Therapeutic targets in the ASK1-dependent stress signaling pathways

Biological effect of U(VI) exposure on lung epithelial BEAS-2B cells

In this study, the biological effects of U(VI) exposure on lung epithelial cells were investigated by MTT assay, immunofluorescence, flow cytometry, and Western blotting. U(VI)-induced stress triggers oxidative stress in cells, activates MAPK signaling pathways, and promotes inflammation. Additionally, U(VI) causes damage to the cell membrane structure and severe DNA injury, impacting the accuracy of transcription and translation. The results demonstrate that U(VI) exposure significantly inhibits cell proliferation and migration. This is attributed to the disruption of the PI3K/AKT/GSK-3β/β-catenin signaling pathway and the reduction in CyclinD1 expression, leading to a delayed cell cycle, decreased growth rate, mitochondrial damage, and reduced energy metabolism. This study provides a comprehensive understanding of the molecular mechanisms underlying uranium-induced cellular toxicity in lung epithelial cells.

Potential for Drug Repositioning of Midazolam as an Inhibitor of Inflammatory Bone Resorption

Drug repositioning is a method for exploring new effects of existing drugs, the safety and pharmacokinetics of which have been confirmed in humans. Here, we demonstrate the potential drug repositioning of midazolam (MDZ), which is used for intravenous sedation, as an inhibitor of inflammatory bone resorption. We cultured a mouse macrophage-like cell line with or without MDZ and evaluated its effects on the induction of differentiation of these cells into osteoclasts. For in vivo investigations, we administered lipopolysaccharide (LPS) together with MDZ (LPS+MDZ) to the parietal region of mice and evaluated the results based on the percentage of bone resorption and calvaria volume. Furthermore, we examined the effects of MDZ on the production of reactive oxygen species (ROS) in cells and on its signaling pathway. MDZ inhibited osteoclast differentiation and bone resorption activity. In animal studies, the LPS+MDZ group showed a decreasing trend associated with the rate of bone resorption. In addition, the bone matrix volume in the LPS+MDZ group was slightly higher than in the LPS only group. MDZ inhibited osteoclast differentiation by decreasing ROS production and thereby negatively regulating the p38 mitogen-activated protein kinase pathway. Thus, we propose that MDZ could potentially be used for treating inflammatory bone resorption, for example, in periodontal disease.

Personalizing Therapy Outcomes through Mitogen-Activated Protein Kinase Pathway Inhibition in Non-Small Cell Lung Cancer

Lung cancer (LC) is a highly invasive malignancy and the leading cause of cancer-related deaths, with non-small cell lung cancer (NSCLC) as its most prevalent histological subtype. Despite all breakthroughs achieved in drug development, the prognosis of NSCLC remains poor. The mitogen-activated protein kinase signaling cascade (MAPKC) is a complex network of interacting molecules that can drive oncogenesis, cancer progression, and drug resistance when dysregulated. Over the past decades, MAPKC components have been used to design MAPKC inhibitors (MAPKCIs), which have shown varying efficacy in treating NSCLC. Thus, recent studies support the potential clinical use of MAPKCIs, especially in combination with other therapeutic approaches. This article provides an overview of the MAPKC and its inhibitors in the clinical management of NSCLC. It addresses the gaps in the current literature on different combinations of selective inhibitors while suggesting two particular therapy approaches to be researched in NSCLC: parallel and aggregate targeting of the MAPKC. This work also provides suggestions that could serve as a potential guideline to aid future research in MAPKCIs to optimize clinical outcomes in NSCLC.

The scaffold protein disabled 2 (DAB2) and its role in tumor development and progression

BACKGROUND

Disabled 2 (DAB2) is a multifunctional protein that has emerged as a critical component in the regulation of tumor growth. Its dysregulation is implicated in various types of cancer, underscoring its importance in understanding the molecular mechanisms underlying tumor development and progression. This review aims to unravel the intricate molecular mechanisms by which DAB2 exerts its tumor-suppressive functions within cancer signaling pathways.

METHODS AND RESULTS

We conducted a comprehensive review of the literature focusing on the structure, expression, physiological functions, and tumor-suppressive roles of DAB2. We provide an overview of the structure, expression, and physiological functions of DAB2. Evidence supporting DAB2's role as a tumor suppressor is explored, highlighting its ability to inhibit cell proliferation, induce apoptosis, and modulate key signaling pathways involved in tumor suppression. The interaction between DAB2 and key oncogenes is examined, elucidating the interplay between DAB2 and oncogenic signaling pathways. We discuss the molecular mechanisms underlying DAB2-mediated tumor suppression, including its involvement in DNA damage response and repair, regulation of cell cycle progression and senescence, and modulation of epithelial-mesenchymal transition (EMT). The review explores the regulatory networks involving DAB2, covering post-translational modifications, interactions with other tumor suppressors, and integration within complex signaling networks. We also highlight the prognostic significance of DAB2 and its role in pre-clinical studies of tumor suppression.

CONCLUSION

This review provides a comprehensive understanding of the molecular mechanisms by which DAB2 exerts its tumor-suppressive functions. It emphasizes the significance of DAB2 in cancer signaling pathways and its potential as a target for future therapeutic interventions.

Steatotic Liver Disease: Pathophysiology and Emerging Pharmacotherapies

Steatotic liver disease (SLD) displays a dynamic and complex disease phenotype. Consequently, the metabolic dysfunction-associated steatotic liver disease (MASLD)/metabolic dysfunction-associated steatohepatitis (MASH) therapeutic pipeline is expanding rapidly and in multiple directions. In parallel, noninvasive tools for diagnosing and monitoring responses to therapeutic interventions are being studied, and clinically feasible findings are being explored as primary outcomes in interventional trials. The realization that distinct subgroups exist under the umbrella of SLD should guide more precise and personalized treatment recommendations and facilitate advancements in pharmacotherapeutics. This review summarizes recent updates of pathophysiology-based nomenclature and outlines both effective pharmacotherapeutics and those in the pipeline for MASLD/MASH, detailing their mode of action and the current status of phase 2 and 3 clinical trials. Of the extensive arsenal of pharmacotherapeutics in the MASLD/MASH pipeline, several have been rejected, whereas other, mainly monotherapy options, have shown only marginal benefits and are now being tested as part of combination therapies, yet others are still in development as monotherapies. Although the Food and Drug Administration (FDA) has recently approved resmetirom, additional therapeutic approaches in development will ideally target MASH and fibrosis while improving cardiometabolic risk factors. Due to the urgent need for the development of novel therapeutic strategies and the potential availability of safety and tolerability data, repurposing existing and approved drugs is an appealing option. Finally, it is essential to highlight that SLD and, by extension, MASLD should be recognized and approached as a systemic disease affecting multiple organs, with the vigorous implementation of interdisciplinary and coordinated action plans. SIGNIFICANCE STATEMENT: Steatotic liver disease (SLD), including metabolic dysfunction-associated steatotic liver disease and metabolic dysfunction-associated steatohepatitis, is the most prevalent chronic liver condition, affecting more than one-fourth of the global population. This review aims to provide the most recent information regarding SLD pathophysiology, diagnosis, and management according to the latest advancements in the guidelines and clinical trials. Collectively, it is hoped that the information provided furthers the understanding of the current state of SLD with direct clinical implications and stimulates research initiatives.

Discovery of benzoheterocyclic-substituted amide derivatives as apoptosis signal-regulating kinase 1 (ASK1) inhibitors

Three series of benzoheterocyclic-substituted amide derivatives were designed and synthesized as potent ASK1 inhibitors in this work. After undergoing continuous structural optimization, compound 17a was discovered to be a novel inhibitor of ASK1 with good potency (kinase, IC50 = 26 nM), noteworthy liver microsomal stability (human, T1/2 = 340.4 min), good pharmacokinetic parameters (rat, T1/2 p.o. = 2.11 h, AUClast p.o. = 10 900 h ng mL-1) and high oral bioavailability (rat, F = 97.9%), while also being inactive towards hERG (IC50 > 10 μM).

Spinosin inhibits activated hepatic stellate cell to attenuate liver fibrosis by targeting Nur77/ASK1/p38 MAPK signaling pathway

AIM

Liver fibrosis remains a great challenge in the world. Spinosin (SPI), a natural flavonoid-C-glycoside, possesses various pharmacological activities including anti-inflammatory and anti-myocardial fibrosis effects. In this study, we investigate whether SPI can be a potential lead for the treatment of liver fibrosis and explore whether the orphan nuclear receptor Nur77, a negative regulator of liver fibrosis development, plays a critical role in SPI's action.

