SP600125, an anthrapyrazolone inhibitor of Jun N-terminal kinase

Mechanisms of LPS-induced toxicity in endothelial cells and the protective role of geniposidic acid

Vascular inflammation and oxidative stress are critical pathogenic factors in cardiovascular diseases. Lipopolysaccharide (LPS)-induced endothelial cytotoxicity, driven by oxidative stress and inflammation, remains incompletely understood. This study highlights the molecular mechanisms underlying LPS toxicity, focusing on the ROS/JNK/NLRP3 signaling axis. LPS disrupts mitochondrial function, increases ROS accumulation, activates JNK phosphorylation, and induces NLRP3 inflammasome activation, culminating in pyroptosis through caspase-1-mediated GSDMD cleavage. Mechanistic studies with the JNK inhibitor SP600125 confirmed the critical role of the ROS/JNK/NLRP3 pathway in LPS-induced endothelial damage. Additionally, PGC-1α, a key regulator of mitochondrial homeostasis, was identified as a protective factor suppressed by LPS, exacerbating ROS overproduction and inflammasome activation. To validate these findings, geniposidic acid (GPA), a natural antioxidant and anti-inflammatory compound, was employed. GPA effectively reduced ROS levels, inhibited JNK activation, and suppressed pyroptosis, supporting its utility as a chemical tool to confirm the pivotal role of ROS/JNK/NLRP3 signaling. This study elucidates the intricate interplay between oxidative stress, mitochondrial dysfunction, and pyroptosis, providing a comprehensive framework for addressing inflammation-driven vascular damage.

MAPK signaling mediated intestinal inflammation induced by endoplasmic reticulum stress and NOD2

Endoplasmic reticulum (ER) stress is crucially involved in inflammatory bowel disease (IBD), but the mechanisms remain incompletely understood. This study aimed to elucidate how ER stress promotes inflammation in IBD. ER stress marker Grp78 and NOD2 in colon tissues of Crohn's disease (CD) patients and IBD model mice were detected by immunohistochemical analysis. THP-1 cells were exposed to ER stress and the expression of NOD2 and inflammatory cytokines was detected by PCR. We found that ER stress markers Grp78 and NOD2 were upregulated in intestinal tissues of CD patients and in THP-1 cells exposed to ER stress. ER stress inhibitor reduced Grp78 and NOD2 expression in colitis model mice and alleviated colitis. ER stress inducer cooperated with NOD2 ligand MDP to upregulate TNF-α, IL-8 and IL-1β, and activate MAPK signaling in THP-1 cells. Moreover, inhibitors of MAPK signaling led to the downregulation of IL-1β, IL-8 and TNF-α in THP-1 cells stimulated by ER stress inducer and MDP. In conclusion, ER stress upregulates NOD2 and promotes inflammation in IBD, at least partially due to the activation of MAPK pathway.

Piperine induces cellular stresses, apoptosis, and cytotoxicity via JNK signaling and has concentration-dependently additive or synergistic effects with sorafenib in hepatocellular carcinoma: an in-vitro study

We aimed to determine the effects of piperine on cell viability, cellular stresses, and apoptosis first, then the relationship of piperine's effects with the c-Jun N-terminal kinase (JNK) signaling pathway, and also the interaction of piperine with sorafenib in hepatocellular carcinoma. Hepatocellular carcinoma (HepG2 and Hep3B) and non-cancerous hepatocyte (AML12) cell lines were used. The cell viability was determined by using MTT assay. Cellular stresses, apoptosis, and JNK signaling markers were measured by Western blotting. Cells were pre-treated with SP600125 as a JNK inhibitor. The inhibitory concentration 50% (IC50) values and interaction of piperine with sorafenib were calculated by using CompuSyn software. IC50 values of piperine were 97 µM for HepG2, 58 µM for Hep3B, and 184 µM for AML12 with incubation for 48 h. Piperine caused a significant concentration-dependent increase in cellular stresses, apoptosis, and activated JNK signaling in hepatocellular carcinoma cells. Pre-treatment with a JNK inhibitor significantly reduced piperine-induced cellular stresses, apoptosis, and cytotoxicity. Piperine had concentration-dependent additive or synergistic effects when combined with sorafenib in both HepG2 and Hep3B cells. We found that piperine induces cellular stresses, apoptosis, and cytotoxicity via JNK signaling and has concentration-dependently additive or synergistic effects with sorafenib in hepatocellular carcinoma.

A "Ligand First" Approach toward Selective, Covalent JNK2/3 Inhibitors

All JNK isoforms play a specific role in various diseases. The role of the JNK2 isoform has so far received little attention compared to its JNK1 and JNK3 counterparts with JNK3 being a potential target for neurodegenerative diseases and an inhibitor with JNK1 bias being currently investigated in clinical trials. Using an iterative, structure-guided optimization approach starting from a reported reversible binding aminopyrazole-derived scaffold, novel highly potent JNK2/3 selective inhibitors were generated ("ligand-first approach"). These reversible inhibitors were further transformed to covalent inhibitors by attaching an electrophilic warhead moiety, able to address a conserved cysteine side chain present in JNKs. Reversible and covalent inhibitors presented in this study show high JNK2/3 isoform selectivity and activity in cells. The covalently acting lead compound 56d shows good kinetic data with a kinact/KI (JNK2) = 38,200 M-1 s-1 as well as cellular isoform selectivity and a clean kinome profile.

Epstein-Barr virus latent membrane protein 1 subverts IMPDH pathways to drive B-cell oncometabolism

Epstein-Barr virus (EBV) is associated with multiple types of cancers, many of which express the viral oncoprotein Latent Membrane Protein 1 (LMP1). LMP1 contributes to both epithelial and B-cell transformation. Although metabolism reprogramming is a cancer hallmark, much remains to be learned about how LMP1 alters lymphocyte oncometabolism. To gain insights into key B-cell metabolic pathways subverted by LMP1, we performed systematic metabolomic analyses on B cells with conditional LMP1 expression. This approach highlighted that LMP highly induces de novo purine biosynthesis, with xanthosine-5-P (XMP) as one of the most highly LMP1-upregulated metabolites. Consequently, IMPDH inhibition by mycophenolic acid (MPA) triggered death of LMP1-expressing EBV-transformed lymphoblastoid cell lines (LCL), a key model for EBV-driven immunoblastic lymphomas. Whereas MPA instead caused growth arrest of Burkitt lymphoma cells with the EBV latency I program, conditional LMP1 expression triggered their death, and this phenotype was rescuable by guanosine triphosphate (GTP) supplementation, implicating LMP1 as a key driver of B-cell GTP biosynthesis. Although both IMPDH isozymes are expressed in LCLs, only IMPDH2 was critical for LCL survival, whereas both contributed to proliferation of Burkitt cells with the EBV latency I program. Both LMP1 C-terminal cytoplasmic tail domains critical for primary human B-cell transformation were important for XMP production, and each contributed to LMP1-driven Burkitt cell sensitivity to MPA. Metabolomic analyses further highlighted roles of NF-kB, mitogen activated kinase and protein kinase C downstream of LMP1 in support of XMP abundance. Of these, only protein kinase C activity was important for supporting GTP levels in LMP1 expressing Burkitt cells. MPA also de-repressed EBV lytic antigens, including LMP1 itself in latency I Burkitt cells, highlighting crosstalk between the purine biosynthesis pathway and the EBV epigenome. These results suggest novel oncometabolism-based therapeutic approaches to LMP1-driven lymphomas.

Mutant huntingtin induces neuronal apoptosis via derepressing the non-canonical poly(A) polymerase PAPD5

MicroRNAs (miRNAs) are small non-coding RNAs that play crucial roles in post-transcriptional gene regulation. Poly(A) RNA polymerase D5 (PAPD5) catalyzes the addition of adenosine to the 3' end of miRNAs. In this study, we demonstrate that the Yin Yang 1 protein, a transcriptional repressor of PAPD5, is recruited to both RNA foci and protein aggregates, resulting in an upregulation of PAPD5 expression in Huntington's disease (HD). Additionally, we identify a subset of PAPD5-regulated miRNAs with increased adenylation and reduced expression in our disease model. We focus on miR-7-5p and find that its reduction causes the activation of the TAB2-mediated TAK1-MKK4-JNK pro-apoptotic pathway. This pathway is also activated in induced pluripotent stem cell-derived striatal neurons and post-mortem striatal tissues isolated from HD patients. In addition, we discover that a small molecule PAPD5 inhibitor, BCH001, can mitigate cell death and neurodegeneration in our disease models. This study highlights the importance of PAPD5-mediated miRNA dysfunction in HD pathogenesis and suggests a potential therapeutic direction for the disease.

