P38 MAPK Signaling Cascade Research Articles

PRPF4 Knockdown Suppresses Glioblastoma Progression via the p38 MAPK and ERK Signaling Pathways.

Pre-mRNA processing factor 4 (PRPF4), a core protein of U4/U6 small nuclear ribonucleoproteins (snRNPs), is crucial for maintaining their structure by interacting with PRPF3 and Cyclophilin H. Beyond its role in splicing, PRPF4 has been implicated in cell survival, apoptosis, and oncogenesis. Although PRPF4 mutations have been associated with retinitis pigmentosa, its role in glioblastoma (GBM) remains unclear. This study aimed to investigate the function of PRPF4 in GBM progression and its potential as a therapeutic target. Gene expression profiling was conducted to compare PRPF4 levels between GBM tumors and normal tissues. PRPF4 expression was also evaluated in various cancer and GBM cell lines. Stable PRPF4 knockdown cell lines were established using A172 and T98G GBM cell lines. Cellular proliferation, apoptosis, migration, and invasion were assessed through gene expression and functional assays. Additionally, molecular pathways affected by PRPF4 knockdown were examined, focusing on the p38 MAPK signaling pathway. Finally, metabolic processes in PRPF4 knockdown cells were estimated through proteomic analysis. PRPF4 expression was elevated in GBM. Knockdown of PRPF4 reduced cell proliferation, induced apoptosis, and suppressed migration and invasion in GBM cells. PRPF4 knockdown also suppressed MKK3/6-p38-ATF2 and RAS-MEK-ERK1/2 signaling pathways. Proteome analysis revealed disruptions in metabolic pathways, including glutathione and carbon metabolisms, which are associated with GBM progression. PRPF4 knockdown inhibits GBM progression by reducing p38 MAPK and ERK signaling cascade with metabolic alterations. Targeting PRPF4 may offer novel therapeutic strategies for GBM treatment.

CTIM-27. DOC1021 CELL-BASED VACCINATION AS ADJUVANT THERAPY FOR GLIOBLASTOMA: PHASE I CLINICAL TRIAL ANALYSIS

Abstract Glioblastoma is an aggressive tumor for which median survival remains 14-18 months despite aggressive standard of care. Cellular immunotherapy approaches have recently shown promise. Homologous antigenic loading is an ex-vivo technique that leverages p38MAPK and mTORC1 signaling cascades to initiate powerful cDC1-like skewing in monocyte-derived dendritic cells, leading to downstream induction of tissue-infiltrating, cytolytic effector memory T-cells. This open-label phase I clinical trial evaluated the autologous dendritic cell vaccine DOC1021 prepared through homologous antigenic loading and administered bilaterally near the deep cervical lymph nodes. Three courses of vaccine were administered every 2 weeks after completion of chemoradiation, adjuvanted concurrently with six weeks of weekly type I interferon. Four dose levels from 3.5x106 to 3.6x107 total vaccine cells were tested. Tumor progression prior to vaccination was not an exclusion criterion. Sixteen newly diagnosed IDH-WT patients completed treatment, median age 63 years and 94% MGMTp unmethylated. The most common related AEs were grade 1 injection-site reactions and grade 1-3 fatigue and urticaria. No DLTs were observed. Immunohistochemistry of tumors derived from early post-vaccination second resections showed enhanced CD8+ T-cell infiltration and pathologic findings consistent with residual rather than relapsed GBM in 2/3 patients. Analysis of post-vaccination PBMC in dose level cohorts 2-4 indicated expansion of both CD4+ (13/13) and CD8+ (11/13) central memory T-cell compartments (p<0.002 and p<0.05, respectively) as well as expansion of CD8+CD127+ T-cells (12/13; p<0.001). Among three patients for whom tissue was obtained pre- and post-vaccination, clinical outcomes correlated with Visium spatial transcriptomic analysis. Median survival for the MGMTp unmethylated cohort (n=15) has not yet been reached but is statistically greater (p<0.05) than that of matched historic controls. The results indicate that DOC1021 is safe, can be effectively integrated within existing standards of care and is potentially efficacious in a challenging patient population.

