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FGF9 is a potent mitogen and survival factor, but FGF9 protein levels are generally low and restricted to a few adult organs. Aberrant expression of FGF9 usually results in cancer. However, the mechanism of FGF9 action has not been fully established. Previous studies showed that FGF1 and FGF2 directly bind to integrin αvβ3, and this interaction is critical for signaling functions (FGF-integrin crosstalk). FGF1 and FGF2 mutants defective in integrin binding were defective in signaling, whereas the mutants still bound to FGFR suppressed angiogenesis and tumor growth, indicating that they act as antagonists. We hypothesize that FGF9 requires direct integrin binding for signaling. Here, we show that docking simulation of the interaction between FGF9 and αvβ3 predicted that FGF9 binds to the classical ligand-binding site of αvβ3. We show that FGF9 bound to integrin αvβ3 and generated FGF9 mutants in the predicted integrin-binding interface. An FGF9 mutant (R108E) was defective in integrin binding, activating FRS2α and ERK1/2, inducing DNA synthesis, cancer cell migration, and invasion in vitro. R108E suppressed DNA synthesis and activation of FRS2α and ERK1/2 induced by WT FGF9 (dominant-negative effect). These findings indicate that FGF9 requires direct integrin binding for signaling and that R108E has potential as an antagonist to FGF9 signaling.

Background: Colorectal cancer is a major global health concern, exacerbated by tumor necrosis factor-alpha(TNF-α) and its role in inflammation, with the effects of Mitotic Arrest Deficient 2 Like 2 (MAD2L2) in this context still unclear. Methods: The colorectal carcinoma cell lines HCT116 and SW620 were exposed to TNF-α for a period of 24 h to instigate an inflammatory response. Subsequent assessments were conducted to measure the expression of inflammatory cytokines, the activity within the p38 mitogen-activated protein kinase (p38 MAPK) and Phosphoinositide 3-Kinase/AKT Serine/Threonine Kinase pathway (PI3K/AKT) signaling cascades. Transcriptome sequencing and subsequent integrative analysis with the Cancer Genome Atlas (TCGA) program database revealed a significant downregulation of the key factor MAD2L2. Enhancement of MAD2L2 expression was facilitated via lentiviral vector-mediated transfection. The influence of this overexpression on TNF-α-prompted inflammation, intracellular signaling pathways, and the migratory and invasive behaviors of the colorectal cancer cells was then scrutinized. Results: TNF-α treatment significantly increased the expression of Interleukin-1 beta (IL-1β) and Interleukin-6 (IL-6), activated the MAPK p38 and PI3K/AKT signaling pathways, and enhanced cell migration and invasion. A decrease in MAD2L2 expression was observed following TNF-α treatment. However, overexpression of MAD2L2 reversed the effects of TNF-α, reducing IL-1β and IL-6 levels, attenuating PI3K/AKT pathway activation, and inhibiting cell migration and invasion. Conclusions: Overexpression of MAD2L2 attenuates the pro-inflammatory effects of TNF-α, suggesting that MAD2L2 plays a protective role against TNF-α-induced migration and invasion of colorectal carcinoma cells. Therefore, MAD2L2 holds potential as a therapeutic target in the treatment of colorectal cancer. [ABSTRACT FROM AUTHOR]

The mitogen‐activated protein kinase (MAPK) cascade (MAPKKK‐MAPKK‐MAPK) plays a critical role in biotic and abiotic stress responses and abscisic acid (ABA) signalling. A previous study has shown that the ABA‐activated MKK1‐MPK1 cascade is essential in regulating ABA response and stress tolerance in rice. However, the specific MAPKKK upstream of the MKK1‐MPK1 cascade in ABA signalling remains unknown. Here, we identified that MAPKKK28, a previously uncharacterized member of the rice MEKK family, is involved in regulating ABA responses, including seed germination, root growth, stomatal closure, and the tolerance to oxidative stress and osmotic stress. We found that MAPKKK28 directly interacts with and phosphorylates MKK1. Further analysis indicated that the activation of both MKK1 and MPK1 depends on MAPKKK28 in ABA signalling. Genetic analysis revealed that MAPKKK28 functions upstream of the MKK1‐MPK1 cascade to positively regulate ABA responses and enhance tolerance to oxidative and osmotic stress. These results not only reveal a new complete MAPK cascade in plants but also uncover its importance in ABA signalling. Summary statement: This manuscript demonstrated that MAPKKK28, a previously uncharacterized mitogen‐activated protein kinase kinase kinase in rice, functions upstream of the MKK1‐MPK1 cascade to positively regulate abscisic acid responses and the tolerance to oxidative stress and osmotic stress. [ABSTRACT FROM AUTHOR]