The JNK signalling pathway gene BmJun is involved in the regulation of egg quality and production in the silkworm, Bombyx mori

The Jun N-terminal kinase (JNK) signalling pathway has a key role in tissue remodelling during insect metamorphosis by regulating programmed cell death. However, multiple members of the JNK pathway in Lepidoptera remain uncharacterized. In this study, two key genes of the JNK pathway, BmJun and BmFos, were cloned from the silkworm Bombyx mori, a lepidopteran model insect, and their effects on reproductive development were investigated. BmJun and BmFos encode 239 and 380 amino acids, respectively. Both proteins have typical basic leucine zipper domains and form a BmJUN-BmFOS dimer activator protein to exert transcriptional regulation. During the wandering stage of silkworm development, interference in BmJun expression had no effect on pupation, whereas B. mori vitellogenin (BmVg) expression, which is essential for egg development, was suppressed in the fat body and egg laying was significantly reduced. Additionally, numerous eggs appeared shrivelled and deformed, suggesting that they were nutritionally stunted. Inhibition of the JNK pathway caused abnormal pupal metamorphosis, an increase in shrivelled, unfertilized eggs, a decrease in fat body synthesis, and accumulation of BmVg in the ovaries of female B. mori. The results indicated that BmJUN and BmFOS can form an AP-1 dimer. Interfering with BmJun or inhibiting the phosphorylation of BmJUN leads to a reduction in the synthesis of BmVg in the fat body and its accumulation in the ovaries, thereby affecting the quality and production of the progeny eggs. These findings suggest that regulating Jun in the JNK pathway could be a potential way to inhibit female reproduction in Lepidoptera.

Probenecid Inhibits NLRP3 Inflammasome Activity and Mitogen-Activated Protein Kinases (MAPKs)

Probenecid has long been a versatile drug in pharmacological therapies, primarily known for blocking active tubular secretion in the kidney, affecting both endogenous substances like uric acid and exogenous ones like penicillin. Beyond its renal applications, probenecid has shown capabilities in crossing the blood-brain barrier and modulating the activity of various membrane channels and transporters. This compound has emerged as a potent antiviral agent, demonstrating efficacy against multiple viruses, including influenza, COVID-19, and RSV. Clinical trials with COVID-19 patients have confirmed its antiviral potential, sparking further investigation into its mechanisms of action. This study explores probenecid's significant anti-inflammatory properties, focusing on its ability to inhibit inflammasome activation. Our study aims to unravel the anti-inflammatory effects of probenecid on the NLRP3 inflammasome and MAPK signaling pathways using murine macrophages as a relevant inflammation model. We reveal that probenecid treatment blocks JNK and ERK signaling without affecting p38 MAPK, suppressing NLRP3 inflammasome activation. Additionally, probenecid does not affect NFκB-directed protein expression, although it efficiently inhibits NLRP3 inflammasome outputs, e.g., IL-1β and pyroptosis. These results indicate probenecid's potential therapeutic applications.

SP600125, a selective JNK inhibitor, is a potent inhibitor of NAD(P)H: quinone oxidoreductase 1 (NQO1)

The c-Jun N-terminal kinases (JNKs) has been identified as a critical modulator in multiple cellular processes, including stress stimulus, inflammation, cell proliferation, apoptosis, etc. SP600125 is a widely used ATP-competitive reversible JNKs inhibitor. NAD(P)H: quinone oxidoreductase 1 (NQO1) is a flavoprotein mediated two or four electron-reduction of quinones. Here, we showed that SP600125 bind to the active pocket of NQO1 and inhibit NQO1 activity. SP600125 exhibits comparable inhibitory effects on NQO1-mediated quinone bioactivation, H2O2 generation, and cell death, as the specific NQO1 inhibitor dicoumarol (DIC). Importantly, the inhibitory effects of SP600125 on NQO1 are independent of JNKs inhibition. These results suggested that SP600125 is a novel NQO1 inhibitor, which provides new insights into the mechanism of action of SP600125. Furthermore, SP600125 should be used more cautiously as a JNKs inhibitor, especially when NQO1 is highly expressed. SP600125 competed with β-Lap (NQO1-bioactivated drugs) for binding to NQO1, and inhibited NQO1-dependent cell death.

Nanotherapy targeting anti-aging skin cells: harnessing ursolic acid from Ocimum sanctum Linn for precision skin rejuvenation - a molecular perspective

The necessity of this work lies in the innovative application of nanotherapy to target anti-ageing skin cells, utilising ursolic acid from Ocimum sanctum Linn for precise and effective skin rejuvenation at a molecular level. Ursolic acid (UA), a pentacyclic triterpenoid compound, found in abundance in the plant O. sanctum Linn, has long been recognised for its potential anti-inflammatory, antioxidant, and anti-ageing properties. Despite its promising benefits, the direct application of UA in skincare has been limited, primarily due to its low aqueous solubility and poor skin penetration. This study explores a groundbreaking molecular approach, employing nanotechnology to enhance the delivery of UA, targeting skin cells for effective anti-ageing treatment. Through a comprehensive investigation, UA was encapsulated into biocompatible nanocarriers, ensuring increased stability, improved dermal penetration, and sustained release of the compound at the targeted site. By harnessing the specificity and efficiency of nanodelivery systems, the study achieved significant improvement in the absorption of UA in the deeper layers of the skin. This targeted intervention at the cellular and molecular level paved the way for maximising the potential of UA as an anti-ageing agent. In conclusion, the nanotherapeutic delivery of UA from O. sanctum Linn offers a paradigm shift in skincare, bringing forth a promising molecular strategy to combat skin ageing. With further advancements, this approach has the potential to revolutionise anti-ageing treatments, integrating traditional botanical wisdom with cutting-edge nanotechnology.

PIN1 Prolyl Isomerase Promotes Initiation and Progression of Bladder Cancer through the SREBP2-Mediated Cholesterol Biosynthesis Pathway

SIGNIFICANCE

This study provides deeper insights into the regulatory role of the phospho-dependent prolyl isomerase PIN1 in bladder cancer. The identification of the link between PIN1 and SREBP2-mediated transcription and cholesterol biosynthesis offers the potential for developing novel therapeutic strategies for bladder cancer.

G protein-coupled oestrogen receptor regulates branched-chain amino acid metabolism through c-Jun N-terminal kinase

Branched-chain amino acids (BCAA) are essential requirements for overall protein turnover, signalling and energy balance, and dysregulation of their metabolic pathway has been associated with many pathophysiological events. Despite the importance of BCAA in human health, our understanding of their metabolic regulation is limited. Here, we present evidence that G protein-coupled oestrogen receptor (GPER) activation inhibits the key BCAA metabolic regulatory enzyme branched-chain α-keto acid dehydrogenase complex (BCKDH) by phosphorylating S293. Inhibition of BCKDH results in leucine, isoleucine and valine accumulation in cells. Interestingly, GPER did not alter the levels of the kinase BCKDK and the phosphatase PPM1K, which regulate BCKDH activity, but activated MAPK signalling. Using gene silencing, we identified that JNK intercedes GPER-mediated BCKDH inhibition. Together, our results demonstrate that GPER inhibits BCAA metabolism through JNK signalling.

Identification of Autophagy-Related Genes in Patients with Acute Spinal Cord Injury and Analysis of Potential Therapeutic Targets

Autophagy has been implicated in the pathogenesis and progression of spinal cord injury (SCI); however, its specific mechanisms remain unclear. This study is aimed at identifying potential molecular biomarkers related to autophagy in SCI through bioinformatics analysis and exploring potential therapeutic targets. The mRNA expression profile dataset GSE151371 was obtained from the GEO database, and R software was used to screen for differentially expressed autophagy-related genes (DE-ARGs) in SCI. A total of 39 DE-ARGs were detected in this study. Enrichment analysis, protein-protein interaction (PPI) network, TF-mRNA-miRNA regulatory network analysis, and the DSigDB database were used to investigate the regulatory mechanisms between DE-ARGs and identify potential drugs for SCI. Enrichment analysis revealed associations with autophagy, apoptosis, and cell death. PPI analysis identified the highest-scoring module and selected 10 hub genes to construct the TF-mRNA-miRNA network, revealing regulatory mechanisms. Analysis of the DSigDB database indicated that 1,9-Pyrazoloanthrone may be a potential therapeutic drug. Machine learning algorithms identified 3 key genes as candidate biomarkers. Additionally, immune cell infiltration results revealed significant correlations between PINK1, NLRC4, VAMP3, and immune cell accumulation. Molecular docking simulations revealed that imatinib can exert relatively strong regulatory effects on the three key proteins. Finally, in vivo experimental data revealed that the overall biological process of autophagy was disrupted. In summary, this study successfully identified 39 DE-ARGs and discovered several promising biomarkers, significantly contributing to our understanding of the underlying mechanisms of autophagy in SCI. These findings offer valuable insights for the development of novel therapeutic strategies.