A novel neurodevelopmental-neurodegenerative syndrome that cosegregates with a homozygous SPAG9/JIP4 stop-codon deletion

This report outlines the clinical features of a complex neurological phenotype shared by three siblings from a consanguineous family, characterized by intellectual disabilities, speech developmental delay, gait disturbance, cerebellar syndrome signs, cataracts, and dysmorphic features (square and coarse facial features, thick lips, deep palate, small and spaced teeth, low-set ears, strabismus, eyelid ptosis, and blond hair). Seizures and brain atrophy were later evident. In the cosegregation analysis, five family members and 12 family controls were studied by whole-exome and Sanger sequencing. The structural and functional effects of the protein were explored to define the mutated variant's potential deleterious impairment. Neurological and neuropsychological follow-ups and brain magnetic resonance imaging (MRI) were performed. We identified a single frameshift homozygous nucleotide deletion in the SPAG9/JIP4 gene (NM_001130528.3): c.2742del (p. Tyr914Ter), causing a premature stop codon and truncating the protein and originating a possible loss of function. The variant cosegregated in affected individuals as an autosomal recessive trait. The in silico protein functional analyses indicate a potential loss of 66 phosphorylation and 29 posttranslational modification sites. Additionally, a mutated protein structure model shows a significant modification of the folding that very likely will compromise functional interactions. SPAG9/JIP4 is a dynein-dynactin motor adapter for retrograde axonal transport, regulating the constitutive movement of neurotrophic factor signaling and autophagy-lysosomal products. Under stress conditions, it can potentiate this transport by the p38 mitogen-activated protein kinases (p38MAPK) signaling cascade. Both functions could be associated with the disease mechanism, altering the axon's development and growth, neuronal specification, dendrite formation, synaptogenesis, neuronal pruning, recycling neurotransmitters and finally, neuronal homeostasis—promising common mechanisms to be used with investigational molecules for neurodevelopmental diseases and neurodegeneration.

Abstract CT093: Vaccine immunotherapy by homologous antigenic loading as adjuvant therapy for glioblastoma: Ongoing phase I analysis

Abstract Glioblastoma (GBM) is a devastating tumor of the central nervous system (CNS) for which median survival remains 14-18 months despite aggressive standard of care. Early clinical studies of dendritic cell (DC) vaccination for the adjuvant treatment of GBM previously suggested mild to moderate clinical benefit, but results were both inconsistent and inconclusive. Homologous antigenic loading is an ex vivo technique that leverages p38MAPK and mTORC1 signaling cascades to initiate powerful cDC1-like skewing in monocyte-derived DC, leading to downstream induction of CD161int CD8+ cytolytic memory effectors. Here we report ongoing results of a completed phase I clinical trial with minimal exclusion criteria in which dendritic cell vaccines were prepared through homologous antigenic loading and administered to newly-diagnosed patients bilaterally in the vicinity of the deep cervical lymph nodes, assisted by ultrasound sonography. Patients were additionally adjuvanted with six weeks of concurrent type I interferon. Four dose levels from 3.5 x 106 to 3.6 x 107 total vaccine cells were tested, none of which resulted in AEs > grade 2 attributable to the investigational regimen. Immunohistochemistry of tumors derived from early post-vaccination second resections displayed enhanced CD8+ T-cell infiltration and pathologic findings consistent with residual rather than relapsed GBM in 2/3 patients. Radiologic pseudoprogression was also routinely observed among patients of all cohorts. Analysis of post-vaccination circulating PBMC indicated expansion of both CD4+ and CD8+ central memory T-cell compartments (p<0.05 for each by student’s two-tailed t-test) as well as expansion of CD8+CD127+ T-cells (p<0.05 by student’s two tailed t-test) in 4/4 patients analyzed. With an average of 10.9 months follow-up, median survival of this largely MGMT promoter unmethylated cohort was not yet reached and was statistically greater (p<0.05 by log-rank[Mantle-Cox]) than that of matched historical controls. At the time of submission, 13/15 trial patients remained alive with ECOG </= 2. The results suggest that modern dendritic cell vaccines are safe, potentially efficacious, and can be effectively integrated within existing standards of care. Citation Format: Joseph F. Georges, Mazen Zaher, Corey M. Mossop, Christopher J. Bilbao, Christina M. Clay, Sabina Amin, Hamza A. Shaikh, Akshar Trivedi, Wei Liu, Madhuri Namekar, Colby J. Hofferek, Keenan Ernste, Eva H. Schumann, Mia Vu, Damilola Oyewole-Said, Nalini Bisht, Jonathan Vazquez-Perez, Ashley M. Goralczyk, Lindsey Colman, Lynne S. Kohler, Thuy V. Cao, Ngozi Okereke, Benjamin L. Musher, Vinod Ravi, Jan O. Kemnade, Rodrick C. Zvavanjanja, Jay-Jiguang Zhu, Sigmund H. Hsu, Yoshua Esquenazi-Levy, Nitin Tandon, Alan Turtz, Vanaja Konduri, William Karl Decker. Vaccine immunotherapy by homologous antigenic loading as adjuvant therapy for glioblastoma: Ongoing phase I analysis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr CT093.

