Search Results (1,112)

In end-stage renal disease (ESRD), the accumulation of solutes normally excreted by the kidneys contributes to multiple complications, including vascular calcification (VC), a key factor in the heightened cardiovascular risk seen in these patients. Among VC drivers, hyperphosphatemia and the uremic milieu are major contributors. Kynurenine, a tryptophan metabolite classified as a uremic toxin, may further exacerbate this process. This study investigated whether kynurenine amplifies high phosphate (Pi)-induced calcification in human aortic endothelial cells (HAEC). Cells were treated with Pi and kynurenine for up to seven days. Kynurenine increased Pi-induced calcium deposition by 36%, accompanied by enhanced endothelial-to-mesenchymal transition (EndMT) and osteoblastic differentiation. Mechanistically, kynurenine activated the aryl hydrocarbon receptor (AhR) pathway, and pharmacological inhibition of AhR partially attenuated this effect. These findings suggest that kynurenine contributes to VC in ESRD by potentiating phosphate-induced endothelial dysfunction via AhR signaling. Full article

Soil salinity severely impairs plant growth, and polyamines such as spermidine (Spd) are known to bolster stress tolerance by acting as osmoprotectants and signaling molecules. Using TiO₂ enrichment, iTRAQ quantification, and bioinformatics analysis, we identified 870 proteins and 157 differentially phosphorylated proteins. Functional annotation showed that salt stress activated key components of the Salt Overly Sensitive pathway, particularly serine threonine kinases (SOS2) and Ca²⁺ binding sensors (SOS3). Among thirty-six SOS-associated kinases detected, eight SOS2 isoforms, four MAPKs, and two SOS3 homologs were significantly upregulated by NaCl, and Spd further increased the phosphorylation of six SOS2 proteins and one SOS3 protein under salt stress, with no detectable effect on SOS1. qRT PCR revealed enhanced expression of MAPKs and calcium-dependent protein kinases, suggesting a phosphorylation-centered model in which Spd amplifies Ca²⁺-mediated SOS signaling and reinforces ion homeostasis through coordinated transcriptional priming and post-translational control. Additional, proteins involved in protein synthesis and turnover (ribosomal subunits, translation initiation factors, ubiquitin–proteasome components), DNA replication and transcription, and RNA processing showed differential expression under salt or Spd treatment. Central metabolic pathways were reprogrammed, involving glycolysis, the TCA cycle, the pentose phosphate pathway, as well as ammonium transporters and amino acid biosynthetic enzymes. These findings indicate that exogenous Spd regulated phosphorylation-mediated networks involving the SOS signaling pathway, protein homeostasis, and metabolism, thereby enhancing cucumber salt tolerance. Full article

Atherosclerosis is a multifactorial, chronic inflammatory disorder characterized by the progressive accumulation of plaque within the arterial wall. Recent research has highlighted the pivotal role of bioactive peptides in modulating vascular homeostasis and inflammation. Among these, salusin-α and salusin-β have emerged as critical regulators of atherogenesis. These peptides are generated via differential proteolytic processing of preprosalusin: an amino acid precursor encoded by the torsin family 2 member A gene. Despite their common origin, salusin-α and salusin-β exhibit divergent biological activities. Salusin-β promotes vascular inflammation by enhancing oxidative stress, activating the nuclear factor kappa B signaling pathway, and upregulating proinflammatory cytokines as well as adhesion molecules, and it also facilitates foam cell formation by increasing the expression of acyl-CoA/cholesterol acyltransferase 1 and scavenger receptors, thereby contributing to plaque progression. In contrast, salusin-α appears to exert protective, anti-inflammatory, and anti-atherogenic effects by increasing the expression of the interleukin-1 receptor antagonist and inhibiting key proinflammatory mediators. Additionally, these peptides modulate the proliferation of vascular smooth muscle cells and fibroblasts, with salusin-β promoting cellular proliferation and fibrosis via calcium and 3′,5′-cyclic adenosine monophosphate-mediated pathways, while the role of salusin-α in these processes is less well defined. Altered plasma levels of salusins have been correlated with the presence and severity of atherosclerotic lesions, suggesting their potential as diagnostic biomarkers and therapeutic targets. This review provides a comprehensive overview of biosynthesis, tissue distribution, and dual roles of salusins in vascular inflammation and remodeling, emphasizing their significance in the pathogenesis and early detection of atherosclerotic cardiovascular disease. Full article

