Search Results (620)

Cells are continuously exposed to physiological and environmental stressors that disrupt homeostasis, triggering adaptive mechanisms such as the integrated stress response (ISR). A central feature of ISR is the selective translation of activating transcription factor 4 (ATF4), which orchestrates gene programs essential for metabolic adaptation and survival. Stress-induced acute ATF4 expression occurs in diverse mammalian cell types and is typically protective; however, chronic activation contributes to pathologies including cancer and neurodegeneration. Canonical ISR (c-ISR) is initiated by phosphorylation of eIF2α in response to stressors such as endoplasmic reticulum or mitochondrial dysfunction, hypoxia, nutrient deprivation, and infections. This modification suppresses global protein synthesis while promoting ATF4 translation through upstream open reading frames (uORFs) in its 5′UTR. Recently, an alternative pathway, split ISR (s-ISR), enabling ATF4 translation independently of eIF2α phosphorylation, was identified in mice, suggesting ISR adaptability, though its relevance in humans remains unclear. Under normal conditions, cap-dependent translation predominates, mediated by the eIF4F complex and requiring the activity of eIF2B at its initial steps. During translational stress, eIF2α phosphorylation inhibits eIF2B activity, resulting in the formation of stalled initiation complexes, which can aggregate into stress granules (SGs). SGs sequester mRNAs and translation initiation factors, further repressing global translation, while ATF4 mRNA largely escapes sequestration, enabling selective translation. This partitioning highlights a finely tuned regulatory mechanism balancing ATF4 expression during stress. Recent advances reveal that, beyond cis-regulatory uORFs, trans-acting factors such as translation initiation factors and associated RNA-binding proteins critically influence ATF4 translation. Understanding these mechanisms provides insight into ISR plasticity and its implications for development, aging, and disease. Full article

Kidney cells are exposed to a wide range of physiological and pathological stresses, including hormonal changes, mechanical forces, hypoxia, hyperglycemia, and inflammation. These insults can trigger adaptive responses, but when they persist, they can lead to organelle stress. Organelles such as mitochondria, the endoplasmic reticulum, and primary cilia sustain cellular metabolism and tissue homeostasis. When organelle stress occurs, it disrupts cellular processes and organelle communication, leading to metabolic dysfunction, inflammation, fibrosis, and progression of kidney disease. Sex and hormonal factors play a significant role in the development of renal disorders. Many glomerular diseases show distinct differences between the sexes. Chronic Kidney Disease is more common in women, while men often experience a faster decline in kidney function, partly due to the influence of androgens. Additionally, the loss of female hormonal protection after menopause highlights the importance of sex as a factor in renal susceptibility. This narrative review synthesizes preclinical evidence on how sexual dimorphism and sex hormones affect organelle stress in mitochondria, the endoplasmic reticulum, and primary cilia, from 33 studies identified through a non-systematic literature search of the PubMed database, to provide an overview of how these mechanisms contribute to sex-specific differences in kidney disease pathophysiology. Full article

Background and Objectives: Metabolic syndrome (MetS) is a complex condition marked by insulin resistance, central obesity, dyslipidemia, and chronic inflammation. Emerging evidence highlights the roles of hypoxia and mitochondrial stress in its pathophysiology. Hypoxia-inducible factor-1 alpha (HIF1α) and the mitophagy-associated proteins BNIP3 and BNIP3L are key components of hypoxia-responsive mitochondrial stress signaling. This study aimed to evaluate the circulating levels of HIF1α, BNIP3, and BNIP3L in MetS and to explore their associations with metabolic and inflammatory parameters. Materials and Methods: Serum concentrations of HIF1α, BNIP3, and BNIP3L were measured by ELISA in 40 patients with MetS and 40 age and sex-matched controls. Biochemical, hematological, and anthropometric parameters were assessed, and receiver operating characteristic (ROC) analyses were performed to evaluate diagnostic performance. Results: Serum levels of HIF1α, BNIP3, and BNIP3L levels were significantly higher in MetS patients compared with controls (p = 0.001). ROC analysis demonstrated strong diagnostic potential, particularly for BNIP3 (AUC = 0.928), followed by HIF1α (AUC = 0.885) and BNIP3L (AUC = 0.770). These markers showed significant associations with metabolic indicators such as BMI, fasting glucose, triglycerides, and inflammatory markers. Conclusions: The coordinated upregulation of circulating HIF1α, BNIP3, and BNIP3L in MetS is associated with metabolic dysregulation and systemic inflammation, reflecting alterations in hypoxia-responsive mitophagy-associated signaling rather than direct functional impairment of mitophagy. These findings support the potential relevance of these markers as indicators of metabolic stress in MetS. Further tissue-based and mechanistic studies are warranted to clarify their role in disease pathophysiology. Full article

