DUSPs, twists and turns in the Journey to Vascular Inflammation

Exploring the mechanism of berberine treatment for atherosclerosis combined with non-alcoholic fatty liver disease based on bioinformatic and experimental study

Atherosclerosis (AS) and Non-alcoholic fatty liver disease (NAFLD) are chronic metabolic disorders with high prevalence and significant health impacts. Both conditions share common pathophysiological pathways including abnormal lipid metabolism and inflammation. Berberine (BBR), an isoquinoline alkaloid, is known for its beneficial effects on various metabolic and cardiovascular disorders. This study investigates BBR's impact on AS and NAFLD through bioinformatics analysis and experimental models. This study utilized various bioinformatics methods, including transcriptome analysis, weighted gene co-expression network analysis (WGCNA), machine learning, and molecular docking, to identify key genes and pathways involved in AS and NAFLD. Subsequently an animal model of AS combined with NAFLD was established using ApoE-/- mice fed a high-fat diet. The efficacy and mechanism of action of BBR were verified using methods such as hematoxylin and eosin (HE) staining, Oil Red O staining, and real-time quantitative PCR (RTqPCR). Through transcriptome analysis, WGCNA, and machine learning, this study identified 48 key genes involved in both AS and NAFLD. Function analysis revealed that the implicated genes were significantly involved in pathways like cytokine-cytokine receptor interaction, chemokine signaling, and IL-17 signaling pathway, suggesting their role in inflammation and immune responses. Single cell validation identified six key genes: dual specificity phosphatase 6 (DUSP6), chemokine ligand 3 (CCL3), complement component 5a receptor 1 (C5AR1), formyl peptide receptor 1 (FPR1), myeloid nuclear differentiation antigen (MNDA), and proviral integration site of murine 2(PIM2). Finally, molecular docking and animal experiments showed that BBR significantly reduced lipid deposits and inflammatory markers in liver and aortic tissues. In conclusion, BBR can improve AS combined with NAFLD by regulating genes like MNDA, PIM2, DUSP6, CCL3, C5AR1, and FPR1, with the mechanism related to inflammation control. The findings suggest potential clinical benefits of BBR in reducing the progression of both AS and NAFLD, warranting further investigation.

Bioinformatics analysis and identification of potential key genes and pathways in the pathogenesis of nonischemic cardiomyopathy

Nonischemic cardiomyopathy (NICM) is a major cause of advanced heart failure, and the morbidity and mortality associated with NICM are serious medical problems. However, the etiology of NICM is complex and the related mechanisms involved in its pathogenesis remain unclear. The microarray datasets GSE1869 and GSE9128 retrieved from the Gene Expression Omnibus database were used to identify differentially expressed genes (DEGs) between NICM and normal samples. The co-expressed genes were identified using Venn diagrams. Kyoto Encyclopedia of Genes and Genomes pathway analyses and gene ontology enrichment were used to clarify biological functions and signaling pathways. Analysis of protein-protein interaction networks using Search Tool for the Retrieval of Interacting Genes/Proteins online to define the hub genes associated with NICM pathogenesis. A total of 297 DEGs were identified from GSE1869, 261 of which were upregulated genes and 36 were downregulated genes. A total of 360 DEGs were identified from GSE9128, 243 of which were upregulated genes and 117 were downregulated genes. In the 2 datasets, the screening identified 36 co-expressed DEGs. Kyoto Encyclopedia of Genes and Genomes pathway and gene ontology analysis showed that DEGs were mainly enriched in pantothenate and CoA biosynthesis, beta-alanine metabolism, kinetochore, G-protein beta/gamma-subunit complex, and other related pathways. The PPI network analysis revealed that DUSP6, EGR1, ZEB2, and XPO1 are the 4 hub genes of interest in the 2 datasets. Bioinformatics analysis of hub genes and key signaling pathways is an effective way to elucidate the mechanisms involved in the development of NICM. The results will facilitate further studies on the pathogenesis and therapeutic targets of NICM.

Targeting protein phosphatases for the treatment of inflammation-related diseases: From signaling to therapy

Inflammation is the common pathological basis of autoimmune diseases, metabolic diseases, malignant tumors, and other major chronic diseases. Inflammation plays an important role in tissue homeostasis. On one hand, inflammation can sense changes in the tissue environment, induce imbalance of tissue homeostasis, and cause tissue damage. On the other hand, inflammation can also initiate tissue damage repair and maintain normal tissue function by resolving injury and restoring homeostasis. These opposing functions emphasize the significance of accurate regulation of inflammatory homeostasis to ameliorate inflammation-related diseases. Potential mechanisms involve protein phosphorylation modifications by kinases and phosphatases, which have a crucial role in inflammatory homeostasis. The mechanisms by which many kinases resolve inflammation have been well reviewed, whereas a systematic summary of the functions of protein phosphatases in regulating inflammatory homeostasis is lacking. The molecular knowledge of protein phosphatases, and especially the unique biochemical traits of each family member, will be of critical importance for developing drugs that target phosphatases. Here, we provide a comprehensive summary of the structure, the "double-edged sword" function, and the extensive signaling pathways of all protein phosphatases in inflammation-related diseases, as well as their potential inhibitors or activators that can be used in therapeutic interventions in preclinical or clinical trials. We provide an integrated perspective on the current understanding of all the protein phosphatases associated with inflammation-related diseases, with the aim of facilitating the development of drugs that target protein phosphatases for the treatment of inflammation-related diseases.

