Targeting JNK Research Articles

Development of Novel 1,3,4‐Trisubstituted Pyrazole Derivatives Bearing Sulfonamide Moiety as Anticancer Agents Targeting JNK Kinases

AbstractIn the present work, a new set of N‐(2‐((4‐(1,3‐diphenyl‐1H‐pyrazol‐4‐yl)pyridine sulfonamide derivatives was synthesized. Final target compounds were tested against JNK1 and JNK2 isoforms. Compounds 8f and 8d showed the highest activity over both JNK isoforms. They showed submicromolar activity over JNK1 (IC50 0.90 µM and 0.96 µM, respectively). They also showed excellent activity over JNK2 (IC50 0.62 µM and 1.07 µM, respectively). Moreover, the final target compounds were tested over HL‐60 and K‐562 cell lines for assessing the in vitro anticancer activity using sorafenib as a positive control. Compound 8f showed the highest potency at IC50 values of 6.21 and 7.43 µM, respectively. Furthermore, compounds 8e and 8g exhibited strong effects on both acute leukemia cancer cell lines with IC50 values of 13.83 and 10.02 µM, respectively, as well as chronic leukemia cancer cell line with IC50 of 12.65 and 9.51 µM, respectively. Compound 8f was also tested to examine its effect on the cell cycle. Finally, a molecular docking study was conducted to understand the plausible binding modes of the most active compounds 8d and 8f within the JNK1 and JNK2 binding sites.

Discovery of Piperazin‐2‐yl‐pyrimidines as Anticancer Agents via Targeting JNK Signaling Pathway in Human MCF‐7 Breast Carcinoma

AbstractBreast cancer (BC) is the second leading cause of cancer‐related mortality in women, and targeting biological pathways such as the JNK pathway has proven to be a viable therapeutic target for BC therapy. Here, we synthesized piperazin‐2‐yl‐pyrimidines and evaluated them for anticancer activity against MCF‐7 cells. In addition, antioxidant, reactive oxygen species (ROS) inhibition, caspase activity, and toxicity in platelets were studied in the presence and absence of active compound IA‐6 or IA‐7. Our detailed experimental analysis found that the compound IA‐7 showed anticancer activity by either activating p‐JNK or by inducing radical species in cancer and thrombosis model. Evident to in vitro analysis, the structure based molecular interaction studies of binding of IA‐7 to JNK3S exhibited a significant binding energy of −7.56 kcal/mol which was found to be a better binder when compared to previously reported JNK inducer (PC‐12). Overall, we herein report the analytically pure IA‐7 as lead structure that could be used as a template to develop target based anticancer agents where JNK modulation is predominant.

Inhibition of JNK ameliorates rod photoreceptor degeneration in a mouse model of retinitis pigmentosa.

Retinitis pigmentosa (RP) is an inherited eye disease that causes progressive vision loss. Microglial activation and inflammation play essential roles in photoreceptor degeneration in RP, although the underlying mechanisms remain unclear. Here, we examined the progressive degeneration of photoreceptors in rd1 mice, a mouse model of RP. We investigated the molecular changes in various retinal cells in rd1 mice using single-cell RNA sequencing and found that potentiation of JNK signaling is associated with photoreceptor degeneration in RP. Moreover, inflammation-related molecules, which function downstream of JNK, are elevated in RP. Furthermore, inhibiting JNK alleviates microglial activation and rescues photoreceptor degeneration in rd1 mice. Thus, our findings suggest that targeting JNK is a promising approach for slowing RP progression.

Baicalin attenuates aflatoxin B1-induced hepatotoxicity via suppressing c-Jun-N-terminal kinase-mediated cell apoptosis.