Background: Hyperbaric oxygen therapy (HBOT) is considered a potential adjunctive modality to enhance tissue regeneration in oral and maxillofacial surgery. By increasing tissue oxygen availability, HBOT may support bone and soft-tissue repair under hypoxic and chronically inflamed conditions. Aim: This narrative review evaluates current experimental and clinical evidence regarding HBOT in high-risk dental indications, including osteoradionecrosis (ORN), medication-related osteonecrosis of the jaw (MRONJ), chronic osteomyelitis, poorly healing postoperative wounds, and procedures in patients with systemic comorbidities. Methods: A structured search of PubMed, Web of Science, and the Cochrane Library identified 123 relevant English-language publications (from 1 January 2000–September 2025) addressing HBOT mechanisms and clinical applications in oral and maxillofacial surgery, including clinical trials, observational studies, preclinical models, and systematic reviews. Results: Available evidence suggests that HBOT may improve healing outcomes and reduce complication rates in early-stage ORN and MRONJ when used as an adjunct to surgery and systemic therapy. However, findings in implantology—particularly in irradiated or diabetic patients—and in periodontal therapy remain limited, heterogeneous, and methodologically inconsistent. Conclusions: HBOT may be considered in selected clinical scenarios, particularly where healing is impaired by hypoxia or systemic disease. Nevertheless, current evidence remains insufficient to support routine use. Standardized, high-quality studies with clearly defined endpoints and uniform therapeutic protocols are needed to determine its clinical effectiveness and optimal indications. Full article

Background/Objectives: The cardiac hypoxia- and inflammation-associated processes in patients with chronic coronary artery disease remain unknown. The coronary sinus (CS) can be used to explore changes in cardiac microenvironment. This study sought to evaluate acute changes in the CS concentration of hypoxia and inflammation-associated biomarkers after the percutaneous revascularization of chronic total occlusions (CTO-PCI). Additionally, we explored changes in systemic inflammation and the potential of CS biomarkers to predict left ventricular ejection fraction (LVEF) improvement on follow-up. Methods: Thirty-three patients undergoing CTO-PCI were included. Samples from CS were collected before and after the revascularization. Twenty-six protein biomarkers associated with hypoxia and inflammation were measured using proximity extension assay technology. Systemic inflammation markers and LVEF on cardiac magnetic resonance imaging were assessed at baseline and 6-month follow-up. Results: CTO-PCI yielded a significant decrease in the concentration of CS pro-angiogenic biomarkers (angiopoietin-1, vascular endothelial growth factors). In addition, there was a significant increase in the anti-inflammatory biomarker interleukin-10 and a decrease in several pro-inflammatory biomarkers like interleukin-1β. The acute response in cardiac microenvironment was followed by a mid-term reduction in systemic inflammatory markers, particularly high-sensitivity C-reactive protein. Notably, interleukin-10 showed good performance to identify patients achieving LVEF improvement on follow-up in our cohort. Conclusions: Our results suggest that CTO-PCI might attenuate cardiac hypoxic and inflammatory stress. These exploratory findings warrant confirmation in larger, controlled studies. Full article

Obesity, sarcopenia, and heart failure with preserved ejection fraction (HFpEF) constitute an interconnected clinical triad driven by multisystem mechanisms centered on the adipokine axis. Adipose tissue, now recognized as a dynamic endocrine organ, undergoes pathological remodeling in obesity, characterized by hypoxia, chronic low-grade inflammation, and dysregulated adipokine secretion. These changes impair endothelial function, promote myocardial fibrosis, and disrupt skeletal muscle metabolism, thereby linking cardiometabolic and musculoskeletal dysfunction. This review integrates current evidence on homeostatic adipokines, such as adiponectin, apelin, and omentin, that preserve vascular and muscular resilience, as well as stress-inducible adipokines, such as leptin, resistin, and GDF15, that reflect or amplify metabolic and inflammatory injury. A maladaptive adipokine milieu associates with a self-reinforcing cycle of endothelial dysfunction, myocardial stiffening, and muscle atrophy that characterizes s HFpEF in the context of obesity and sarcopenia. We further discuss emerging translational applications, including diagnostic and prognostic adipokine signatures, targeted modulation of adipokine pathways, and the therapeutic impact of GLP-1 receptor agonists on adipose–cardiovascular–muscle crosstalk. Remaining challenges, including the adiponectin paradox and pleiotropic adipokine effects, highlight the need for precision-medicine approaches integrating multimodal biomarker profiling with cardiometabolic and musculoskeletal phenotyping. Full article