LRRC8A-containing anion channels promote glioblastoma proliferation via a WNK1/mTORC2-dependent mechanism

Leucine-rich repeat-containing protein 8A (LRRC8A) is the essential subunit of ubiquitous volume-regulated anion channels (VRACs). LRCC8A is overexpressed in several cancers and promotes negative survival outcomes via a poorly defined mechanism. Here, we explored the role of LRRC8A and VRACs in the progression of glioblastoma (GBM), the most common and deadly primary brain tumor. We found that, as compared to healthy controls, LRRC8A mRNA was strongly upregulated in surgical GBM specimens, patient-derived GBM cell lines, and GBM datasets from The Cancer Genome Atlas (TCGA). Our in-silico analysis indicated that patients belonging to the lowest LRRC8A expression quartile demonstrated a trend for extended life expectancy. In patient-derived GBM cultures, siRNA-driven LRRC8A knockdown reduced cell proliferation and additionally decreased intracellular chloride levels and inhibited activity of mTOR complex 2. The antiproliferative effect of LRRC8A downregulation was recapitulated with a pharmacological inhibitor of VRAC. Our ensuing biochemical and molecular biology analyses established that the LRRC8A-containing VRACs facilitate GBM proliferation via a new mechanism involving non-enzymatic actions of the chloride-sensitive protein kinase WNK1. Accordingly, the chloride-bound WNK1 stimulates mTORC2 and the mTORC2-dependent protein kinases AKT and SGK, which promote proliferation. These findings establish the new mTORC2-centric axis for VRAC dependent regulation of cellular functions and uncover potential targets for GBM intervention.

Amyloid-β can activate JNK signalling via WNT5A-ROR2 to reduce synapse formation in Alzheimer's disease

Wnt signalling is an essential signalling system in neurogenesis, with a crucial role in synaptic plasticity and neuronal survival, processes that are disrupted in Alzheimer's disease (AD). Within this network, the Wnt/β-catenin pathway has been studied for its neuroprotective role, and this is suppressed in AD. However, the involvement of the non-canonical Wnt-planar cell polarity (Wnt/PCP) pathway in AD remains to be determined. This study investigates the role of ROR2, a Wnt/PCP co-receptor, in synaptogenesis. We demonstrate that WNT5A-ROR2 signalling activates the JNK pathway, leading to synapse loss in mature neurons. This effect mirrors the synaptotoxic actions of Aβ1-42 and DKK1, which are elevated in AD. Notably, blocking ROR2 and JNK mitigates Aβ1-42 and DKK1-induced synapse loss, suggesting their dependence on ROR2. In induced pluripotent stem cell (iPSC)-derived cortical neurons carrying a PSEN1 mutation, known to increase the Aβ42/40 ratio, we observed increased WNT5A-ROR2 clustering and reduced numbers of synapses. Inhibiting ROR2 or JNK partially rescued synaptogenesis in these neurons. These findings suggest that, unlike the Wnt/β-catenin pathway, the Wnt/PCP-ROR2 signalling pathway can operate in a feedback loop with Aβ1-42 to enhance JNK signalling and contribute to synapse loss in AD.

Discovery of a selective and potent inhibitor of c-Jun N-terminal kinase 1 with anti-pulmonary fibrosis effect

We synthesized and evaluated a series of derivatives based on the pyrimidine-2,4-diamine scaffold as potential JNK1 inhibitors, incorporating bridging rings and spirocyclic modifications to enhance their inhibitory activity. These compounds were biologically assessed through JNK enzyme inhibition assays and Western Blot analysis. Compounds 13, 14 and 19 demonstrated significant inhibitory activity at both the enzyme and cellular level compared to the lead compound 1 and clinical candidate CC-90001. Notably, 14 exhibited strong inhibitory potency against JNK1 with sub-nanomolar efficacy and suppresses TGF-β-induced epithelial-mesenchymal transition, indicating its potential as a promising candidate for further development as an anti-pulmonary fibrosis agent targeting JNK1.

Huber S. JNK Inhibition Overcomes Resistance of Metastatic Tetraploid Cancer Cells to Irradiation-Induced Apoptosis

Tetraploidy is a condition in which the entire set of chromosomes doubles, most often due to errors during cell division. Tetraploidy can lead to genomic instability and significant consequences, in particular metastasis and treatment failure in tumours, including radiotherapy. The development of new strategies to sensitise these cells to treatment is of great importance. In our study, we investigated the in vitro combination of chemical treatment with the kinase inhibitor SP600125 and irradiation on diploid versus metastatic tetraploid RKO colon cancer clones. We assessed mitochondrial transmembrane potential, cell cycle and subG1 population by flow cytometry and performed clonogenic assays to evaluate cell sensitivity. We found that the combination overcomes irradiation resistance in metastatic tetraploid clones. To identify the main pathway involved in cell sensitivity, we screened the Harvard Medical School KINOMEscan library and performed a gene ontology biological process analysis. We found that the major kinases inhibited by SP600125 were ANKK1, BIKE, IKKA, JNK1, MP2K3, MP2K4, MKNK2, MYLK, PLK4, RPS6KA4(Kin,Dom,1), MYLK4 and TTK, and the pathways involved in clone sensitivity were DNA damage repair, radiation resistance and apoptosis, through JNK pathway inhibition. Finally, our main finding was that combined treatment with SP600125 and radiotherapy reduced the resistance of metastatic tetraploid cells to treatment, essentially by inhibiting the JNK pathway. This result supports a promising anti-cancer strategy to overcome the resistance of tetraploid cancer cells to irradiation.

Cellular Crosstalk Promotes Hepatic Progenitor Cell Proliferation and Stellate Cell Activation in 3D Co-culture

BACKGROUND & AIMS

Following liver damage, ductular reaction often coincides with liver fibrosis. Proliferation of hepatic progenitor cells is observed in ductular reaction, whereas activated hepatic stellate cells (HSCs) are the main drivers of liver fibrosis. These observations may suggest a functional interaction between these 2 cell types. Here, we report on an in vitro co-culture system to examine these interactions and validate their co-expression in human liver explants.

METHODS

In a 3D organoid co-culture system, we combined freshly isolated quiescent mouse HSCs and fluorescently labeled progenitor cells (undifferentiated intrahepatic cholangiocyte organoids), permitting real-time observation of cell morphology and behavior. After 7 days, cells were sorted based on the fluorescent label and analyzed for changes in gene expression.

RESULTS

In the 3D co-culture system, the proliferation of progenitor cells is enhanced, and HSCs are activated, recapitulating the cellular events observed in the patient liver. Both effects in 3D co-culture require close contact between the 2 different cell types. HSC activation during 3D co-culture differs from quiescent (3D mono-cultured) HSCs and activated HSCs on plastic (2D mono-culture). Upregulation of a cluster of genes containing Aldh1a2, Cthrc1, and several genes related to frizzled binding/Wnt signaling were exclusively observed in 3D co-cultured HSCs. The localized co-expression of specific genes was confirmed by spatial transcriptomics in human liver explants.

CONCLUSION

An in vitro 3D co-culture system provides evidence for direct interactions between HSCs and progenitor cells, which are sufficient to drive responses that are similar to those seen during ductular reaction and fibrosis. This model paves the way for further research into the cellular basis of liver pathology.

The role of lncRNA NEAT1 in acute graft-versus-host disease: Regulation of macrophage polarization and inflammatory cytokine secretion via JNK/NLRP3 pathway

BACKGROUND

Acute graft-versus-host disease (aGVHD) is a complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT). The role of macrophages as proficient antigen-presenting cells in aGVHD is a prominent area of investigation in contemporary research. The association between long noncoding RNA nuclear enriched abundant transcript 1 (lncRNA NEAT1) and the macrophage function is of significant interest. However, the role of lncRNA NEAT1 in aGVHD needs to be further explored.