Is alteration of ERK1/2 and p38MAPK signaling pathways activity a general mechanism of Alzheimer’s disease and age-related macular degeneration development?

Age is the primary risk factor for Alzheimer’s disease (AD), the most prevalent progressive senile dementia, and age-related macular degeneration (AMD), the main cause of vision loss in individuals over 60. Effective prevention and treatment of these neurodegenerative conditions are lacking due to incomplete knowledge of their pathogenesis. Risk factors such as smoking, hypertension, hypercholesterolemia, atherosclerosis, obesity, and malnutrition intersect with the pathogenesis mechanisms of both AD and AMD. Oxidative stress, inflammation, mitochondrial dysfunction, and impaired proteostasis maintenance are among the pathological factors associated with the aggregation and accumulation of abnormal extracellular deposits — senile plaques in the brains of AD patients and drusen in AMD patients. Alterations in the regulation of MAPK signaling pathways with age may be associated to the emergence of these abnormalities. Impaired MAPK signaling was confirmed as a significant contributor to the pathogenesis of AD through the results of numerous investigations. MAPK is a potential target for therapeutic interventions. Information on its age-related changes, however, is limited. Virtually no data exist on retinal MAPK activity during AD and AMD development. This study aims to compare changes in ERK1/2 and p38MAPK signaling activity in brain and retina structures with age and AD/AMD progression. Wistar and OXYS rats were used as models of accelerated aging that show concomitant signs of AD and AMD. At the initial stage of the study, we examined the gene expression related to ERK1/2 and p38MAPK signaling pathways via comparing the transcriptomes (RNA-seq data) of the retina, prefrontal cortex, and hippocampus of OXYS and Wistar rats. The analysis was conducted when the rats were 20 days old and showed no signs of AMD and AD symptoms, during their manifestation period (age 3–5 months) and active progression stage (age 18 months). Changes in gene expression, involved in EPK1/2 [1] and p38MAPK signaling pathways according to the Rat Genome Database, are tissue-specific and dependent on the animal genotype. In the retina, the number of genes associated with ERK1/2 and p38MAPK decreased in both Wistar and OXYS rats with age and was minimal at 18 months of age. The greatest differences in the expression levels of these genes were detected when the rats were 20 days old, at the preclinical stage of AMD-like pathology development in OXYS rats. Both activators and inhibitors of the EPK1/2 and p38MAPK pathways were present among the differentially expressed genes (DEGs) with increased mRNA levels. At 3 months, the number of DEGs decreased, while activator genes predominated among those with increased mRNA levels. At 18 months, the retina of OXYS rats displayed only signs of decreased activity in signaling pathways at the gene expression level. Age-related changes in gene expression profiles related to the ERK1/2 [2] and p38MAPK [3, 4] signaling pathways in Wistar rats differed between brain structures and the retina. In the prefrontal cortex and hippocampus, the number of genes increased with age, and the expression differed between OXYS and Wistar rats. However, no signs of significant activation of the signaling pathway were observed. The phosphorylation level of ERK1/2 and p38MAPK signaling pathway kinases serves as an objective indicator of their activity. For protein level evaluation via Western blot analysis, we examined these levels in the retina, prefrontal cortex, and hippocampus. In both rat strains, a significant increase in phosphorylated forms of ERK1/2 and p38MAPK was observed with aging in all examined tissues. Simultaneously, accumulation of the substance became more active in OXYS rats and increased with progression of AD and AMD symptoms. Therefore, the results indicate that no significant changes in the activity of ERK1/2 and p38MAPK signaling cascades in the retina and brain structures are observed during normal aging of Wistar rats and accelerated aging of OXYS, both at the gene expression and protein level. AD and AMD pathological signs in OXYS rats were found to be associated with increased phosphorylation of ERK1/2 and p38MAPK, suggesting that enhancement of MAPK pathways may be a common mechanism for the early development of AD and AMD.

