The MAPK-Alfin-like 7 module negatively regulates ROS scavenging genes to promote NLR-mediated immunity.

Nucleotide-binding leucine-rich repeat (NLR) receptor-mediated immunity includes rapid production of reactive oxygen species (ROS) and transcriptional reprogramming, which is controlled by transcription factors (TFs). Although some TFs have been reported to participate in NLR-mediated immune response, most TFs are transcriptional activators, and whether and how transcriptional repressors regulate NLR-mediated plant defenses remains largely unknown. Here, we show that the Alfin-like 7 (AL7) interacts with N NLR and functions as a transcriptional repressor. Knockdown and knockout of AL7 compromise N NLR-mediated resistance against tobacco mosaic virus, whereas AL7 overexpression enhances defense, indicating a positive regulatory role for AL7 in immunity. AL7 binds to the promoters of ROS scavenging genes to inhibit their transcription during immune responses. Mitogen-activated protein kinases (MAPKs), salicylic acid-induced protein kinase (SIPK), and wound-induced protein kinase (WIPK) directly interact with and phosphorylate AL7, which impairs the AL7-N interaction and enhances its DNA binding activity, which promotes ROS accumulation and enables immune activation. In addition to N, AL7 is also required for the function of other Toll interleukin 1 receptor/nucleotide-binding/leucine-rich repeats (TNLs) including Roq1 and RRS1-R/RPS4. Our findings reveal a hitherto unknown MAPK-AL7 module that negatively regulates ROS scavenging genes to promote NLR-mediated immunity.

Cannabidiol activates MAPK pathway to induce apoptosis, paraptosis, and autophagy in colorectal cancer cells.

Mitogen-activated protein kinase (MAPK) activation by natural compounds is known to be involved in the induction of apoptosis, paraptosis, and autophagy. Cannabidiol (CBD), a bioactive compound found in Cannabis sativa, is endowed with many pharmacological activities. We investigated the cytotoxic effect of CBD in a panel of colorectal cancer (CRC) cells (HT-29, SW480, HCT-116, and HCT-15). CBD induced significant cytotoxicity as evidenced by the results of MTT  assay, live-dead assay, and flow cytometric analysis. Since CBD displayed cytotoxicity against CRC cells, we examined the effect of CBD on apoptosis, paraptosis, and autophagy. CBD decreased the expression of antiapoptotic proteins and increased the Annexin-V-positive as well as TUNEL-positive cells suggesting that CBD induces apoptosis. CBD increased the expression of ATF4 (activating transcription factor 4) and CHOP (CCAAT/enhancer-binding protein homologous protein), elevated endoplasmic reticulum stress, and enhanced reactive oxygen species levels indicating that CBD also promotes paraptosis. CBD also induced the expression of Atg7, phospho-Beclin-1, and LC3 suggesting that CBD also accelerates autophagy. Since, the MAPK pathway is a common cascade that is involved in the regulation of apoptosis, paraptosis, and autophagy, we investigated the effect of CBD on the activation of JNK, p38, and ERK pathways. CBD activated all the forms of MAPK proteins and pharmacological inhibition of these proteins reverted the observed effects. Our findings implied that CBD could induce CRC cell death by activating apoptosis, paraptosis, and autophagy through the activation of the MAPK pathway.

Patch-Based Far-Infrared Radiation (FIR) Therapy Does Not Impact Cell Tracking or Motility of Human Melanoma Cells In Vitro.

Far-Infrared Radiation (FIR) is emerging as a novel non-invasive tool for mitigating inflammation and oxidative stress, offering potential benefits for certain medical conditions such as cardiovascular disease and chronic inflammatory disorders. We previously demonstrated that the application of patch-based FIR therapy on human umbilical vein endothelial cells (HUVECs) reduced the expression of inflammatory biomarkers and the levels of reactive oxygen species (ROS). Several in vitro studies have shown the inhibitory effects of FIR therapy on cell growth in different cancer cells (including murine melanoma cells), mainly using the wound healing assay, without direct cell motility or tracking analysis. The main objective of the present study was to conduct an in-depth analysis of single-cell motility and tracking during the wound healing assay, using an innovative high-throughput technique in the human melanoma cell line M14/C2. This technique evaluates various motility descriptors, such as average velocity, average curvature, average turning angle, and diffusion coefficient. Our results demonstrated that patch-based FIR therapy did not impact cell proliferation and viability or the activation of mitogen-activated protein kinases (MAPKs) in the human melanoma cell line M14/C2. Moreover, no significant differences in cell motility and tracking were observed between control cells and patch-treated cells. Altogether, these findings confirm the beneficial effects of the in vitro application of patch-based FIR therapy in human melanoma cell lines, although such effects need to be confirmed in future in vivo studies.