Aflatoxin B1 (AFB1) is classified as a Class I carcinogen and common pollutant in human and animal food products. Prolonged exposure to AFB1 can induce hepatocyte apoptosis and lead to hepatotoxicity. Therefore, preventing AFB1-induced hepatotoxicity remains a critical issue and is of great significance. Baicalin, a polyphenolic compound derived from Scutellaria baicalensis Georgi, has a variety of pharmacodynamic activities, such as antiapoptotic and anticancer activities. This study systematically investigated the alleviating effect of baicalin on AFB1-induced hepatotoxicity from the perspective of apoptosis and explored the possible molecular mechanism. In the normal human liver cell line L02, baicalin treatment significantly inhibited AFB1-induced c-Jun-N-terminal Kinase (JNK) activation and cell apoptosis. In addition, the in vitro mechanism study demonstrated that baicalin alleviates AFB1-induced hepatocyte apoptosis through suppressing the translocation of phosphorylated JNK to the nucleus and decreasing the phosphorylated c-Jun/c-Jun ratio and the Bax/Bcl2 ratio. Molecular docking and drug affinity responsive target stability assays demonstrated that baicalin has the potential to target JNK. This study provides a basis for the therapeutic effect of baicalin on hepatocyte apoptosis caused by AFB1, indicating that the development of baicalin and JNK pathway inhibitors has broad application prospects in the prevention of hepatotoxicity, especially hepatocyte apoptosis.

Synthesis, Characterization, In‐Vitro and In‐Vivo Anti‐Cancer Evaluation of Novel Benzopyrylium Salts on Colorectal Cancer Model of Drosophila Melanogaster

AbstractA total of 10 benzopyrylium salts, 7 being novel, were synthesized by Claisen‐Schmidt condensation reaction and characterized by 1H and 13C NMR, High‐Resolution Mass Spectrometry, FT‐IR, and UV‐Vis spectroscopy. The purity of these synthesized compounds was determined by HPLC. The in‐vitro anti‐cancer evaluation of these synthesized benzopyrylium salts was done at National Cancer Institute (NCI), USA, against 60 human cancer cell lines. The compounds 4 and 8 showed promising anti‐cancer activities against various human cancer cell lines. The docking studies of the compounds were carried out against the oncogenic target JNK and their docking scores were compared to that of the known JNK inhibitor SP600125 (Pyrazolanthrone). Compound 4 exhibited an outstanding docking score of −9.0 kcal/mol, comparable to the docking score of SP600125 (−9.3 kcal/mol). The ex‐vivo studies in the hind‐gut of Drosophila were carried out and the inhibitory activity of compound 4 supported the findings of the docking studies. Furthermore, the potent compounds 4 and 8 were taken up for their in‐vivo anti‐cancer evaluation in the colorectal cancer model (CRC) of Drosophila melanogaster. The toxicity studies of these potent compounds were carried out both in wild type and mutant type Drosophila and the lethal doses were determined to be 200 μM.

Hepatoprotective effects of Elaeagnus latifolia fruit extract against acetaminophen-induced hepatotoxicity in mice: Mechanistic insights

Elaeagnus latifolia fruit extract (EE) has been reported to contain antioxidant and anti-inflammatory phytochemicals. The present study aimed to examine the anti-hepatotoxic effects of EE in acetaminophen (APAP)-injected mice. Pretreatment with EE for 7 days in APAP mice showed significant reductions in the levels of AST and ALT and necrotic area, accompanied by decreases in liver oxidative stress, nitric oxide, and infiltrating inflammatory cells, compared to the APAP-only group. EE markedly down-regulated expression of CYP2E1, JNK, Bax, NOX subunit, and NF-κB target genes, and up-regulated expression of Bcl-2 and Nrf2 target genes in the livers. Furthermore, EE effectively lowered serum and hepatic lipids, and down-regulated expression of SREBP-1c/2 genes. EE was found to contain phenolic compounds, flavonoids, and proanthocyanidins. Therefore, mechanistic insights into EE's anti-hepatotoxic effects may be associated with preventing the abnormal expression of genes involved in toxic metabolite generation, hepatotoxic signaling, apoptosis, oxidative stress, inflammation, and lipid synthesis.

