patients undergoing PD. As an essential trace element, zinc is also an antioxidant, potentially playing an anti-OS role and slowing down peritoneal fibrosis progression. This study summarises and analyses recent research conducted by domestic and foreign scholars on the possible mechanisms through which zinc prevents peritoneal fibrosis.

Alpha-synuclein, autophagy-lysosomal pathway, and Lewy bodies: Mutations, propagation, aggregation, and the formation of inclusions

Research into the pathophysiology of Parkinson's disease (PD) is a fast-paced pursuit, with new findings about PD and other synucleinopathies being made each year. The involvement of various lysosomal proteins, such as TFEB, TMEM175, GBA, and LAMP1/2, marks the rising awareness about the importance of lysosomes in PD and other neurodegenerative disorders. This, along with recent developments regarding the involvement of microglia and the immune system in neurodegenerative diseases, has brought about a new era in neurodegeneration: the role of proinflammatory cytokines on the nervous system, and their downstream effects on mitochondria, lysosomal degradation, and autophagy. More effort is needed to understand the interplay between neuroimmunology and disease mechanisms, as many of the mechanisms remain enigmatic. α-synuclein, a key protein in PD and the main component of Lewy bodies, sits at the nexus between lysosomal degradation, autophagy, cellular stress, neuroimmunology, PD pathophysiology, and disease progression. This review revisits some fundamental knowledge about PD while capturing some of the latest trends in PD research, specifically as it relates to α-synuclein.

Metformin ameliorates neuroinflammatory environment for neurons and astrocytes during in vitro and in vivo stroke and tobacco smoke chemical exposure: Role of Nrf2 activation

Despite the protective nature of the blood-brain barrier (BBB) and brain-protecting tissues, some types of CNS injury or stress can cause cerebral cytokine production and profound alterations in brain function. Neuroinflammation, which can also be accompanied by increased cerebral cytokine production, has a remarkable impact on the pathogenesis of many neurological illnesses, including loss of BBB integrity and ischemic stroke, yet effective treatment choices for these diseases are currently lacking. Although little is known about the brain effects of Metformin (MF), a commonly prescribed first-line antidiabetic drug, prior research suggested that it may be useful in preventing BBB deterioration and the increased risk of stroke caused by tobacco smoking (TS). Therefore, reducing neuroinflammation by escalating anti-inflammatory cytokine production and declining pro-inflammatory cytokine production could prove an effective therapeutic strategy for ischemic stroke. Hence, the current investigation was planned to explore the potential role of MF against stroke and TS-induced neuroinflammation and reactive oxygen species (ROS) production. Our studies revealed that MF suppressed releasing pro-inflammatory mediators like tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) by aiming at the nuclear factor kappa B (NF-κB) signaling pathway in primary neurons and astrocytes. MF also upregulated anti-inflammatory mediators, like interleukin-10 (IL-10), and interleukin-4 (IL-4), by upregulating the Nrf2-ARE signaling pathway. Adolescent mice receiving MF along with TS exposure also showed a notable decrease in NF-κB expression compared to the mice not treated with MF and significantly decreased the level of TNF-α, IL-1β, MCP-1, and MIP-2 and increased the levels of IL-10 and IL-4 through the activation of Nrf2-ARE signaling pathway. These results suggest that MF has anti-neuroinflammatory effects via inhibiting NF-κB signaling by activating Nrf2-ARE. These studies support that MF could be a strong candidate drug for treating and or preventing TS-induced neuroinflammation and ischemic stroke.

The role of Nrf2 in immune cells and inflammatory autoimmune diseases: a comprehensive review

INTRODUCTION

Nrf2 regulates mild stress, chronic inflammation, and metabolic changes by regulating different immune cells via downstream signaling. Collection of information about the role of Nrf2 in inflammatory autoimmune diseases will better understand the therapeutic potential of targeting Nrf2 in these diseases.

AREAS COVERED

In this review, we comprehensively discussed biological function of Nrf2 in different immune cells, including Nrf2 preventing oxidative tissue injury, affecting apoptosis of immune cells and inflammatory cytokine production. Moreover, we discussed the role of Nrf2 in the development of inflammatory autoimmune diseases.

EXPERT OPINION

Nrf2 binds to downstream signaling molecules and then provides durable protection against different cellular and organ stress. It has emerged as an important target for inflammatory autoimmune diseases. Development of Nrf2 modulator drugs needs to consider factors such as target specificity, short/long term safety, disease indication identification, and the extent of variation in Nrf2 activity. We carefully discussed the dual role of Nrf2 in some diseases, which helps to better target Nrf2 in the future.