The small RNA biogenesis in rice is regulated by MAP kinase-mediated OsCDKD phosphorylation.

CDKs are the master regulator of cell division and their activity is controlled by the regulatory subunit cyclins and phosphorylation by the CAKs. However, the role of MAP kinases in regulating plant cell cycle or CDKs have not been explored. Here, we report that the MAP kinases OsMPK3, OsMPK4, and OsMPK6 physically interact and phosphorylate OsCDKD and its regulatory subunit OsCYCH in rice. MAP kinases phosphorylate CDKD at Ser-168 and Thr-235 residues in OsCDKD. The MAP kinase-mediated phosphorylation of OsCDKD is required for its activation to control the small RNA biogenesis. The phosphodead version of OsCDKD fails to activate the C-terminal domain of RNA Polymerase II, thereby negatively impacting small RNA transcription. Further, the overexpression lines of wild-type (WT) OsCDKD and phosphomimic OsCDKD show increased root growth, plant height, tiller number, panicle number, and seed number in comparison to WT, phosphodead OsCDKD-OE, and kinase-dead OsCDKD-OE plants. In a nutshell, our study establishes a novel regulation of OsCDKD by MAPK-mediated phosphorylation in rice. The phosphorylation of OsCDKD by MAPKs imparts a positive effect on rice growth and development by regulating miRNAs transcription.

Sustainable inflammatory activation following spinal cord injury is driven by thrombin-mediated dynamic expression of astrocytic chemokines.

Acute spinal cord injury (SCI) always results in sustainable recruitment of inflammatory cells driven by sequentially generated chemokines, thereby eliciting excessive neuroinflammation. However, the underlying mechanism of temporally produced chemokines remains elusive. Reactive astrocytes are known to be the main sources of chemokines at the lesion site, which can be immediately activated by thrombin following SCI. In the present study, SCI was shown to induce a sequential production of chemokines CCL2 and CCL5 from astrocytes, which were associated with a persistent infiltration of macrophages/microglia. The rapidly induced CCL2 and later induced CCL5 from astrocytes were regulated by thrombin at the damaged tissues. Investigation of the regulatory mechanism revealed that thrombin facilitated astrocytic CCL2 production through activation of ERK/JNK/NFκB pathway, whereas promoted CCL5 production through PLCß3/NFκB and ERK/JNK/NFκB signal pathway. Inhibition of thrombin activity significantly decreased production of astrocytic CCL2 and CCL5, and reduced the accumulation of macrophages/microglia at the lesion site. Accordingly, the locomotor function of rats was remarkably improved. The present study has provided a new regulatory mechanism on thrombin-mediated sequential production of astrocytic chemokines, which might be beneficial for clinical therapy of CNS neuroinflammation.

Tobacco smoke condensate-induced senescence in endothelial cells was ameliorated by colchicine treatment via suppression of NF-κB and MAPKs P38 and ERK pathways activation.

Smoking is the major cause of cardiovascular diseases and cancer. It induces oxidative stress, leading to DNA damage and cellular senescence. Senescent cells increase the expression and release of pro-inflammatory molecules and matrix metalloproteinase, which are known to play a vital role in the initiation and progression of cardiovascular diseases and metastasis in cancer. The current study investigated the smoking induced cellular senescence and employed colchicine that blocked senescence in endothelial cells exposed to tobacco smoke condensate. Colchicine prevented oxidative stress and DNA damage in tobacco smoke-condensate-treated endothelial cells. Colchicin reduced ß-gal activity, improved Lamin B1, and attenuated cell growth arrest markers P21 and P53. Colchicine also ameliorated the expression of SASP factors and inhibited the activation of NF-kB and MAPKs P38 and ERK. In summary, colchicine inhibited tobacco smoke condensate-induced senescence in endothelial cells by blocking the activation of NF-kB and MAPKs P38 and ERK.