METHODS

Peripheral blood mononuclear cells (PBMCs) were collected from patients with or without aGVHD (non-aGVHD) after allo-HSCT. RAW264.7 cells and bone marrow-derived macrophages (BMDMs) were transduced with NEAT1 lentiviral vector or transfected with NEAT1 small interfering RNA to change the expression level of lncRNA NEAT1. Finally, an aGVHD mouse model was established to evaluate the role of JNK inhibitor or NLRP3 inhibitor in aGVHD.

RESULTS

Compared with non-aGVHD patients, lncRNA NEAT1 was significantly up-regulated in the PBMCs of aGVHD patients. ROC and AUC analysis confirmed that the expression of lncRNA NEAT1 was correlated with the occurrence of aGVHD. The overexpression of lncRNA NEAT1 in RAW264.7 could significantly promote the proliferation, migration, and differentiation into M1 macrophages. Knockdown of lncRNA NEAT1 could significantly decrease the proportion of M1 macrophages, regulate pro-inflammatory cytokines secretion, and affect the JNK/NLRP3 pathway in lipopolysaccharides (LPS)-induced BMDMs. Correspondingly, JNK and NLRP3 inhibitors reduced LPS-induced pro-inflammatory responses in macrophages. Furthermore, JNK and NLRP3 inhibitors regulated macrophage polarization and improved symptoms in aGVHD mice.

CONCLUSIONS

The aforementioned data suggest that lncRNA NEAT1 potentially plays a significant role in macrophage polarization and the secretion of inflammatory cytokines through its modulation of the JNK/NLRP3 pathway. Consequently, this study establishes a foundation for the development of novel therapeutic approaches targeting aGVHD.

bta-miR-484 Inhibits Bovine Intramuscular Adipogenesis by Regulating Mitotic Clonal Expansion via the MAP3K9/JNK/CCND1 Axis

Intramuscular fat (IMF) content is a critical indicator of the beef nutritional value and flavor. In this study, we focused on bta-miR-484, a microRNA that is differentially expressed during the adipogenic differentiation of bovine intramuscular adipocytes and is negatively correlated with the IMF content across different cattle breeds. Our findings demonstrate that bta-miR-484 inhibits adipogenic differentiation without altering the fatty acid composition of bovine intramuscular adipocytes. miRNA pull-down and dual-luciferase reporter assays confirmed that MAP3K9 is a target gene of bta-miR-484. Furthermore, bta-miR-484 suppresses the JNK signaling pathway by targeting MAP3K9, leading to decreased CCND1 expression, which impedes the mitotic clonal expansion (MCE) process and inhibits intramuscular adipocyte differentiation. In summary, this study uncovers a novel mechanism by which bta-miR-484 regulates bovine IMF content and provides the first exploration of MCE during intramuscular adipocyte adipogenic differentiation. These findings offer valuable theoretical insights into beef cattle breeding and molecular improvements.

Antisense mediated blockade of Dickkopf 1 attenuates tumor survival, metastases and bone damage in experimental osteosarcoma

Osteosarcoma (OS) is the most common primary bone malignancy. The canonical Wnt inhibitor Dickkopf-1 (Dkk-1) has been implicated in bone destruction, tumor survival and metastases during OS. We examined the role of Dkk-1 in OS disease progression and explored strategies for targeting its activity. Dkk-1 enhances OS survival by amplifying a non-canonical Wnt pathway that upregulates aldehyde dehydrogenase 1A1. Targeting of Dkk-1 transcription with a vivo morpholino (DkkMo) reduced OS survival and enhanced osteogenic activity of OS in vitro. DkkMo as a single agent slowed tumor expansion, increased tumor necrosis, inhibited metastases and preserved bone in a PDX model of OS. DkkMo also reduced the frequency of dividing tumor cells and reinitiated a regenerative osteogenic phenotype in tumors and stroma while reducing infiltration of inflammatory cells. These findings indicate that DkkMo has the potential to safely target osteosarcoma growth, survival, metastases and bone destruction.

Exploring New Structures of Kinase Inhibitors and Multitarget Strategies in Alzheimer's Disease Treatment

Alzheimer's disease (AD) treatments currently available have ineffective results. Previously employed Acetylcholine esterase inhibitors and memantine, an NMDA receptor antagonist, target a single target structure that plays a complex role in the multifactorial progression of disease. Memantine moderates the toxic effects of excessive glutamate activity by blocking NMDA receptors, which decreases neurotoxicity in AD, while acetylcholine esterase inhibitors function by blocking cholinergic receptors (muscarinic and nicotinic), preventing the breakdown of acetylcholine, thereby enhancing cholinergic transmission, thus improving cognitive functions in mild to moderate stages of AD. Every drug class targets a distinct facet of the intricate pathophysiology of AD, indicating the diverse strategy required to counteract the advancement of this neurodegenerative disorder. Thus, patients are currently not getting much benefit from current drugs. A closer look at the course of AD revealed several potential target structures for future drug discovery. AD drug development strategies focus on developing new target structures in addition to well-established ones for combination treatment regimens, ideally with a single drug that can target two different target structures. Because of their roles in AD progression pathways like pathologic tau protein phosphorylations as well as amyloid β toxicity, protein kinases have been identified as potential targets. This review will give a quick rundown of the first inhibitors of single protein kinases, such as glycogen synthase kinase (gsk3) β, along with cyclin-dependent kinase 5. We will also look into novel inhibitors that target recently identified protein kinases in Alzheimer's disease, such as dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A). Additionally, multitargeting inhibitors, which target multiple protein kinases as well as those thought to be involved in other processes related to AD will be discussed. This kind of multitargeting offers prospective hope for improved patient outcomes down the road since it is the most effective way to impede multifactorial disease development.

Accelerating CAR-T Cell Therapies with Small-Molecule Inhibitors

Chimeric antigen receptor T-cell therapies have markedly improved the survival rates of patients with B-cell malignancies. However, their efficacy in other hematological cancers, such as acute myeloid leukemia, and in solid tumors has been limited. Key obstacles include the downregulation or loss of antigen expression on cancer cells, restricted accessibility to target cells, and the poor persistence of these "living drugs" because of the highly immunosuppressive tumor microenvironment. Additionally, manufacturing these immunotherapies presents significant challenges, and patients frequently experience side effects such as cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome. This review emphasizes the potential of small-molecule inhibitors, many of which are already approved for clinical use, to facilitate chimeric antigen receptor T-cell manufacturing, enhance their anti-tumor efficacy, and mitigate their side effects. Although substantial work remains, the robust pre-clinical data and the growing clinical interest suggest significant promise for using cancer signaling pathway inhibitors to enhance and refine chimeric antigen receptor T-cell therapy for both hematological and solid tumors. Exploring these combination strategies could lead to more effective therapies, offering new hope for patients with resistant forms of cancer.

Targeting STMN2 for neuroprotection and neuromuscular recovery in Spinal Muscular Atrophy: evidence from in vitro and in vivo SMA models

The development of ground-breaking Survival Motor Neuron (SMN) replacement strategies has revolutionized the field of Spinal Muscular Atrophy (SMA) research. However, the limitations of these therapies have now become evident, highlighting the need for the development of complementary targets beyond SMN replacement. To address these challenges, here we explored, in in vitro and in vivo disease models, Stathmin-2 (STMN2), a neuronal microtubule regulator implicated in neurodegenerative diseases like Amyotrophic Lateral Sclerosis (ALS), as a novel SMN-independent target for SMA therapy. Our findings revealed that STMN2 overexpression effectively restored axonal growth and outgrowth defects in induced pluripotent stem cell-(iPSC)-derived motor neurons (MNs) from SMA patients. Intracerebroventricular administration of adeno-associated virus serotype 9 (AAV9) carrying Stmn2 cDNA significantly ameliorated survival rates, motor functions, muscular and neuromuscular junction pathological features in SMA mice, mirrored by in vitro outcomes. Overall, this pioneering study not only provides insight into the therapeutic potential of STMN2 in SMA, but also suggests its broader applications for MN diseases, marking a substantial step forward in addressing the multifaceted challenges of neurological diseases treatment.