Mechanical forces shape immune responses in both health and disease. PIEZO1 and PIEZO2, two mechanosensitive ion channels, have emerged as critical transducers of these forces, influencing inflammation, pain, fibrosis, and neuroimmune regulation. This review aims to synthesize the current evidence on the role of PIEZO channels in mechano-inflammation, with a specific focus on their regulatory function in neuroimmune crosstalk. A comprehensive narrative synthesis was performed using the literature from PubMed, Scopus, and Web of Science up to June 2025. Experimental, translational, and mechanistic studies involving PIEZO channels in inflammatory, fibrotic, and neuroimmune processes were included. PIEZO1 is broadly expressed in immune cells, fibroblasts, and endothelial cells, where it regulates calcium-dependent activation of pro-inflammatory pathways, such as NF-kB and STAT1. PIEZO2, enriched in sensory neurons, contributes to mechanosensory amplification of inflammatory pain. Both channels are mechanistically involved in neuroinflammation, glial activation, blood–brain barrier dysfunction, connective tissue fibrosis, and visceral hypersensitivity. PIEZO channels act as integrators of biomechanical and immunological signaling. Their roles as context-dependent gatekeepers of neuroimmune crosstalk make them attractive targets for novel therapies. Full article

Photophores are light-producing organs found in many fish species living in the mesopelagic, bathypelagic, and abyssal layers of the ocean. They function to attract prey, confuse predators, and communicate with other individuals of the same species. Understanding the structure and function of photophores is crucial to exploring bioluminescence and the ecological adaptations of marine life in deep-sea environments. The present study is the first to investigate the photophore anatomy of the mesopelagic fish Ichthyococcus ovatus (Cocco, 1838), using specimens naturally stranded along the coast of the Strait of Messina. The morphology of the ventral photophores of I. ovatus includes four functional parts: a tank containing photogenic cells, a lens filter, a reflector surrounding the entire organ, and a pigmented layer. An immunohistochemical assay was conducted using anti-nNOS and anti-S100p antibodies. The presence of nNOS/NOS type I immunolabeling the pigmented layer surrounding the photophores and the nerve fibers reaching the lens suggests a potential role of neuronal nitric oxide signaling in modulating light shielding by the pigment sheath, controlling light exposure, and adjusting light focusing though the lens-associated nerves. S100p immunostaining was observed in the nerve fibers reaching the photophores, highlighting its potential involvement in regulating neuronal calcium levels and, consequently, influencing signal transmission to control bioluminescence output. A sensory feedback pathway from the photophore to the CNS is suggested. Within the lens and in the irregularly shaped cells located in the photophore’s lens, S100p immunolabeling could indicate active signaling and differentiation processes. These findings expand our understanding of light-emitting systems in mesopelagic fishes and offer a valuable foundation for future studies on the functional and evolutionary significance of photophores. Full article