Long-term intake of sulforaphene alleviates D-galactose-induced skin senescence by activating AMPK-Sirt 1 pathway.

D-Galactose (D-gal) accumulation triggers the generation of oxygen free radicals, resulting in skin aging. Sulforaphene (SFE), an isothiocyanate compound derived from radish seeds, possesses diverse biological activities, including protective effects against inflammation and oxidative damage. This investigation delves into the antioxidant impact of SFE on age-related skin injury. In vivo experiments demonstrate that SFE treatment significantly improves the macro- and micro-morphology of dorsal skin. It effectively diminishes the elevation of oxidative stress biomarkers in mice skin tissue treated with D-gal, concurrently enhancing the activity of antioxidant enzymes. Additionally, SFE mitigates collagen mRNA degradation, lowers pro-inflammatory cytokine levels, and downregulates MAPK-related protein expression in the skin. Moreover, SFE supplementation reduces lipid metabolite levels and elevates amino acid metabolites, such as L-cysteine and L-histidine. These findings suggest that SFE holds promise as a natural remedy to mitigate aging induced by oxidative stress.

Protective effects of nordalbergin against LPS-induced endotoxemia through inhibiting MAPK/NF-κB signaling pathway, NLRP3 inflammasome activation, and ROS production.

OBJECTIVE: Nordalbergin is a coumarin extracted from Dalbergia sissoo DC. To date, the biological effects of nordalbergin have not been well investigated. To investigate the anti-inflammatory responses and the anti-oxidant abilities of nordalbergin using lipopolysaccharide (LPS)-activated macrophages and LPS-induced sepsis mouse model. MATERIALS AND METHODS: Production of nitrite oxide (NO), prostaglandin E2 (PGE2), pro-inflammatory cytokines (tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-1ß), reactive oxygen species (ROS), tissue damage and serum inflammatory markers, and the activation of the NLRP3 inflammasome were examined. RESULTS: Our results indicated that nordalbergin reduced the production of NO and pro-inflammatory cytokines in vitro and ex vivo. Nordalbergin also suppressed iNOS and cyclooxygenase-2 expressions, decreased NF-κB activity, and attenuated MAPKs signaling pathway activation by decreasing JNK and p38 phosphorylation by LPS-activated J774A.1 macrophages. Notably, nordalbergin diminished NLRP3 inflammasome activation via repressing the maturation of IL-1ß and caspase-1 and suppressing ROS production by LPS/ATP- and LPS/nigericin-activated J774A.1 macrophages. Furthermore, nordalbergin exhibited protective effects against the infiltration of inflammatory cells and also inhibited the levels of organ damage markers (AST, ALT, BUN) by LPS-challenged mice. CONCLUSION: Nordalbergin possesses anti-inflammatory effects in macrophage-mediated innate immune responses, alleviates ROS production, decreases NLRP3 activation, and exhibits protective effects against LPS-induced tissue damage in mice.

Syringin from Tinospora crispa downregulates pro-inflammatory mediator production through MyD88-dependent pathways in lipopolysaccharide (LPS)-induced U937 macrophages.

BACKGROUND: Syringin, a phenylpropanoid glycoside, has exhibited numerous biological properties including inhibitory activities against various immune and inflammatory disorders. In this study, syringin isolated from Tinospora crispa was evaluated for its ability to down-regulate activated nuclear factor-kappa B (NF-κB), phosphoinositide-3-kinase-Akt (PI3K-Akt) and mitogen-activated protein kinases (MAPKs) signal transducing networks in U937 macrophages activated by lipopolysaccharide. METHODS: The attenuating effects of syringin on the productions of prostaglandin E2 (PGE2), cyclooxygenase-2 (COX-2), interleukin-1ß (IL-1ß), and tumor necrosis factor-α (TNF-α), and the expressions of signaling molecules of the signaling pathways were investigated by using ELISA, Western blot, and qRT-PCR. RESULTS: Syringin downregulated the NF-κB, MAPKs, and PI3K-Akt signal networks by significantly reducing PGE2 production in the macrophages via suppression of COX-2 gene and protein expression levels. It also reduced TNF-α and IL-1ß secretion and their mRNA expression, suppressed phosphorylation of NF-κB (p65), IKKα/ß, and IκBα, and restored ability of IκBα to degrade. Syringin dose-dependently attenuated Akt, p38 MAPKs, JNK, and ERK phosphorylation. Also, the expression of corresponding upstream signaling molecules toll-like receptor 4 (TLR4) and myeloid differentiation primary response gene 88 (MyD88) were down-regulated in response to syringin treatment. CONCLUSION: The suppressive effect of syringin on the inflammatory signaling molecules in MyD88-dependent pathways suggested it's potential as a drug candidate for development into an agent for treatment of various immune-mediated inflammatory disorders.