Diabetic wounds remain chronically non-healing due to impaired angiogenesis, persistent inflammation, and defective extracellular matrix remodelling. In recent years, stem cell-derived exosomes have emerged as a potent cell-free regenerative strategy capable of recapitulating the therapeutic benefits of mesenchymal stem cells while avoiding risks associated with direct cell transplantation. This review critically evaluates the preclinical evidence supporting the use of exosomes derived from adipose tissue, bone marrow, umbilical cord, and induced pluripotent stem cells for diabetic wound repair. These exosomes deliver bioactive cargos such as microRNAs, proteins, lipids, and cytokines that modulate key signalling pathways, including Phosphatidylinositol 3-kinase/Protein kinase (PI3K/Akt), Nuclear factor kappa B (NF-κB), Mitogen-activated protein kinase (MAPK), Transforming growth factor-beta (TGF-β/Smad), and Hypoxia inducible factor-1α/Vascular endothelial growth factor (HIF-1α/VEGF), thereby promoting angiogenesis, accelerating fibroblast and keratinocyte proliferation, facilitating re-epithelialization, and restoring immune balance through M2 macrophage polarization. A central focus of this review is the recent advances in exosome-based delivery systems, including hydrogels, microneedles, 3D scaffolds, and decellularized extracellular matrix composites, which significantly enhance exosome stability, retention, and targeted release at wound sites. Comparative insights between stem cell therapy and exosome therapy highlight the superior safety, scalability, and regulatory advantages of exosome-based approaches. We also summarize progress in exosome engineering, manufacturing, quality control, and ongoing clinical investigations, along with challenges related to standardization, dosage, and translational readiness. Collectively, this review provides a comprehensive mechanistic and translational framework that positions stem cell-derived exosomes as a next-generation, cell-free regenerative strategy with the potential to overcome current therapeutic limitations and redefine clinical management of diabetic wound healing. Full article

Pulmonary hypertension is a progressive and life-threatening disorder affecting approximately 1% of the global population, with increasing prevalence among elderly individuals. Although it most commonly arises as a complication of chronic cardiac or pulmonary diseases, it may also develop in otherwise healthy individuals exposed to chronic hypoxia at high altitude. In this setting, sustained alveolar hypoxia triggers pulmonary vasoconstriction and vascular remodeling, key processes driving the elevation of pulmonary arterial pressure and highlighting the critical role of environmental stressors in disease pathogenesis. In this review, we examine the molecular mechanisms underlying the hypoxia-pulmonary hypertension axis, focusing on the complex and interconnected signaling networks involving redox imbalance, PI3K–Akt signaling, Na⁺/H⁺ exchange, nitric oxide bioavailability, autophagy, mitochondrial dynamics and mitophagy, metabolic reprogramming, inflammation, adventitial remodeling with particular emphasis on pulmonary arterial adventitial fibroblasts, and erythropoietin signaling. We also discuss current knowledge gaps and emerging therapeutic opportunities that may arise from a deeper understanding of these pathways. Collectively, while many of the signaling mechanisms implicated in hypoxia-induced pulmonary hypertension offer therapeutic promise, none have yet proven fully translatable, underscoring the multifactorial and tightly integrated nature of this disease. Full article

Radiation cystitis (RC) is a clinically challenging and often progressive complication of pelvic radiotherapy, marked by urothelial injury, vascular dysfunction, chronic inflammation, and fibrotic remodeling. Early diagnosis remains elusive due to nonspecific symptoms and the absence of validated molecular tools. As a biofluid in direct contact with the irradiated bladder, urine offers a unique molecular window into RC pathogenesis. In this review, we synthesize the current landscape of urinary biomarkers associated with the acute, latent, and chronic phases of RC, including inflammatory cytokines, oxidative stress products, epithelial injury markers, extracellular vesicles, microRNAs, proteomic signatures, and metabolomic alterations. We also integrate emerging mechanistic insights such as DNA damage responses, ROS generation, mitochondrial dysfunction, urothelial barrier disruption, senescence-associated secretory phenotypes, hypoxia-driven vascular injury, and profibrotic TGF-β signaling, all of which contribute to the release of urinary analytes. By linking phase-specific molecular pathways with corresponding urinary signatures, we highlight opportunities to leverage urine-based measurements for early detection, risk stratification, severity assessment, and therapeutic monitoring. A deeper understanding of the molecular mechanisms shaping urinary biomarker profiles will be essential for advancing precision diagnostics and improving long-term outcomes for patients with radiation cystitis. Full article