C-Jun N-terminal kinase signaling in aging.

Aging encompasses a wide array of detrimental effects that compromise physiological functions, elevate the risk of chronic diseases, and impair cognitive abilities. However, the precise underlying mechanisms, particularly the involvement of specific molecular regulatory proteins in the aging process, remain insufficiently understood. Emerging evidence indicates that c-Jun N-terminal kinase (JNK) serves as a potential regulator within the intricate molecular clock governing aging-related processes. JNK demonstrates the ability to diminish telomerase reverse transcriptase activity, elevate β-galactosidase activity, and induce telomere shortening, thereby contributing to immune system aging. Moreover, the circadian rhythm protein is implicated in JNK-mediated aging. Through this comprehensive review, we meticulously elucidate the intricate regulatory mechanisms orchestrated by JNK signaling in aging processes, offering unprecedented molecular insights with significant implications and highlighting potential therapeutic targets. We also explore the translational impact of targeting JNK signaling for interventions aimed at extending healthspan and promoting longevity.

JNKs protect from cholestatic liver disease progression by modulating Apelin signalling

Cholestatic liver injury is associated with c-Jun N-terminal kinases (JNK) activation in distinct cell types. Its hepatocyte-specific function during cholestasis, however, has not yet been established. Therefore, in our present study, we investigated the role of JNK1/2 during cholestasis and dissected its hepatocyte-specific function. A cohort of patients with primary biliary cholangitis (n= 29) and primary sclerosing cholangitis (n= 37) was examined. Wild-type, hepatocyte-specific knockout mice for Jnk2 (Jnk2Δhepa) or Jnk1 and Jnk2 (Jnk1Δhepa/2Δhepa) were generated. Mice were subjected to bile duct ligation (BDL) or carbon tetrachloride (CCl4) treatment. Finally, Apelin signalling was blocked using a specific inhibitor. As an interventional approach, Jnk1/2 were silenced in wild-type mice using lipid nanoparticles for small interfering RNA delivery. JNK activation was increased in liver specimens from patients with chronic cholestasis (primary biliary cholangitis and primary sclerosing cholangitis) and in livers of Mdr2-/- and BDL-treated animals. In Jnk1Δhepa/2Δhepa animals, serum transaminases increased after BDL, and liver histology demonstrated enhanced cell death, compensatory proliferation, hepatic fibrogenesis, and inflammation. Furthermore, microarray analysis revealed that hepatocytic Jnk1/2 ablation induces JNK-target genes involved in oxidative stress and Apelin signalling after BDL. Consequently, blocking Apelin signalling attenuated BDL-induced liver injury and fibrosis in Jnk1Δhepa/2Δhepa mice. Finally, we established an interventional small interfering RNA approach of selective Jnk1/2 targeting in hepatocytes invivo, further demonstrating the essential protective role of Jnk1/2 during cholestasis. Jnk1 and Jnk2 work together to protect hepatocytes from cholestatic liver disease by controlling Apelin signalling. Dual modification of JNK signalling in hepatocytes is feasible, and enhancing its expression might be an attractive therapeutic approach for cholestatic liver disease. The cell-specific function of Jnk genes during cholestasis has not been explicitly explored. In this study, we showed that combined Jnk1/2, but not Jnk2 deficiency, in hepatocytes exacerbates liver damage and fibrosis by enhancing Apelin signalling, which contributes to cholestasis progression. Combined cell-specific Jnk targeting may be a new molecular strategy for treating cholestatic liver disease.

Glucagon-like Peptide-1 Acts as Signaling Mediator to Modulate Human Sperm Performance via Targeting Akt, JNK and IRS-1 Cell Signaling Cascades: Novel Insights into Sperm Physiopathology.