The retina is highly sensitive to oxygen and blood supply, and hypoxia plays a key role in retinal diseases such as diabetic retinopathy (DR) and age-related macular degeneration (AMD). Müller glial cells, which are essential for retinal homeostasis, respond to injury and hypoxia with reactive gliosis, characterized by the upregulation of the glial fibrillary acidic protein (GFAP) and vimentin, cellular hypertrophy, and extracellular matrix changes, which can impair retinal function and repair. The retinal pigment epithelium (RPE) supports photoreceptors, forms part of the blood–retinal barrier, and protects against oxidative stress; its dysfunction contributes to retinal degenerative diseases such as AMD, retinitis pigmentosa (RP), and Stargardt disease (SD). Extracellular vesicles (EVs) play a crucial role in intercellular communication, protein homeostasis, and immune modulation, and have emerged as promising diagnostic and therapeutic tools. Understanding the role of extracellular vesicles’ (EVs’) signaling machinery of glial cells and the retinal pigment epithelium (RPE) is critical for developing effective treatments for retinal degeneration. In this study, we investigated the bidirectional EV-mediated crosstalk between RPE and Müller cells under hypoxic conditions and its impact on cellular metabolism and retinal cell integrity. Our findings demonstrate that RPE-derived extracellular vesicles (RPE EVs) induce time-dependent metabolic reprogramming in Müller cells. Short-term exposure (24 h) promotes pathways supporting neurotransmitter cycling, calcium and mineral absorption, and glutamate metabolism, while prolonged exposure (72 h) shifts Müller cell metabolism toward enhanced mitochondrial function and ATP production. Conversely, Müller cell-derived EVs under hypoxia influenced RPE metabolic pathways, enhancing fatty acid metabolism, intracellular vesicular trafficking, and the biosynthesis of mitochondrial co-factors such as ubiquinone. Proteomic analysis revealed significant modulation of key regulatory proteins. In Müller cells, hypoxic RPE-EV exposure led to reduced expression of Dyskerin Pseudouridine Synthase 1 (DKc1), Eukaryotic Translation Termination Factor 1 (ETF1), and Protein Ser/Thr phosphatases (PPP2R1B), suggesting alterations in RNA processing, translational fidelity, and signaling. RPE cells exposed to hypoxic Müller cell EVs exhibited elevated Ribosome-binding protein 1 (RRBP1), RAC1/2, and Guanine Nucleotide-Binding Protein G(i) Subunit Alpha-1 (GNAI1), supporting enhanced endoplasmic reticulum (ER) function and cytoskeletal remodeling. Functional assays also revealed the compromised barrier integrity of the outer blood–retinal barrier (oBRB) under hypoxic co-culture conditions. These results underscore the adaptive but time-sensitive nature of retinal cell communication via EVs in response to hypoxia. Targeting this crosstalk may offer novel therapeutic strategies to preserve retinal structure and function in ischemic retinopathies. Full article

Dibutyl phthalate (DBP) is used as a plasticizer to enhance flexibility in several household products, cosmetics, and food-contact materials. Due to its harmful effects, DBP is restricted or banned in children’s products and food items, particularly in Europe. Due to its endocrine disruptor properties and considering its ability to cross the placental barrier, it is imperative to study DBP’s vascular effects in pregnancy, given the vulnerability of this period. Thus, this study investigated the potential effects of DBP on the cardiovascular system using umbilical arteries from healthy pregnant women. Specifically, the impact of DBP on the vascular reactivity after both rapid and 24 h DBP exposure was analyzed, as well as the contractility and the cell viability of vascular smooth muscle cells (VSMC). DBP did not exhibit overt cytotoxic effects on VSMCs, possibly due to its adsorption onto polystyrene surfaces, potentially limiting bioavailability. Interestingly, DBP induced vasorelaxation in a concentration-dependent manner. Although mechanistic insights remain to be fully elucidated, the results suggest the involvement of pathways associated with nitric oxide signaling and calcium handling. Overall, DBP exposure appears to modulate arterial tone regulation, which may have implications for vascular function during pregnancy. Full article

Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a systemic ciliopathy resulting from loss-of-function mutations in the PKD1 and PKD2 genes, which encode polycystin-1 (PC1) and polycystin-2 (PC2), respectively. PC1 and PC2 regulate mechanosensation, calcium signaling, and key pathways controlling tubular epithelial structure and function. Loss of PC1/PC2 disrupts calcium homeostasis, elevates cAMP, and activates proliferative cascades such as PKA–B-Raf–MEK–ERK, mTOR, and Wnt, driving cystogenesis via epithelial proliferation, impaired apoptosis, fluid secretion, and fibrosis. Recent evidence also implicates novel signaling axes in ADPKD progression including, the Hippo pathway, where dysregulated YAP/TAZ activity enhances c-Myc-mediated proliferation; the stimulator of interferon genes (STING) pathway, which is activated by mitochondrial DNA release and linked to NF-κB-driven inflammation and fibrosis; and the TWEAK/Fn14 pathway, which mediates pro-inflammatory and pro-apoptotic responses via ERK and NF-κB activation in tubular cells. Mitochondrial dysfunction, oxidative stress, and maladaptive extracellular matrix remodeling further exacerbate disease progression. A refined understanding of ADPKD’s complex signaling networks provides a foundation for precision medicine and next-generation therapeutics. This review gathers recent molecular insights and highlights both established and emerging targets to guide targeted treatment strategies in ADPKD. Full article