METHODS

A dual luciferase reporter system of α-SMA was established to evaluate the effect of SPI on hepatic stellate cell (HSC) activation in LX2 and HSC-T6 cells. A mouse model of CCl4-induced liver fibrosis was used to test the efficacy of SPI against liver fibrosis. The expression levels of Nur77, inflammatory cytokines and collagen were determined by Western blotting and qPCR. Potential kinase pathways involved were also analyzed. The affinity of Nur77 with SPI was documented by fluorescence titration.

RESULTS

SPI can strongly suppress TGF-β1-mediated activation of both LX2 and HSC-T6 cells in a dose-dependent manner. SPI increases the expression of Nur77 and reduces TGF-β1-mediated phosphorylation levels of ASK1 and p38 MAPK, which can be reversed by knocking out of Nur77. SPI strongly inhibits collagen deposition (COLA1) and reduces inflammatory cytokines (IL-6 and IL-1β), which is followed by improved liver function in the CCl4-induced mouse model. SPI can directly bind to R515 and R563 in the Nur77-LBD pocket with a Kd of 2.14 μM.

CONCLUSION

Spinosin is the major pharmacological active component of Ziziphus jujuba Mill. var. spinosa which has been frequently prescribed in traditional Chinese medicine. We demonstrate here for the first time that spinosin is a new therapeutic lead for treatment of liver fibrosis by targeting Nur77 and blocking the ASK1/p38 MAPK signaling pathway.

Anti-inflammatory effects of TNF-α and ASK1 inhibitory compounds isolated from Schkuhria pinnata used for the treatment of dermatitis

ETHNO-PHARMACOLOGICAL RELEVANCE

The Andean Schkuhria pinnata species commonly known as 'Canchalagua' is used as an infusion in Andean countries to treat various anti-inflammatory and skin-related pathologies.

AIM OF THE STUDY

This study determined the anti-inflammatory activity of the aqueous extract from Schkuhria pinnata, identified compounds with high biological activity and performed a structure-activity relationship analysis to determine their binding mechanism.

MATERIALS AND METHODS

A bio-guided isolation of the active compounds of Schkuhria pinnata was carried out by selecting the most active sub-extracts and fractions to test their anti-inflammatory activity against the ASK1 and TNF-α cytokines.

RESULTS

Three compounds were obtained, and their structures were elucidated by nuclear magnetic resonance. The compounds were (3R,4R)-4-(3,4-dimethoxybenzyl)-3-(4-hydroxy-3-methoxybenzyl) dihydrofuran-2(3H)-one (1), N-[2,3-dihydro-1,3-dimethyl-6-[(2R)-2-methyl-1-piperazinyl]-2-oxo-1H-benzimidazol-5-yl]-2-methoxybenzamide (2), and N-hydroxy-1-cyclopentene-1-carboxamide (3). Regarding their anti-inflammatory activity, the three compounds inhibited the TNF-α and ASK1 cytokines, however, compound 2 was the most active, with an IC50 of 19.08 and 8.94 nM, respectively.

CONCLUSION

The anti-inflammatory activity of the aqueous extract of Schkuhria pinnata was evaluated, followed by the isolation of three compounds and the study of their pharmacological activity. The three compounds have been shown as promising treatment against dermatitis, confirming at the same time their traditional use.

Genes That Extend Lifespan May Do So by Mitigating the Increased Risk of Death Posed by Having Hypertension

BACKGROUND

Genetic factors influence lifespan. In humans, there appears to be a particularly strong genetic effect in those aged ≥ 90 years. An important contribution is nutrient sensing genes which confer cell resilience.

METHODS

Our research has been investigating the genetic factors by longitudinal studies of American men of Japanese descent living on the island of Oahu in Hawaii. This cohort began as the Honolulu Heart Program in the mid-1960s and most subjects are now deceased.

RESULTS

We previously discovered various genes containing polymorphisms associated with longevity. In recent investigations of the mechanism involved we found that the longevity genotypes ameliorated the risk of mortality posed by having a cardiometabolic disease (CMD)-most prominently hypertension. For the gene FOXO3 the protective alleles mitigated the risk of hypertension, coronary heart disease (CHD) and diabetes. For the kinase MAP3K5 it was hypertension, CHD and diabetes, for the kinase receptor PIK3R1 hypertension, CHD and stroke, and for the growth hormone receptor gene (GHR) and vascular endothelial growth factor receptor 1 gene (FLT1), it was nullifying the higher mortality risk posed by hypertension. Subjects with a CMD who had a longevity genotype had similar survival as men without CMD. No variant protected against risk of death from cancer. We have postulated that the longevity-associated genotypes reduced mortality risk by effects on intracellular resilience mechanisms. In a proteomics study, 43 "stress" proteins and associated biological pathways were found to influence the association of FOXO3 genotype with reduced mortality.

CONCLUSIONS

Our landmark findings indicate how heritable genetic components affect longevity.

Off-target pharmacological activity at various kinases: Potential functional and pathological side effects

In drug discovery, during the lead optimization and candidate characterization stages, novel small molecules are frequently evaluated in a battery of in vitro pharmacology assays to identify potential unintended, off-target interactions with various receptors, transporters, ion channels, and enzymes, including kinases. Furthermore, these screening panels may also provide utility at later stages of development to provide a mechanistic understanding of unexpected safety findings. Here, we present a compendium of the most likely functional and pathological outcomes associated with interaction(s) to a panel of 95 kinases based on an extensive curation of the scientific literature. This panel of kinases was designed by AbbVie based on safety-related data extracted from the literature, as well as from over 20 years of institutional knowledge generated from discovery efforts. For each kinase, the scientific literature was reviewed using online databases and the most often reported functional and pathological effects were summarized. This work should serve as a practical guide for small molecule drug discovery scientists and clinical investigators to predict and/or interpret adverse effects related to pharmacological interactions with these kinases.

The Combination of Sinusoidal Perfusion Enhancement and Apoptosis Inhibition by Riociguat Plus a Galactose-PEGylated Bilirubin Multiplexing Nanomedicine Ameliorates Liver Fibrosis Progression

Chronic liver injury and continuous wound healing lead to extracellular matrix (ECM) deposition and liver fibrosis. The elevated production of reactive oxygen species (ROS) in the liver leads to the apoptosis of hepatocytes and the activation of hepatic stellate cells (HSCs). In the current study, we describe a combination strategy of sinusoidal perfusion enhancement and apoptosis inhibition enabled by riociguat together with a tailor-designed galactose-PEGylated bilirubin nanomedicine (Sel@GBRNPs). Riociguat enhanced sinusoidal perfusion and decreased the associated ROS accumulation and inflammatory state of the fibrotic liver. Concurrently, hepatocyte-targeting galactose-PEGylated bilirubin scavenged excessive ROS and released encapsulated selonsertib. The released selonsertib inhibited apoptosis signal-regulating kinase 1 (ASK1) phosphorylation to alleviate apoptosis in hepatocytes. The combined effects on ROS and hepatocyte apoptosis attenuated the stimulation of HSC activation and ECM deposition in a mouse model of liver fibrosis. This work provides a novel strategy for liver fibrosis treatment based on sinusoidal perfusion enhancement and apoptosis inhibition.

The function of long non-coding RNA in non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease is a disease that is currently prevalent in the world, increasingly becoming the mainstay of liver diseases. And its prevalence is rapidly increasing, but its pathogenesis is not entirely understood. Long non-coding RNAs have increasingly gained attention as science has progressed in recent years. Studies have shown that long non-coding RNAs are involved in a variety of biological processes in vivo, such as proliferation, differentiation, and apoptosis, and can affect disease by regulating gene expression. This review explores the biological processes involving long non-coding RNAs, including lipid metabolism, glucose metabolism, liver fibrosis, and apoptosis. In addition, we summarize how the different long non-coding RNAs involved in each process function. Finally, the shortcomings of long non-coding RNAs as potential therapeutic targets are briefly described. In conclusion, this article provides a clear visualization of the link that exists between long non-coding RNAs and non-alcoholic fatty liver disease.