Recent evidence suggests that the male gonad is a potential target of glucagon-like peptide-1 (GLP-1). We investigated the effects of glucagon-like peptide-1 (GLP-1) on sperm function and the molecular mechanisms through which it may act. Semen samples of healthy men were incubated in the presence or absence of a GLP-1 mimetic analog, exendin-4 (Exe). In a different analysis, sperm were exposed to tumor necrosis factor (TNF-α) alone and, in some tubes, TNF-α was added after previous exposure to exendin-4 (Exe). Sperm parameters and protein-kinase B (p-Akt), insulin receptor substrate-1 (p-IRS-1 Ser312), and c Jun N-terminal protein kinase (p-JNK Thr183/Tyr185) were considered and evaluated. Sperm parameters, when incubated for 4 h in a simple defined balanced salt solution lacking protein, declined progressively with incubation time. The maximum decline was associated with a significant decrease in phosphorylated protein kinase B (p-Akt), concomitantly to an increase in insulin receptor substrate-1 (p-IRS-1 Ser312) and c Jun N-terminal protein kinase (p-JNK Thr183/Tyr185). Preincubation with exendin-4 (Exe) prevented this decline and maintained sperm motility (progressive-PM and total-TM). TNF-α exposure resulted in decreased sperm motility (PM and TM) and viability (V) in a concentration-dependent manner. Exe addition attenuated this TNF-α negative effect on sperm parameters. Glucagon-like peptide-1 (GLP-1) also acts by reducing levels of the "negative" kinases p-IRS-1Ser312 and p-JNK. An imbalance involving these three kinases in sperm, as it occurs in somatic cells, is a novel scenario that may participate in sperm physiopathology.

A Novel Perilla frutescens (L.) Britton Cell-Derived Phytocomplex Regulates Keratinocytes Inflammatory Cascade and Barrier Function and Preserves Vaginal Mucosal Integrity In Vivo

In the last years, the medicinal plant Perilla frutescens (L.) Britton has gained scientific interest because leaf extracts, due to the presence of rosmarinic acid and other polyphenols, have shown anti-allergic and skin protective potential in pre-clinical studies. Nevertheless, the lack of standardized extracts has limited clinical applications to date. In this work, for the first time, a standardized phytocomplex of P. frutescens, enriched in rosmarinic acid and total polyphenols, was produced through innovative in vitro cell culture biotechnology and tested. The activity of perilla was evaluated in an in vitro inflammatory model of human keratinocytes (HaCaT) by monitoring tight junctions, filaggrin, and loricrin protein levels, the release of pro-inflammatory cytokines and JNK MAPK signaling. In a practical health care application, the perilla biotechnological phytocomplex was tested in a multilayer model of vaginal mucosa, and then, in a preliminary clinical observation to explore its capacity to preserve vaginal mucosal integrity in women in peri-menopause. In keratinocytes cells, perilla phytocomplex demonstrated to exert a marked activity in epidermis barrier maintenance and anti-inflammatory effects, preserving tight junction expression and downregulating cytokines release through targeting JNK activation. Furthermore, perilla showed positive effects in retaining vaginal mucosal integrity in the reconstructed vaginal mucosa model and in vivo tests. Overall, our data suggest that the biotechnological P. frutescens phytocomplex could represent an innovative ingredient for dermatological applications.

Non-kinase targeting of oncogenic c-Jun N-terminal kinase (JNK) signaling: the future of clinically viable cancer treatments.

c-Jun N-terminal Kinases (JNKs) have been identified as key disease drivers in a number of pathophysiological settings and central oncogenic signaling nodes in various cancers. Their roles in driving primary tumor growth, positively regulating cancer stem cell populations, promoting invasion and facilitating metastatic outgrowth have led JNKs to be considered attractive targets for anti-cancer therapies. However, the homeostatic, apoptotic and tumor-suppressive activities of JNK proteins limit the use of direct JNK inhibitors in a clinical setting. In this review, we will provide an overview of the different JNK targeting strategies developed to date, which include various ATP-competitive, non-kinase and substrate-competitive inhibitors. We aim to summarize their distinct mechanisms of action, review some of the insights they have provided regarding JNK-targeting in cancer, and outline the limitations as well as challenges of all strategies that target JNKs directly. Furthermore, we will highlight alternate drug targets within JNK signaling complexes, including recently identified scaffold proteins, and discuss how these findings may open up novel therapeutic options for targeting discrete oncogenic JNK signaling complexes in specific cancer settings.

