Intracellular Signaling Mechanisms Research Articles

Mechanistic insights into Wnt-β-catenin pathway activation and signal transduction.

In multicellular organisms, Wnt proteins govern stem and progenitor cell renewal and differentiation to regulate embryonic development, adult tissue homeostasis and tissue regeneration. Defects in canonical Wnt signalling, which is transduced intracellularly by β-catenin, have been associated with developmental disorders, degenerative diseases and cancers. Although a simple model describing Wnt-β-catenin signalling is widely used to introduce this pathway and has largely remained unchanged over the past 30 years, in this Review we discuss recent studies that have provided important new insights into the mechanisms of Wnt production, receptor activation and intracellular signalling that advance our understanding of the molecular mechanisms that underlie this important cell-cell communication system. In addition, we review the recent development of molecules capable of activating the Wnt-β-catenin pathway with selectivity in vitro and in vivo that is enabling new lines of study to pave the way for the development of Wnt therapies for the treatment of human diseases.

Evaluation of mechanisms involved in regulation of intrinsic excitability by extracellular calcium in CA1 pyramidal neurons of rat.

It is well recognized that changes in the extracellular concentration of calcium ions influence the excitability of neurons, yet what mechanism(s) mediate these effects is still a matter of debate. Using patch-clamp recordings from rat hippocampal CA1 pyramidal neurons, we examined the contribution of G-proteins and intracellular calcium-dependent signaling mechanisms to changes in intrinsic excitability evoked by altering the extracellular calcium concentration from physiological (1.2 mM) to a commonly used experimental (2 mM) level. We find that the inhibitory effect on intrinsic excitability of calcium ions is mainly expressed as an increased threshold for action potential firing (with no significant effect on resting membrane potential) that is not blocked by either the G-protein inhibitor GDPβS or the calcium chelator BAPTA. Our results therefore argue that in the concentration range studied, G-protein coupled calcium-sensing receptors, non-selective cation conductances, and intracellular calcium signaling pathways are not involved in mediating the effect of extracellular calcium ions on intrinsic excitability. Analysis of the derivative of the action potential, dV/dt versus membrane potential, indicates a current shift towards more depolarized membrane potentials at the higher calcium concentration. Our results are thus consistent with a mechanism in which extracellular calcium ions act directly on the voltage-gated sodium channels by neutralizing negative charges on the extracellular surface of these channels to modulate the threshold for action potential activation.

Abstract 4126304: A Cardiac Targeting Peptide Linked to miRNA106a Targets and Suppresses Genes Known to Cause Heart Failure: Reversing Heart Failure at the Source

Background: About one in five adults at age 40 will develop heart failure (HF) during their lifetime. Risk factors for HF (e.g., hypertension, etc.) alter cardiomyocytes structure and function resulting in HF. At the cellular level, these changes consist of mis/over-expression of genes that regulate cardiac identity (e.g., CamK2d, PKC, etc). The current paradigm for treating HF is pharmacological intervention or surgery; however, with few exceptions, the condition worsens with time. We are proposing a paradigm-shift for treating HF from a drug-centric system to a molecular approach that would reverse hypertrophy and adverse remodeling. Methods: A cardiac targeting peptide (CTP) was generated and linked by disulfide bond to miRNA106a, which was then introduced into a HF mouse model to measure its ability to reverse multiple heart failure parameters. CTP-miRNA106a was also introduced into a human cardiac cell line, followed by multiple analyses including Western Blot, qPCR, FACS, immunofluorescence all used to identify mechanism(s) utilized by CTP-miRNA106a to reverse HF characteristics. Results: Bio-distribution studies showed CTP delivered its miRNA106a cargo specifically to the heart within 30 mins, followed by clearance of CTP from the heart to the kidneys and liver by 3-5hrs post systemic drug injection. MiRNA106a persisted in cardiomyocytes until day 7 (latest tested time-point). CTP-miRNA106a reversed Ang2/Iso induced hypertrophy in 90% of the experimental mice ( Fig1 ). We also identified two potential HF intracellular signaling mechanisms (PLCb1/PKC/IP3 and NfkB) targeted by CTP-miRNA106a that could benefit both types of HF, HFrEF and HFpEF. PLCβ1 is a direct target for miRNA106a while the Nfkb pathway is indirectly targeted by decreased Camk2d (an miRNA106a target) signaling to IκBα. NfkB activity is quelled by miRNA106a. Conclusions: Our approach utilizes the function of miRNA106a to downregulate genes involved in cardiac hypertrophy and inflammation through the PLCb1 and CamKIId/Nfkb pathways. Most importantly, using a CTP-miRNA106a, we show delivery of miRNA106a cargo is specific to cardiomyocytes both in vitro and in vivo and that once delivered, many HF parameters including hypertrophy are reversed.