Skeletal muscle development is a critical economic trait in livestock, governed by myogenic satellite cell regulation. Integrins mediate mechanical anchorage to the ECM and enable ECM–intracellular signaling. CIB2, as an EF-hand-domain protein involved in mechanotransduction, shows significant developmental regulation in goat muscle. Although the role of CIB2 in skeletal muscle growth is poorly characterized, we observed pronounced developmental upregulation of IB2 in postnatal goat muscle. CIB2 expression increased >20-fold by postnatal day 90 (P90) compared to P1, sustaining elevation through P180 (p < 0.05). Functional investigations indicated that siRNA-mediated knockdown of CIB2 could inhibit myoblast proliferation by inducing S-phase arrest (p < 0.05) and downregulating the expression of CDK4/Cyclin D/E. Simultaneously, CIB2 interference treatment was found to decrease the proliferative activity of goat myogenic satellite cells, yet it significantly promoted differentiation by upregulating the expression of MyoD/MyoG/MyHC (p < 0.01). Mechanistically, CTCF was identified as a transcriptional repressor binding to an intragenic region of the CIB2 gene locus (ChIP enrichment: 2.3-fold, p < 0.05). Knockdown of CTCF induced upregulation of CIB2 (p < 0.05). RNA-seq analysis established CIB2 as a calcium signaling hub: its interference activated IL-17/TNF and complement cascades, while overexpression suppressed focal adhesion/ECM–receptor interactions and enriched neuroendocrine pathways. Collectively, this study identifies the CTCF-CIB2–integrin α7β1–PI3K/AKT axis as a novel molecular mechanism that regulates the balance of myogenic fate in goats. These findings offer promising targets for genomic selection and precision breeding strategies aimed at enhancing muscle productivity in ruminants. Full article

Heterotopic ossification (HO) refers to the pathological formation of bone in soft tissues, typically following trauma, surgical procedures, or as a result of genetic disorders. Notably, injuries to the central nervous system significantly increase the risk of HO, a condition referred to as neurogenic HO (NHO). This review outlines the cellular and molecular mechanisms driving HO, focusing on the inflammatory response, progenitor cell reprogramming, and current treatment strategies. HO is primarily fuelled by a prolonged and dysregulated inflammatory response, characterized by sustained expression of osteoinductive cytokines secreted by M1 macrophages. These cytokines promote the aberrant differentiation of fibro-adipogenic progenitor cells (FAPs) into osteoblasts, leading to ectopic mineralization. Additional factors such as hypoxia, BMP signalling, and mechanotransduction pathways further contribute to extracellular matrix (ECM) remodelling and osteogenic reprogramming of FAPs. In the context of NHO, neuroendocrine mediators enhance ectopic bone formation by influencing both local inflammation and progenitor cell fate decisions. Current treatment options such as nonsteroidal anti-inflammatory drugs (NSAIDs), radiation therapy, and surgical excision offer limited efficacy and are associated with significant risks. Novel therapeutic strategies targeting inflammation, neuropeptide signalling, and calcium metabolism may offer more effective approaches to preventing or mitigating HO progression. Full article