Inhibition of JNK Signaling Overcomes Cancer-Associated Fibroblast-Mediated Immunosuppression and Enhances the Efficacy of Immunotherapy in Bladder Cancer

Currently, only 20% to 40% of patients with cancer benefit from immune checkpoint inhibitors. Understanding the mechanisms underlying the immunosuppressive tumor microenvironment (TME) and characterizing dynamic changes in the immunologic landscape during treatment are critical for improving responsiveness to immunotherapy. In this study, we identified JNK signaling in cancer-associated fibroblasts (CAF) as a regulator of the immunosuppressive TME. Single-cell RNA sequencing of bladder cancer samples treated with a JNK inhibitor revealed enhanced cytotoxicity and effector functions of CD8+ T cells. In untreated tumors, CAFs interacted frequently with CD8+ T cells and mediated their exhaustion. JNK inhibition abrogated the immunosuppression function of CAFs by downregulating the expression of thymic stromal lymphopoietin (TSLP), thereby restoring CD8+ T-cell cytotoxicity. In addition, blockade of CAF-derived TSLP in combination with anti-PD-1 treatment promoted tumor elimination by CD8+ T cells in vivo. Collectively, these results indicate that JNK signaling plays an important immunosuppressive role in the TME by promoting expression of TSLP in CAFs and suggest that inhibiting JNK signaling could be a promising immunotherapeutic strategy for cancer treatment. Significance: JNK signaling promotes the secretion of TSLP by bladder cancer-associated fibroblasts to impede CD8+ T-cell activity, which can be circumvented by combination treatment targeting JNK signaling and PD-1.

Pharmacological inhibition of the MAP2K7 kinase in human disease

The MAP2K7 signaling pathway activates the c-Jun NH2-terminal protein kinase (JNK) in response to stress signals, such as inflammatory cytokines, osmotic stress, or genomic damage. While there has been interest in inhibiting JNK due to its involvement in inflammatory processes and cancer, there is increasing focus on developing MAP2K7 inhibitors to enhance specificity when MAP2K7 activation is associated with disease progression. Despite some progress, further research is needed to fully comprehend the role of MAP2K7 in cancer and assess the potential use of kinase inhibitors in cancer therapy. This review examines the role of MAP2K7 in cancer and the development of small-molecule inhibitors.

Transcriptome and Proteome Analyses Revealed Differences in JEV-Infected PK-15 Cells in Response to Ferroptosis Agonists and Antagonists

Epidemic encephalitis B caused by Japanese encephalitis virus (JEV) is a common zoonotic disease that poses threats to both pigs and humans. The cellular defense mechanism is closely tied to the body's resistance to viral invasion. Regulated cell death, such as ferroptosis, is a strategy employed by host cells to defend against viral invasions. To understand the effect of ferroptosis on the proliferation of JEV, experimentally infected PK15 cells were treated with a ferroptosis agonist or antagonist. The results indicated that the ferroptosis agonist can suppress JEV proliferation, whereas the ferroptosis antagonist promotes JEV proliferation. Functional enrichment analysis showed that the ferroptosis agonist Erastin and antagonist SP600125 could affect JEV proliferation through the TNF, IL-17, Toll-like receptor, PI3K-AKT, and chemokine signaling pathways, as well as ECM-receptor interactions. Combined transcriptome and proteome analyses revealed 31 important genes, which are significantly associated with ferroptosis and the inflammatory response. Our results provide a better understanding of the molecular mechanisms through which ferroptosis affects the proliferation of JEV.

Probenecid Inhibits Extracellular Signal-Regulated Kinase and c-Jun N-Terminal Kinase Mitogen-Activated Protein Kinase Pathways in Regulating Respiratory Syncytial Virus Response

We examined the effect of probenecid in regulating the ERK and JNK downstream MAPK pathways affecting respiratory syncytial virus replication.

BACKGROUND

We have previously shown that probenecid inhibits RSV, influenza virus, and SARS-CoV-2 replication in vitro in preclinical animal models and in humans. In a Phase two randomized, placebo-controlled, single-blind, dose range-finding study using probenecid to treat non-hospitalized patients with symptomatic, mild-to-moderate COVID-19, we previously showed that a 1000 mg twice daily treatment for 5 days reduced the median time to viral clearance from 11 to 7 days, and a 500 mg twice daily treatment for 5 days reduced the time to viral clearance from 11 to 9 days more than the placebo.

METHODS

In this study, we sought to determine the mechanism of action of the probenecid inhibition of RSV replication in human respiratory epithelial (A549) cells.

RESULTS

We show that probenecid inhibits the RSV-induced phosphorylation of JNKs and ERKs and the downstream phosphorylation of c-jun, a component of the AP-1 transcription complex needed for virus replication. The inhibition of JNKs by probenecid reversed the repression of transcription factor HNF-4.

CONCLUSION

The probenecid inhibition of JNK and ERK phosphorylation involves the MAPK pathway that precludes virus replication.

Downregulation of nuclear receptor-binding SET domain protein 1 induces proinflammatory cytokine expression via mitogen-activated protein kinase pathways in U87MG cells

Haploinsufficiency of the nuclear receptor binding SET domain-containing protein 1 gene (NSD1) leads to a neurodevelopmental disorder known as Sotos syndrome (SOTOS). This study investigated the effects of NSD1 knockdown in glial cells. U87MG glioma cells were transfected with siRNA targeting NSD1, which resulted in morphological changes characteristic of activated astrocytes. These activated phenotypes were accompanied by specific activation of mitogen-activated protein kinase (MAPK) signaling pathways, particularly those mediated by p38 MAPK and c-Jun N-terminal kinase (JNK). Transcriptome analysis showed increased expression of proinflammatory cytokine genes, particularly interleukin (IL)-1α, IL-1β, and IL-6, following NSD1 knockdown. Treatment with MAPK inhibitors significantly reduced the cytokine induction caused by NSD1 knockdown, with the p38 MAPK inhibitor being more effective than the JNK inhibitor. These findings provide new insights into the role of NSD1 loss in neurological dysfunctions associated with SOTOS.

Dichotomous outcomes of TNFR1 and TNFR2 signaling in NK cell-mediated immune responses during inflammation

Natural killer (NK) cell function is regulated by a balance of activating and inhibitory signals. Tumor necrosis factor (TNF) is an inflammatory cytokine ubiquitous across homeostasis and disease, yet its role in regulation of NK cells remains unclear. Here, we find upregulation of the immune checkpoint protein, T cell immunoglobulin and mucin domain 3 (Tim3), is a biomarker of TNF signaling in NK cells during Salmonella Typhimurium infection. In mice with conditional deficiency of either TNF receptor 1 (TNFR1) or TNF receptor 2 (TNFR2) in NK cells, we find TNFR1 limits bacterial clearance whereas TNFR2 promotes it. Mechanistically, via single cell RNA sequencing we find that both TNFR1 and TNFR2 induce the upregulation of Tim3, while TNFR1 accelerates NK cell death but TNFR2 promotes NK cell accumulation and effector function. Our study thus highlights the complex interplay of TNF-based regulation of NK cells by the two TNF receptors during inflammation.

Refrigerated amniotic membrane maintains its therapeutic qualities for 48 hours

During wound healing, the migration of keratinocytes is critical for wound closure. The application of amniotic membrane (AM) on wounds with challenging contexts (e.g., chronification and diabetic foot ulcer) has proven very successful. However, the use of AM for clinical practice has several restraints when applied to patients; the most important restriction is preserving AM's therapeutic properties between its thawing and application onto the patient's wound. Moreover, AM collection and processing requires a cleanroom, together with specialized staff and equipment, and facilities that are not usually available in many hospitals and healthcare units. In this publication, we kept previously cryopreserved AM at different temperatures (37°C, 20°C, and 4°C) in different media (DMEM high glucose and saline solution with or without human albumin) and for long incubation time periods after thawing (24 h and 48 h). HaCaT keratinocytes and TGF-β1-chronified HaCaT keratinocytes were used to measure several parameters related to wound healing: migration, cell cycle arrest rescue, and the expression of key genes and migration-related proteins. Our findings indicate that AM kept in physiological saline solution at 4°C for 24 h or 48 h performed excellently in promoting HaCaT cell migration compared to AM that had been immediately thawed (0 h). Indeed, key proteins, extracellular signal-regulated kinase (ERK) and c-Jun, were induced by AM at 4°C in saline solution. Similarly, cell proliferation and different genes related to survival, inflammation, and senescence had, in all cases, the same response as to standard AM. These data suggest that the handling method in saline solution at 4°C does not interfere with AM's therapeutic properties.