Advancements of anticancer agents by targeting the Hippo signalling pathway: biological activity, selectivity, docking analysis, and structure-activity relationship.

The Hippo signalling pathway is prominent andgoverns cell proliferation and stem cell activity, acting as a growth regulator and tumour suppressor. Defects in Hippo signalling and hyperactivation of its downstream effector's Yes-associated protein (YAP) and transcriptional co-activator with PDZ-binding motif (TAZ) play roles in cancer development, implying that pharmacological inhibition of YAP and TAZ activity could be an effective cancer treatment strategy. Conversely, YAP and TAZ can also have beneficial effects in promoting tissue repair and regeneration following damage, therefore their activation may be therapeutically effective in certain instances. Recently, a complex network of intracellular and extracellular signalling mechanisms that affect YAP and TAZ activity has been uncovered. The YAP/TAZ-TEAD interaction leads to tumour development and the protein structure of YAP/TAZ-TEAD includes three interfaces and one hydrophobic pocket. There are clinical and preclinical trial drugs available to inhibit the hippo signalling pathway, but these drugs have moderate to severe side effects, so researchers are in search of novel, potent, and selective hippo signalling pathway inhibitors. In this review, we have discussed the hippo pathway in detail, including its structure, activation, and role in cancer. We have also provided the various inhibitors under clinical and preclinical trials, and advancement of small molecules their detailed docking analysis, structure-activity relationship, and biological activity. We anticipate that the current study will be a helpful resource for researchers.

The Gq/11 family of Gα subunits is necessary and sufficient for lower jaw development.

Vertebrate jaw development is coordinated by highly conserved ligand-receptor systems such as the peptide ligand Endothelin 1 (Edn1) and Endothelin receptor type A (Ednra), which are required for patterning of lower jaw structures. The Edn1/Ednra signaling pathway establishes the identity of lower jaw progenitor cells by regulating expression of numerous patterning genes, but the intracellular signaling mechanisms linking receptor activation to gene regulation remain poorly understood. As a first step towards elucidating this mechanism, we examined the function of the Gq/11 family of Gα subunits in zebrafish using pharmacological inhibition and genetic ablation of Gq/11 activity and transgenic induction of a constitutively active Gq protein in edn1 -/- embryos. Genetic loss of Gq/11 activity fully recapitulated the edn1 -/- phenotype, with genes encoding G11 being most essential. Furthermore, inducing Gq activity in edn1 -/- embryos not only restored Edn1/Ednra-dependent jaw structures and gene expression signatures but also caused homeosis of the upper jaw structure into a lower jaw-like structure. These results indicate that Gq/11 is necessary and sufficient to mediate the lower jaw patterning mechanism for Ednra in zebrafish.