Biologically active franchetine-type diterpenoid alkaloids: Isolation, synthesis, anti-inflammatory, agalgesic activities, and molecular docking.

In this study, four franchetine-type diterpenoid alkaloids (1-4) were isolated from Aconitum sinoaxillare, and fourteen diverse franchetine analogs (5-18) were synthesized. Compounds 1, 2, 7 and 16 exhibited stronger inhibitory effects on NO production when compared to celecoxib. Among them, compound 1 had the best inhibitory effect on iNOS and COX-2 inflammatory proteins. The in vitro studies displayed that the anti-inflammatory effect of the most active compound 1 was ascribed to the inhibition of the TLR4-MyD88/NF-κB/MAPKs signalling pathway. Consequently, this led to a inhibition in the expression of inflammatory factors or mediators including NO, ROS, TNF-α, IL-6, IL-1ß, iNOS, and COX-2. Additionally, compound 1 had low toxicity (LD50 > 20 mg/kg) in mice, and it had notable analgesic effects on acetic acid-induced visceral pain (ED50 = 2.15 ± 0.07 mg/kg). Moreover, compound 1 exhibited a distinct reduction in the NaV1.7 and NaV1.8 channel currents during both resting and half-inactivated states at 50 µM. The present study enriches the pharmacological activities of franchetine derivatives and provides valuable insights for the development of novel anti-inflammatory and analgesic agents.

Macrophage-specific FGFR1 deletion alleviates high-fat-diet-induced liver inflammation by inhibiting the MAPKs/TNF pathways.

Non-alcoholic fatty liver disease (NAFLD) is a common metabolic disease that is substantially associated with obesity-induced chronic inflammation. Macrophage activation and macrophage-medicated inflammation play crucial roles in the development and progression of NAFLD. Furthermore, fibroblast growth factor receptor 1 (FGFR1) has been shown to be essentially involved in macrophage activation. This study investigated the role of FGFR1 in the NAFLD pathogenesis and indicated that a high-fat diet (HFD) increased p-FGFR1 levels in the mouse liver, which is associated with increased macrophage infiltration. In addition, macrophage-specific FGFR1 knockout or administration of FGFR1 inhibitor markedly protected the liver from HFD-induced lipid accumulation, fibrosis, and inflammatory responses. The mechanistic study showed that macrophage-specific FGFR1 knockout alleviated HFD-induced liver inflammation by suppressing the activation of MAPKs and TNF signaling pathways and reduced fat deposition in hepatocytes, thereby inhibiting the activation of hepatic stellate cells. In conclusion, the results of this research revealed that FGFR1 could protect the liver of HFD-fed mice by inhibiting MAPKs/TNF-mediated inflammatory responses in macrophages. Therefore, FGFR1 can be employed as a target to prevent the development and progression of NAFLD.

The inhibitory impact of Schisandrin on inflammation and oxidative stress alleviates LPS-induced acute kidney injury.

Inflammation and oxidative stress (OS) are the major pathogenic characteristics of acute kidney injury (AKI). Studies have shown that Schisandrin (Sch) could regulate inflammatory disease. However, the function and mechanism of Sch in AKI progression are still unknown. Here, we investigated Sch's potential effects and mechanism on mice's renal damage and macrophages induced by lipopolysaccharide (LPS). Sch decreased LPS-induced inflammatory factor production while increasing the activity of related antioxidant enzymes in macrophages and mouse kidney tissues. Hematoxylin and eosin staining revealed that Sch may have the ability to profoundly inhibit inflammatory cell invasion and tissue damage caused by LPS in renal tissue. Furthermore, Western blot and immunohistochemical studies showed that Sch exerted its effects mainly through up-regulation of nuclear factor erythroid 2-related factor 2/heme oxygenase-1 and inhibition of Toll-like receptor 4‒mitogen-activated protein kinases/nuclear factor-kappa B pathways. Collectively, this study illustrates that Sch suppresses LPS-stimulated AKI by descending inflammation and OS, illuminating prospective AKI treatment options.