Abstract 12359: Thioridazine Suppresses Endothelial Inflammation and Atherogenesis Through Inhibition of Yap-jnk Signaling Axis

Introduction: Atherosclerosis is a critical public health issue as cardiovascular disease has been on the rise globally for decades. Our previous study found that YAP plays a critical role in endothelial inflammation and atherosclerosis, indicating that YAP is a promising therapeutic target against atherosclerotic vascular diseases. Therefore, we established the drug screening platform, aiming to seek new YAP inhibitors through repurposing FDA-approved drugs. Methods and Results: Drug screening was initially performed by luciferase reporter gene assay. We found that the anti-psychotic drug thioridazine can significantly inhibit the YAP/TAZ activity in human endothelial cells. Thioridazine downregulated the mRNA levels of YAP/TAZ target genes (ANKRD1, CTGF, CYR61) in endothelial cells. Thioridazine also increased the phosphorylation of YAP and inhibited the nuclear translocation of YAP in endothelial cells. Thioridazine suppressed endothelial inflammation, as demonstrated by downregulation of JNK phosphorylation, activity of JNK effector AP-1 as well as mRNA expression of pro-inflammatory markers including JNK target genes. Moreover, we observed that oral administration of thioridazine alleviated the formation of atherosclerotic plaques in ApoE -/- mice on a western diet. Conclusion: Overall, the FDA-approved clinical drug, thioridazine suppresses endothelial inflammation and atherogenesis through inhibition of YAP-JNK signaling pathway. As a novel YAP inhibitor, thioridazine might need further investigation and development for potential use of treating atherosclerotic vascular disease.

WNT4 overexpression and secretion in thymic epithelial tumors drive an autocrine loop in tumor cells in vitro.

BackgroundWNT4-driven non-canonical signaling is crucial for homeostasis and age-related involution of the thymus. Abnormal WNT signaling is important in many cancers, but the role of WNT signaling in thymic tumors is largely unknown.Materials & MethodsExpression and function of WNT4 and FZD6 were analyzed using qRT–PCR, Western blot, ELISA, in biopsies of non-neoplastic thymi (NT), thymoma and thymic carcinomas. ShRNA techniques and functional assays were used in primary thymic epithelial cells (pTECs) and TC cell line 1889c. Cells were conventionally (2D) grown and in three-dimensional (3D) spheroids.ResultsIn biopsy, WHO classified B3 thymomas and TCs showed increased WNT4 expression compared with NTs. During short-term 2D culture, WNT4 expression and secretion declined in neoplastic pTECs but not in 3D spheroids or medium supplemented with recombinant WNT4 cultures. Under the latter condition, the growth of pTECs was accompanied by increased expression of non-canonical targets RAC1 and JNK. Down-regulation of WNT4 by shRNA induced cell death in pTECs derived from B3 thymomas and led to decreased RAC1, but not JNK protein phosphorylation. Pharmacological inhibition of NF-κB decreased both RAC1 and JNK phosphorylation in neoplastic pTECs.ConclusionsLack of the age-related decline of non-canonical WNT4 expression in TETs and restoration of declining WNT4 expression through exogeneous WNT4 or 3D culture of pTECs hints at an oncogenic role of WNT4 in TETs and is compatible with the WNT4 autocrine loop model. Crosstalk between WNT4 and NF-κB signaling may present a promising target for combined interventions in TETs.

