Search Results (540)

Background/Objective: Early-onset neonatal sepsis (EOS), defined as infection occurring within the first 72 h after birth, remains a major contributor to neonatal morbidity and mortality worldwide. Although advances in perinatal care have improved overall outcomes, the diagnosis of EOS continues to be challenging. Clinical presentations are often nonspecific, laboratory confirmation is often delayed, and immune responses vary considerably among neonates. Expanding our understanding of the molecular mechanisms underlying EOS is essential in enhancing early detection, refining risk stratification, and guiding therapeutic strategies. This systematic review aims to synthesize the available information on the molecular pathways involved in EOS, focusing on pathogen-induced inflammation, systemic immune responses, sterile inflammatory processes, interactions between infectious and non-infectious pathways, as well as emerging molecular diagnostic approaches. Methods: A comprehensive review of original research articles and reviews published between January 2015 and January 2025 was conducted; studies were included based on their focus on human neonates and their analysis of molecular or immunological mechanisms relevant to EOS pathogenesis, immune dysregulation, or novel diagnostic strategies. Results: Pathogen-driven inflammation typically involves the activation of Toll-like receptors (TLRs), the recruitment of neutrophils, and the release of pro-inflammatory cytokines such as IL-6, IL-1β, and TNF-α, particularly in response to vertical transmission of organisms like Escherichia coli and Streptococcus agalactiae. Systemic inflammatory responses are marked by cytokine dysregulation, contributing to multi-organ dysfunction. Sterile inflammation, often initiated by hypoxia–reperfusion injury or intrauterine stress, amplifies susceptibility to sepsis. Interactions between immune, metabolic, and endothelial pathways further exacerbate tissue injury. Recent advances, including transcriptomic profiling, microRNA-based biomarkers, and immune checkpoint studies, offer promising strategies for earlier diagnosis and individualized therapeutic options. Conclusions: EOS arises from a complex interplay of infectious and sterile inflammatory mechanisms. A deeper molecular understanding holds promise for advancing correct diagnostics and targeted therapies, aiming to improve neonatal outcomes. Full article

The developmental processes of microglia follow a general pattern, from immature amoeboid (activated) cells to fully ramified (inactivated) surveilling microglia. However, little is known about the mechanisms controlling the transition of microglia from an activated to an inactivated state during brain development. Due to the complexity of microenvironmentally dynamic changes during neuronal differentiation, interactions between developing nerve cells and microglia might be involved in this process. Extracellular vesicles (EVs) are cell-released particles that serve as mediators of cellular crosstalk and regulation. Using neural progenitor cells (NPCs) and a long-term neuron culture system, we found that EVs derived from NPCs or developing neurons possessed differential capacity on the induction of microglial activation. The exposure of microglia to NPC- or immature neuron (DIV7)-derived EVs resulted in the higher expression of protein and mRNA of multiple inflammatory cytokines (e.g., TNF-α, IL-1β, and IL-6), when compared with mature neuron-derived EVs. Exploration of the intracellular signaling pathways revealed that MAPK signaling, IκBα phosphorylation/degradation, and NF-κB p65 nuclear translocation were strongly induced in microglia treated with NPC- or immature neuron-derived EVs. Using a pharmacological approach, we further demonstrate that Toll-like receptor (TLR) 7-mediated activation of NF-κB and MAPK signaling cascades contribute to EV-elicited microglial activation. Additionally, the application of conditioned media derived from microglia treated with NPC- or immature neuron-derived EVs is found to promote the survival of late-developing dopaminergic neurons. Thus, our results highlight a novel mechanism used by NPCs and developing neurons to modulate the developmental phases and functions of microglia through EV secretion. Full article