Type I IFN Induces TCR-dependent and -independent Antimicrobial Responses in γδ Intraepithelial Lymphocytes

Intraepithelial lymphocytes (IELs) expressing the TCRγδ survey the intestinal epithelium to limit the invasion of microbial pathogens. The production of type I IFN is a central component of an antiviral immune response, yet how these proinflammatory cytokines contribute to γδ IEL effector function remains unclear. Based on the unique activation status of IELs and their ability to bridge innate and adaptive immunity, we investigated the extent to which type I IFN signaling modulates γδ IEL function. Using an ex vivo culture model, we find that type I IFN alone is unable to drive IFN-γ production, yet low-level TCR activation synergizes with type I IFN to induce IFN-γ production in murine γδ IELs. Further investigation into the underlying molecular mechanisms of costimulation revealed that TCRγδ-mediated activation of NFAT and JNK is required for type I IFN to promote IFN-γ expression in a STAT4-dependent manner. Whereas type I IFN rapidly upregulates antiviral gene expression independent of a basal TCRγδ signal, neither tonic TCR triggering nor the presence of a TCR agonist was sufficient to elicit type I IFN-induced IFN-γ production in vivo. However, bypassing proximal TCR signaling events synergized with IFNAR/STAT4 activation to induce γδ IEL IFN-γ production. These findings indicate that γδ IELs contribute to host defense in response to type I IFN by mounting a rapid antimicrobial response independent of TCRγδ signaling, and may produce IFN-γ in a TCR-dependent manner under permissive conditions.

Blood vessel organoids generated by base editing and harboring single nucleotide variation in Notch3 effectively recapitulate CADASIL-related pathogenesis

Human blood vessel organoids (hBVOs) offer a promising platform for investigating vascular diseases and identifying therapeutic targets. In this study, we focused on in vitro modeling and therapeutic target finding of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), the most common form of hereditary stroke disorder caused by mutations in the NOTCH3 gene. Despite the identification of these mutations, the underlying pathological mechanism is elusive, and effective therapeutic approaches are lacking. CADASIL primarily affects the blood vessels in the brain, leading to ischemic strokes, migraines, and dementia. By employing CRISPR/Cas9 base-editing technology, we generated human induced pluripotent stem cells (hiPSCs) carrying Notch3 mutations. These mutant hiPSCs were differentiated into hBVOs. The NOTCH3 mutated hBVOs exhibited CADASIL-like pathology, characterized by a reduced vessel diameter and degeneration of mural cells. Furthermore, we observed an accumulation of Notch3 extracellular domain (Notch3ECD), increased apoptosis, and cytoskeletal alterations in the NOTCH3 mutant hBVOs. Notably, treatment with ROCK inhibitors partially restored the disconnection between endothelial cells and mural cells in the mutant hBVOs. These findings shed light on the pathogenesis of CADASIL and highlight the potential of hBVOs for studying and developing therapeutic interventions for this debilitating human vascular disorder.

Mechanism of Alzheimer type II astrocyte development in hepatic encephalopathy

Type C hepatic encephalopathy (Type C HE) is a major and complex neurological condition that occurs following chronic liver failure. The molecular basis of Type C HE remains elusive. Type C HE is characterized by mental confusion, cognitive and motor disturbances. The presence of Alzheimer type II astrocytes (AT2A) is the key histopathological finding observed in Type C HE. However, nothing is currently known regarding AT2A development and its involvement in cognitive, and motor deficits in Type C HE. We, therefore, examined in rats the mechanisms by which liver failure contributes to the progression of AT2A, and its role in the development of cognitive and motor deficits in thioacetamide (TAA) model of Type C HE. We and others earlier reported increased oxidative/nitrosative stress (ONS), JNK1/2, and cMyc activation in ammonia-treated astrocyte cultures, as well as in brains from chronic liver failure. We now found increased levels of astrocytic glia maturation factor (GMF, a factor strongly implicated in neuroinflammation), as well as various inflammatory factors (IL-1β, TNF-α, IL-6, MMP-3, COX2, CXCL1, and PGE2), and reduced levels of GFAP and increased levels of aggregated nuclear protein Lamin A/C in rat brain cortex post-chronic liver failure. We also found increased levels of GMF and inflammatory factors (MMP-3, COX2, CXCL1, and PGE2) in astrocytes post-ammonia treatment in vitro. Additionally, pharmacological inhibition of upstream signaling of GMF (ONS, JNK1/2, and cMyc) or GMF inhibitors W-7 and trifluoperazine significantly reduced the levels of inflammatory factors, the number of AT2A cells, as well as the cognitive and motor deficits in TAA-treated rats. Increased levels of GMF were also identified in human post-mortem brain sections. These findings strongly suggest that increased levels of astrocytic GMF due to elevated levels of ONS, JNK1/2, and cMyc and the subsequent inflammation contribute to the development of AT2A and the consequent cognitive, and motor deficits in chronic liver failure.

A review on synthetic inhibitors of dual-specific tyrosine phosphorylation-regulated kinase 1A (DYRK1A) for the treatment of Alzheimer's disease (AD)

Alzheimer's disease (AD) is a complex disorder that is influenced by a number of variables, such as age, gender, environmental factors, disease, lifestyle, infections, and many more. The main characteristic of AD is the formation of amyloid plaque and neurofibrillary tangles (NFT), which are caused by various reasons such as inflammation, impairment of neurotransmitters, hyperphosphorylation of tau protein, generation of toxic amyloid beta (Aβ) 40/42, oxidative stress, etc. Protein kinases located in chromosome 21, namely dual-specific tyrosine phosphorylation-regulated kinase 1A (DYRK1A), play an essential role in the pathogenesis of AD. DYRK1A stimulates the Aβ peptide aggregation and phosphorylation of tau protein to generate the NFT formation that causes neurodegeneration. Thus, DYRK1A is associated with AD, and inhibition of DYRK1A has the potential to treat AD. In this review, we discussed the pathophysiology of AD, various factors responsible for AD, and the role of DYRK1A in AD. We have also discussed the latest therapeutic potential of DYRK1A inhibitors for neurogenerative disease, along with their structure-activity relationship (SAR) studies. This article provides valuable information for guiding the future discovery of novel and target-specific DYRK1A inhibitors over other kinases and their structural optimization to treat AD.

Mechanism of JNK action in oxidative stress-enhanced gut injury by Clostridium perfringens type A infection

In piglets, oxidative stress can exacerbate gut injury caused by pathogens. C-Jun amino-terminal kinase (JNK) is associated with oxidative stress-induced damage to intestinal epithelial barrier. However, it is unclear whether oxidative stress can increase gut injury by Clostridium perfringens type A (CpA) and whether JNK mediates this process. We aimed to investigate if and how the JNK can regulate the effect of oxidative stress on gut injury induced by CpA infection. In this study, the oxidative stress in IPEC-J2 cells was modeled, and the changes in the susceptibility of IPEC-J2 cells to CpA were examined after treatment of oxidative stressed IPEC-J2 cells with JNK inhibitor (SP600125) and JNK siRNA. Pre-injection with the SP600125 solution was also carried out in oxidative stressed mice, followed by CpA infection. Results indicated that compared to that in the Control group, IPEC-J2 cells under oxidative stress showed reduced transmembrane resistance, degraded tight junction (TJ) proteins, increased membrane permeability, and enhanced CpA infection, all of which were reversed by inhibiting or interfering with JNK expression. Similarly, compared to that in the Control group, mice under oxidative stress showed degradation of jejunal TJ proteins, increased intestinal permeability and barrier damage by CpA, while mice pre-injected with the SP600125 solution showed alleviation of these alterations. These results suggested that oxidative stress enhanced the infection of IPEC-J2 cells and the gut injury caused by CpA, which was mediated by JNK. This study provides important insights regarding the mechanism by which oxidative stress enhanced intestinal damage by CpA.