New perspectives on the role of platelet factors in enhancing wound regeneration

Aim. To analyze the use of biological factors in the stimulation of the wound healing process. In the course of the study, we analysed relevant domestic and foreign literature sources on the given topic.Methods. The literature was reviewed using the key query ‘the role of biological factors in wound healing stimulation’ through the eLIBRARY and PubMed databases.Results. Currently, the range of therapeutic approaches is broad and diverse, incorporating both traditional and experimental methods such as advanced dressings, tissue matrices, growth factors (GFs), cell therapy, and nanotechnology. The wound healing process is regulated by a complex interplay of intercellular, intracellular, and extracellular signalling mechanisms across various phases of healing.Conclusion. The application of platelet-based therapies in different medical fields has shown promising outcomes in certain conditions, such as acute and chronic injuries of bone and cartilage. However, platelet-based preparations have yet to gain widespread clinical use. Several studies have demonstrated the involvement of platelets and related products, such as platelet microparticles (PMPs) and exosomes, in multiple phases of wound healing. The presence of a substantial number of biologically active molecules within platelet granules—exhibiting anti-inflammatory, angiogenic, proliferative, and other properties—renders platelets particularly attractive for use in regenerative medicine, including the stimulation of wound healin

Succinate activates UCP2 to suppress neuroinflammation and confer protection following intracerebral hemorrhage.

Succinate, a metabolite in the tricarboxylic acid cycle, is increasingly recognized to play essential roles in inflammation by functioning either as an intracellular or extracellular signaling molecule. However, the role and mechanisms of succinate in inflammation remain elusive. Here, we investigated the mechanism underlying the effects of succinate on neuroinflammation in intracerebral hemorrhage (ICH) models. We unexpectedly found that succinate robustly inhibited neuroinflammation and conferred protection following ICH. Mechanistically, oxidation of succinate by succinate dehydrogenase (SDH) drove reverse electron transport (RET) at mitochondrial complex I, leading to mitochondrial superoxide production in microglia. Complex I-derived superoxide, in turn, activated uncoupling protein 2 (UCP2). By using mice with specific deletion of UCP2 in microglia/macrophage, we showed that UCP2 was needed for succinate to inhibit neuroinflammation, confer protection, and activate downstream AMP-activated protein kinase (AMPK) following ICH. Moreover, knockdown of SDH, complex I or AMPK abolished the therapeutic effects of succinate following ICH. We provide evidence that driving complex I RET to activate UCP2 is a novel mechanism of succinate intracellular signaling and a mechanism underlying the inhibition of neuroinflammation by succinate. succinate; uncoupling protein 2; microglia; neuroinflammation; intracerebral hemorrhage.

Tomivosertib reduces ectopic activity in dorsal root ganglion neurons from patients with radiculopathy.

Spontaneous activity in dorsal root ganglion (DRG) neurons is a key driver of neuropathic pain in patients suffering from this largely untreated disease. While many intracellular signalling mechanisms have been examined in preclinical models that drive spontaneous activity, none have been tested directly on spontaneously active human nociceptors. Using cultured DRG neurons recovered during thoracic vertebrectomy surgeries, we showed that inhibition of mitogen-activated protein kinase interacting kinase (MNK) with tomivosertib (eFT508, 25 nM) reversibly suppresses spontaneous activity in human sensory neurons that are likely nociceptors based on size and action potential characteristics associated with painful dermatomes within minutes of treatment. Tomivosertib treatment also decreased action potential amplitude and produced alterations in the magnitude of after hyperpolarizing currents, suggesting modification of Na+ and K+ channel activity as a consequence of drug treatment. Parallel to the effects on electrophysiology, eFT508 treatment led to a profound loss of eIF4E serine 209 phosphorylation in primary sensory neurons, a specific substrate of MNK, within 2 min of drug treatment. Our results create a compelling case for the future testing of MNK inhibitors in clinical trials for neuropathic pain.

Cannabidiol ameliorates lipopolysaccharide-induced cardiovascular toxicity by its antioxidant and anti-inflammatory activity via regulating IL-6, Hif1α, STAT3, eNOS pathway.