Rheumatoid arthritis (RA) is frequently accompanied by depression, a comorbidity arising from the interplay of chronic systemic inflammation, neuroimmune activation, oxidative stress, and dysregulation of the gut–brain axis. Increasing evidence suggests that nanomedicine offers unique opportunities for the integrated management of RA-associated depression by enabling precise modulation of both peripheral inflammation and central nervous system (CNS) pathology. This review outlines the biological mechanisms linking RA and depression—including cytokine cascades, mitochondrial dysfunction, reactive oxygen species (ROS) accumulation, and microbial metabolite imbalance—and highlights recent progress in nanocarrier platforms capable of dual-site intervention. Liposomes, polymeric nanoparticles (NPs), exosomes, inorganic nanozymes, and emerging carbon-based nanomaterials have demonstrated the ability to target inflamed synovium, reprogram macrophage phenotypes, traverse the blood–brain barrier (BBB), suppress microglial overactivation, enhance neuroplasticity, and restore gut microbial homeostasis. Furthermore, stimulus-responsive nanoplatforms activated by ROS, pH, enzymes, or hypoxia provide spatiotemporally controlled drug release, thereby improving therapeutic precision. Finally, we discuss integrative designs such as dual-targeting nanomedicines, co-delivery systems, and microbiota-modulating nano-interventions, which offer promising strategies for the comprehensive treatment of RA-associated depression. This review aims to provide mechanistic insights and design principles to guide the development of next-generation nanomedicine for coordinated systemic-central modulation in RA comorbidity. Full article

Chronic diabetic wounds are often characterized by persistent hypoxia and poor healing outcomes, highlighting the need for regenerative grafts that not only promote tissue repair but also provide insights into the wound microenvironment. In this study, we introduce a novel strategy for diabetic ulcer treatment through the development of a structurally personalized skin graft. The graft is fabricated via 3D bioprinting of natural porcine skin extracellular matrix (psECM) and integrated with microsensors for oxygen monitoring. We established a porcine skin decellularization protocol that efficiently removed cellular components, while preserving the integrity of the ECM, as verified by DNA quantification and scanning electron microscopy. The resulting psECM bioink demonstrated rheological properties suitable for 3D printing, which depended on psECM concentration and exhibited temperature-responsive gelation behavior. Incorporation of LiNC-BuO oxygen microsensors into the bioink enabled real-time, non-invasive oxygen level monitoring within the printed constructs. Both in vitro and in vivo studies confirmed the cytocompatibility and low immunogenicity of the psECM-based grafts with embedded microsensors. Moreover, the 3D bioprinting technology enabled the manufacturing of grafts tailored to match individual wound geometries. The technological proof of concept presented herein for this multifunctional platform, which integrates the regenerative benefits of ECM scaffolds with advanced biosensing capabilities, represents a promising approach for enhancing future therapeutic outcomes in the management of diabetic ulcers. Full article

Background/Objectives: Chronic obstructive pulmonary disease (COPD) remains a major global health problem, affecting over 300 million people worldwide. Its high morbidity and mortality rates impose substantial psychosocial and financial burdens on patients and healthcare systems. In the emergency setting, managing acute exacerbations of COPD (AECOPD) poses a major clinical challenge, as these patients often present with multi-organ dysfunction secondary to hypoxia and hypercapnia. Identifying reliable prognostic biomarkers could improve early risk stratification, guide therapeutic decisions, and enhance patient outcomes. Methods: This multicenter, prospective, observational study aims to evaluate the prognostic significance of several novel biomarkers—resistin, club cell secretory protein 16 (CC16), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), S100β protein—alongside conventional markers such as N-terminal-pro–B-type-Natriuretic-Peptide (NT-proBNP), D-dimer, high-sensitivity troponin I (hs-cTnI), C-reactive protein (CRP), and procalcitonin in patients with AECOPD admitted to the Emergency Department (ED). Blood samples will be collected at admission. The novel biomarkers (resistin, CC16, IL-6, TNF-α, S100β) will be measured using standardized ELISA kits, while conventional biomarkers (NT-proBNP, troponin I, CRP, procalcitonin) will be analyzed using routine automated clinical laboratory methods. Correlations between biomarker levels, clinical and imaging data, severity scores (GCS, SOFA, CFS, Ottawa COPD Risk Scale, DECAF, BAP-65), and short-term outcomes (hospital discharge status and 28-day survival) will be assessed. The study has received approval from the Ethics Committee of the “Iuliu-Hatieganu” University of Medicine and Pharmacy, Cluj-Napoca, and all participating hospitals. Written informed consent will be obtained from all participants or their legal representatives. Results: This study protocol does not report results, as data collection and analysis are ongoing. Conclusions /Expected Impact: By identifying novel biomarkers with prognostic and pathophysiological relevance, this research aims to inform the development of early risk stratification tools and support future evidence-based approaches to the management of critically ill COPD patients in the ED. Full article