Hydrogen sulfide donor NaHS inhibits formaldehyde-induced epithelial-mesenchymal transition in human lung epithelial cells via activating TGF-β1/Smad2/3 and MAPKs signaling pathways

Formaldehyde (FA) long term exposure leads to abnormal pulmonary function and small airway obstruction of the patients. Hydrogen sulfide (H2S) is one of the recognized gaseous transmitters involved in a wide range of cellular functions. It is unknown the involvement of H2S in FA-induced lung injury. The purpose of this study is to investigate the therapeutic potential and mechanism of H2S on FA-induced epithelial-mesenchymal transition (EMT) of human lung epithelial cells. The cell viability of Beas2B and A549 cells after FA treatment were assessed using MTT assay. The endogenous H2S was visualized by fluorescence microscopy using of the 7-azido-4-methylcoumarin (AzMC). Cell morphology was observed under phase contrast microscope. The mRNAs and proteins level were evaluated by reverse transcription-polymerase chain reaction and western blotting assays. FA treatment downregulated the endogenous H2S levels and the mRNAs and proteins level of H2S synthesizing enzymes, such as cystathionine-β-synthase (CBS), cystathionine-γ-lyase (CSE), and 3-mercaptopyruvate sulfurtransferase (3-MST) in Beas2B and A549 cells. FA treatment changed the cell morphology of Beas2B cells from cuboid to a spindle-shape, while declined the protein level of E-cadherin and increased the protein level of Vimentin. Moreover, FA treatment increased the proteins level of transforming growth factor-β1 (TGF-β1), phosphorylated-Smad2 (p-Smad2), phosphorylated-Smad3 (p-Smad3), phosphorylated-extracellular signal-regulated kinase (p-ERK), phosphorylated-c-Jun N-terminal kinase (p-JNK), and phosphorylated-P38 (p-P38). Furthermore, the inhibitors of TGF-β receptor type 1 (TGFβRI) and mitogen-activated protein kinases (MAPKs) signaling pathways reversed FA-induced decrease in E-cadherin expression and increase in Vimentin expression in Beas2B cells. Sodium hydrogen sulfide (NaHS) increased the level of H2S, while reversed FA-induced the low expression of E-cadherin and the high expression of Vimentin, TGF-β1, p-Smad2, p-Smad3, p-ERK, p-JNK, and p-P38. These findings indicates FA treatment downregulating the endogenous H2S in human lung epithelial cells. NaHS may inhibit FA-induced EMT in human lung epithelial cells via modulating TGF-β1/Smad2/3 and MAPKs signaling pathways. Therefore, we demonstrated that supplementation of exogenous H2S may inhibit FA-induced lung injury.

Chemogenetic neuronal silencing decouples c-Jun activation from cell death in the temporal cortex

Initial symptoms of neurodegenerative diseases are often defined by the loss of the most vulnerable neural populations specific to each disorder. In the early stages of Alzheimer's disease, vulnerable circuits in the temporal lobe exhibit diminished activity prior to overt degeneration. It remains unclear whether these functional changes contribute to regional vulnerability or are simply a consequence of pathology. We previously found that entorhinal neurons in the temporal cortex undergo cell death following transient suppression of electrical activity, suggesting a causal role for activity disruption in neurodegeneration. Here we demonstrate that electrical arrest of this circuit stimulates the injury-response transcription factor c-Jun. Entorhinal silencing induces transcriptional changes consistent with c-Jun activation that share characteristics of gene signatures in other neuronal populations vulnerable to Alzheimer's disease. Despite its established role in the neuronal injury response, inhibiting c-Jun failed to ameliorate entorhinal degeneration following activity disruption. Finally, we present preliminary evidence of integrated stress response activity that may serve as an alternative hypothesis to what drives entorhinal degeneration after silencing. Our data demonstrate that c-Jun is activated in response to neuronal silencing in the entorhinal cortex but is decoupled from subsequent neurodegeneration.

Structure Optimization of c-Jun N-terminal Kinase 1 Inhibitors for Treating Idiopathic Pulmonary Fibrosis

Idiopathic pulmonary fibrosis (IPF) is a progressive and lethal lung disease with an elusive etiology. Aberrant activation of c-Jun N-terminal kinase 1 (JNK1) has been implicated in its pathogenesis. Through a combination of structure-based drug design and structure-activity relationship (SAR) optimization, a series of pyrimidine-2,4-diamine scaffold derivatives have been developed as potent JNK1 inhibitors. Compound E1 was identified with low nanomolar JNK1 inhibitory potency (IC50 = 2.7 nM). The introduction of a dimethylamine side chain has significantly enhanced the ability of E1 to inhibit c-Jun phosphorylation, surpassing the clinical candidate CC-90001. Molecular dynamics simulations revealed a binding free energy of -50.46 kcal/mol for E1. Moreover, E1 displayed satisfactory pharmacokinetic properties, with a bioavailability of 69% in rats. Furthermore, compound E1 exerted significant antifibrotic effects in a bleomycin-induced IPF mouse model and prevented a TGF-β-induced epithelial-to-mesenchymal transition in vitro. These findings position E1 as a promising lead for further drug development targeting IPF.

Autophagy modulation in cancer therapy: Challenges coexist with opportunities

Autophagy, a crucial intracellular degradation process facilitated by lysosomes, plays a pivotal role in maintaining cellular homeostasis. The elucidation of autophagy key genes and signaling pathways has significantly advanced our understanding of this process and has led to the exploration of autophagy as a promising therapeutic approach. This review comprehensively assesses the latest developments in small molecule modulators targeting autophagy. Moreover, the review delves into the most recent strategies for drug discovery, specifically focusing on selective agents that exploit autophagosomes and lysosomes for targeted protein degradation. Additionally, this article highlights the prevailing challenges and outlines potential future advancements in the field. By amalgamating the cutting-edge knowledge in the field, we aim to offer valuable insights and references for the anti-cancer drug development of autophagy-targeted therapies, thus contributing to the advancement of novel therapeutic interventions.

Trehalose Attenuates In Vitro Neurotoxicity of 6-Hydroxydopamine by Reducing Oxidative Stress and Activation of MAPK/AMPK Signaling Pathways

The effects of trehalose, an autophagy-inducing disaccharide with neuroprotective properties, on the neurotoxicity of parkinsonian mimetics 6-hydroxydopamine (6-OHDA) and 1-methyl-4-phenylpiridinium (MPP+) are poorly understood. In our study, trehalose suppressed 6-OHDA-induced caspase-3/PARP1 cleavage (detected by immunoblotting), apoptotic DNA fragmentation/phosphatidylserine externalization, oxidative stress, mitochondrial depolarization (flow cytometry), and mitochondrial damage (electron microscopy) in SH-SY5Y neuroblastoma cells. The protection was not mediated by autophagy, autophagic receptor p62, or antioxidant enzymes superoxide dismutase and catalase. Trehalose suppressed 6-OHDA-induced activation of c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), and AMP-activated protein kinase (AMPK), as revealed by immunoblotting. Pharmacological/genetic inhibition of JNK, p38 MAPK, or AMPK mimicked the trehalose-mediated cytoprotection. Trehalose did not affect the extracellular signal-regulated kinase (ERK) and mechanistic target of rapamycin complex 1 (mTORC1)/4EBP1 pathways, while it reduced the prosurvival mTORC2/AKT signaling. Finally, trehalose enhanced oxidative stress, mitochondrial damage, and apoptosis without decreasing JNK, p38 MAPK, AMPK, or AKT activation in SH-SY5Y cells exposed to MPP+. In conclusion, trehalose protects SH-SY5Y cells from 6-OHDA-induced oxidative stress, mitochondrial damage, and apoptosis through autophagy/p62-independent inhibition of JNK, p38 MAPK, and AMPK. The opposite effects of trehalose on the neurotoxicity of 6-OHDA and MPP+ suggest caution in its potential development as a neuroprotective agent.

SPG21, a potential oncogene targeted by miR-128-3p, amplifies HBx-induced carcinogenesis and chemoresistance via activation of TRPM7-mediated JNK pathway in hepatocellular carcinoma

PURPOSE

Chronic hepatitis B virus (HBV) infection is the primary risk factor for the malignant progression of hepatocellular carcinoma (HCC). It has been reported that HBV X protein (HBx) possesses oncogenic properties, promoting hepatocarcinogenesis and chemoresistance. However, the detailed molecular mechanisms are not fully understood. Here, we aim to investigate the effects of miR-128-3p/SPG21 axis on HBx-induced hepatocarcinogenesis and chemoresistance.

METHODS

The expression of SPG21 in HCC was determined using bioinformatics analysis, quantitative real-time PCR (qRT-PCR), western blotting, and immunohistochemistry (IHC). The roles of SPG21 in HCC were elucidated through a series of in vitro and in vivo experiments, including real-time cellular analysis (RTCA), matrigel invasion assay, and xenograft mouse model. Pharmacologic treatment and flow cytometry were performed to demonstrate the potential mechanism of SPG21 in HCC.

RESULTS

SPG21 expression was elevated in HCC tissues compared to adjacent non-tumor tissues (NTs). Moreover, higher SPG21 expression correlated with poor overall survival. Functional assays revealed that SPG21 fostered HCC tumorigenesis and invasion. MiR-128-3p, which targeted SPG21, was downregulated in HCC tissues. Subsequent analyses showed that HBx amplified TRPM7-mediated calcium influx via miR-128-3p/SPG21, thereby activating the c-Jun N-terminal kinase (JNK) pathway. Furthermore, HBx inhibited doxorubicin-induced apoptosis by engaging the JNK pathway through miR-128-3p/SPG21.