Systemic inflammation causes several organ damage by activating the intracellular signaling mechanisms. Heart and aorta tissues are the structures mostly affected by this situation. By examining underlying processes, this study sought to determine whether cannabidiol (CBD) may have protective effects against the cardiovascular damage brought on by lipopolysaccharide (LPS). A total of 32 female rats were randomly allocated to one of four groups: control, lipopolysaccharide (LPS) (5mg/kg, i.p., single dose), LPS + CBD (5mg/kg, i.p., single dose), and CBD groups. The rats were killed six hours after receiving LPS, and tissues from the heart and aorta were taken. Histopathological and immunohistochemical analyzes were performed. Oxidative stress was evaluated biochemically by spectrophotometric method. Expression levels of genes were studied by RT-qPCR method. Histopathological analysis of the LPS group showed moderate hyperemia, hemorrhages, edema, inflammation, and myocardial cell damage. There was a slight to moderate increase in Cox-1, G-CSF, and IL-3 immunoexpressions, along with enhanced expressions of IL-6, Hif1α, and STAT3 genes, and decreased expressions of eNOS genes. Additionally, there were increased levels of TOS and decreased TAS levels observed biochemically. CBD treatment effectively reversed and improved all of these observed changes. CBD protects the heart and aorta against systemic inflammation through its antioxidant and anti-inflammatory activity via regulating IL-6, Hif1α, STAT3, and eNOS intracellular pathways.

Pathogenesis of cardiovascular diseases: effects of mitochondrial CF6 on endothelial cell function.

Cardiovascular disease (CVD) stands as a predominant global cause of morbidity and mortality, necessitating effective and cost-efficient therapies for cardiovascular risk reduction. Mitochondrial coupling factor 6 (CF6), identified as a novel proatherogenic peptide, emerges as a significant risk factor in endothelial dysfunction development, correlating with CVD severity. CF6 expression can be heightened by CVD risk factors like mechanical force, hypoxia, or high glucose stimuli through the NF-κB pathway. Many studies have explored the CF6-CVD relationship, revealing elevated plasma CF6 levels in essential hypertension, atherosclerotic cardiovascular disease (ASCVD), stroke, and preeclampsia patients. CF6 acts as a vasoactive and proatherogenic peptide in CVD, inducing intracellular acidosis in vascular endothelial cells, inhibiting nitric oxide (NO) and prostacyclin generation, increasing blood pressure, and producing proatherogenic molecules, significantly contributing to CVD development. CF6 induces an imbalance in endothelium-dependent factors, including NO, prostacyclin, and asymmetric dimethylarginine (ADMA), promoting vasoconstriction, vascular remodeling, thrombosis, and insulin resistance, possibly via C-src Ca2+ and PRMT-1/DDAH-2-ADMA-NO pathways. This review offers a comprehensive exploration of CF6 in the context of CVD, providing mechanistic insights into its role in processes impacting CVD, with a focus on CF6 functions, intracellular signaling, and regulatory mechanisms in vascular endothelial cells.

Intracellular signaling mechanism of sweat secretion by PACAP

Intracellular signaling mechanism of sweat secretion by PACAP

Immunoglobulin Superfamily Containing Leucine-Rich Repeat (ISLR) Serves as a Redox Sensor That Modulates Antioxidant Capacity by Suppressing Pyruvate Kinase Isozyme M2 Activity.

Cells defend against oxidative stress by enhancing antioxidant capacity, including stress-activated metabolic alterations, but the underlying intracellular signaling mechanisms remain unclear. This paper reports that immunoglobulin superfamily containing leucine-rich repeat (ISLR) functions as a redox sensor that responds to reactive oxygen species (ROS) stimulation and modulates the antioxidant capacity by suppressing pyruvate kinase isozyme M2 (PKM2) activity. Following oxidative stress, ISLR perceives ROS stimulation through its cysteine residue 19, and rapidly degrades in the autophagy-lysosome pathway. The downregulated ISLR enhances the antioxidant capacity by promoting the tetramerization of PKM2, and then enhancing the pyruvate kinase activity, PKM2-mediated glycolysis is crucial to the ISLR-mediated antioxidant capacity. In addition, our results demonstrated that, in triple-negative breast cancer, cisplatin treatment reduced the level of ISLR, and PKM2 inhibition sensitizes tumors to cisplatin by enhancing ROS production; and argued that PKM2 inhibition can synergize with cisplatin to limit tumor growth. Our results demonstrate a molecular mechanism by which cells respond to oxidative stress and modulate the redox balance.