Arsenic exposure to mouse visceral leishmaniasis model through their drinking water linked to the disease exacerbation via modulation in host protective immunity: a preclinical study

A large body of evidence has shown a direct link between arsenic exposure and drug resistance to Leishmania parasites against antimonial preparations in visceral leishmaniasis (VL) hyper-endemic regions, especially in India and its sub-continent. However, the implicated roles of arsenic on the VL host, pathophysiological changes, and immune function have not yet been clarified, particularly at the reported concentration of arsenic in the VL hyper-endemic area of Bihar, India. Herein, we exposed the mouse VL model to arsenic (0.5 mg/L to 2 mg/L) through their drinking water and analyzed its effect on T cells proliferation, Th1/Th2-mediators, MAPK signaling cascade, and parasite load in preclinical models. Coherently, the parasite count in Giemsa stained spleen imprint has been investigated and found significant positive associations with levels of arsenic exposure. The liver and kidney function tests (AST, ALT, ALP, BUN, Creatinine, Urea, etc.) are apparent to hepatonephric toxicity in arsenic exposed VL mice compared to unexposed. This observation appears to be consistent with the up-regulated expression of immune regulatory Th2 mediators (IL-4, IL-10, TGF-β) and down-regulated expression of Th1 mediators (IL-12, IFN-γ, TNF-α) with a suppressed leishmanicidal function of macrophage (ROS, NO, iNOS). We also established that arsenic exposure modulated the host ERK-1/2 and p38 MAPK signaling cascade, limited T lymphocyte proliferation, and a lower IgG2a/IgG1 ratio to favor the Leishmania parasite survival inside the host. This study suggests that the contorted Th1-subtype and exacerbated Th2-subtype immune responses are involved in the increased susceptibility and pathogenesis of Leishmania parasite among subjects/individuals regularly exposed to arsenic.

Heat shock induces HuR-dependent MKP-1 posttranslational regulation through the p38 MAPK signaling cascade

Previous studies demonstrated that phosphatases play a pivotal role in modulating inflammation-associated signal transduction, particularly in the context of heat shock, where Mitogen-Activated Protein Kinase Phosphatase-1 (MKP-1) appears to have a central role. Recently, Human Antigen R (HuR) has also been identified as a factor that enhances stress-response protein MKP-1 levels. Consequently, we have directed our interest towards elucidating the mechanisms by which heat shock induces MKP-1 mRNA stabilization, dependent on HuR via the p38 MAPK Signaling Cascade. In this study, we subjected Mouse Embryonic Fibroblast (Mef) cells to heat shock treatment, resulting in a potent stabilization MKP-1 mRNA. The RNA-binding protein HuR, known to influence mRNA, was observed to bind to the MKP-1 AU-rich 3 ´untranslated region. Transfection of p38 wild-type Mef cells with a flag-HuR plasmid resulted in a significant increase in MKP-1 mRNA stability. Interestingly, transfection of the siRNA for HuR into Mef cells resulted in diminished MKP-1 mRNA stability following heat shock, inhibition of p38 MAPK activity effectively curtailed heat shock-mediated MKP-1 mRNA stability. Immunofluorescence analyses further revealed that the translocation of HuR was contingent on p38 MAPK Signaling Cascade. Collectively, these findings underscore the regulatory role of heat shock in MKP-1 gene expression at posttranscriptional levels. The mechanisms underlying the observed increased MKP-1 mRNA stability are shown to be partially dependent on HuR through the p38 MAPK Signaling Cascade.

Mitochondria-originated redox signalling regulates KLF-1 to promote longevity in Caenorhabditis elegans

Alternations of redox metabolism have been associated with the extension of lifespan in roundworm Caenorhabditis elegans, caused by moderate mitochondrial dysfunction, although the underlying signalling cascades are largely unknown. Previously, we identified transcriptional factor Krüppel-like factor-1 (KLF-1) as the main regulator of cytoprotective longevity-assurance pathways in the C. elegans long-lived mitochondrial mutants. Here, we show that KLF-1 translocation to the nucleus and the activation of the signalling cascade is dependent on the mitochondria-derived hydrogen peroxide (H2O2) produced during late developmental phases where aerobic respiration and somatic mitochondrial biogenesis peak. We further show that mitochondrial-inducible superoxide dismutase-3 (SOD-3), together with voltage-dependent anion channel-1 (VDAC-1), is required for the life-promoting H2O2 signalling that is further regulated by peroxiredoxin-3 (PRDX-3). Increased H2O2 release in the cytoplasm activates the p38 MAPK signalling cascade that induces KLF-1 translocation to the nucleus and the activation of transcription of C. elegans longevity-promoting genes, including cytoprotective cytochrome P450 oxidases. Taken together, our results underline the importance of redox-regulated signalling as the key regulator of longevity-inducing pathways in C. elegans, and position precisely timed mitochondria-derived H2O2 in the middle of it.