CONCLUSION

The study suggested that SPG21, targeted by miR-128-3p, might be involved in enhancing HBx-induced carcinogenesis and doxorubicin resistance in HCC via the TRPM7/Ca2+/JNK signaling pathway. This insight suggested that SPG21 could be recognized as a potential oncogene, offering a novel perspective on its role as a prognostic factor and a therapeutic target in the context of HCC.

Update on JNK inhibitor patents: 2015 to present

INTRODUCTION

c-Jun N-terminal kinase (JNK) regulates various biological processes through the phosphorylation cascade and is closely associated with numerous diseases, including inflammation, cardiovascular diseases, and neurological disorders. Therefore, JNKs have emerged as potential targets for disease treatment.

AREAS COVERED

This review compiles the patents and literatures concerning JNK inhibitors through retrieving relevant information from the SciFinder, Google Patents databases, and PubMed from 2015 to the present. It summarizes the structure-activity relationship (SAR) and biological activity profiles of JNK inhibitors, offering valuable perspectives on their potential therapeutic applications.

EXPERT OPINION

The JNK kinase serves as a novel target for the treatment of neurodegenerative disorders, pulmonary fibrosis, and other illnesses. A variety of small-molecule inhibitors targeting JNKs have demonstrated promising therapeutic potential in preclinical studies, which act upon JNK kinases via distinct mechanisms, encompassing traditional ATP competitive inhibition, covalent inhibition, and bidentate inhibition. Among them, several JNK inhibitors from PregLem SA, Celegene SA, and Xigen SA have accomplished the early stage of clinical trials, and their results will guide the development and indications of future JNK inhibitors.

MEK1/2- and ERK1/2-Mediated Lung Endothelial Injury and Altered Hemostasis Promote Diffuse Alveolar Hemorrhage in Murine Lupus

OBJECTIVE

About 3% of patients with lupus develop severe diffuse alveolar hemorrhage (DAH) with pulmonary vasculitis. C57BL/6 (B6) mice with pristane-induced lupus also develop DAH, but BALB/c mice are resistant. DAH is independent of Toll-like receptor signaling and other inflammatory pathways. This study examined the role of the MEK1/2 pathway (MEK1/2-ERK1/2, JNK, p38).

METHODS

B6 and BALB/c mice were treated with pristane with or without inhibitors of MEK1/2 (trametinib/GSK1120212 [GSK]), ERK1/2 (SCH772984 [SCH]), JNK, or p38. Effects on lung hemorrhage and hemostasis were determined.

RESULTS

GSK and SCH abolished DAH, whereas JNK and p38 inhibitors were ineffective. Apoptotic cells were present in lung samples from pristane-treated mice but not in mice receiving pristane and GSK, and endothelial dysfunction was normalized. Expression of the ERK1/2-regulated transcription factor early growth response 1 increased in pristane-treated B6, but not BALB/c, mice and was normalized by GSK. Pristane also increased expression of the anticoagulant genes Tfpi and Thbd in B6 mice. The ratio of Tfpi to tissue factor (F3) to Tfpi increased in B6 (but not BALB/c) mice and was normalized by GSK. Circulating thrombomodulin protein levels increased in B6 mice and returned to normal after GSK treatment. Consistent with augmented endothelial anticoagulant activity, pristane treatment increased tail bleeding in B6 mice.

CONCLUSION

Pristane treatment promotes lung endothelial injury and DAH in B6 mice by activating the MEK1/2-ERK1/2 pathway and impairing hemostasis. The hereditary factors determining susceptibility to lung injury and bleeding in pristane-induced lupus are relevant to the pathophysiology of life-threatening DAH in systemic lupus erythematosus and may help to optimize therapy.

The enhancer RNA, AANCR, regulates APOE expression in astrocytes and microglia

Enhancers, critical regulatory elements within the human genome, are often transcribed into enhancer RNAs. The dysregulation of enhancers leads to diseases collectively termed enhanceropathies. While it is known that enhancers play a role in diseases by regulating gene expression, the specific mechanisms by which individual enhancers cause diseases are not well understood. Studies of individual enhancers are needed to fill this gap. This study delves into the role of APOE-activating noncoding RNA, AANCR, in the central nervous system, elucidating its function as a genetic modifier in Alzheimer's Disease. We employed RNA interference, RNaseH-mediated degradation, and single-molecule RNA fluorescence in situ hybridization to demonstrate that mere transcription of AANCR is insufficient; rather, its transcripts are crucial for promoting APOE expression. Our findings revealed that AANCR is induced by ATM-mediated ERK phosphorylation and subsequent AP-1 transcription factor activation. Once activated, AANCR enhances APOE expression, which in turn imparts an inflammatory phenotype to astrocytes. These findings demonstrate that AANCR is a key enhancer RNA in some cell types within the nervous system, pivotal for regulating APOE expression and influencing inflammatory responses, underscoring its potential as a therapeutic target in neurodegenerative diseases.

Evolving significance of kinase inhibitors in the management of Alzheimer's disease

Alzheimer's disease is a neurodegenerative problem with progressive loss of memory and other cognitive function disorders resulting in the imbalance of neurotransmitter activity and signaling progression, which poses the need of the potential therapeutic target to improve the intracellular signaling cascade brought by kinases. Protein kinase plays a significant and multifaceted role in the treatment of Alzheimer's disease, by targeting pathological mechanisms like tau hyperphosphorylation, neuroinflammation, amyloid-beta production and synaptic dysfunction. In this review, we thoroughly explore the essential protein kinases involved in Alzheimer's disease, detailing their physiological roles, regulatory impacts, and the newest inhibitors and compounds that are progressing into clinical trials. All the findings of studies exhibited the promising role of kinase inhibitors in the management of Alzheimer's disease. However, it still poses the need of addressing current challenges and opportunities involved with this disorder for the future perspective of kinase inhibitors in the management of Alzheimer's disease. Further study includes the development of biomarkers, combination therapy, and next-generation kinase inhibitors with increased potency and selectivity for its future prospects.

Ben-JNK signaling is required for host mortality during Periplaneta fuliginosa densovirus infection

BACKGROUND

Cockroaches are widely acknowledged as significant vectors of pathogenic microorganisms. The Periplaneta fuliginosa densovirus (PfDNV) infects the smoky-brown cockroach P. fuliginosa and causes host mortality, which identifies the PfDNV as a species-specific and environmentally friendly biopesticide. However, although the biochemical characterization of PfDNV has been extensively studied, the immune response against PfDNV remains largely unclear.

RESULTS

Here, we investigated the replication of PfDNV and its associated pathological phenotype in the foregut and hindgut. Consequently, we dissected and performed transcriptome sequencing on the foregut, midgut, and hindgut separately. We revealed the up-regulation of immune response signaling pathway c-Jun N-terminal kinase (JNK) and apoptosis in response to viral infection. Furthermore, knockdown of the JNK upstream gene Ben resulted in a decrease in virus titer and delayed host mortality.

CONCLUSION

Taken together, our findings provide evidence that the Ben-JNK signaling plays a crucial role in PfDNV infection, leading to excessive apoptosis in intestinal tissues and ultimately resulting in the death of the host. Our results indicated that the host response to PfDNV fosters viral infection, thereby increasing host lethality. This underscores the potential of PfDNV as a viable, environmentally friendly biopesticide. © 2024 Society of Chemical Industry.

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.

Neuronostatin regulates proliferation and differentiation of rat brown primary preadipocytes

Neuronostatin suppresses the differentiation of white preadipocytes. However, the role of neuronostatin in brown adipose tissue remains elusive. Therefore, we investigated the impact of neuronostatin on the proliferation and differentiation of isolated rat brown preadipocytes. We report that neuronostatin and its receptor (GPR107) are synthesized in brown preadipocytes and brown adipose tissue. Furthermore, neuronostatin promotes the replication of brown preadipocytes via the AKT pathway. Notably, neuronostatin suppresses the expression of markers associated with brown adipogenesis (PGC-1α, PPARγ, PRDM16, and UCP1) and reduces cellular mitochondria content. Moreover, neuronostatin impedes the differentiation of preadipocytes by activating the JNK signaling pathway. These effects were not mimicked by somatostatin. Our results suggest that neuronostatin is involved in regulating brown adipogenesis.