TLR4/7-mediated host-defense responses of gingival epithelial cells.

Gingival epithelial cells (GECs) are physical and immunological barriers against outward pathogens while coping with a plethora of non-pathogenic commensal bacteria. GECs express several members of Toll-like receptors (TLRs) and control subsequent innate immune responses. TLR4 senses lipopolysaccharide (LPS) while TLR7/8 recognizes single-strand RNA (ssRNA) playing important roles against viral infection. However, their distinct roles in GECs have not been fully demonstrated. Here, we analyzed biological responses of GECs to LPSand CL075, a TLR7/8 agonist. GE1, a mouse gingival epithelial cell line, constitutively express TLR4 and TLR7, but not TLR8, like primary skin keratinocytes. Stimulation of GE1 cells with CL075 induced cytokine, chemokine, and antimicrobial peptide expressions, the pattern of which is rather different from that with LPS: higher mRNA levels of interferon (IFN) β, CXCL10, and β-defensin (BD) 14 (mouse homolog of human BD3); lower levels of tumor necrosis factor (TNF), CCL5, CCL11, CCL20, CXCL2, and CX3CL1. As for the intracellular signal transduction of GE1 cells, CL075 rapidly induced significant AKT phosphorylation but failed to activate IKKα/β-NFκB pathway, whereas LPS induced marked IKKα/β-NFκB activation without significant AKT phosphorylation. In contrast, both CL075 and LPS induced rapid IKKα/β-NFκB activation and AKT phosphorylation in a macrophage cell line. Furthermore, specific inhibition of AKT activity abrogated CL075-induced IFNβ, CXCL10, and BD14 mRNA expression in GE1 cells. Thus, TLR4/7 ligands appear to induce rather different host-defense responses of GECs through distinct intracellular signaling mechanisms.

Calcium signalling and transport in the kidney.

The kidney plays a pivotal role in regulating calcium levels within the body. Approximately 98% of the filtered calcium is reabsorbed in the nephron, and this process is tightly controlled to maintain calcium homeostasis, which is required to facilitate optimal bone mineralization, preserve serum calcium levels within a narrow range, and support intracellular signalling mechanisms. The maintenance of these functions is attributed to a delicate balance achieved by various calcium channels, transporters, and calcium-binding proteins in renal cells. Perturbation of this balance due to deficiency or dysfunction of calcium channels and calcium-bindingproteins can lead to severe complications. For example, polycystic kidney disease is linked to aberrant calcium transport and signalling. Furthermore, dysregulation of calcium levels can promote the formation of kidney stones. This Review provides an updated description of the key aspects of calcium handling in the kidney, focusing on the function of various calcium channels and the physiological stimuli that control these channels or are communicated through them. A discussion of the role of calcium as an intracellular second messenger and the pathophysiology of renal calcium dysregulation, as well as a summary of gaps in knowledge and future prospects, are also included.

Individual trombocity reactivity in hematuria associated with nephrolitiasis: the role of purinergic signalisation in the treatment of nesteroid protective preparations