MiRNA-363-3p/DUSP10/JNK axis mediates chemoresistance by enhancing DNA damage repair in diffuse large B-cell lymphoma

Anthracycline-based chemotherapy resistance represents a major challenge in diffuse large B-cell lymphoma (DLBCL). MiRNA and gene expression profiles (n = 47) were determined to uncover potential chemoresistance mechanisms and therapeutic approaches. An independent correlation between high expression of miRNA-363-3p and chemoresistance was observed and validated in a larger cohort (n = 106). MiRNA-363-3p was shown to reduce doxorubicin-induced apoptosis and tumor shrinkage in in vitro and in vivo experiments by ectopic expression and CRISPR/Cas9-mediated knockout in DLBCL cell lines. DNA methylation was found to participate in transcriptional regulation of miRNA-363-3p. Further investigation revealed that dual specificity phosphatase 10 (DUSP10) is a target of miRNA-363-3p and its suppression promotes the phosphorylation of c-Jun N-terminal kinase (JNK). The miRNA-363-3p/DUSP10/JNK axis was predominantly associated with negative regulation of homologous recombination (HR) and DNA repair pathways. Ectopic expression of miRNA-363-3p more effectively repaired doxorubicin-induced double-strand break (DSB) while enhancing non-homologous end joining repair and reducing HR repair. Targeting JNK and poly (ADP-ribose) polymerase 1 significantly inhibited doxorubicin-induced DSB repair, increased doxorubicin-induced cell apoptosis and tumor shrinkage, and improved the survival of tumor-bearing mice. In conclusion, the miRNA-363-3p/DUSP10/JNK axis is a novel chemoresistance mechanism in DLBCL that may be reversed by targeted therapy.

Diacerein protects liver against APAP-induced injury via targeting JNK and inhibiting JNK-mediated oxidative stress and apoptosis

Background and purposeAn overdose of acetaminophen (APAP) causes acute liver damage and lead to liver failure. Therefore, it is of great clinical significance to find drugs for the treatment of APAP-induced liver injury. Diacerein is clinically used drug for the treatment of osteoarthritis. Here, we evaluate the pharmacological effects and potential mechanisms of diacerein in APAP-induced liver injury. Methods and resultsC57BL/6 mice were treated with diacerein by gavage, followed by intraperitoneal injection of APAP (400 mg/kg) to induce acute liver injury in mice. RNA-sequencing analysis and in vitro kinase assay were performed to explore the underlying mechanisms of diacerein. The experimental results showed that pretreatment with diacerein could inhibit APAP-induced elevation of serum AST and ALT levels, hepatic histopathological damage, oxidative stress, hepatocyte death, and mitochondrial damage in mice. The RNA-sequencing analysis and in vitro kinase assay indicated that indicating that JNK (c-Jun N-terminal kinase) is involved in that liver-protective effects of Diacerein. Diacerein could directly and selectively inhibit JNK kinase phosphorylation in cell-free system. We further confirmed that diacerein inhibits APAP-activated JNK pathway to reduce injury response in mouse livers and cultured AML12 cells. Deficiency of JNK in AML12 cells abolished the anti-injury effects of diacerein. ConclusionOur experimental results suggest that diacerein protects APAP-induced liver injury by the inhibition of JNK kinase phosphorylation, rendering diacerein may serve as a potential therapeutic drug for the prevention of acute liver injury.

Acute normobaric hypoxia blunts contraction-mediated mTORC1- and JNK-signaling in human skeletal muscle.