PGC-1α and MEF2 Regulate the Transcription of the Carnitine Transporter OCTN2 Gene in C2C12 Cells and in Mouse Skeletal Muscle.

OCTN2 (SLC22A5) is a carnitine transporter whose main function is the active transport of carnitine into cells. In skeletal muscle and other organs, the regulation of the SLC22A5 gene transcription has been shown to depend on the nuclear transcription factor PPAR-α. Due to the observation that the muscle OCTN2 mRNA level is maintained in PPAR-α knock-out mice and that PGC-1α overexpression in C2C12 myoblasts increases OCTN2 mRNA expression, we suspected additional regulatory pathways for SLC22A5 gene transcription. Indeed, we detected several binding sites of the myocyte-enhancing factor MEF2 in the upstream region of the SLC22A5 gene, and MEF2C/MEF2D stimulated the activity of the OCTN2 promoter in gene reporter assays. This stimulation was increased by PGC-1α and was blunted for a SLC22A5 promoter fragment with a mutated MEF2 binding site. Further, we demonstrated the specific binding of MEF2 to the SLC22A5 gene promoter, and a supershift of the MEF2/DNA complex in electrophoretic mobility shift assays. In immunoprecipitation experiments, we could demonstrate the interaction between PGC-1α and MEF2. In addition, SB203580, a specific inhibitor of p38 MAPK, blocked and interferon-γ stimulated the transcriptional activity of the SLC22A5 gene promoter. Finally, mice with muscle-specific overexpression of OCTN2 showed an increase in OCTN2 mRNA and protein expression in skeletal muscle. In conclusion, we detected and characterized a second stimulatory pathway of SLC22A5 gene transcription in skeletal muscle, which involves the nuclear transcription factor MEF2 and co-stimulation by PGC-1α and which is controlled by the p38 MAPK signaling cascade.

β-Eudesmol Inhibits the Migration of Cholangiocarcinoma Cells by Suppressing Epithelial-Mesenchymal Transition via PI3K/AKT and p38MAPK Modulation.

Cholangiocarcinoma (CCA) is a highly aggressive tumor with a greater risk of distant metastasis. A drug that prevents CCA development and spread is urgently needed. In this research, we investigated the effect of β-eudesmol on the migration and invasion and epithelial-mesenchymal transformation (EMT) of the CCA cell line. MTT and transwell assays were used to investigate the antiproliferative activity, as well as activity on cell migration and cell invasion. Real-time PCR and western blot analysis were used to investigate the expression of EMT marker genes and proteins. β-eudesmol was shown to exhibit potent antiproliferative activity (IC50 92.25-185.67 µM) and to significantly reduce CCA cell migration and invasion (27.3-62.7%). At both mRNA and protein levels, it significantly up-regulated the expression of epithelial marker E-cadherin (3-3.4-fold), while down-regulated the expression of mesenchymal markers-vimentin (0.6-0.8-fold) and snail-1 (0.4-0.6-fold). Furthermore, β-eudesmol inhibited PI3K and AKT phosphorylation (0.5-0.8-fold), while activating p38MAPK activity (1.2-3.6-fold). Altogether, the anti-metastatic activity of β-eudesmol might be due to its suppressive effect on EMT via modulating the PI3K/AKT and p38MAPK signaling cascades.

Abstract 1565: Targeting stromal-specific p38 MAPK signaling to stifle inflammatory reprogramming of cancer-associated fibroblasts in pancreatic cancer