Thioredoxin-interacting protein deficiency protects against severe acute pancreatitis by suppressing apoptosis signal-regulating kinase 1

Acute pancreatitis is a common acute inflammatory abdominal disease. When acute pancreatitis progresses to severe acute pancreatitis (SAP), it can lead to systemic inflammation and even multiple organ failure. Thioredoxin-interacting protein (TXNIP) is an important protein involved in redox reactions of the inflammatory response. However, the specific role of TXNIP in SAP remains unclear. In this study, we investigated the role of thioredoxin interacting protein (TXNIP) in acute pancreatitis when induced by high doses of arginine. We found that pancreatic damage and the inflammatory response associated with acute pancreatitis were largely restrained in TXNIP knock-out mice but were enhanced in mice overexpressing TXNIP. Interestingly, the phosphorylation of p38, JNK, and ASK1 diminished in TXNIP-KO mice with pancreatitis in comparison with wild-type mice. The role of oxidative stress in SAP was explored in two models: TXNIP and AVV-TXNIP. TXNIP knockdown or the inhibition of ASK1 by gs-4997 abrogated the increase in p-p38, p-JNK, and p-ASK1 in AR42J cells incubated with L-Arg. The administration of gs-4997 to mice with pancreatitis largely reduced the upregulation of IL-6, IL-1β, TNF-α, and MCP-1. Systemic inflammatory reactions and injury in the lungs and kidneys were assessed in TXNIP-KO and AVV-TXNIP mice with expected outcomes. In conclusion, TXNIP is a novel mediator of SAP and exerts action by regulating inflammatory responses and oxidative stress via the ASK1-dependent activation of the JNK/p38 pathways. Thus, targeting TXNIP may represent a promising approach to protect against SAP.

Metabolic remodeling in tumor-associated macrophages contributing to antitumor activity of cryptotanshinone by regulating TRAF6-ASK1 axis

Dampening tumor growth by converting tumor-associated macrophages (TAMs) from M2/repair-types to M1/kill-types is of high interest. Here, we show that cryptotanshinone (CPT) can function as an antitumor immune modulator that switches TAMs from an M2 to an M1 phenotype, leading to tumor regression. An orthotopic triple-negative breast cancer (TNBC) implantation model was used to determine the role and mechanism of CPT in suppressing M1-to-M2 repolarization of TAMs. Co-culturing TNBC cells with CPT-treated macrophages reduced TNBC proliferation and motility, while in TNBC orthotopic mouse models, CPT treatment inhibited breast tumor formation.

Moreover, we identified that CPT inhibits mitochondrial oxidative phosphorylation and mitochondrial fusion via autophagy and transcriptional activation of the apoptosis signal-regulating kinase 1 (ASK1) pathway. Suppression of ASK1 downregulates autophagy and abolishes CPT-induced effects upon TAMs. In addition, CPT inhibits M2 macrophage differentiation and causes TRAF6 auto-ubiquitination-dependent activation of the ASK1, leading to M1 polarization. On the contrary, in M1 macrophage, CPT increases interaction of ASK1 and TRAF6 which induces ASK1 ubiquitination and degradation. Intriguingly, CPT plays opposite roles in the M1 and M2 phenotype. Our findings help to illuminate a previously unrecognized antitumor mechanism of CPT and suggest that this natural compound offers a macrophage-based approach for cancer immunotherapy.

Amorphous selenium nanodots alleviate non-alcoholic fatty liver disease via activating VEGF receptor 1 to further inhibit phosphorylation of JNK/p38 MAPK pathways

In clinic, there is still no unified standard for the treatment of non-alcoholic fatty liver disease (NAFLD), and the development of effective novel drugs to alleviate NAFLD remains a challenge. This study aimed to explore the effect and mechanism of amorphous selenium nanodots (A SeNDs) in alleviating NAFLD. Model rats with NAFLD were induced by the high-fat diet (HFD). Histomorphology was used to observe liver tissue, automatic biochemical analyzer was used to analyze liver function indicators, and ELISA kit was used to detect the effect of A SeNDs on oxidative stress and inflammatory factors in NAFLD rats. The results exhibited that A SeNDs could reduce hepatocyte steatosis, liver index, blood lipid level, and transaminase level in NAFLD rats. Furthermore, A SeNDs could relieve the oxidative stress and inflammatory reaction and maintain liver tissue structure in NAFLD rats. Mechanistically, A SeNDs (0.3 mg/kg/day) inhibit the phosphorylation of JNK/p38 MAPK pathways after activating vascular endothelial growth factor receptor 1 (VEGFR1) in the liver of rats with NAFLD to allay oxidative stress and inflammatory response and improves hepatic structure and liver function. Therefore, it should be an important method to mitigate NAFLD by supplementing A SeNDs to normalize hepatic structure and liver function.

SB332235, a CXCR2 antagonist, ameliorates thioacetamide-induced hepatic encephalopathy through modulation of the PI3K/AKT pathways in rats

RATIONALE

Hepatic encephalopathy (HE) is a neuropsychiatric disorder that results from either acute or chronic liver failure. CXCR2 plays an essential role in the pathophysiology of liver and brain diseases. In the present study, the potential beneficial effects of SB332235, a selective inhibitor of CXCR2, against HE were evaluated.

METHODS

HE was induced in male rats by thioacetamide injection (200 mg/kg, i.p.) at three alternative days. SB332235 was injected in rats 1 h before TAA at a dose of 1 and 3 mg/kg i.p.

RESULTS

SB332235 alleviated oxidative stress as shown by the decreased serum NO and reduced MDA, elevated GSH and SOD levels, and reduced TNF-α and NF-κB levels in both brain and liver tissues of rats. Additionally, SB332235 suppressed brain ASK-1, JNK, IL-8, and caspase-3 expression, and activated PI3K/AKT expression in brain tissues. Markers of brain dysfunction, such as ammonia, and markers of hepatic injury, such as LDH, albumin, bilirubin, γGT, AST, ALT, and ALP, were significantly ameliorated. Also, the protective effect of SB332235 was confirmed by histological examination of both brain and liver tissues.

CONCLUSIONS

Both doses (1 and 3 mg/kg) of SB332235 revealed significant hepatic/neuroprotective effects due to their anti-inflammatory, antioxidant, and antiapoptotic activities via activation of the PI3K/AKT pathway. Between the two, the 1 mg/kg dose provided significantly improved outcomes.

Crystallographic mining of ASK1 regulators to unravel the intricate PPI interfaces for the discovery of small molecule

Protein seldom performs biological activities in isolation. Understanding the protein–protein interactions’ physical rewiring in response to pathological conditions or pathogen infection can help advance our comprehension of disease etiology, progression, and pathogenesis, which allow us to explore the alternate route to control the regulation of key target interactions, timely and effectively. Nonalcoholic steatohepatitis (NASH) is now a global public health problem exacerbated due to the lack of appropriate treatments. The most advanced anti-NASH lead compound (selonsertib) is withdrawn, though it is able to inhibit its target Apoptosis signal-regulating kinase 1 (ASK1) completely, indicating the necessity to explore alternate routes rather than complete inhibition. Understanding the interaction fingerprints of endogenous regulators at the molecular level that underpin disease formation and progression may spur the rationale of designing therapeutic strategies. Based on our analysis and thorough literature survey of the various key regulators and PTMs, the current review emphasizes PPI-based drug discovery’s relevance for NASH conditions. The lack of structural detail (interface sites) of ASK1 and its regulators makes it challenging to characterize the PPI interfaces. This review summarizes key regulators interaction fingerprinting of ASK1, which can be explored further to restore the homeostasis from its hyperactive states for therapeutics intervention against NASH.

Genomics and proteomics combined analysis revealed the toxicity response of silkworm Bombyx mori to the environmental pathogen Bacillus cereus ZJ-4

Bacterial contamination has caused a major public health problem worldwide. Bacillus cereus is a conditional environmental pathogenic bacteria that can cause food poisoning. Whether environmental pathogens can cause widespread transmission in the insect kingdom is unclear. In this study, a Bacillus cereus ZJ-4 was isolated from the hospital environment of Zhenjiang City, Jiangsu Province, China. It was fatal by injection into the silkworm hemolymph. To investigated the potential toxic factors of ZJ-4 and clarified the toxicity response mechanism of silkworm by the ZJ-4 infection. Then, the whole genome of ZJ-4 was sequenced, and the immune mechanism of silkworm fat body to ZJ-4 pathogen was studied by HE pathological section and proteomics. Bacterial genome sequencing indicated that ZJ-4 had 352 drug resistance genes and 6 virulence genes. After 36 h of subcutaneous puncture with ZJ-4 suspension, the pathological changes were obviously found in HE pathological sections of fat body tissue. Comparative proteomic results indicated that differentially expressed proteins are mainly involved in stress reactions, biological regulation, and innate immunity. The qRT-PCR analysis showed that the expressions of β-GRP, Spaetzle, MyD88, Tube and Dorsal genes in Toll pathway were up-regulated, while Pell and Cactus genes were down-regulated; in the antimicrobial peptide pathway, Glv2, Lzm, Mor, and Leb3 genes were up-regulated, while attacin1 and defensin genes were down-regulated; Sod gene was up-regulated, while Cat gene was down-regulated in the antioxidant pathway; Ldh, Sdh, and Mdh genes were down-regulated in glucose metabolism pathway. These results indicated that ZJ-4 can damage the innate immune pathway of silkworm, and also affect the normal immune function of fat body cells.