Adipose tissue is far more than a passive reservoir for surplus energy: it is an active metabolic and endocrine organ that senses nutrient availability and orchestrates systemic energy balance. When caloric intake chronically exceeds expenditure, adipocytes become engorged with lipids and exposed to metabolic, mechanical, and hypoxic stress. To adapt, they initiate a fibro-inflammatory response that may be protective in the short term. As this response becomes chronic, adipocytes lose their metabolic flexibility, acquire a maladaptive fibro-inflammatory phenotype, and contribute to the cascade of inflammation, insulin resistance, and metabolic disease that characterizes obesity. In this review, we dissect the cellular and molecular cues that trigger fibro-inflammation, from nutrient excess and mitochondrial stress to hypoxia and immunometabolic rewiring, and highlight how these processes reshape adipocyte identity and tissue homeostasis. Full article

Psoriasis is a chronic inflammatory skin disease driven by the IL-23/IL-17 axis and characterized by keratinocyte hyperproliferation, epidermal thickening, and immune infiltration. While immune cell-intrinsic roles of hypoxia-inducible factor-1α (HIF-1α) have been reported, the contribution of keratinocyte HIF-1α remains less clear. In this study, we investigated epithelial HIF function in murine models of skin inflammation using keratinocyte-specific HIF-1α knockout (K14-Cre Hif1a^fl/fl) mice. HIF-1α deficiency attenuated epidermal hyperplasia and type 3 inflammation in the imiquimod (IMQ)-induced psoriasiform model but had little effect in DNFB-induce contact hypersensitivity and MC903-induced atopic dermatitis model. Flow cytometry of draining lymph nodes revealed reduced frequencies of inflammatory cells including IL-17-producing γδ T cells in HIF-1α-deficient mice. In IMQ-treated skin, HIF-1α deficiency led to reduced Il17, Il23 and neutrophil-attracting chemokine transcript levels and diminished Ly6G⁺ neutrophil infiltration. These findings identify keratinocyte HIF-1α as a central regulator of psoriasiform inflammation and suggest that epithelial HIF signaling could be a potential therapeutic target for psoriasis. Full article

High-altitude exposure poses significant health challenges to mountaineers, military personnel, travelers, and indigenous residents. Altitude-related illnesses encompass acute conditions such as acute mountain sickness (AMS), high-altitude pulmonary edema (HAPE), and high-altitude cerebral edema (HACE), and chronic manifestations like chronic mountain sickness (CMS). Hypobaric hypoxia induces oxidative stress and inflammatory cascades, causing alterations in multiple organ systems through co-related amplification mechanisms. Therefore, this review aims to systematically discuss the injury mechanisms and comprehensive intervention strategies involved in high-altitude diseases. In summary, these pathologies involve key damage pathways: oxidative stress activates inflammatory pathways through NF-κB and NOD-like receptor thermal protein domain-associated protein 3 (NLRP3) inflammasomes; energy depletion impairs calcium homeostasis, leading to cellular calcium overload; mitochondrial dysfunction amplifies injury through mitochondrial permeability transition pore (mPTP) opening and apoptotic factor release. These mechanisms could be converged in organ-specific patterns—blood–brain barrier disruption in HACE, stress failure in HAPE, and right heart dysfunction in chronic exposure. Promising strategies include multi-level therapeutic approaches targeting oxygenation (supplemental oxygen, acetazolamide), specific pathway modulation (antioxidants, calcium channel blockers, HIF-1α regulators), and damage repair (glucocorticoids). Notably, functional foods show significant therapeutic potential: dietary nitrates (beetroot) enhance oxygen delivery, tea polyphenols and anthocyanins (black goji berry) provide antioxidant effects, and traditional herbal bioactives (astragaloside, ginsenosides) offer multi-targeted organ protection. Full article