Background: Signaling pathways like those depending on cAMP/PKA, calcium/calmodulin/CaMK, MEK-1/MAPK or PI3K/Akt have been described to modulate suprachiasmatic nucleus (SCN) neuronal signaling via influencing transcription factors like CREB. Here, we analyzed the effect of cyclic nucleotide phosphodiesterase inhibitors and structurally similar substances commonly used as autophagy modulators on a cell line stably expressing a cyclic nucleotide element-driven luciferase reporter. Methods: We used an SCN cell line stably transfected with a CRE-luciferase reporter (SCNCRE) to evaluate signaling and vitality responses to various isoform-selective PDE inhibitors and autophagy modulators to evaluate the mechanism of action of the latter. Results: In this study the different impacts of common PDE inhibitors and autophagy modulators on CRE-luciferase activity applied alone and in combination with known CRE-luciferase activating agents showed that (1) PDE3, 4 and 5 are present in SCNCRE cells, with (2) PDE3 being the most active and (3) the autophagy inhibitor 3-Methyladenin (3-MA) displaying PDE inhibitor-like behavior. Conclusions: Experiments provide evidence that, in addition to the extracellular signaling pathways components shown before to be involved in CRE-luciferase activity regulation like cAMP analogs, adenylate cyclase activators and beta-adrenoceptor agonists, cyclic nucleotide metabolism as realized by phosphodiesterase activity, or molecule/agents influencing processes like autophagy or inflammation, modulate transcriptional CRE-dependent activity in these cells. Specifically, we provide evidence that the autophagy inhibitor 3-MA, given that PDEs are expressed, may also act as a PDE inhibitor and inducer of CRE-mediated transcriptional activity. Full article

Low-temperature stress severely limits plant growth and reduces agricultural productivity. Calmodulin-like (CML) proteins are crucial calcium sensors in plant cold responses. Transcriptome analysis of cold-stressed Saussurea involucrata identified seven differentially expressed CML genes. qRT-PCR confirmed that SiCML6 was strongly induced at 4 °C and −2 °C. Bioinformatics analysis showed that SiCML6 encodes a transmembrane protein containing an EF-hand domain. This protein carries a signal peptide and shows the closest phylogenetic relationship to Helianthus annuus CML3. Its promoter contains ABA, methyl jasmonate (MeJA), and cold-response elements. Arabidopsis plants overexpressing SiCML6 showed significantly higher survival rates at −2 °C than wild-type plants. Under freezing stress, SiCML6-overexpressing lines exhibited reduced malondialdehyde content, relative electrolyte leakage, and ROS accumulation (H₂O₂ and O₂⁻), along with increased proline, soluble sugars, soluble proteins, and total antioxidant capacity (T-AOC). SiCML6 elevated the expression of cold-responsive genes CBF3 and COR15a under normal conditions and further upregulated CBF1/2/3 and COR15a at 4 °C. Thus, low temperatures induced SiCML6 expression, which was potentially regulated by ABA/MeJA. SiCML6 enhances freezing tolerance by mitigating oxidative damage through boosted T-AOC and osmoprotectant accumulation while activating the CBF-COR signaling pathway. This gene is a novel target for improving crop cold resistance. Full article

Alzheimer’s disease (AD) is increasingly recognized as a multifactorial disorder driven by a combination of disruptions in proteostasis and organelle communication. The 2020 Lancet commission reported that approximately 10 million people worldwide were affected by AD in the mid-20th century. AD is the most prevalent cause of dementia. By early 2030, the global cost of dementia is projected to rise by USD 2 trillion per year, with up to 85% of that cost attributed to daily patient care. Several factors have been implicated in the progression of neurodegeneration, including increased oxidative stress, the accumulation of misfolded proteins, the formation of amyloid plaques and aggregates, the unfolded protein response (UPR), and mitochondrial–endoplasmic reticulum (ER) calcium homeostasis. However, the exact triggers that initiate these pathological processes remain unclear, in part because clinical symptoms often emerge gradually and subtly, complicating early diagnosis. Among the early hallmarks of neurodegeneration, elevated levels of reactive oxygen species (ROS) and the buildup of misfolded proteins are believed to play pivotal roles in disrupting proteostasis, leading to cognitive deficits and neuronal cell death. The accumulation of amyloid-β (Aβ) plaques and tau neurofibrillary tangles is a characteristic feature of AD. These features contribute to chronic neuroinflammation, which is marked by the release of pro-inflammatory cytokines and chemokines that exacerbate oxidative stress. Given these interconnected mechanisms, targeting stress-related signaling pathways, such as oxidative stress (ROS) generated in the mitochondria and ER, ER stress, UPR, and cytosolic chaperones, represents a promising strategy for therapeutic intervention. This review focuses on the relationship between stress chaperone responses and organelle function, particularly the interaction between mitochondria and the ER, in the development of new therapies for AD and related neurodegenerative disorders. Full article