QNZ alleviated hepatocellular carcinoma by targeting inflammatory pathways in a rat model

The pathogenicity of HCC could be enhanced by TNF-α and NFκB, which are crucial parts of the inflammatory pathway inside the HCC microenvironment. Therefore, we aimed to discover the therapeutic effects of QNZ, an inhibitor of both TNF-α and NFκB, in an experimental model of HCC in rats. HCC was experimentally induced in rats by thioacetamide, and some of the rats were treated with QNZ. The expression levels of nuclear factor (NF)κB, tumor necrosis factor (TNF)-α, apoptosis signal regulating kinase (ASK)-1, β-catenin, glycogen synthase kinase (GSK)-3 and TNF receptor-associated factor (TRAF) were examined in hepatic samples. In addition, hepatic tissues were stained with hematoxylin/eosin and anti-TNF-α antibodies. QNZ blocked HCC-induced expression of both NFκB and TNF-α. It significantly reduced both α-fetoprotein and the average number of nodules and increased the survival rate of the HCC rats. Moreover, hematoxylin and eosin liver sections from the HCC rats showed vacuolated cytoplasm and necrotic nodules. All of these effects were alleviated by QNZ treatment. Finally, treating HCC rats with QNZ resulted in a reduction in the expression of TRAF, ASK-1 and β-catenin, as well as increased expression of GSK-3. In conclusion, inhibition of the inflammatory pathway in HCC with QNZ produced therapeutic effects, as indicated by an increased survival rate, reduced serum α-fetoprotein levels, decreased liver nodules and improved the hepatocyte structure. In addition, QNZ significantly reduced the expression of TRAF, ASK-1 and β-catenin that were associated with increased expression of GSK-3.

p47phox-Dependent Oxidant Signalling through ASK1, MKK3/6 and MAPKs in Angiotensin II-Induced Cardiac Hypertrophy and Apoptosis

The p47phox is a key regulatory subunit of Nox2-containing NADPH oxidase (Nox2) that by generating reactive oxygen species (ROS) plays an important role in Angiotensin II (AngII)-induced cardiac hypertrophy and heart failure. However, the signalling pathways of p47phox in the heart remains unclear. In this study, we used wild-type (WT) and p47phox knockout (KO) mice (C57BL/6, male, 7-month-old, n = 9) to investigate p47phox-dependent oxidant-signalling in AngII infusion (0.8 mg/kg/day, 14 days)-induced cardiac hypertrophy and cardiomyocyte apoptosis. AngII infusion resulted in remarkable high blood pressure and cardiac hypertrophy in WT mice. However, these AngII-induced pathological changes were significantly reduced in p47phox KO mice. In WT hearts, AngII infusion increased significantly the levels of superoxide production, the expressions of Nox subunits, the expression of PKCα and C-Src and the activation of ASK1 (apoptosis signal-regulating kinase 1), MKK3/6, ERK1/2, p38 MAPK and JNK signalling pathways together with an elevated expression of apoptotic markers, i.e., γH2AX and p53 in the cardiomyocytes. However, in the absence of p47phox, although PKCα expression was increased in the hearts after AngII infusion, there was no significant activation of ASK1, MKK3/6 and MAPKs signalling pathways and no increase in apoptosis biomarker expression in cardiomyocytes. In conclusion, p47phox-dependent redox-signalling through ASK1, MKK3/6 and MAPKs plays a crucial role in AngII-induced cardiac hypertrophy and cardiomyocyte apoptosis.

DUSP12 acts as a novel endogenous protective signal against hepatic ischemia-reperfusion damage by inhibiting ASK1 pathway

Ischemia–reperfusion injury (IRI) consequent to major liver surgery is a still unmet clinical problem. The activation of endogenous systems of hepatoprotection can prevent the damaging effects of ischemia–reperfusion (IR) as shown by the phenomenon known as ‘ischemic preconditioning’. The identification of endogenous signal mediators of hepatoprotection is of main interest since they could be targeted in future therapeutic interventions. Qiu et al. recently reported in Clin. Sci. (Lond.) (2020) 134(17), 2279–2294, the discovery of a novel protective molecule against hepatic IR damage: dual-specificity phosphatase 12 (DUSP12). IR significantly decreased DUSP12 expression in liver whereas DUSP12 overexpression in hepatocytes protected IRI and DUSP12 deletion in DUSP12 KO mice exacerbated IRI. The protective effects of DUSP12 depended on apoptosis signal-regulating kinase 1 (ASK1) and acted through the inhibition of the ASK1-dependent kinases c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK). These results enlighten DUSP12 as a novel intermediate negative regulator of the pro-inflammatory and pro-apoptotic ASK1/JNK-p38 MAPK pathway activated during hepatic IR and identify DUSP12 as potential therapeutic target for IRI.

An RNAi screen of the kinome in epithelial follicle cells of the Drosophila melanogaster ovary reveals genes required for proper germline death and clearance

Programmed cell death and cell corpse clearance are an essential part of organismal health and development. Cell corpses are often cleared away by professional phagocytes such as macrophages. However, in certain tissues, neighboring cells known as nonprofessional phagocytes can also carry out clearance functions. Here, we use the Drosophila melanogaster ovary to identify novel genes required for clearance by nonprofessional phagocytes. In the Drosophila ovary, germline cells can die at multiple time points. As death proceeds, the epithelial follicle cells act as phagocytes to facilitate the clearance of these cells. We performed an unbiased kinase screen to identify novel proteins and pathways involved in cell clearance during two death events. Of 224 genes examined, 18 demonstrated severe phenotypes during developmental death and clearance while 12 demonstrated severe phenotypes during starvation-induced cell death and clearance, representing a number of pathways not previously implicated in phagocytosis. Interestingly, it was found that several genes not only affected the clearance process in the phagocytes, but also non-autonomously affected the process by which germline cells died. This kinase screen has revealed new avenues for further exploration and investigation.

Elaidic Acid Potentiates Extracellular ATP-Induced Apoptosis via the P2X7-ROS-ASK1-p38 Axis in Microglial Cell Lines

trans-Fatty acids (TFAs) are unsaturated fatty acids with at least one carbon-carbon double bond in trans configuration. TFA consumption has been epidemiologically associated with neurodegenerative diseases (NDs) including Alzheimer's disease. However, the underlying mechanisms of TFA-related NDs remain unknown. Here, we show a novel microglial signaling pathway that induces inflammation and cell death, which is dramatically enhanced by elaidic acid (EA), the most abundant TFA derived from food. We found that extracellular ATP, one of the damage-associated molecular patterns (DAMPs) leaked from injured cells, induced activation of the apoptosis signal-regulating kinase 1 (ASK1)-p38 pathway, which is one of the major stress-responsive mitogen-activated protein (MAP) kinase signaling pathways, and subsequent caspase-3 cleavage and DNA ladder formation (hallmarks of apoptosis) in mouse microglial cell lines including BV2 and MG6 cells. Furthermore, we found that in these microglial cell lines, EA, but not its cis isomer oleic acid, facilitated extracellular ATP-induced ASK1/p38 activation and apoptosis, which was suppressed by pharmacological inhibition of either p38, reactive oxygen species (ROS) generation, P2X purinoceptor 7 (P2X₇), or Ca²⁺/calmodulin-dependent kinase II (CaMKII). These results demonstrate that in microglial cells, extracellular ATP induces activation of the ASK1-p38 MAP kinase pathway and ultimately apoptosis downstream of P2X₇ receptor and ROS generation, and that EA promotes ATP-induced apoptosis through CaMKII-dependent hyperactivation of the ASK1-p38 pathway, in the same manner as in macrophages. Our study may provide an insight into the pathogenesis of NDs associated with TFAs.

Neuroprotective effects of microRNA-211-5p on chronic stress-induced neuronal apoptosis and depression-like behaviours

Findings from recent studies have revealed that microRNAs (miRNAs) are related to numerous neurological disorders. However, whether miRNAs regulate neuronal anomalies involved in the pathogenesis of depression remain unclear. In the present study, we screened miRNA expression profiles in the CA1 hippocampus of a rat model of depression and found that a specific miRNA, microRNA-211-5p, was significantly down-regulated in depressed rats. When miR-211-5p was up-regulated in these rats, neuronal apoptosis within the CA1 area was suppressed, effects which were accompanied with an amelioration of depression-like behaviours in these rats. These neuroprotective effects of miR-211-5p in depressed rats appear to result through suppression of the Dyrk1A/ASK1/JNK signalling pathway within the CA1 area. In further support of this proposal are the findings that knock-down of miR-211-5p within the CA1 area of normal rats activated the Dyrk1A/ASK1/JNK pathway, resulting in the promotion of neuronal apoptosis and display of depression-like behaviours in these rats. Taken together, these results demonstrate that deficits in miR-211-5p contribute to neuronal apoptosis and thus depression-like behaviours in rats. Therefore, the miR-211-5p/Dyrk1A pathway may be critically involved in the pathogenesis of depression and serve as a potential therapeutic target for the treatment of depression.