Abstract Introduction: Major contributors to therapeutic resistance in pancreatic ductal adenocarcinoma (PDAC) are the desmoplastic stroma that acts as a barrier to drug delivery and effector immune cell infiltration. In our efforts to identify mediators of therapeutic resistance, we identified the pro-inflammatory cytokine interleukin-1α (IL-1) to be critical in the activation and reprogramming of neighboring cancer-associated fibroblasts (CAFs) within the stroma to a pro-inflammatory phenotype to promote myeloid cell chemotaxis. Our mechanistic studies have identified the p38 MAPK pathway as a novel mediator of IL-1-induced CAF activation from quiescent stellate cells into the inflammatory fibroblast. Our central hypothesis is that disruption of the IL-1/p38 MAPK signaling cascade in pancreatic stellate cells (PSCs) and CAFs can improve therapeutic resistance by remodeling the fibrotic stromal landscape and the overall immune microenvironment in PDAC tumors. Methods: Inhibition of phosphorylated p38 MAPK was achieved pharmacologically with Pexmetinib and genetically with an shRNA lentiviral system in CAF and PSC cell lines. Inflammatory PSC/CAF activation was determined by qPCR, immunofluorescence, and vitamin A assay. Ptf1acre/+;LSL-KrasG12D/+; Tgfbr2flox/flox (PKT) mice were treated with the p38 inhibitor, pexmetinib (30mg/kg, daily PO), or vehicle control for 2.5 weeks prior to sacrifice. For survival studies, PKT mice were treated with vehicle, gemcitabine (20 μg/twice weekly), pexmetinib, or combination until moribund. Results: Inhibition of p38 MAPK in PSCs prevented activation into an inflammatory fibroblast in vitro when stimulated with IL-1 or tumor cell cocultures. p38 MAPK inhibition in vivo resulted in signification reduction of PDGFR+ CAFs in a PDAC GEMM. Additionally, p38 MAPK inhibition resulted in a significant reduction of circulating myeloid cells (CD11b+) and intratumoral monocytic MDSCs (Ly6C+). p38 inhibition, in combination with chemotherapy, significantly improves overall survival in a PDAC GEMM. Conclusions: These findings provide important mechanistic data to explore p38 MAPK inhibition to target the fibrotic stroma and reduce immunosuppressive myeloid levels in tumors and provide compelling preclinical evidence to combine pexmetinib with chemotherapy to improve overall survival in PDAC. Citation Format: Samara Singh, Austin R. Dosch, Siddharth Mehra, Iago de Castro Silva, Anna Bianchi, Vanessa Tonin Garrido, Nilesh Deshpande, Zhiqun Zhou, Jashodeep Datta, Nagaraj Nagathihalli, Nipun Merchant. Targeting stromal-specific p38 MAPK signaling to stifle inflammatory reprogramming of cancer-associated fibroblasts in pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1565.

A Potential Probiotic Lactobacillus plantarum JBC5 Improves Longevity and Healthy Aging by Modulating Antioxidative, Innate Immunity and Serotonin-Signaling Pathways in Caenorhabditis elegans.

Since the hypothesis of Dr. Elie Metchnikoff on lactobacilli-mediated healthy aging, several microbes have been reported to extend the lifespan with different features of healthy aging. However, a microbe affecting diverse features of healthy aging is of choice for broader acceptance and marketability as a next-generation probiotic. We employed Caenorhabditis elegans as a model to understand the potential of Lactobacillus plantarum JBC5 (LPJBC5), isolated from fermented food sample on longevity and healthy aging as well as their underlying mechanisms. Firstly, LPJBC5 enhanced the mean lifespan of C. elegans by 27.81% compared with control (untreated). LPBC5-induced longevity was accompanied with better aging-associated biomarkers, such as physical functions, fat, and lipofuscin accumulation. Lifespan assay on mutant worms and gene expression studies indicated that LPJBC5-mediated longevity was due to upregulation of the skinhead-1 (skn-1) gene activated through p38 MAPK signaling cascade. Secondly, the activated transcription factor SKN-1 upregulated the expression of antioxidative, thermo-tolerant, and anti-pathogenic genes. In support, LPJBC5 conferred resistance against abiotic and biotic stresses such as oxidative, heat, and pathogen. LPJBC5 upregulated the expression of intestinal tight junction protein ZOO-1 and improved gut integrity. Thirdly, LPJBC5 improved the learning and memory of worms trained on LPJBC5 compared with naive worms. The results showed upregulation of genes involved in serotonin signaling (ser-1, mod-1, and tph-1) in LPJBC5-fed worms compared with control, suggesting that serotonin-signaling was essential for LPJBC5-mediated improved cognitive function. Fourthly, LPJBC5 decreased the fat accumulation in worms by reducing the expression of genes encoding key substrates and enzymes of fat metabolism (i.e., fat-5 and fat-7). Lastly, LPJBC5 reduced the production of reactive oxygen species and improved mitochondrial function, thereby reducing apoptosis in worms. The capability of a single bacterium on pro-longevity and the features of healthy aging, including enhancement of gut integrity and cognitive functions, makes it an ideal candidate for promotion as a next-generation probiotic.