Post-traumatic stress disorder (PTSD) has traditionally been viewed as a psychiatric disorder of fear, memory, and emotional regulation. However, growing evidence implicates systemic and neuroinflammation as key contributors. Individuals with PTSD often exhibit elevated blood levels of pro-inflammatory cytokines such as IL-1β, IL-6, TNF-α, and C-reactive protein, indicating immune dysregulation. Dysfunctions in the hypothalamic–pituitary–adrenal (HPA) axis marked by reduced cortisol levels impair the body’s ability to regulate inflammation, allowing persistent immune activation. Circulating cytokines cross a weakened blood–brain barrier and activate microglia, which release additional inflammatory mediators. This neuroinflammatory loop can damage brain circuits critical to emotion processing including the hippocampus, amygdala, and prefrontal cortex, and disrupt neurotransmitter systems like serotonin and glutamate, potentially explaining PTSD symptoms such as hyperarousal and persistent fear memories. Rodent models of PTSD show similar inflammatory profiles, reinforcing the role of neuroinflammation in disease pathology. Bromo-epi-androsterone (BEA), a synthetic analog of dehydroepiandrosterone (DHEA), has shown potent anti-inflammatory effects in clinical trials, significantly reducing IL-1β, IL-6, and TNF-α. By modulating immune activity, BEA represents a promising candidate for mitigating neuroinflammation and its downstream effects in PTSD. These findings support the rationale for initiating clinical trials of BEA as a novel therapeutic intervention for PTSD. Full article

Objectives: Colorectal cancer (CRC) is a leading cause of cancer-related mortality, driven by chronic inflammation, gut microbiota dysbiosis, and complex tumor microenvironment interactions. Current therapies are limited by systemic toxicity and poor tumor accumulation. This study aimed to develop a ROS/enzyme dual-responsive oral drug delivery system, KGM-CUR/PSM microspheres, to achieve precise drug release in CRC and enhance tumor-specific drug accumulation, which leverages high ROS levels in CRC and the β-mannanase overexpression in colorectal tissues. Methods: In this study, we synthesized a ROS-responsive prodrug polymer (PSM) by conjugating polyethylene glycol monomethyl ether (mPEG) and mesalazine (MSL) via a thioether bond. CUR was then encapsulated into PSM using thin-film hydration to form tumor microenvironment-responsive micelles (CUR/PSM). Subsequently, konjac glucomannan (KGM) was employed to fabricate KGM-CUR/PSM microspheres, enabling targeted delivery for colorectal cancer therapy. The ROS/enzyme dual-response properties were confirmed through in vitro drug release studies. Cytotoxicity, cellular uptake, and cell migration were assessed in SW480 cells. In vivo efficacy was evaluated in AOM/DSS-induced CRC mice, monitoring tumor growth, inflammatory markers (TNF-α, IL-1β, IL-6, MPO), and gut microbiota composition. Results: In vitro drug release studies demonstrated that KGM-CUR/PSM microspheres exhibited ROS/enzyme-responsive release profiles. CUR/PSM micelles demonstrated significant anti-CRC efficacy in cytotoxicity assays, cellular uptake studies, and cell migration assays. In AOM/DSS-induced CRC mice, KGM-CUR/PSM microspheres significantly improved survival and inhibited CRC tumor growth, and effectively reduced the expression of inflammatory cytokines (TNF-α, IL-1β, IL-6) and myeloperoxidase (MPO). Histopathological and microbiological analyses revealed near-normal colon architecture and microbial diversity in the KGM-CUR/PSM group, confirming the system’s ability to disrupt the “inflammation-microbiota-tumor” axis. Conclusions: The KGM-CUR/PSM microspheres demonstrated a synergistic enhancement of anti-tumor efficacy by inducing apoptosis, alleviating inflammation, and modulating the intestinal microbiota, which offers a promising stimuli-responsive drug delivery system for future clinical treatment of CRC. Full article