Targeting the TGF-β signaling pathway for fibrosis therapy: a patent review (2015-2020)

INTRODUCTION

Fibrosis is a serious disease that occurs in many organs, such as kidney, liver and lung. The deterioration of these organs ultimately leads to death. Due to the complex mechanisms of fibrosis, research and development of antifibrotic drugs is difficult. One solution is to focus on core pathways, one of which is the TGF-β signaling pathway. In virtually every type of fibrosis, TGF-β signaling is recognized as a critical pathway.

AREA COVERED

This review discusses patents on active molecules related to the TGF-β signaling. Molecules targeting components related to the activation of TGF-β are introduced. Several strategies preventing signal propagation from active TGF-β to downstream targets are also introduced, including TGF-β antibodies, TGF-β ligand traps, and inhibitors of TGF-β receptor kinases. Finally, molecules affecting downstream targets in both canonical and noncanonical TGF-β signaling pathways are described.

EXPERT OPINION

Since the approval of pirfenidone, targeting TGF-β signaling has been anticipated as an effective therapy for fibrosis. The potential of this therapy has been further supported by emerging patents on the TGF-β signaling. This pathway can be entirely inhibited, from the activation of TGF-β to downstream signaling. Inhibiting TGF-β signaling is expected to provide more effective treatments for fibrosis.

Hepatic Stellate Cell Activation and Inactivation in NASH-Fibrosis-Roles as Putative Treatment Targets?

Hepatic fibrosis is the primary predictor of mortality in patients with non-alcoholic steatohepatitis (NASH). In this process, the activated hepatic stellate cells (HSCs) constitute the principal cells responsible for the deposition of a fibrous extracellular matrix, thereby driving the hepatic scarring. HSC activation, migration, and proliferation are controlled by a complex signaling network involving growth factors, lipotoxicity, inflammation, and cellular stress. Conversely, the clearance of activated HSCs is a prerequisite for the resolution of the extracellular fibrosis. Hence, pathways regulating the fate of the HSCs may represent attractive therapeutic targets for the treatment and prevention of NASH-associated hepatic fibrosis. However, the development of anti-fibrotic drugs for NASH patients has not yet resulted in clinically approved therapeutics, underscoring the complex biology and challenges involved when targeting the intricate cellular signaling mechanisms. This narrative review investigated the mechanisms of activation and inactivation of HSCs with a focus on NASH-associated hepatic fibrosis. Presenting an updated overview, this review highlights key cellular pathways with potential value for the development of future treatment modalities.

Lifespan extension conferred by mitogen-activated protein kinase kinase kinase 5 (MAP3K5) longevity-associated gene variation is confined to at-risk men with a cardiometabolic disease

Genetic variants of the kinase signaling gene MAP3K5 are associated with longevity. Here we explore whether the longevity-association involves protection against mortality in all individuals, or only in individuals with aging-related diseases. We tested the strongest longevity associated single nucleotide polymorphism (SNP), rs2076260, for association with mortality in 3,516 elderly American men of Japanese ancestry. At baseline (1991-1993), 2,461 had either diabetes (n=990), coronary heart disease (CHD; n=724), or hypertension (n=1,877), and 1,055 lacked any of these cardiometabolic diseases (CMDs). The men were followed from baseline until Dec 31, 2019. Longevity-associated genotype CC in a major allele homozygote model, and CC+TT in a heterozygote disadvantage model were associated with longer lifespan in individuals having a CMD (covariate-adjusted hazard ratio [HR] 1.23 [95% CI: 1.12-1.35, p=2.5x10-5] in major allele homozygote model, and 1.22 [95% CI: 1.11-1.33, p=1.10x10-5] in heterozygote disadvantage model). For diabetes, hypertension and CHD, HR p-values were 0.019, 0.00048, 0.093, and 0.0024, 0.00040, 0.0014, in each respective genetic model. As expected, men without a CMD outlived men with a CMD (p=1.9x10-6). There was, however, no difference in lifespan by genotype in men without a CMD (p=0.21 and 0.86, respectively, in each genetic model). In conclusion, we propose that in individuals with a cardiometabolic disease, longevity-associated genetic variation in MAP3K5 enhances resilience mechanisms in cells and tissues to help protect against cardiometabolic stress caused by CMDs. As a result, men with CMD having longevity genotype live as long as all men without a CMD.

DYRK1A: a down syndrome-related dual protein kinase with a versatile role in tumorigenesis

Dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A) is a dual kinase that can phosphorylate its own activation loop on tyrosine residue and phosphorylate its substrates on threonine and serine residues. It is the most studied member of DYRK kinases, because its gene maps to human chromosome 21 within the Down syndrome critical region (DSCR). DYRK1A overexpression was found to be responsible for the phenotypic features observed in Down syndrome such as mental retardation, early onset neurodegenerative, and developmental heart defects. Besides its dual activity in phosphorylation, DYRK1A carries the characteristic of duality in tumorigenesis. Many studies indicate its possible role as a tumor suppressor gene; however, others prove its pro-oncogenic activity. In this review, we will focus on its multifaceted role in tumorigenesis by explaining its participation in some cancer hallmarks pathways such as proliferative signaling, transcription, stress, DNA damage repair, apoptosis, and angiogenesis, and finally, we will discuss targeting DYRK1A as a potential strategy for management of cancer and neurodegenerative disorders.

The role of selenium in cell survival and its correlation with protective effects against cardiovascular disease: A literature review

Selenium is a trace element that provides protection against cellular damage and death. Previous research using several types of cells identified anti-oxidant, anti-inflammatory, and anti-apoptotic effects for selenium. One of the diseases related to selenium is cardiovascular disease, as low selenium intake has been linked to cardiomyopathy. However, the mechanism of the cardioprotective effects of selenium is not thoroughly understood. Several studies supported the possible effects of selenium on heart cell survival. In this review, we analyzed recent research (2015-2020) on the roles and mechanism of action of selenium in cell survival and its cardioprotective effects. Furthermore, the prevention of apoptosis through both intrinsic and extrinsic pathways is discussed in this review. Signalling pathways that regulate cell survival such as the p-AMPK, poly (ADP-ribose) polymerase-1, nuclear factor-erythroid 2-related factor-2, AKT/PI3K, and STAT pathways are involved in the protective effects of selenium. In addition, signaling pathways that affect heart cell survival include the AKT and STAT pathways. It also affects autophagy through the PPAR-γ pathway. These findings should facilitate further research on the cardioprotective effects of selenium.

Depletion of ASK1 blunts stress-induced senescence in adipocytes

Increasing energy expenditure via induction of browning in white adipose tissue has emerged as a potential strategy to treat obesity and associated metabolic complications. We previously reported that ASK1 inhibition in adipocytes protected from high-fat diet (HFD) or lipopolysaccharide (LPS)-mediated downregulation of UCP1 both in vitro and in vivo. Conversely, adipocyte-specific ASK1 overexpression attenuated cold-induction of UCP-1 in inguinal fat. Herein, we provide evidence that both TNFα-mediated and HFD-induced activation of p38 MAPK in white adipocytes are ASK1-dependent. Moreover, expression of senescence markers was reduced in HFD-fed adipocyte-specific ASK1 knockout mice. Similarly, LPS-induced upregulation of senescence markers was blunted in ASK1-depleted adipocytes. Thus, our study identifies a previously unknown role for ASK1 in the induction of stress-induced senescence.