Deletion of the SPAG9 gene cause autosomal‐recessive intellectual disability

AbstractBackgroundIntellectual disability (ID) is the limitation of intellectual functioning and adaptive behavior before 18 years of age. In a consanguineous family of 149 members, this disease is expressed in 9 individuals. Here, we report one branch of a family tree with three siblings, presenting severe ID, delayed speech development, cataracts, strabismus, gait disturbance, cerebellar syndrome, seizures in one of them, and eyelid ptosis in two. Brain magnetic resonance imaging (MRI) with hippocampal malrotation, brain atrophy and white matter hyperintensities in all cases. Thinning of the corpus callosum in two of them.MethodWe conducted whole exome sequencing analysis in nine subjects from one multigenerational family of Colombian origin. The study was carried out at the University of Antioquia,Colombia with the approval of the ethics committee. A medical, neurological, neuropsychological examination and brain MRI were performed in all cases.ResultWe identified a single nucleotide deletion in the SPAG9 gene, which codes for the JIP4 protein. The frameshift generates a premature stop codon (p.Tyr914Ter). The deletion is classified as pathogenic, according to the ACMG / AMP guidelines. The variant co‐segregated in the respective family as an autosomal recessive trait.ConclusionJIP 4 has two functions: As scaffold protein that potentiates the p38 MAPK signaling cascade under stress conditions and as dynein‐dynactin motor adapter for lysosomal retrograde flow, regulating the constitutive transport of lysosomes. Both functions could be associated in the disease mechanism. The absence of JIP 4 may be responsible for the disease in the family, altering neuronal homeostasis.

Retraction: Leishmania-Specific Promiscuous Membrane Protein Tubulin Folding Cofactor D Divulges Th1/Th2 Polarization in the Host via ERK-1/2 and p38 MAPK Signaling Cascade.

[This retracts the article DOI: 10.3389/fimmu.2020.00817.].

Mesenchymal stem cells regulate inflammatory milieu within degenerative nucleus pulposus cells via p38 MAPK pathway.

It has been established that excessive apoptosis of nucleus pulposus cells (NPCs) are responsible for pathogenesis of human intervertebral disc degeneration (IDD). The present study aimed to shed light on the molecular mechanisms underlying the protective effects of mesenchymal stem cells (MSCs) on NPCs in an inflammatory environment. NPCs were treated with TNF-α to induce inflammation and then co-cultured with Wharton's Jelly-derived MSCs (WJ-MSCs)without direct interaction. The levels of inflammation markers (IL-1β, IL-6 and IL-8) in NPCs were detected by performing enzyme-linked immunosorbent assay (ELISA), and expression of metalloproteases and aggrecan, as well as the activity of p38 MAPK pathway were determined through immunoblotting. SB-203580 was used to inhibit p38 signaling, prior to evaluation of the effects of Wharton's Jelly-derived MSCs (WJ-MSCs) on inflammatory response within the co-cultured NPCs. After TNF-α treatment, the levels of inflammatory cytokines, MMP-3, and MMP-13 in NPCs were increased whereas aggrecan was decreased, which was then dramatically reversed by WJ-MSCs co-culture. Likewise, WJ-MSCs suppressed TNF-α-induced phosphorylation of p38 MAPK signaling components including p38, ASK-1, MKK-3 and MKK-6. Blocking p38 MAPK pathway enhanced the anti-inflammatory impact of WJ-MSCs, and there was no significant difference between NPCs co-cultured with WJ-MSCs or the cells cultured alone. WJ-MSCs co-culture mitigate TNF-α-induced inflammatory response and ECM degeneration in NPCs, the major pathological events are implicated in IDD development, probably by suppressing the p38 MAPK signaling cascade.

Compound kushen injection relieves tumor-associated macrophage-mediated immunosuppression through TNFR1 and sensitizes hepatocellular carcinoma to sorafenib

BackgroundThere is an urgent need for effective treatments for hepatocellular carcinoma (HCC). Immunotherapy is promising especially when combined with traditional therapies. This study aimed to investigate the immunomodulatory function of...

Anthocyanins attenuate neuroinflammation through the suppression of MLK3 activation in a mouse model of perioperative neurocognitive disorders

Perioperative neurocognitive disorder (PND) is a common complication that lacks effective prevention and treatment measures. Neuroinflammation is considered to be one of the important mechanisms of PND. In this study, we investigated the effect and mechanism of anthocyanins (ANT), a natural plant ingredient, on postoperative cognition and neuroinflammation. Mice were subjected to laparotomy and treated with ANT (50–100 mg/kg, orally) 4 weeks before surgery and then once per day for 7 days after surgery. Morris water maze and fear conditioning tests were used to evaluate learning and memory function. Western blotting, RT-PCR and immunofluorescence were used to test the neuroprotective effects and mechanism of ANT. The results showed that ANT improved learning and memory in mice after surgery. ANT also inhibited MLK3 activation and its downstream JNK and p38 MAPK signaling cascades. Moreover, the inhibitor of MLK3 could mimic the effects of ANT. In addition, treatment with ANT significantly reduced neuroinflammation and microglia activation. In conclusion, MLK3 represents a novel target in surgery-induced neuroinflammation and cognitive dysfunction. ANT could inhibit the activation of MLK3 and be a promising agent for the prevention and treatment of PND.