Background: Increased IL-1β levels may promote carcinogenesis and metastasis by affecting tumor biology and the tumor microenvironment (TME). In this context, extracellular vesicles (EVs) play a key role in cell-to-cell communication, thus modulating the TME and immune response. Here, we aimed to test whether tumor-derived small EVs (TEVs) isolated from sensitive and osimertinib-resistant (OR) non-small-cell lung cancer (NSCLC) cells may promote EMT via fibronectin binding to α5β1 integrin as well as suppress the immune system and if these effects may be favored by IL-1β. Methods: TEVs were isolated from control, OR, and IL-1β-stimulated NSCLC cells. Expressions of fibronectin and PD-L1 were screened in TEVs and the mRNA levels of vimentin and SMAD3 were also assessed in cancer cells after TEV co-culturing. Furthermore, to detect the effect on immune cells, we co-cultured TEVs with lung cancer patients’ peripheral blood mononuclear cells (PBMCs). Results: TEVs were positive for fibronectin and the highest protein levels were found in TEVs obtained from the OR and IL-1β-stimulated cells. TEV-mediated activation of α5β1 signaling led to the upregulation of vimentin and SMAD3 mRNA in NSCLC cells and stimulated cell migration. EVs also increased PD-1, CTLA-4, FOXP3, TNF-α, IL-12, and INF-γ mRNA in lung cancer patients’ immune cells. Conclusions: Our findings indicate that TEVs promote EMT in NSCLC cells by the activation of the fibronectin–α5β1 axis. Finally, IL-1β stimulation induces TEV release with biological properties similar to OR TEVs, thus leading to cancer invasion and immune suppression and suggesting that inflammation can promote tumor spreading. Full article

Background/Objectives: The aim of this study was to investigate the role and potential mechanism of deer antler peptides (DAP) in D-galactose (D-gal)-induced brain injury. Methods: In the in vivo study, C57BL/6J mice were intraperitoneally injected with 400 mg/kg D-gal and gavaged with DAP (50 and 200 mg/kg) for 5 weeks. In vitro studies, D-gal (30 μg/mL) induced senescent BV2 cells were used for further research. Results: DAP increased the expression of BDNF and VEGF in the brain tissue of aging mice, reduced the levels of oxidative stress and inflammatory factors in serum, and decreased the pathological damage of brain tissue. In vitro, DAP promoted the proliferation of D-gal-induced senescent BV2 cells, reduced ROS level, and inhibited the release of IL-1β, IL-6 and TNF-α. In addition, DAP significantly reduced the protein expressions of TLR4 and MyD88, and inhibited the phosphorylation of NF-κB. Conclusions: DAP can inhibit the TLR4/MyD88/NF-κB signaling pathway, reduce oxidative stress and inflammation, and promote neovascularization. This indicates the therapeutic potential of DAP as a natural bioactive substance in preventing aging-related brain injury. Full article

Traumatic brain injury (TBI) leads to severe neurological dysfunction, disability, and even death. Surgical intervention and neurorehabilitation represent the current clinical management methods, yet there remains no effective treatment for recovery after TBI. Post-traumatic hyperinflammation and vascular injury are the key therapeutic challenges. Therefore, a novel-designed multifunctional HT/SAA/HSYA hydrogel based on hyaluronic acid (HA) co-loaded with salvianolic acid A (SAA) and hydroxysafflor yellow A (HSYA) was developed in order to simultaneously target inflammation and vascular injury, addressing key pathological processes in TBI. The HT hydrogel was formed through covalent cross-linking of tyramine-modified HA catalyzed by horseradish peroxidase (HRP). Results demonstrated that the HT hydrogel possesses a porous structure, sustained release capabilities of loaded drugs, suitable biodegradability, and excellent biocompatibility both in vitro and in vivo. WB, immunofluorescence staining, and PCR results revealed that SAA and HSYA significantly reduced the expression level of pro-inflammatory cytokines (IL-1β and TNF-α) and inhibited M1 macrophage polarization through the suppression of the TLR4/NF-κB inflammatory pathway. In vivo experiments confirmed that the HT/SAA/HSYA hydrogel exhibited remarkable pro-angiogenic effects, as evidenced by increased expression of CD31 and α-SMA. Finally, H&E staining showed that the HT/SAA/HSYA hydrogel effectively reduced the lesion volume in a mouse TBI model, and demonstrated more pronounced effects in promoting brain repair at the injury site, compared to the control and single-drug-loaded hydrogel groups. In conclusion, the HT hydrogel co-loaded with SAA and HSYA demonstrates excellent anti-inflammatory and pro-angiogenic effects, offering a promising therapeutic approach for brain repair following TBI. Full article