Selonsertib Inhibits Liver Fibrosis via Downregulation of ASK1/ MAPK Pathway of Hepatic Stellate Cells

Liver fibrosis constitutes a significant health problem worldwide due to its rapidly increasing prevalence and the absence of specific and effective treatments. Growing evidence suggests that apoptosis-signal regulating kinase 1 (ASK1) is activated in oxidative stress, which causes hepatic inflammation and apoptosis, leading to liver fibrogenesis through a mitogen-activated protein kinase (MAPK) downstream signals. In this study, we investigated whether selonsertib, a selective inhibitor of ASK1, shows therapeutic efficacy for liver fibrosis, and elucidated its mechanism of action in vivo and in vitro. As a result, selonsertib strongly suppressed the growth and proliferation of hepatic stellate cells (HSCs) and induced apoptosis by increasing Annexin V and TUNEL-positive cells. We also observed that selonsertib inhibited the ASK1/MAPK pathway, including p38 and c-Jun N-terminal kinase (JNK) in HSCs. Interestingly, dimethylnitrosamine (DMN)-induced liver fibrosis was significantly alleviated by selonsertib treatment in rats. Furthermore, selonsertib reduced collagen deposition and the expression of extracellular components such as α-smooth muscle actin (α-SMA), fibronectin, and collagen type I in vitro and in vivo. Taken together, selonsertib suppressed fibrotic response such as HSC proliferation and extracellular matrix components by blocking the ASK1/MAPK pathway. Therefore, we suggest that selonsertib may be an effective therapeutic drug for ameliorating liver fibrosis.

Protective Antioxidant Effects of Amentoflavone and Total Flavonoids from Hedyotis diffusa on H2 O2 -Induced HL-O2 Cells through ASK1/p38 MAPK Pathway

In this study, total flavonoids and total triterpenoid acid were extracted with ethyl acetate from Hedyotis diffusa Willd, and hepatoprotective activities of them and five compounds from total flavonoids against H₂ O₂ induced hepatocyte damage on HL-02 cells were determined. In particular, amentoflavone and total flavonoids had influence on the leakage of ALT, AST, LDH, the activities of SOD and the content of MDA. They effectively reduced the loss of MMP, the release of Cyt C, and then inhibited activation of caspase-3/caspase-9 cascade in hepatotoxic cells. The contents of ROS were significantly reduced to inhibit p38 in amentoflavone and flavonoids groups which decreased ASK1 and p-p38 levels through increasing thioredoxin Trx1 and reductase TrxR1. These results suggesting that the antioxidant protection of amentoflavone and flavonoids might be reducing ROS to inhibit the H₂ O₂ -induced upstream of pathway via increasing levels of Trx1 and TrxR1, which were pivotal in blocking the down streaming effectors of ASK1/p38 MAPK pathway and alleviating hepatotoxicity.

Apoptosis signal-regulating kinase 1 inhibition in in vivo and in vitro models of pulmonary hypertension

Pulmonary arterial hypertension, group 1 of the pulmonary hypertension disease family, involves pulmonary vascular remodelling, right ventricular dysfunction and cardiac failure. Oxidative stress, through activation of mitogen-activated protein kinases is implicated in these changes. Inhibition of apoptosis signal-regulating kinase 1, an apical mitogen-activated protein kinase, prevented pulmonary arterial hypertension developing in rodent models. Here, we investigate apoptosis signal-regulating kinase 1 in pulmonary arterial hypertension by examining the impact that its inhibition has on the molecular and cellular signalling in established disease. Apoptosis signal-regulating kinase 1 inhibition was investigated in in vivo pulmonary arterial hypertension and in vitro pulmonary hypertension models. In the in vivo model, male Sprague Dawley rats received a single subcutaneous injection of Sugen SU5416 (20 mg/kg) prior to two weeks of hypobaric hypoxia (380 mmHg) followed by three weeks normoxia (Sugen/hypoxic), then animals were either maintained for three weeks on control chow or one containing apoptosis signal-regulating kinase 1 inhibitor (100 mg/kg/day). Cardiovascular measurements were carried out. In the in vitro model, primary cultures of rat pulmonary artery fibroblasts and rat pulmonary artery smooth muscle cells were maintained in hypoxia (5% O₂) and investigated for proliferation, migration and molecular signalling in the presence or absence of apoptosis signal-regulating kinase 1 inhibitor. Sugen/hypoxic animals displayed significant pulmonary arterial hypertension compared to normoxic controls at eight weeks. Apoptosis signal-regulating kinase 1 inhibitor decreased right ventricular systolic pressure to control levels and reduced muscularised vessels in lung tissue. Apoptosis signal-regulating kinase 1 inhibition was found to prevent hypoxia-induced proliferation, migration and cytokine release in rat pulmonary artery fibroblasts and also prevented rat pulmonary artery fibroblast-induced rat pulmonary artery smooth muscle cell migration and proliferation. Apoptosis signal-regulating kinase 1 inhibition reversed pulmonary arterial hypertension in the Sugen/hypoxic rat model. These effects may be a result of intrinsic changes in the signalling of adventitial fibroblast.

Selective deficiency in endothelial PTP1B protects from diabetes and endoplasmic reticulum stress-associated endothelial dysfunction via preventing endothelial cell apoptosis

Diabetes notably increases the risk for endothelial dysfunction, a main precursor for microvascular complications. While endoplasmic reticulum stress (ERS) and protein tyrosine phosphatase 1B (PTP1B) have been associated with endothelial dysfunction in resistance vessels, whether these mechanisms also contribute to diabetes-mediated endothelial dysfunction in conduit arteries remains unknown. Herein, we tested the hypothesis that diabetes induces macrovascular endothelial dysfunction via endothelial ERS-induced, PTP1B-mediated apoptosis. We showed that diabetes concomitantly increased the expression of PTP1B and of markers of ERS, including GRP78, XBP1, splXBP1 and CHOP in human vessels. Exposure of aortic rings from wild-type mice to the ERS inducers tunicamycin and thapsigargin markedly reduced endothelium-dependent relaxation. Global and endothelial-specific deletion of PTP1B as well as pharmacological inhibition protected aortic rings from ERS-mediated endothelial dysfunction. Nitric oxide synthase inhibition with l-NAME abolished relaxation in the presence and absence of ERS, but neither reactive oxygen species scavenging with tempol or peg-catalase, nor cyclooxygenase inhibition with indomethacin prevented ERS-mediated endothelial dysfunction. However, both p38-MAPK and JNK inhibition protected aortic rings from ERS-mediated endothelial dysfunction. In HUVECs, PTP1B deletion prevented ERS-induced PARP cleavage and apoptosis. Lastly, acute ERS inhibition in aortic rings and selective deficiency of endothelial PTP1B in mice protected mice from diabetes-induced endothelial dysfunction. Altogether, these data support the contribution of the p38/JNK-apoptosis pathway in ERS-mediated endothelial dysfunction and present endothelial PTP1B as a major regulator of endothelial cell viability in conduit vessels and a potential target for the management of macrovascular diseases in diabetes.

Role of Endoplasmic Reticulum Stress Sensor IRE1α in Cellular Physiology, Calcium, ROS Signaling, and Metaflammation

Inositol-requiring transmembrane kinase endoribonuclease-1α (IRE1α) is the most prominent and evolutionarily conserved unfolded protein response (UPR) signal transducer during endoplasmic reticulum functional upset (ER stress). A IRE1α signal pathway arbitrates yin and yang of cellular fate in objectionable conditions. It plays several roles in fundamental cellular physiology as well as in several pathological conditions such as diabetes, obesity, inflammation, cancer, neurodegeneration, and in many other diseases. Thus, further understanding of its molecular structure and mechanism of action during different cell insults helps in designing and developing better therapeutic strategies for the above-mentioned chronic diseases. In this review, recent insights into structure and mechanism of activation of IRE1α along with its complex regulating network were discussed in relation to their basic cellular physiological function. Addressing different binding partners that can modulate IRE1α function, UPRosome triggers different downstream pathways depending on the cellular backdrop. Furthermore, IRE1α are in normal cell activities outside the dominion of ER stress and activities under the weather of inflammation, diabetes, and obesity-related metaflammation. Thus, IRE1 as an ER stress sensor needs to be understood from a wider perspective for comprehensive functional meaning, which facilitates us with assembling future needs and therapeutic benefits.

Discovery and development of ASK1 inhibitors

Aberrant activation of mitogen-activated protein kinases (MAPKs) like c-Jun N-terminal kinase (JNK) and p38 is an event involved in the pathophysiology of numerous human diseases. The apoptosis signal-regulating kinase 1 (ASK1) is an upstream target that gets activated only under pathological conditions and as such is a promising target for therapeutic intervention. In the first part of this review the molecular mechanisms leading to ASK1 activation and regulation will be described as well as the evidences supporting a pathogenic role for ASK1 in human disease. In the second part, an update on drug discovery efforts towards the discovery and development of ASK1-targeting therapies will be provided.

Inhibition of apoptosis signal-regulating kinase 1 ameliorates left ventricular dysfunction by reducing hypertrophy and fibrosis in a rat model of cardiorenal syndrome

BACKGROUND

Cardiorenal syndrome (CRS) is a major health burden worldwide in need of novel therapies, as current treatments remain suboptimal. The present study assessed the therapeutic potential of apoptosis signal-regulating kinase 1 (ASK1) inhibition in a rat model of CRS.