AimHypoxia has been shown to reduce resistance exercise‐induced stimulation of protein synthesis and long‐term gains in muscle mass. However, the mechanism whereby hypoxia exerts its effect is not clear. Here, we examine the effect of acute hypoxia on the activity of several signalling pathways involved in the regulation of muscle growth following a bout of resistance exercise.MethodsEight men performed two sessions of leg resistance exercise in normoxia or hypoxia (12% O2) in a randomized crossover fashion. Muscle biopsies were obtained at rest and 0, 90,180 minutes after exercise. Muscle analyses included levels of signalling proteins and metabolites associated with energy turnover.ResultsExercise during normoxia induced a 5‐10‐fold increase of S6K1Thr389 phosphorylation throughout the recovery period, but hypoxia blunted the increases by ~50%. Phosphorylation of JNKThr183/Tyr185 and the JNK target SMAD2Ser245/250/255 was increased by 30‐ to 40‐fold immediately after the exercise in normoxia, but hypoxia blocked almost 70% of the activation. Throughout recovery, phosphorylation of JNK and SMAD2 remained elevated following the exercise in normoxia, but the effect of hypoxia was lost at 90‐180 minutes post‐exercise. Hypoxia had no effect on exercise‐induced Hippo or autophagy signalling and ubiquitin‐proteasome related protein levels. Nor did hypoxia alter the changes induced by exercise in high‐energy phosphates, glucose 6‐P, lactate or phosphorylation of AMPK or ACC.ConclusionWe conclude that acute severe hypoxia inhibits resistance exercise‐induced mTORC1‐ and JNK signalling in human skeletal muscle, effects that do not appear to be mediated by changes in the degree of metabolic stress in the muscle.

Baicalein regulates NEDD4L-mediated TLR2 ubiquitination to relieve Mycobacterium tuberculosis-induced pneumonia in mice

Baicalein has strong anti-inflammatory activity, but its efficacy and mechanism in pneumonia of mice is still unclear. Herein, RAW264.7 cells were infected with M. tuberculosis H37Rv (MOI 1:10) after pre-incubation with 50 μM baicalein, and the result found that baicalein incubation ameliorated the increase of bacterial load, and reduced the levels of ROS, IL-12p40, TLR2 protein, phosphorylated JNK protein and M1 polarization markers (iNOS and CD11c), and increased the levels of IL-10, M2 polarization markers (Arg1, Mrc1 and CD206) and NEDD4L protein in H37Rv infected-RAW264.7 cells. And lentivirus-mediated NEDD4L overexpression vector (LV-NEDD4L) transfection had the same effect as baicalein, while small interfering RNA target NEDD4L (si-NEDD4L) transfection or JNK pathway inhibitor IQ 3 treatment reversed the effects of baicalein, and ubiquitin inhibitor MG132 treatment reversed the effects of LV-NEDD4L. Co-immunoprecipitation (Co-IP) and TLR2 ubiquitination assays found that the binding of NEDD4L and TLR2 promoted the ubiquitination of TLR2. In vivo, C57BL/6 mice were nasal infected with H37Rv (1000 ± 150 CFU/mouse) to establish a mouse pneumonia model, and then administered with baicalein. The result found that baicalein improved H37Rv-induced pneumonia in mice. In conclusion, baicalein increased NEDD4L-mediated ubiquitination of TLR2, promoting macrophage M2 polarization and alleviating H37Rv-induced pneumonia.

Targeting JNK as a Novel Approach to Drug Metabolism Regulation

The management of pharmacokinetics and pharmacodynamics of drugs constitutes an approach for personalizing pharmacotherapy. This can be achieved by controlling xenobiotic metabolism. This research aimed to study the possibility of controlling the biotransformation of substances in the body through targeted regulation of intracellular signal transduction. By UPLC-MS/MS, the effect of JNK inhibitors on the metabolism of venlafaxine xenobiotic by liver cells was investigated in vitro. The blocking of JNK in hepatic homogenate cells containing the antidepressant was accompanied by an increase in the intensity of its biotransformation. There was a significant increase in forming a single pharmacologically active metabolite of O-desmethylvenlafaxine in the cell suspension and its further chemical conversion. Data from experiments indicate marked induction of venlafaxine metabolism by the JNK inhibitor. These properties of JNK inhibitors can be used to develop a novel approach to the characterization of antidepressant treatment. Also, the results indicate the prospect of studying activity modifiers of intracellular signaling molecules (in particular, mitogen-activated protein kinases) to develop methods of controlling the process of xenobiotic transformation and create a novel class of pharmaceuticals - targeted drug metabolism regulators.