Clinical value of serum JKAP in acute ischemic stroke patients

Background

Jun N‐terminal kinase pathway‐associated phosphatase (JKAP) regulates neuronal function, T helper (Th) 1/2/17 cell differentiation, and inflammatory process, but its clinical role in acute ischemic stroke (AIS) patients remains unclear. Hence, this study intended to evaluate JKAP level and its relationship with disease severity, Th1, 2, 17 secreted cytokines, adhesion molecules, and prognosis of AIS patients.

Methods

Serum JKAP of 122 AIS patients and 50 controls was detected by ELISA. For AIS patients only, Th1, 2, 17 secreted cytokines IFN‐γ, IL‐4, IL‐17; TNF‐α, ICAM‐1, and VCAM‐1 were also detected by ELISA.

Results

JKAP was decreased in AIS patients compared with controls (46.350 (interquartile range (IQR): 34.250–59.875) pg/ml vs. 84.500 (IQR: 63.175–113.275) pg/ml, p < 0.001), which could distinguish AIS patients from controls (area under curve (AUC): 0.810, 95% confidence interval (CI): 0.732–0.888). In AIS patients, JKAP negatively linked with the National Institutes of Health Stroke Scale (NIHSS) score (r_s = −0.342, p < 0.001); besides, it was positively related to IL‐4 (r_s = 0.213, p = 0.018) and negatively associated with IL‐17 (r_s = −0.270, p = 0.003) but not related to IFN‐γ (r_s = −0.146, p = 0.109). Furthermore, elevated JKAP associated with declined TNF‐α (r_s = −0.219, p = 0.015) and ICAM‐1 (r_s = −0.235, p = 0.009) but not related to VCAM‐1 (r_s = −0.156, p = 0.085). Besides, declined JKAP was linked with 2‐year recurrence (p = 0.027) and 3‐year recurrence (p = 0.010) in AIS patients; while JKAP was not related to 1‐year recurrence or death risk (both p > 0.050).

Conclusion

JKAP may sever as a candidate prognostic biomarker in AIS patients, indicating its potency for AIS management.

Targeting DUSP7 signaling alleviates hepatic steatosis, inflammation and oxidative stress in high fat diet (HFD)-fed mice via suppression of TAK1

The non-alcoholic fatty liver disease (NAFLD), as a critical liver disease, is still lack of effective treatments because the molecular mechanism revealing the NAFLD pathogenesis remains unclear. Dual specific phosphatase 6 (DUSP7) shows effects on inflammatory response and is a negative feedback mechanism of the mitogen-activated protein kinase (MAPK) superfamily, which are critical factors in regulating NAFLD progression. However, the effects of DUSP7 on hepatic steatosis are still not fully understood. Here, we found that DUSP7 functioned as a negative regulator of NAFLD and in various metabolic disorders. DUSP7 expression was markedly reduced in liver samples from patients with simple hepatic steatosis or non-alcoholic steatohepatitis (NASH), as well as in liver tissues from high fat diet (HFD)-challenged mice or genetically obese (ob/ob) mice. DUSP7 knockout markedly accelerated insulin resistance, glucose intolerance, liver dysfunction, fibrosis and hepatic steatosis in HFD-fed mice. In addition, inflammatory response was significantly exacerbated in HFD-challenged mice with DUSP7 deletion, which was associated with the elevated activation of nuclear factor-κB (NF-κB) and MAPKs signaling pathways. Moreover, oxidative stress was detected in liver of HFD-induced mice, and this phenomenon was aggravated in mice with DUSP7 knockout. Importantly, we demonstrated that DUSP7 physically interacted with transforming growth factor β (TGF-β)-activated kinase (TAK1). DUSP7 deletion considerably promoted the activation of TAK1 in mice after HFD feeding, contributing to the lipid deposition, inflammatory response and reactive oxygen species (ROS) production. Taken together, DUSP7 might function as a protective factor against NAFLD development and metabolic disorder through alleviating dyslipidemia, inflammation and oxidative stress by directly interacting with TAK1 in hepatocytes, which was involved in the suppression of fibrosis. Thus, we may provide an effective strategy for the treatment of hepatic steatosis via targeting DUSP7.