Aim of the study was to establish the significance of TR-receptor, P2X1-receptor and P2Y-receptor synergism for the efficiency of TC aggregation in patients with different sensitivity to non-selective NSAIDs, which will allow us to approach an understanding the causes of the variability of hematuria associated with NLT. Material and methods. The study was prospective and included 60 patients with nephrolithiasis who were treated with high doses of NSAIDs for analgesia. The cohort of patients was divided into two groups: with effective (group 1. n=30) and ineffective (group 2. n=30) COX inhibition. The severity of hematuria was assessed during 7 days of drug therapy. The activity of TR receptors, purine P2X1- and P2Y- receptors of platelets (Tc) was analysed by turbidimetric method on ChronoLog analyser (USA). Agonists (ATP, ADP and Arachidonic acid) were used at EC50 and EC10 concentrations. Results. In the 1 group of patients, hyporeactivity of the TP receptor was established within 72 hours, which was restored to the level of normoreactivity on the 5th day of therapy. Optimal modulation of the compensatory reaction of Pl in response to hematuria was provided through the synergism of purine P2X1 and P2Y receptors. Optimal modulation of the compensatory reaction of Tc in response to hematuria was provided through the synergism of purine P2X1 and P2Y receptors. On the 7th day, a residual level of COX activity was reached, while intracellular signaling associated with stimulation of the TP receptor and purine P2 receptors did not provide the limitation of hematuria. In the 2 group, when patients were prescribed NSAIDs for 7 days, hyperreactivity of the TP receptor, P2 receptors and a stable level of microhematuria remained. In the case of COX resistance and increased production of TxA2, the maximum increase in proaggregant Tc activity was ensured through the stereotypical mechanism of intracellular signaling associated with stimulation of P2Y receptors (through Gi- and Gq- proteins) and the TP receptor (through Gq- and Gq12/13- proteins). Conclusion. Further study of the mechanisms of crosstalk signaling pathways with different COX activity will allow us to establish promising directions for pharmacological correction aimed at preventing hematuria and ensuring hemostasis in nephrolithiasis.

Parthenolide induces gallbladder cancer cell apoptosis via MAPK signalling.

Parthenolide (PTL) has a wide range of clinical applications owing to its anti-inflammatory and antitumor effects. To date, the antitumor effect of PTL on gallbladder cancer (GBC) remains largely unknown. Therefore, we aimed to investigate the biological effects of PTL on GBC. The cellular viability and proliferation of GBC-SD and NOZ cell lines after treatment with different concentrations of PTL were analyzed using the Cell Counting Kit-8 (CCK8)assay and colony formation assay. Apoptosis analysis was performed using flow cytometry. Hoechst staining was performed. RNA sequencing (RNA-seq) was performed to identify PTL-related genes and signalling pathways. Furthermore, we confirmed the involvement of these signalling pathways by qRT-PCR and western blotting. For the in-vivo experiments, a xenograft model was used to evaluate the effects of PTL on the proliferation of NOZ cells. PTL significantly inhibited GBC cell growth in vitro and induced apoptosis in the GBC-SD and NOZ cell lines in a dose-dependent manner. RNA sequencing data showed that the immune response and mitogen-activated protein kinase (MAPK) signalling pathways are closely associated with PTL-induced gallbladder cancer cell apoptosis. PTL upregulated BAX, cleaved PARP-1, cleaved caspase-3, cleaved caspase-9, P53 and decreased the expression of BCL-2, phosphorylated ERK, and phosphorylated MEK in vitro. Tumour volume and weight were also suppressed by PTL in vivo. Moreover, the effects of PTL on GBC cells might be mediated by the MAPK pathway. PTL significantly inhibits gallbladder cancer cell proliferation and induces apoptosis through the MAPK pathway, which is a potential molecular reagent for treating GBC. However, further exploration is needed to verify the antitumor effects of PTL and its intracellular signalling mechanism.

Inspiratory and sigh breathing rhythms depend on distinct cellular signalling mechanisms in the preBötzinger complex.