The Edwardsiella piscicida thioredoxin-like protein inhibits ASK1-MAPKs signaling cascades to promote pathogenesis during infection.

It is important that bacterium can coordinately deliver several effectors into host cells to disturb the cellular progress during infection, however, the precise role of effectors in host cell cytosol remains to be resolved. In this study, we identified a new bacterial virulence effector from pathogenic Edwardsiella piscicida, which presents conserved crystal structure to thioredoxin family members and is defined as a thioredoxin-like protein (Trxlp). Unlike the classical bacterial thioredoxins, Trxlp can be translocated into host cells, mimicking endogenous thioredoxin to abrogate ASK1 homophilic interaction and phosphorylation, then suppressing the phosphorylation of downstream Erk1/2- and p38-MAPK signaling cascades. Moreover, Trxlp-mediated inhibition of ASK1-Erk/p38-MAPK axis promotes the pathogenesis of E. piscicida in zebrafish larvae infection model. Taken together, these data provide insights into the mechanism underlying the bacterial thioredoxin as a virulence effector in downmodulating the innate immune responses during E. piscicida infection.

Diterpenoid alkaloids from Aconitum brevicalcaratum as autophagy inducers

A new C19 diterpenoid alkaloid, brevicanine (1) and six known ones (2–7) were isolated from Aconitum brevicalcaratum (Finet et Gagnep.) Diels. Their structures were elucidated on the basis of extensive spectroscopic analyses. The cytotoxicity of those compounds was investigated against HCT116 human cancer cell line, which showed none of them possessing considerable anti-proliferative activities. To evaluate the autophagy effect of compounds 1–7, Western blot was used to detect the expression of autophagic marker by stimulating human cancer HCT116 cells. The results showed that compound 6 induced protective autophagy in HCT116 cells. Mechanistic insight showed that compound 6 induced protective autophagy through p53 activation, ERK1/2 and p38 MAPK signaling cascade.

Zerumbone protects human skin keratinocytes against UVA-irradiated damages through Nrf2 induction

Ultraviolet A (UVA) irradiation is toxic to skin as it penetrates deep into the dermis and damages cellular components through excessive reactive oxygen species (ROS) production, which accelerates photoaging and skin cancer. We evaluated the dermato-protective efficacies of zerumbone (natural sesquiterpene of Zingiber zerumbet) in UVA-irradiated human skin keratinocyte (HaCaT) cells and mouse epidermis. Zerumbone pretreatment (2–10 μM) substantially suppressed UVA (15 J/cm2)-induced HaCaT cell death and lactate dehydrogenase release in a dose-dependent manner. UVA-induced excessive ROS production, DNA single-strand breaks, apoptotic DNA fragmentation and a dysregulated Bax/Bcl-2 ratio were remarkably reversed by zerumbone in keratinocytes. Zerumbone-mediated cytoprotective properties were associated with increased nuclear translocation of nuclear factor-E2-related factor-2 (Nrf2) and elevated antioxidant response element (ARE) luciferase activity. Activation of Nrf2/ARE signaling was accompanied by induction of heme oxygenase-1 (HO-1) and γ-glutamyl cysteine ligase (γ-GCLC) genes in zerumbone-treated keratinocytes. Zerumbone-induced Nrf2 transcriptional activation was mediated by the p38 MAPK, PI3K/AKT and PKC signaling cascades. Notably, silencing of Nrf2 (siRNA transfection) significantly diminished zerumbone-mediated cytoprotective effects, as evidenced by impaired antioxidant genes, uncontrolled ROS/apoptotic DNA fragmentation and keratinocytes death, following UVA irradiation. In vivo evidence demonstrated that zerumbone treatment to nude mice (55 and 110 μg/day) significantly ameliorated UVA (15 J/cm2/every 2-day/14-day) cytotoxicity via increased nuclear localization of Nrf2 and Nrf2-dependent antioxidant genes (HO-1 and γ-GCLC) in UVA-treated skin tissues. Our findings emphasized the significance of Nrf2/ARE-signaling in zerumbone-mediated induction of antioxidant genes against UVA-toxicity. The molecular evidence suggests zerumbone can be a natural medicine to treat/prevent UVA-induced skin damage/photoaging.