Rutin alleviates Pb-induced oxidative stress, inflammation and cell death via activating Nrf2/ARE system in SH-SY5Y cells

Lead (Pb) is harmful to almost all organs, particularly the developmental neural system, and previous studies revealed oxidative stress played an important role in Pb neurotoxicity. Rutin, a type of flavonoid glycoside found in various plants and fruits, is widely used as a dietary supplement due to its antioxidant and anti-inflammatory properties, but whether rutin could protect against Pb neurotoxicity is unclear. In this study, we found rutin treatment significantly alleviated Pb-induced cell death, oxidative stress, and inflammation, resulting in cell survival. Moreover, rutin treatment promoted nuclear factor erythroid 2-related factor 2 (Nrf2) translocation from cytoplasm to nucleus and subsequently activated antioxidant and detoxifying enzymes expression including HO-1. Knocking down Nrf2 by siRNA transfection abolished this protection of rutin against Pb. Overall, rutin could alleviate Pb-induced oxidative stress, inflammation, and cell death by activating the Nrf2/antioxidant response elements (ARE) system.

Thymol and p-Cymene Protect the Liver by Mitigating Oxidative Stress, Suppressing TNF-α/NF-κB, and Enhancing Nrf2/HO-1 Expression in Immobilized Rats

This study aimed to investigate the effects of the monoterpenes thymol and p-cymene on the liver of rats subjected to prolonged immobilization stress and to discover the possible mechanism behind this effect. For 14 consecutive days, the rats were placed in a restrainer for 2.5 h every day to expose them to stress. During the same period, thymol (10 mg/kg, gavage) and p-cymene (50 mg/kg, intraperitoneally) were also administered. Thymol and p-cymene prevented the increase in malondialdehyde levels and the decrease in glutathione content in the liver of rats exposed to chronic immobility. They also increased the activity of the glutathione peroxidase enzyme in the liver of stressed animals, but only thymol could increase the activity of superoxide dismutase. These monoterpenes reduced the expression of pro-inflammatory cytokines tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, and IL-6 and nuclear factor kappa B (NF-κB) in the liver of stressed animals. They increased the expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1). Thymol and p-cymene greatly prevented the infiltration of inflammatory cells in the liver parenchyma of stressed rats. In conclusion, the study found that thymol and p-cymene have a hepatoprotective effect on immobilized rats, likely exerted by suppressing oxidative stress and inflammation, stimulating Nrf2/HO-1 signaling, and inhibiting the TNF-α/NF-κB pathway.

Taming neuroinflammation in Alzheimer's disease: The protective role of phytochemicals through the gut-brain axis

Alzheimer's disease (AD) is a progressive degenerative neurological condition characterized by cognitive decline, primarily affecting memory and logical thinking, attributed to amyloid-β plaques and tau protein tangles in the brain, leading to neuronal loss and brain atrophy. Neuroinflammation, a hallmark of AD, involves the activation of microglia and astrocytes in response to pathological changes, potentially exacerbating neuronal damage. The gut-brain axis is a bidirectional communication pathway between the gastrointestinal and central nervous systems, crucial for maintaining brain health. Phytochemicals, natural compounds found in plants with antioxidant and anti-inflammatory properties, such as flavonoids, curcumin, resveratrol, and quercetin, have emerged as potential modulators of this axis, suggesting implications for AD prevention. Intake of phytochemicals influences the gut microbial composition and its metabolites, thereby impacting neuroinflammation and oxidative stress in the brain. Consumption of phytochemical-rich foods may promote a healthy gut microbiota, fostering the production of anti-inflammatory and neuroprotective substances. Early dietary incorporation of phytochemicals offers a non-invasive strategy for modulating the gut-brain axis and potentially reducing AD risk or delaying its onset. The exploration of interventions targeting the gut-brain axis through phytochemical intake represents a promising avenue for the development of preventive or therapeutic strategies against AD initiation and progression.

Effects of ashwagandha (Withania somnifera) root extract on aging-related changes in healthy geriatric dogs: A randomized, double-blinded placebo-controlled study

BACKGROUND AND AIM

This study aimed to explore the clinical potential of Withania somnifera/ashwagandha root extract (ARE) to mitigate age-related changes in healthy geriatric dogs. We hypothesized that ARE can reduce the effects of advancing age, including physiological changes, immune response decline and susceptibility to diseases, by its immunomodulatory effects.

METHODS

A randomized, double-blind, placebo-controlled trial was conducted in Telangana, India, from July 2022 to September 2022. Twenty apparently healthy dogs, aged 8 years or older, were enrolled. The dogs were divided into two groups to receive ARE (15 mg/kg, once daily, orally) or a placebo control. Various parameters, including serum cortisol levels, haematological profiles, biochemical markers, antioxidant indicators and anti-inflammatory responses, were assessed at the initiation of study, day 30, and day 60.

RESULTS

The erythrocyte count and haemoglobin levels were significantly increased with ARE (p < 0.001), whereas leukocyte count decreased (p < 0.05). Moreover, significant decreases in important markers of liver function (alanine aminotransferase, aspartate aminotransferase, albumin and globulin; p < 0.001 at day 60), as well as kidney function markers (creatinine and blood urea nitrogen; p < 0.001 at days 30 and 60), were observed in ARE-treated dogs compared to the placebo control group. In addition, the levels of markers of oxidative stress (superoxide dismutase, catalase, glutathione and malondialdehyde) were significantly modulated by ARE intervention, indicating strong antioxidant effects. Interestingly, serum cortisol levels reduced significantly with ARE (p < 0.001). Compared to baseline, ARE significantly decreased key inflammatory markers, including interferon-γ, tumour necrosis factor-α, nuclear factor kappa light chain enhancer of activated B cells and interleukin-10 (p < 0.001) levels at day 60.