Oxidative Stress-Induced Platelet Apoptosis/Activation: Alleviation by Purified Curcumin via ASK1-JNK/p-38 Pathway.

Platelets are known for their indispensable role in hemostasis and thrombosis. However, alteration in platelet function due to oxidative stress is known to mediate various health complications, including cardiovascular diseases and other health complications. To date, several synthetic molecules have displayed antiplatelet activity; however, their uses are associated with bleeding and other adverse effects. The commercially available curcumin is generally a mixture of three curcuminoids: curcumin, demethoxycurcumin, and bisdemethoxycurcumin. Although crude curcumin is known to inhibit platelet aggregation, the effect of purified curcumin on platelet apoptosis, activation, and aggregation remains unclear. Therefore, in this study, curcumin was purified from a crude curcumin mixture and the effects of this preparation on the oxidative stress-induced platelet apoptosis and activation was evaluated. 2,2'-Azobis(2-methylpropionamidine) dihydrochloride (AAPH) compound was used as an inducer of oxidative stress. Purified curcumin restored AAPH-induced platelet apoptotic markers like reactive oxygen species, intracellular calcium level, mitochondrial membrane potential, cardiolipin peroxidation, cytochrome c release from mitochondria to the cytosol, and phosphatidyl serine externalization. Further, it inhibited the agonist-induced platelet activation and aggregation, demonstrating its antiplatelet activity. Western blot analysis confirms protective effect of the purified curcumin against oxidative stress-induced platelet apoptosis and activation via downregulation of MAPKs protein activation, including ASK1, JNK, and p-38. Together, these results suggest that the purified curcumin could be a potential therapeutic bioactive molecule to treat the oxidative stress-induced platelet activation, apoptosis, and associated complications.

Flame retardant, hexabromocyclododecane, increases production of pro-inflammatory cytokines, interleukin 1-beta and interleukin 6, in human immune cells.

Hexabromocyclododecane (HBCD) is an environmental contaminant due to its use as a flame retardant in a variety of applications ranging from building insulation, furniture upholstery, and housing for appliances and electronics. HBCD is found in wildlife, human breastmilk, and serum. Interleukin 1-beta (IL-1ß) and interleukin 6 (IL-6) are pro-inflammatory cytokines, whose dysregulation is associated with chronic inflammation and the pathologies that result, such as tumor growth, rheumatoid arthritis, Crohn's disease, and multiple sclerosis. HBCD has been shown to increase the secretion of both IL-1ß and IL-6 from human immune cells. However, it is not clear if these increases are due solely to HBCD effects on the secretory process or whether it is stimulating cellular production of IL-1ß and IL-6. This study examines if HBCD can increase the production of IL-1ß and IL-6 by immune cells by simultaneously assessing secreted levels and cellular levels of these cytokines. Additionally, the mechanisms for any observed changes in production are investigated. Peripheral blood mononuclear cells were exposed to HBCD over a range of concentrations and lengths of exposure. HBCD was found to stimulate IL-1ß and IL-6 production after 6 hrs. of exposure and production was sustained and intensified at 24 hrs. This increase in IL-1ß and IL-6 production appears to, in part, be a result of increased mRNA expression. Additionally, the MAPK pathways, specifically the p38 and p44/42 pathways, appear to be required for HBCD-induced increases in IL-1ß and IL-6 production.

SUMO enables substrate selectivity by mitogen-activated protein kinases to regulate immunity in plants.