For centuries, researchers have been fascinated by the composition of scorpion venom and its local and systemic effects on humans. During a sting, scorpions inject peptides and proteins that can affect immune cells and neurons. While the immune and nervous systems have been studied independently in the context of scorpion stings, here we reveal part of the mechanism by which Tityus serrulatus venom induces hyperalgesia in mice. Through behavioral, immune, imaging assays, and mice genetics, we demonstrate evidence of neuroimmune crosstalk during scorpion stings. Tityus serrulatus venom induced mechanical and thermal hyperalgesia in a dose-dependent manner, as well as overt pain-like behavior. The venom directly activated dorsal root ganglia neurons and increased the recruitment of macrophages and neutrophils, releasing pro-inflammatory cytokines TNF-α and IL-1β. Blocking TRPV1⁺ neurons, TNF-α, IL-1β, and NFκB reduced the mechanical and thermal hyperalgesia, overt pain-like behavior, and the migration of macrophages and neutrophils induced by Tityus serrulatus venom. Collectively, Tityus serrulatus venom targets primary afferent nociceptive TRPV1⁺ neurons to induce hyperalgesia through the recruitment of macrophages and neutrophils and the release of pro-inflammatory cytokines. Full article

Background/Objectives: To study the efficacy and pharmacological mechanism of the dual-target liposome complex AD808 in the treatment of Alzheimer’s disease. Methods: Using APP/PS1 mouse models, the therapeutic efficacy and pharmacological mechanism of AD808 on Alzheimer’s disease were studied through water maze tests, brain tissue staining, immunofluorescence, and ELISA for inflammatory and neurotrophic factors. Results: AD808 exhibited significant pharmacodynamic effects in improving behavioral and cognitive abilities (70% reduction in escape latency) and repairing damaged nerve cells (90% reduction in Aβ plaque) in Alzheimer’s disease mice. The efficacy of the liposome complex AD808 was significantly better than that of ST707 or gh625-Zn₇MT3 alone. AD808 significantly reduced brain inflammation (57.3% and 61.5% reductions in TNF-α and IL-1β, respectively) in AD (Alzheimer’s disease) mouse models and promoted the upregulation of neurotrophic factors and nerve growth factors (142.8% increase in BDNF, 275.9% in GDNF, and 111.3% in NGF-1) in brain homogenates. By activating the PI3K/AKT signaling pathway in brain microglia, AD808 upregulated TREM2 protein expression and removed Aβ amyloid plaques in the brain. Additionally, it promoted the transition of microglia from the pro-inflammatory M1 phenotype to the anti-inflammatory M2 phenotype, regulated the M1/M2 balance, released anti-inflammatory and neurotrophic factors, reduced chronic inflammation, and enhanced neurological repair. Based on these results, the potential pharmacological mechanism of AD808 against Alzheimer’s disease was proposed. Conclusions: As a dual-target liposome complex, AD808 has shown promising therapeutic potential in the treatment of Alzheimer’s disease, providing a new strategy for innovative drug development. Full article

Wound healing is a complex biological process that benefits from advanced biomaterials capable of modulating inflammation and promoting tissue regeneration. In this study, cerium oxide nanoparticles (CeO₂NPs) were green-synthesized using Hemerocallis citrina extract, which served as both a reducing and stabilizing agent. The CeO₂NPs exhibited a spherical morphology, a face-centered cubic crystalline structure, and an average size of 9.39 nm, as confirmed by UV-Vis spectroscopy, FTIR, XRD, and TEM analyses. These nanoparticles demonstrated no cytotoxicity and promoted fibroblast migration, while significantly suppressing the production of inflammatory mediators (TNF-α, IL-6, iNOS, NO, and ROS) in LPS-stimulated RAW264.7 macrophages. Gene expression analysis indicated M2 macrophage polarization, with upregulation of Arg-1, IL-10, IL-4, and TGF-β. Aligned polycaprolactone/polylactic acid (PCL/PLA) nanofibers embedded with CeO₂NPs were fabricated using electrospinning. The composite nanofibers exhibited desirable physicochemical properties, including porosity, mechanical strength, swelling behavior, and sustained cerium ions release. In a rat full-thickness wound model, the CeO₂ nanofiber-treated group showed a 22% enhancement in wound closure compared to the control on day 11. Histological evaluation revealed reduced inflammation, enhanced granulation tissue, neovascularization, and increased collagen deposition. These results highlight the therapeutic potential of CeO₂-incorporated nanofiber scaffolds for accelerated wound repair and inflammation modulation. Full article