METHODS

Adult male Sprague-Dawley rats underwent surgery for myocardial infarction (MI) (week 0) followed by 5/6 subtotal nephrectomy (STNx) at week 4 to induce to induce a combined model of heart and kidney dysfunction. At week 6, MI + STNx animals were randomized to receive either 0.5% carboxymethyl cellulose (Vehicle, n = 15, Sham = 10) or G226 (15 mg/kg daily, n = 11). Cardiac and renal function was assessed by echocardiography and glomerular filtration rate (GFR) respectively, prior to treatment at week 6 and endpoint (week 14). Haemodynamic measurements were determined at endpoint prior to tissue analysis.

RESULTS

G226 treatment attenuated the absolute change in left ventricular (LV) fractional shortening and posterior wall thickness compared to Vehicle. G226 also attenuated the reduction in preload recruitable stroke work. Increased myocyte cross sectional area, cardiac interstitial fibrosis, immunoreactivity of cardiac collagen-I and III and cardiac TIMP-2 activation, were significantly reduced following G226 treatment. Although we did not observe improvement in GFR, G226 significantly reduced renal interstitial fibrosis, diminished renal collagen-I and -IV, kidney injury molecule-1 immunoreactivity as well as macrophage infiltration and SMAD2 phosphorylation.

CONCLUSION

Inhibition of ASK1 ameliorated LV dysfunction and diminished cardiac hypertrophy and cardiorenal fibrosis in a rat model of CRS. This suggests that ASK1 is a critical pathway with therapeutic potential in the CRS setting.

ASK1 inhibits browning of white adipose tissue in obesity

Increasing energy expenditure via induction of adipose tissue browning has become an appealing strategy to treat obesity and associated metabolic complications. Herein, we identify adipocyte-expressed apoptosis signal-regulating kinase 1 (ASK1) as regulator of adipose tissue browning. High fat diet-fed adipocyte-specific ASK1 knockout mice reveal increased UCP1 protein levels in inguinal adipose tissue concomitant with elevated energy expenditure, reduced obesity and ameliorated glucose tolerance compared to control littermates. In addition, ASK1-depletion blunts LPS-mediated downregulation of isoproterenol-induced UCP1 in subcutaneous fat both in vitro and in vivo. Conversely, adipocyte-specific ASK1 overexpression in chow-fed mice attenuates cold-induced UCP1 protein levels in inguinal fat. Mechanistically, ASK1 phosphorylates interferon regulatory factor 3 (IRF3) resulting in reduced Ucp1 expression. Taken together, our studies unravel a role of ASK1 in mediating the inhibitory effect of caloric surplus or LPS-treatment on adipose tissue browning. Adipocyte ASK1 might be a pharmacological target to combat obesity and associated morbidities.

Toxicity response of silkworm intestine to Bacillus cereus SW7-1 pathogen

Bacillus cereus is a foodborne pathogen that causes gastrointestinal disease in hosts. The interactions between pathogenic bacteria and silkworms (Bombyx mori L.) involve complex processes. This study aimed to investigate the potential genetic traits of B. cereus SW7-1 and profile the toxicity response of silkworm intestine upon infection by the SW7-1 pathogen. Bacterial genome sequencing and polymerase chain reaction (PCR) detection indicated that B. cereus SW7-1 possesses multiple antibiotic-resistant genes and nine virulence factor genes. Then, silkworm larvae were infected with SW7-1. Comparative transcriptomic analysis revealed that 273 differentially expressed genes (DEGs) with known functions were successfully annotated to the silkworm reference genome. Specifically, 18 DEGs were up-regulated, and 255 DEGs were down-regulated. Compared with the control group, the treated group revealed down-regulated DEGs that are related to stress reactions, immunity, autophagy and apoptosis, DNA replication, ribosomal stress, and carbohydrate metabolism. Quantitative real time PCR analysis showed that many key genes in the Toll pathway, immune deficiency pathway, Janus kinase/signal transducers and activators of transcription pathway, and melanization reaction were up-regulated. Thus, B. cereus SW7-1 pathogen could damage the silkworm intestine, as confirmed by the histological section assay. In addition, SW7-1 can affect the normal physiological functions of intestinal cells. This study contributes toward an improved understanding of the toxicity response of silkworm to the B. cereus pathogen and provides new insights into the molecular mechanisms of the complex interactions between pathogenic microbes and silkworms.

A novel chemoprotective effect of tiopronin against diethylnitrosamine-induced hepatocellular carcinoma in rats: Role of ASK1/P38 MAPK-P53 signalling cascade

Hepatocellular carcinoma (HCC) is the second leading cause of cancer-related death worldwide. Oxidative stress contributes significantly to HCC pathogenesis. In this study, we investigated the possible chemoprotective effect of the thiol group-containing compound, tiopronin, against HCC induced chemically by diethylnitrosamine (DENA) in rats. In addition, we elucidated the possible underlying molecular mechanism. Adult male Wistar rats were divided into: Control group, DENA-treated group and tiopronin + DENA-treated group. Liver function tests (ALT, AST, ALP, albumin, total and direct bilirubin) as well as alpha fetoprotein (AFP) concentration were measured in the sera of samples. Oxidative stress biomarkers such as malondialdehyde, nitric oxide, catalase and glutathione peroxidase were measured in the liver tissue homogenates. Determination of the phosphorylated apoptosis signal-regulating kinase 1 (phospho-ASK1), phospho-P38 and phospho-P53 proteins by western blotting, caspase 3 by immunofluorescence in addition to histopathological examination of the liver tissues were performed. Our results showed that tiopronin prevented the DENA-induced elevation of the liver function enzymes and AFP. It also preserved the activities of antioxidant enzymes as well as providing protection from the appearance of HCC histopathological features. Interestingly, tiopronin significantly decreased the expression level of phospho-ASK1, phospho-P38 and phospho-P53, caspase 3 in the liver tissues. These novel findings suggested that tiopronin is an antioxidant drug with a chemoprotective effect against DENA-induced HCC through maintaining the normal activity of ASK1/ P38 MAPK/ P53 signalling pathway.

Pharmacological Therapy of Non-Alcoholic Fatty Liver Disease: What Drugs Are Available Now and Future Perspectives

The non-alcoholic fatty liver disease (NAFLD) is rapidly becoming the most common cause of chronic liver disease as well as the first cause of liver transplantation. NAFLD is commonly associated with metabolic syndrome (MetS), and this is the most important reason why it is extremely difficult to treat this disease bearing in mind the enormous amount of interrelationships between the liver and other systems in maintaining the metabolic health. The treatment of NAFLD is a key point to prevent NASH progression to advanced fibrosis, to prevent cirrhosis and to prevent the development of its hepatic complications (such as liver decompensation and HCC) and even extrahepatic one. A part of the well-known healthy effect of diet and physical exercise in this setting it is important to design the correct pharmaceutical strategy in order to antagonize the progression of the disease. In this regard, the current review has the scope to give a panoramic view on the possible pharmacological treatment strategy in NAFLD patients.

Docking-based inverse virtual screening strategy for identification of novel protein targets for triclosan

Triclosan (TCS) is chemically designated as 5-chloro-2-(2,4-dichlorophenoxy) phenol and is considered as endocrine-disrupting chemical (EDC). The various diseases found due to exposure of TCS, have been linked with modulation of the human enoyl-acyl carrier protein-reductase (hER). However, the new protein targets for TCS other than hER, which are responsible for various diseases, are still unknown. In the present study, a bioinformatics approach was used to identify new possible targets for TCS. A text mining study was initially performed to understand the association of TCS in various biochemical processes. Discovery studio software 4.1 was used to carry out inverse virtual screening for 226 numbers of pathway proteins by docking study using CHARMm based docking tool, and twenty proteins were screened. CDOCKER energy values lower than -12.65 kcal/mol was considered for the screening of selected proteins. Three new proteins; Receptor-interacting protein 1 (RIP1), Apoptosis signal-regulating kinase 1 (ASK1) and B-cell lymphoma 2 (Bcl-2) from Apoptosis Signaling Pathway revealed best CDOCKER energy with triclosan which was -26.88, -23.34 and -22.96 kcal/mol respectively. The interaction of TCS with RIP1 and ASK1 were mostly hydrophobic; however, hydrogen bond type interaction was found in TCS/Bcl2 complex. Therefore, docking-based inverse virtual screening study suggests that TCS has other targets rather than hER, which can modulate various biochemical processes. The docking protocol was validated through evaluation of root-mean-square deviation (RMSD), key interaction score system (KISS) and the relationship between the docking energy and toxicity data available in ToxCast database. Low RMSD value (0.55 ˚A) and high KISS score (0.66) along with higher correlation (R² = 0.9798) between docking affinity and toxicity indicated that docking protocol can be used to optimize the binding energetics.