The versatility of mitogen-activated protein kinases (MAPKs) in translating exogenous and endogenous stimuli into appropriate cellular responses depends on its substrate specificity. In animals, several mechanisms have been proposed about how MAPKs maintain specificity to regulate distinct functional pathways. However, little is known of mechanisms that enable substrate selectivity in plant MAPKs. Small ubiquitin-like modifier (SUMO), a posttranslational modification system, plays an important role in plant development and defense by rapid reprogramming of cellular events. In this study we identified a functional SUMO interaction motif (SIM) in Arabidopsis MPK3 and MPK6 that reveals a mechanism for selective interaction of MPK3/6 with SUMO-conjugated WRKY33, during defense. We show that WRKY33 is rapidly SUMOylated in response to Botrytis cinerea infection and flg22 elicitor treatment. SUMOylation mediates WRKY33 phosphorylation by MPKs and consequent transcription factor activity. Disruption of either WRKY33 SUMO or MPK3/6 SIM sites attenuates their interaction and inactivates WRKY33-mediated defense. However, MPK3/6 SIM mutants show normal interaction with a non-SUMOylated form of another transcription factor, SPEECHLESS, unraveling a role for SUMOylation in differential substrate selectivity by MPKs. We reveal that the SUMO proteases, SUMO PROTEASE RELATED TO FERTILITY1 (SPF1) and SPF2 control WRKY33 SUMOylation and demonstrate a role for these SUMO proteases in defense. Our data reveal a mechanism by which MPK3/6 prioritize molecular pathways by differentially selecting substrates using the SUMO-SIM module during defense responses.

Sophoridine exerts anti-arthritic effects on fibroblast-like synoviocytes and collagen-induced arthritis in rats.

The discovery of alternative medicines with fewer adverse effects is urgently needed for rheumatoid arthritis (RA). Sophoridine (SR), the naturally occurring quinolizidine alkaloid isolated from the leguminous sophora species, has been demonstrated to possess a wide range of pharmacological activities. However, the effect of SR on RA remains unknown. In this study, the collagen-induced arthritis (CIA) rat model and tumor necrosis factor alpha (TNFα)-induced fibroblast-like synoviocytes (FLSs) were utilized to investigate the inhibitory effect of SR on RA. The anti-arthritic effect of SR was evaluated using the CIA rat model in vivo and TNFα-stimulated FLSs in vitro. Mechanistically, potential therapeutic targets and pathways of SR in RA were analyzed through drug target databases and disease databases, and validation was carried out through immunofluorescence, immunohistochemistry, and Western blot. The in vivo results revealed that SR treatment effectively ameliorated synovial inflammation and bone erosion in rats with CIA. The in vitro studies showed that SR could significantly suppress the proliferation and migration in TNFα-induced arthritic FLSs. Mechanistically, SR treatment efficiently inhibited the activation of MAPKs (JNK and p38) and NF-κB pathways in TNFα-induced arthritic FLSs. These findings were further substantiated by Immunohistochemistry results in the CIA rat. SR exerts an anti-arthritic effect in CIA rats through inhibition of the pathogenic characteristic of arthritic FLSs via suppressing NF-κB and MAPKs (JNK and p38) signaling pathways. SR may have a great potential for development as a novel therapeutic agent for RA treatment.

In vitro and in†vivo biological evaluation of Lappaconitine derivatives as potential anti-inflammatory agents.

Natural products and their derivatives are a precious treasure in the pursuit of potent anti-inflammatory drugs. In this work, we measured the toxicity of 78 LA derivatives at 20 µM using MTT, then we evaluated the NO release of compounds without obvious toxicity in LPS-induced RAW.264.7 by Griess reagent, we identified three compounds, namely compounds 6, 19, 70, which exhibited promising anti-inflammatory potential. These compounds exhibited IC50 values of 10.34±2.05 µM, 18.18±4.80 µM and 15.66±0.88 µM. In addition, through ELISA kits, compounds 6, 19, 70 significantly reduce the production of inflammatory factors (TNF-α, IL-6, IL-1ß). Real-time PCR and western blot analysis showed that compounds 6, 19, 70 inhibited the mRNA and protein expression of iNOS and COX-2. Notably, compound 6 exhibited the most potent inhibitory activity. In vitro, it inhibits LPS-induced phosphorylation of NF-κB p65, IκBα, ERK1/2, JNK, and p38 MAPKs in RAW264.7 cells. In vivo, compound 6 potently inhibits the secretion of inflammatory mediators and neutrophil activation in ALI mice. Our findings suggest that compound 6 may be a potential anti-inflammatory drug.