High-Throughput Identification of MiR-145 Targets in Human Articular Chondrocytes

MicroRNAs (miRNAs) play key roles in cartilage development and homeostasis and are dysregulated in osteoarthritis. MiR-145 modulation induces profound changes in the human articular chondrocyte (HAC) phenotype, partially through direct repression of SOX9. Since miRNAs can simultaneously silence multiple targets, we aimed to identify the whole targetome of miR-145 in HACs, critical if miR-145 is to be considered a target for cartilage repair. We performed RIP-seq (RNA-immunoprecipitation and high-throughput sequencing) of miRISC (miRNA-induced silencing complex) in HACs overexpressing miR-145 to identify miR-145 direct targets and used cWords to assess enrichment of miR-145 seed matches in the identified targets. Further validations were performed by RT-qPCR, Western immunoblot, and luciferase assays. MiR-145 affects the expression of over 350 genes and directly targets more than 50 mRNAs through the 3′UTR or, more commonly, the coding region. MiR-145 targets DUSP6, involved in cartilage organization and development, at the translational level. DUSP6 depletion leads to MMP13 upregulation, suggesting a contribution towards the effect of miR-145 on MMP13 expression. In conclusion, miR-145 directly targets several genes involved in the expression of the extracellular matrix and inflammation in primary chondrocytes. Thus, we propose miR-145 as an important regulator of chondrocyte function and a new target for cartilage repair.

Targeting DUSP16/TAK1 signaling alleviates hepatic dyslipidemia and inflammation in high fat diet (HFD)-challenged mice through suppressing JNK MAPK

Nonalcoholic fatty liver disease (NAFLD) is featured by hepatic steatosis, insulin resistance, lipid deposition and inflammation. However, the pathogenic mechanism of NAFLD is still poorly understood. Dual-specificity phosphatase 16 (DUSP16), a c-Jun N-terminal kinase-specific phosphatase, has been reported to negatively modulate the mitogen-activated protein kinases (MAPKs) signaling, and it has never been investigated in NAFLD progression. In the study, we identified that DUSP16 could directly interact with TAK1 in human hepatocytes. DUSP16 knockdown in the isolated primary hepatocytes stimulated by palmitate (PA) showed accelerated lipid deposition and inflammatory response, along with the exacerbated activation of c-Jun NH2-terminal kinase (JNK), Transforming growth factor β (TGF-β)-activated kinase (TAK1) and nuclear factor-κB (NF-κB) signaling pathways; however, the opposite results were detected in PA-treated hepatocytes with DUSP16 over-expression. The in vivo experiments confirmed that DUSP16 knockout significantly aggravated the metabolic disorder and insulin resistance in high fat diet (HFD)-challenged mice. In addition, HFD-provoked hepatic lipid accumulation and inflammation were further promoted in mice with DUSP16 knockout through the same molecular mechanism as detected in vitro. Herein, these findings demonstrated that DUSP16 could directly interact with TAK1 and negatively regulate JNK signaling to alleviate metabolic stress-induced hepatic steatosis, and thus could be considered as a promising new molecular target for NAFLD treatment.

Circulating JNK pathway-associated phosphatase level correlates with decreased risk, activity, inflammation level and reduced clinical response to tumor necrosis factor-α inhibitor in Crohn disease patients

OBJECTIVE

This study aimed to investigate the correlation of serum Jun-amino-terminal kinase (JNK) pathway-associated phosphatase (JKAP) level with disease risk, severity, inflammation, and treatment response to tumor necrosis factor (TNF)-α inhibitor in Crohn disease (CD) patients.

METHOD

Ninety-six active CD patients and 90 healthy controls (HCs) were consecutively enrolled. Serum JKAP level of participants was determined via enzyme-linked immunosorbent assay (ELISA). In CD patients, C-reactive protein (CRP), erythrocyte sedimentation rate, Crohn disease activity index (CDAI), and inflammatory cytokine levels (determined by ELISA) were recorded. All CD patients underwent infliximab (IFX) treatment for 12 weeks, then treatment response (defined as decrement of CDAI ≥70) was assessed at week 12 (W12).

RESULTS

Serum JKAP level in CD patients was lower compared to HCs, and it disclosed a good predictive value for decreased CD risk; meanwhile, it was negatively correlated with CRP level, CDAI score, TNF-α, interleukin (IL)-6, and IL-17 levels in CD patients. Sixty-eight (70.8%) patients achieved treatment response to IFX at W12, and JKAP level was increased at W12 compared to baseline. Interestingly, baseline JKAP level in response patients was decreased compared to nonresponse patients, and it exhibited a good predictive value for decreased treatment response to IFX, multivariate logistic regression revealed that JKAP was an independent factor for predicting reduced IFX response.

CONCLUSION

Circulating JKAP expression correlates with decreased disease risk, activity, and inflammation level, and it could be served as a novel biomarker for predicting reduced clinical response to TNF-α inhibitor in CD patients.