Sarcopenia is a progressive age-related musculoskeletal disorder characterized by loss of muscle mass, strength, and physical performance, contributing to functional decline and increased risk of disability. Emerging evidence suggests that vitamin D (Vit D) plays a pivotal role in skeletal muscle physiology beyond its classical functions in bone metabolism. This review aims to critically analyze the relationship between serum Vit D levels and sarcopenia in older adults, focusing on pathophysiological mechanisms, diagnostic criteria, clinical evidence, and preventive strategies. An integrative narrative review of observational studies, randomized controlled trials, and meta-analyses published in the last decade was conducted. The analysis incorporated international diagnostic criteria for sarcopenia (EWGSOP2, AWGS, FNIH, IWGS), current guidelines for Vit D sufficiency, and molecular mechanisms related to Vit D receptor (VDR) signaling in muscle tissue. Low serum 25-hydroxyvitamin D levels are consistently associated with decreased muscle strength, reduced physical performance, and increased prevalence of sarcopenia. Although interventional trials using Vit D supplementation report variable results, benefits are more evident in individuals with baseline deficiency and when combined with protein intake and resistance training. Mechanistically, Vit D influences muscle health via genomic and non-genomic pathways, regulating calcium homeostasis, mitochondrial function, oxidative stress, and inflammatory signaling. Vit D deficiency represents a modifiable risk factor for sarcopenia and functional impairment in older adults. While current evidence supports its role in muscular health, future high-quality trials are needed to establish optimal serum thresholds and dosing strategies for prevention and treatment. An individualized, multimodal approach involving supplementation, exercise, and nutritional optimization appears most promising. Full article

Background: Induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) hold transformative potential for cardiovascular regenerative medicine, yet their clinical application is hindered by suboptimal mitochondrial maturation and metabolic inefficiencies. This systematic review evaluates targeted strategies for optimizing mitochondrial function, integrating metabolic preconditioning, substrate selection, and pathway modulation to enhance energy production and cellular resilience. Additionally, we examine the role of extracellular matrix stiffness and mechanical stimulation in mitochondrial adaptation, given their influence on metabolism and maturation. Methods: A comprehensive analysis of recent advancements in iPSC-CM maturation was conducted, focusing on metabolic interventions that enhance mitochondrial structure and function. Studies employing metabolic preconditioning, lipid and amino acid supplementation, and modulation of key signaling pathways, including PGC-1α, AMPK, and mTOR, were reviewed. Computational modeling approaches predicting optimal metabolic shifts were assessed, alongside insights into reactive oxygen species (ROS) signaling, calcium handling, and the impact of electrical pacing on energy metabolism. Results: Evidence indicates that metabolic preconditioning with fatty acids and oxidative phosphorylation enhancers improves mitochondrial architecture, cristae density, and ATP production. Substrate manipulation fosters a shift toward adult-like metabolism, while pathway modulation refines mitochondrial biogenesis. Computational models enhance precision, predicting interventions that best align iPSC-CM metabolism with native cardiomyocytes. The synergy between metabolic and biomechanical cues offers new avenues for accelerating maturation, bridging the gap between in vitro models and functional cardiac tissues. Conclusions: Strategic metabolic optimization is essential for overcoming mitochondrial immaturity in iPSC-CMs. By integrating biochemical engineering, predictive modeling, and biomechanical conditioning, a robust framework emerges for advancing iPSC-CM applications in regenerative therapy and disease modeling. These findings pave the way for more physiologically relevant cell models, addressing key translational challenges in cardiovascular medicine. Full article