Asynchronous Pattern of MAPKs' Activity during Aging of Different Tissues and of Distinct Types of Skeletal Muscle.

The MAPK p38α was proposed to be a prominent promoter of skeletal muscle aging. The skeletal muscle tissue is composed of various muscle types, and it is not known if p38α is associated with aging in all of them. It is also not known if p38α is associated with aging of other tissues. JNK and ERK were also proposed to be associated with aging of several tissues. Nevertheless, the pattern of p38α, JNK, and ERK activity during aging was not documented. Here, we documented the levels of phosphorylated/active p38α, Erk1/2, and JNKs in several organs as well as the soleus, tibialis anterior, quadriceps, gastrocnemius, and EDL muscles of 1-, 3-, 6-, 13-, 18-, and 24-month-old mice. We report that in most tissues and skeletal muscles, the MAPKs' activity does not change in the course of aging. In most tissues and muscles, p38α is in fact active at younger ages. The quadriceps and the lungs are exceptions, where p38α is significantly active only in mice 13 months old or older. Curiously, levels of active JNK and ERKs are also elevated in aged lungs and quadriceps. RNA-seq analysis of the quadriceps during aging revealed downregulation of proteins related to the extra-cellular matrix (ECM) and ERK signaling. A panel of mRNAs encoding cell cycle inhibitors and senescence-associated proteins, considered to be aging markers, was not found to be elevated. It seems that the pattern of MAPKs' activation in aging, as well as expression of known 'aging' components, are tissue- and muscle type-specific, supporting a notion that the process of aging is tissue- and even cell-specific.

Petanin Potentiated JNK Phosphorylation to Negatively Regulate the ERK/CREB/MITF Signaling Pathway for Anti-Melanogenesis in Zebrafish.

Petanin, an acylated anthocyanin from the Solanaceae family, shows potential in tyrosinase inhibitory activity and anti-melanogenic effects; however, its mechanism remains unclear. Therefore, to investigate the underlying mechanism of petanin's anti-melanogenic effects, the enzyme activity, protein expression and mRNA transcription of melanogenic and related signaling pathways in zebrafish using network pharmacology, molecular docking and molecular dynamics simulation were combined for analysis. The results showed that petanin could inhibit tyrosinase activity and melanogenesis, change the distribution and arrangement of melanocytes and the structure of melanosomes, reduce the activities of catalase (CAT) and peroxidase (POD) and enhance the activity of glutathione reductase (GR). It also up-regulated JNK phosphorylation, inhibited ERK/RSK phosphorylation and down-regulated CREB/MITF-related protein expression and mRNA transcription. These results were consistent with the predictions provided through network pharmacology and molecular docking. Thus, petanin could inhibit the activity of tyrosinase and the expression of tyrosinase by inhibiting and negatively regulating the tyrosinase-related signaling pathway ERK/CREB/MITF through p-JNK. In conclusion, petanin is a good tyrosinase inhibitor and anti-melanin natural compound with significant market prospects in melanogenesis-related diseases and skin whitening cosmetics.

Natural Compounds for Bone Remodeling: A Computational and Experimental Approach Targeting Bone Metabolism-Related Proteins.

Osteoporosis, characterized by reduced bone density and increased fracture risk, affects over 200 million people worldwide, predominantly older adults and postmenopausal women. The disruption of the balance between bone-forming osteoblasts and bone-resorbing osteoclasts underlies osteoporosis pathophysiology. Standard treatment includes lifestyle modifications, calcium and vitamin D supplementation and specific drugs that either inhibit osteoclasts or stimulate osteoblasts. However, these treatments have limitations, including side effects and compliance issues. Natural products have emerged as potential osteoporosis therapeutics, but their mechanisms of action remain poorly understood. In this study, we investigate the efficacy of natural compounds in modulating molecular targets relevant to osteoporosis, focusing on the Mitogen-Activated Protein Kinase (MAPK) pathway and the gut microbiome's influence on bone homeostasis. Using an in silico and in vitro methodology, we have identified quercetin as a promising candidate in modulating MAPK activity, offering a potential therapeutic perspective for osteoporosis treatment.