CONCLUSION

In conclusion, the findings of this study suggest that ARE has adaptogenic properties in healthy geriatric dogs by improving haematological and biochemical profiles, enhancing antioxidant defence, reducing stress and modulating inflammatory responses.

Nrf2-Keap1 in Cardiovascular Disease: Which Is the Cart and Which the Horse?

High levels of oxidant stress in the form of reactive oxidant species are prevalent in the circulation and tissues in various types of cardiovascular disease including heart failure, hypertension, peripheral arterial disease, and stroke. Here we review the role of nuclear factor erythroid 2-related factor 2 (Nrf2), an important and widespread antioxidant and anti-inflammatory transcription factor that may contribute to the pathogenesis and maintenance of cardiovascular diseases. We review studies showing that downregulation of Nrf2 exacerbates heart failure, hypertension, and autonomic function. Finally, we discuss the potential for using Nrf2 modulation as a therapeutic strategy for cardiovascular diseases and autonomic dysfunction.

Maternal exposure to airborne particulate matter during pregnancy and lactation induces kidney injury in rat dams and their male offspring: the role of vitamin D in pregnancy and beyond

BACKGROUND

Little is known about the transgenerational effects of maternal exposure to fine particulate matter (PM2.5) on offspring kidney health. This study investigated the effect of maternal administration of PM2.5 or PM2.5 with vitamin D during pregnancy and lactation on renal injury in rat dams and their offspring.

METHODS

Nine pregnant Sprague-Dawley rats received oral administration of normal saline, airborne PM2.5, or PM2.5 with vitamin D from gestational day 11 to postpartum day 21. Kidneys of rat dams (n = 3 for each group) and their male offspring (n = 5 for each group) were taken for analysis on postpartum or postnatal day 21.

RESULTS

Maternal PM2.5 exposure increased glomerular damage, tubulointerstitial injury, and cortical macrophage infiltration in both dams and pups; all increases were attenuated by vitamin D administration. In dam kidneys, PM2.5 increased the protein expression of vitamin D receptor (VDR), klotho, and tumor necrosis factor-α; vitamin D lessened these changes. The expressions of renin, nuclear factor erythroid 2-related factor 2 (Nrf2), and nuclear factor-kappa B (NF-κB) p50 decreased in rat dams exposed to PM2.5. In offspring kidneys, exposure to maternal PM2.5 reduced the expression of VDR, renin, angiotensin-converting enzyme (ACE), Nrf2, and NF-κB p50, but increased cytochrome P450 24A1 expression. Maternal vitamin D administration with PM2.5 enhanced VDR, ACE, and NF-κB p50 activities in pup kidneys.

CONCLUSION

PM2.5 exposure during nephrogenesis may exert transgenerational renal impairment, and maternal vitamin D intake could attenuate PM2.5-induced kidney damage in mothers and their offspring.

Transcriptional coactivation of NRF2 signaling in cardiac fibroblasts promotes resistance to oxidative stress

We recently discovered that steroid receptor coactivators (SRCs) SRCs-1, 2 and 3, are abundantly expressed in cardiac fibroblasts (CFs) and their activation with the SRC small molecule stimulator MCB-613 improves cardiac function and dramatically lowers pro-fibrotic signaling in CFs post-myocardial infarction. These findings suggest that CF-derived SRC activation could be beneficial in the mitigation of chronic heart failure after ischemic insult. However, the cardioprotective mechanisms by which CFs contribute to cardiac pathological remodeling are unclear. Here we present studies designed to identify the molecular and cellular circuitry that governs the anti-fibrotic effects of an MCB-613 derivative, MCB-613-10-1, in CFs. We performed cytokine profiling and whole transcriptome and proteome analyses of CF-derived signals in response to MCB-613-10-1. We identified the NRF2 pathway as a direct MCB-613-10-1 therapeutic target for promoting resistance to oxidative stress in CFs. We show that MCB-613-10-1 promotes cell survival of anti-fibrotic CFs exposed to oxidative stress by suppressing apoptosis. We demonstrate that an increase in HMOX1 expression contributes to CF resistance to oxidative stress-mediated apoptosis via a mechanism involving SRC co-activation of NRF2, hence reducing inflammation and fibrosis. We provide evidence that MCB-613-10-1 acts as a protectant against oxidative stress-induced mitochondrial damage. Our data reveal that SRC stimulation of the NRF2 transcriptional network promotes resistance to oxidative stress and highlights a mechanistic approach toward addressing pathologic cardiac remodeling.