The Jun N-terminal kinases signaling pathway plays a "seesaw" role in ovarian carcinoma: a molecular aspect

Ovarian cancer is the most common gynecological malignancy that causes cancer-related deaths in women today; this being the case, developing an understanding of ovarian cancer has become one of the major driving forces behind cancer research overall. Moreover, such research over the last 20 years has shown that the Jun N-terminal kinase (JNK) signaling pathway plays an important role in regulating cell death, survival, growth and proliferation in the mitogen-activated protein kinases (MAPK) signaling pathway, an important pathway in the formation of cancer. Furthermore, the JNK signaling pathway is often regulated by an abnormal activation in human tumors and is frequently reported in the literature for its effect on the progression of ovarian cancer. Although the FDA has approved some JNK inhibitors for melanoma, the agency has not approved JNK inhibitors for ovarian cancer. However, there are some experimental data on inhibitors and activators of the JNK signaling pathway in ovarian cancer, but related clinical trials need to be further improved. Although the Jun N-terminal kinase (JNK) signaling pathway is implicated in the formation of cancer in general, research has also indicated that it has a role in suppressing cancer as well. Here, we summarize this seemingly contradictory role of the JNK signaling pathway in ovarian cancer, that ‘seesaws’ between promoting and suppressing cancer, as well as summarizing the application of several JNK pathway inhibitors in cancer in general, and ovarian cancer in particular.

The Thioredoxin System is Regulated by the ASK-1/JNK/p38/Survivin Pathway During Germ Cell Apoptosis

The aim is to explore the mechanism of the apoptosis signal-regulating kinase-1 (ASK-1) signaling pathway and the involvement of the thioredoxin (Trx) system during testicular ischemia reperfusion injury (tIRI) by using ASK-1 specific inhibitor, NQDI-1. Male Sprague-Dawley rats (n = 36, 250–300 g) were equally divided into 3 groups: sham, tIRI, and tIRI + NQDI-1 (10 mg/kg, i.p, pre-reperfusion). For tIRI induction, the testicular cord and artery were occluded for 1 h followed by 4 h of reperfusion. Histological analyses, protein immunoexpression, biochemical assays, and real-time PCR were used to evaluate spermatogenesis, ASK-1/Trx axis expression, enzyme activities, and relative mRNA expression, respectively. During tIRI, ipsilateral testes underwent oxidative stress indicated by low levels of superoxide dismutase (SOD) and Glutathione (GSH), increased oxidative damage to lipids and DNA, and spermatogenic damage. This was associated with induced mRNA expression of pro-apoptosis genes, downregulation of antiapoptosis genes, increased caspase 3 activity and activation of the ASK-1/JNK/p38/survivin apoptosis pathway. In parallel, the expression of Trx, Trx reductase were significantly reduced, while the expression of Trx interacting protein (TXNIP) and the NADP⁺/ nicotinamide Adenine Dinucleotide phosphate (NADPH) ratio were increased. These modulations were attenuated by NQDI-1 treatment. In conclusion, the Trx system is regulated by the ASK-1/Trx/TXNIP axis to maintain cellular redox homeostasis and is linked to tIRI-induced germ cell apoptosis via the ASK-1/JNK/p38/survivin apoptosis pathway.

The c-Jun N-terminal kinase signaling pathway in epilepsy: activation, regulation, and therapeutics

Epilepsy affects approximately 50-70 million people worldwide and 30-40% of patients do not benefit from medication. Therefore, it is necessary to identify novel targets for epileptic treatments. c-Jun N-terminal kinase (JNK) is a member of the mitogen-activated protein kinase (MAPK) family that activates diverse substrates, such as transcriptional factors, adaptor proteins, and signaling proteins, and has a wide variety of functions in both physiological and pathological conditions. The excessive activation of JNK is found not only in the acute phase of epilepsy, but also in the chronic phase, which potentiates it as a promising target in epilepsy control. In this review, we discuss the activation of the JNK pathway in epilepsy and its role in neuronal death, astrocyte activation, and mossy fiber sprouting (MFS) based on recent updates. Finally, we briefly introduce the current agents that target JNK signaling to control epilepsy.

Screening of Duck Tembusu Virus NS3 Interacting Host Proteins and Identification of Its Specific Interplay Domains

NS3 protein is a member of the non-structural protein of duck Tembusu virus (DTMUV), which contains three domains, each of which has serine protease, nucleotide triphosphatase, and RNA helicase activities, respectively. It performs a variety of biological functions that are involved in the regulation of the viral life cycle and host immune response. Based on the yeast two-hybrid system, we successfully transformed pGBKT7-NS3 bait plasmid into Y2H Gold, tested it to prove that it has no self-activation and toxicity, and then hybridized it with the prey yeast strain of the duck embryo fibroblast cDNA library for screening. After high-stringency selection, positive alignment with the National Center for Biotechnology Information database revealed nine potential interactive proteins: MGST1, ERCC4, WIF1, WDR75, ACBD3, PRDX1, RPS7, ND5, and LDHA. The most interesting one (PRDX1) was selected to be verified with full-length NS3 protein and its three domains S7/DEXDc/HELICc using yeast regressive verification and GST Pull-Down assay. It denoted that PRDX1 does indeed interact with HELICc domains of NS3. NS3 is involved in the RNA uncoiling process of viral replication, which may cause mitochondrial overload to create oxidative stress (OS) during DTMUV attack. We deduced that the HELICc domain binding partner PRDX1, which regulates the p38/mitogen-activated protein kinase pathway (p38/MAPK) to avert OS, causing apoptosis, making it possible for viruses to escape host immune responses.

[Selenium compounds in redox regulation of inflammation and apoptosis]

Monocytes and macrophages play a key role in the development of inflammation: under the action of lipopolysaccharides (LPS), absorbed from the intestine, monocytes and macrophages form reactive oxygen species (ROS) and cytokines, this leads to the development of oxidative stress, inflammation and/or apoptosis in all types of tissues. In the cells LPS induce an "internal" TLR4-mediated MAP-kinase inflammatory signaling pathway and cytokines through the superfamily of tumor necrosis factor receptor (TNFR) and the "death domain" (DD) initiate an "external" caspase apoptosis cascade or necrosis activation that causes necroptosis. Many of the proteins involved in intracellular signaling cascades (MYD88, ASK1, IKKa/b, NF-kB, AP-1) are redox-sensitive and their activity is regulated by antioxidants thioredoxin, glutaredoxin, nitroredoxin, and glutathione. Oxidation of these signaling proteins induced by ROS enhances the development of inflammation and apoptosis, and their reduction with antioxidants, on the contrary, stabilizes the signaling cascades speed, preventing the vicious circle of oxidative stress, inflammation and apoptosis that follows it. Antioxidant (AO) enzymes thioredoxin reductase (TRXR), glutaredoxin reductase (GLRXR), glutathione reductase (GR) are required for reduction of non-enzymatic antioxidants (thioredoxin, glutaredoxin, nitroredoxin, glutathione), and AO enzymes (SOD, catalase, GPX) are required for ROS deactivation. The key AO enzymes (TRXR and GPX) are selenium-dependent; therefore selenium deficiency leads to a decrease in the body's antioxidant defense, the development of oxidative stress, inflammation, and/or apoptosis in various cell types. Nrf2-Keap1 signaling pathway activated by selenium deficiency and/or oxidative stress is necessary to restore redox homeostasis in the cell. In addition, expression of some genes is changed with selenium deficiency. Consequently, growth and proliferation of cells, their movement, development, death, and survival, as well as the interaction between cells, the redox regulation of intracellular signaling cascades of inflammation and apoptosis, depend on the selenium status of the body. Prophylactic administration of selenium-containing preparations (natural and synthetic (organic and inorganic)) is able to normalize the activity of AO enzymes and the general status of the body. Organic selenium compounds have a high bioavailability and, depending on their concentration, can act both as selenium donors to prevent selenium deficiency and as antitumor drugs due to their toxicity and participation in the regulation of signaling pathways of apoptosis. Known selenorganic compounds diphenyldiselenide and ethaselen share similarity with the Russian organo selenium compound, diacetophenonylselenide (DAPS-25), which serves as a source of bioavailable selenium, exhibits a wide range of biological activity, including antioxidant activity, that governs cell redox balance, inflammation and apoptosis regulation.