Pneumonia is a serious and life‐threatening lung inflammation with high morbidity and mortality. Accumulating evidence has suggested that esculin, a derivative of coumarin, possesses potent anti‐inflammatory effects. This study is designed to explore the pharma role and underlying mechanism of esculin against lipopolysaccharides (LPS)‐induced pneumonia. TC‐1 cells were stimulated by LPS to mimic the inflammatory injury model in vitro. Cell viability, proliferation, and apoptosis were determined using MTT assay, 5‐ethynyl‐2′‐deoxyuridine assay, and flow cytometry. Interleukin‐1β and tumor necrosis factor α levels were analyzed using an enzyme‐linked immunosorbent assay. Reactive oxygen species and superoxide dismutase were examined using special assay kits. Macrophage polarization was detected using flow cytometry. Mitogen‐activated protein kinase 14 (MAPK14) level was detected by real‐time quantitative polymerase chain reaction. MAPK14 and ubiquitin‐specific protease 7 (USP7) protein levels were determined using western blot assay. After Ubibrowser database prediction, the interaction between USP7 and MAPK14 was verified using a Co‐immunoprecipitation assay. The biological role of esculin was verified in LPS‐challenged ALI mice in vivo. Here, we found that esculin significantly relieved LPS‐induced TC‐1 cell proliferation inhibition, and apoptosis, inflammatory response, oxidative stress, and M1‐type macrophage polarization promotion. MAPK14 and USP7 expressions were enhanced in LPS‐treated TC‐1 cells, which was partly abolished by esculin treatment. Overexpressing MAPK14 attenuated the repression of esculin on LPS‐triggered TC‐1 cell injury. At the molecular level, USP7 interacted with MAPK14 and maintained its stability by removing ubiquitin. Moreover, esculin repressed the progression of pneumonia in vivo by regulating MAPK14. Taken together, esculin exposure could mitigate LPS‐induced TC‐1 cell injury partly by targeting the USP7/MAPK14 axis, providing a better understanding of the role of esculin in the anti‐inflammatory therapeutics for pneumonia. Esculin treatment could relieve LPS‐induced TC‐1 cell proliferation inhibition, and apoptosis, inflammation, oxidative stress, macrophage M1 polarization promotion in vitro, as well as pneumonia progression in vivo by regulating the USP7/mitogen‐activated protein kinase 14 (MAPK14) axis. Furthermore, USP7 could facilitate protein stability and MAPK14 expression in TC‐1 cells. [ABSTRACT FROM AUTHOR]

Increasing evidence has revealed that cellular senescence drives NDs, including Alzheimer's disease (AD) and Parkinson's disease. Different senescent cell populations secrete senescence-associated secretory phenotypes (SASP), including matrix metalloproteinase-3, interleukin (IL)-1α, IL-6, and IL-8, which can harm adjacent microglia. Moreover, these cells possess high expression levels of senescence hallmarks (p16 and p21) and elevated senescence-associated β-galactosidase activity in in vitro and in vivo ND models. These senescence phenotypes contribute to the deposition of β-amyloid and tau-protein tangles. Selective clearance of senescent cells and SASP regulation by inhibiting p38/mitogen-activated protein kinase and nuclear factor kappa B signaling attenuate β-amyloid load and prevent tau-protein tangle deposition, thereby improving cognitive performance in AD mouse models. In addition, telomere shortening, a cellular senescence biomarker, is associated with increased ND risks. Telomere dysfunction causes cellular senescence, stimulating IL-6, tumor necrosis factor-α, and IL-1β secretions. The forced expression of telomerase activators prevents cellular senescence, yielding considerable neuroprotective effects. This review elucidates the mechanism of cellular senescence in ND pathogenesis, suggesting strategies to eliminate or restore senescent cells to a normal phenotype for treating such diseases. [ABSTRACT FROM AUTHOR]

E3 ubiquitin ligases, key components of the ubiquitin proteasome system, orchestrate protein degradation through ubiquitylation and profoundly impact cellular biology. Small HERC E3 ligases (HERC3-6) have diverse functions in mammals, including roles in spermatogenesis, protein degradation, and immunity. Until now, only mammals' HERC3, HERC5, and HERC6 are known to participate in immune responses, with major involvement in the antiviral response. Interestingly, an exclusive HERC7 has been characterized in fish showing great molecular conservation and antiviral roles. Thus, this study identifies and characterizes the herc7 gene in the European sea bass teleost. The European sea bass herc7 gene and the putative protein show good conservation of the promoter binding sites for interferons and the RCC1 and HECT domains characteristic of HERC proteins, respectively. The phylogenetic analysis shows a unique cluster with the fish-exclusive HERC7 orthologues. During ontogeny, the herc7 gene is expressed from 3 days post-fertilization onwards, being constitutively and widely distributed in adult tissues. In vitro, stimulated leucocytes up-regulate the herc7 gene in response to mitogens and viruses, pointing to a role in the immune response. Furthermore, sea bass herc7 expression is related to the interferon response intensity and viral load in different tissues upon in vivo infection with red-grouper betanodavirus (RGNNV), suggesting the potential involvement of fish HERC7 in ISGylation-based antiviral activity, similarly to mammalian HERC5. This study broadens the understanding of small HERC proteins in fish species and highlights HERC7 as a potential contributor to the immune response in European sea bass, with implications for antiviral defense mechanisms. Future research is needed to unravel the precise actions and functions of HERC7 in teleost fish immunity, providing insights into direct antiviral activity and viral evasion. [ABSTRACT FROM AUTHOR]

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

Setd8 regulates transcription elongation, mitotic DNA condensation, DNA damage response and replication licensing. Here we show that, in mitogen-stimulated liver-specific Setd8-KO mice, most of the hepatocytes are eliminated by necrosis but a significant number of them survive via entering a stage exhibiting several senescence-related features. Setd8-deficient hepatocytes had enlarged nuclei, chromosomal hyperploidy and nuclear engulfments progressing to the formation of intranuclear vesicles surrounded by nuclear lamina. These vesicles contain glycogen, cytoplasmic proteins and even entire organelles. We term this process "endonucleosis". Intranuclear vesicles are absent in hepatocytes of Setd8/Atg5 knockout mice, suggesting that the process requires the function of the canonical autophagy machinery. Endonucleosis and hyperploidization are temporary, early events in the surviving Setd8-deficient cells. Larger vesicles break down into microvesicles over time and are eventually eliminated. The results reveal sequential events in cells with extensive DNA damage, which function as part of survival mechanisms to prevent necrotic death. Extensive cellular stress or DNA damage can alter nuclear morphology. Here, the authors show that cells lacking Setd8 or under metabolic stress internalize cytoplasmic material into the nucleus. [ABSTRACT FROM AUTHOR]