Hepatic Mitochondrial SAB Deletion or Knockdown Alleviates Diet-Induced Metabolic Syndrome, Steatohepatitis, and Hepatic Fibrosis.

The hepatic mitogen-activated protein kinase (MAPK) cascade leading to c-Jun N-terminal kinase (JNK) activation has been implicated in the pathogenesis of nonalcoholic fatty liver (NAFL)/NASH. In acute hepatotoxicity, we previously identified a pivotal role for mitochondrial SH3BP5 (SAB; SH3 homology associated BTK binding protein) as a target of JNK, which sustains its activation through promotion of reactive oxygen species production. Therefore, we assessed the role of hepatic SAB in experimental NASH and metabolic syndrome. In mice fed high-fat, high-calorie, high-fructose (HFHC) diet, SAB expression progressively increased through a sustained JNK/activating transcription factor 2 (ATF2) activation loop. Inducible deletion of hepatic SAB markedly decreased sustained JNK activation and improved systemic energy expenditure at 8weeks followed by decreased body fat at 16weeks of HFHC diet. After 30weeks, mice treated with control-antisense oligonucleotide (control-ASO) developed steatohepatitis and fibrosis, which was prevented by Sab-ASO treatment. Phosphorylated JNK (p-JNK) and phosphorylated ATF2 (p-ATF2) were markedly attenuated by Sab-ASO treatment. After 52weeks of HFHC feeding, control N-acetylgalactosamine antisense oligonucleotide (GalNAc-Ctl-ASO) treated mice fed the HFHC diet exhibited progression of steatohepatitis and fibrosis, but GalNAc-Sab-ASO treatment from weeks 40 to 52 reversed these findings while decreasing hepatic SAB, p-ATF2, and p-JNK to chow-fed levels. Hepatic SAB expression increases in HFHC diet-fed mice. Deletion or knockdown of SAB inhibited sustained JNK activation and steatohepatitis, fibrosis, and systemic metabolic effects, suggesting that induction of hepatocyte Sab is an important driver of the interplay between the liver and the systemic metabolic consequences of overfeeding. In established NASH, hepatocyte-targeted GalNAc-Sab-ASO treatment reversed steatohepatitis and fibrosis.

Curcumin analogue C66 attenuates obesity-induced myocardial injury by inhibiting JNK-mediated inflammation

Obesity has been recognized as a major risk factor for the development of chronic cardiomyopathy, which is associated with increased cardiac inflammation, fibrosis, and apoptosis. We previously developed an anti-inflammatory compound C66, which prevented inflammatory diabetic complications via targeting JNK. In the present study, we have tested the hypothesis that C66 could prevent obesity-induced cardiomyopathy by suppressing JNK-mediated inflammation. High-fat diet (HFD)-induced obesity mouse model and palmitic acid (PA)-challenged H9c2 cells were used to develop inflammatory cardiomyopathy and evaluate the protective effects of C66. Our data demonstrate a protective effect of C66 against obesity-induced cardiac inflammation, cardiac hypertrophy, fibrosis, and dysfunction, overall providing cardio-protection. C66 administration attenuates HFD-induced myocardial inflammation by inhibiting NF-κB and JNK activation in mouse hearts. In vitro, C66 prevents PA-induced myocardial injury and apoptosis in H9c2 cells, accompanied with inhibition against PA-induced JNK/NF-κB activation and inflammation. The protective effect of C66 is attributed to its potential to inhibit JNK activation, which led to reduced pro-inflammatory cytokine production and reduced apoptosis in cardiomyocytes both in vitro and in vivo. In summary, C66 provides significant protection against obesity-induced cardiac dysfunction, mainly by inhibiting JNK activation and JNK-mediated inflammation. Our data indicate that inhibition of JNK is able to provide significant protection against obesity-induced cardiac dysfunction.