Breathing behaviour involves the generation of normal breaths (eupnoea) on a timescale of seconds and sigh breaths on the order of minutes. Both rhythms emerge in tandem from a single brainstem site, but whether and how a single cell population can generate two disparate rhythms remains unclear. We posit that recurrent synaptic excitation in concert with synaptic depression and cellular refractoriness gives rise to the eupnoea rhythm, whereas an intracellular calcium oscillation that is slower by orders of magnitude gives rise to the sigh rhythm. A mathematical model capturing these dynamics simultaneously generates eupnoea and sigh rhythms with disparate frequencies, which can be separately regulated by physiological parameters. We experimentally validated key model predictions regarding intracellular calcium signalling. All vertebrate brains feature a network oscillator that drives the breathing pump for regular respiration. However, in air-breathing mammals with compliant lungs susceptible to collapse, the breathing rhythmogenic network may have refashioned ubiquitous intracellular signalling systems to produce a second slower rhythm (for sighs) that prevents atelectasis without impeding eupnoea. KEY POINTS: A simplified activity-based model of the preBötC generates inspiratory and sigh rhythms from a single neuron population. Inspiration is attributable to a canonical excitatory network oscillator mechanism. Sigh emerges from intracellular calcium signalling. The model predicts that perturbations of calcium uptake and release across the endoplasmic reticulum counterintuitively accelerate and decelerate sigh rhythmicity, respectively, which was experimentally validated. Vertebrate evolution may have adapted existing intracellular signalling mechanisms to produce slow oscillations needed to optimize pulmonary function in mammals.

Stomatal responses to VPD utilize guard cell intracellular signaling components.

Stomatal pores, vital for CO2 uptake and water loss regulation in plants, are formed by two specialized guard cells. Despite their importance, there is limited understanding of how guard cells sense and respond to changes in vapor pressure difference (VPD). This study leverages a selection of CO2 hyposensitive and abscisic acid (ABA) signaling mutants in Arabidopsis, including heterotrimeric G protein mutants and RLK (receptor-like kinase) mutants, along with a variety of canola cultivars to delve into the intracellular signaling mechanisms prompting stomatal closure in response to high VPD. Stomatal conductance response to step changes in VPD was measured using the LI-6800F gas exchange system. Our findings highlight that stomatal responses to VPD utilize intracellular signaling components. VPD hyposensitivity was particularly evident in mutants of the ht1 (HIGH LEAF TEMPERATURE1) gene, which encodes a protein kinase expressed mainly in guard cells, and in gpa1-3, a null mutant of the sole canonical heterotrimeric Gα subunit, previously implicated in stomatal signaling. Consequently, this research identifies a nexus in the intricate relationships between guard cell signal perception, stomatal conductance, environmental humidity, and CO2 levels.

Tension regulates the cartilage phenotypic expression of endplate chondrocytes through the α-catenin/actin skeleton/Hippo pathway.

The study aimed to investigate the regulatory mechanism of intracellular tension signaling in endplate chondrocytes and its impact on extracellular matrix synthesis. Human endplate chondrocytes were subjected to tension load using Flexcell FX-5000™, and changes in phenotype, morphology, and the expression of Hippo signaling pathway and α-Catenin were assessed through various techniques. Through the overexpression of YAP and inhibition of α-Catenin, the study clarified the intracellular tension signaling pathway and its regulation of extracellular matrix synthesis in endplate cartilage. In vitro-cultured human endplate chondrocytes significantly suppressed phenotype-related genes and proteins, accompanied by distinct changes in cytoskeleton morphology. Tension activation resulted in the substantial activation of the Hippo pathway, increased phosphorylation of YAP, and reduced nuclear translocation of YAP. YAP overexpression alleviated the inhibitory effect of tension on extracellular matrix synthesis in endplate chondrocytes. Tension also upregulated the expression of α-Catenin in endplate chondrocytes, which was attenuated by inhibiting α-Catenin expression, thereby reducing the impact of tension on cytoskeletal morphology and YAP nuclear translocation. Taken together, the α-Catenin/actin skeleton/Hippo-coupled network is a crucial signaling pathway for tension signaling in endplate chondrocytes, providing potential therapeutic targets for the treatment of endplate cartilage degeneration.

WNT4 Regulates Cellular Metabolism via Intracellular Activity at the Mitochondria in Breast and Gynecologic Cancers.

WNT4 regulates breast and gynecologic cancer metabolism via a previously unappreciated intracellular signaling mechanism at the mitochondria, with WNT4 mediating metabolic remodeling. Understanding WNT4 dysregulation by estrogen and genetic polymorphism offers new opportunities for defining tumor biology, precision therapeutics, and personalized cancer risk assessment.