Recent advances in cannabinoid-based therapies identified the natural CB2 receptor agonist β-caryophyllene (BCP) as a promising anti-inflammatory and neuroprotective agent. To further explore its therapeutic potential on the management of neurodegenerative disorders, in the present study we investigated the ability of BCP to prevent neuroinflammation and promote neuroprotection by using both in vitro and ex vivo models of β-amyloid induced neurotoxicity. Our data showed that BCP significantly protected human microglial HMC3 cells from Aβ_25-35-induced cytotoxicity, reducing the release of pro-inflammatory cytokines (TNF-α, IL-6) while enhancing IL-10 secretion. These effects were associated with a reduced activation of the NF-κB pathway, which emerged as a central mediator of BCP action. Notably, the use of CB2R- or PPARγ-selective antagonists revealed that the observed NF-κB inhibition by BCP may involve the coordinated activation of both canonical (e.g., CB2R) and non-canonical (e.g., PPARγ) receptors. Moreover, BCP restored the expression of SIRT1, PGC-1α, and BDNF, indicating the involvement of neurotrophic pathways. Clear neuroprotective properties for BCP have been highlighted in Aβ_1-42-treated brain slice preparations, where BCP demonstrated the rescue of both the amyloid-dependent depression of BDNF expression and long-term synaptic potentiation (LTP) impairment. Overall, our results suggest that BCP constitutes an attractive natural molecule for the treatment of Aβ-induced neuroinflammation and synaptic dysfunction, warranting further exploration for its clinical application. Full article

Multiple lines of evidence suggest that endothelial dysfunction is a key player in the pathogenesis of COVID-19, with cytokine storm as one of the main primary causes. Among the mechanisms underlying endothelial damage, clinical findings identify alterations in arginine metabolism, as patients with severe COVID-19 exhibit lower levels of nitric oxide synthase (eNOS) and upregulated arginase. In this study, we investigated, in human endothelial cells (HUVECs), the effect of conditioned medium from macrophages activated with SARS-CoV-2 Spike protein (CM_S1) on arginine metabolism. The results indicate that CM_S1 causes a marked decrease in eNOS and an increase in arginase, along with a greater intracellular arginine content and the induction of the CAT2 transporter. These effects are ascribable to the inflammatory mediators released by macrophages in CM_S1, mainly TNFα and IL-1β. Since infliximab, an antibody targeting TNFα, and baricitinib, an inhibitor of the JAK/STAT pathway, correct the observed imbalance between eNOS and arginase, our findings suggest the potential efficacy of a combined therapy to counteract endothelial dysfunction in COVID-19. Full article

Gastric ulcer is a concerning condition that affects numerous individuals globally. Omeprazole (OMP), a well-known drug for treating stomach ulcers, has been associated with several adverse effects and limited solubility. The study aimed to create an omeprazole nanosuspension (OMP-NS) with improved solubility and bioavailability. Additionally, the study investigated the potential therapeutic effects of OMP-NS on ethanol-induced gastric injury in rats, comparing it to traditional OMP therapy to identify novel therapeutic alternatives. The characterization of the OMP-NS was assessed using DLS, TEM, XRD, FTIR, UV spectrophotometric analysis, in vitro release studies, and entrapment efficiency (EE) assays. A total of 24 male Wistar albino rats (weighing 150–200 g, aged 8–10 weeks) were randomly divided into four groups (six rats/group). Gastric injury was induced using absolute ethanol (5 mL/kg), followed by oral administration of either OMP or OMP-NS (20 mg/kg) for 7 days. Data were analyzed using one-way ANOVA accompanied by the Bonferroni post hoc test or the Kruskal–Wallis test, based on data distribution, with significance set at p < 0.05. The OMP-NS demonstrated a Z-average diameter of 216.1 nm, a polydispersity index of 0.2, and a zeta potential of −19.6 mV. The particles were predominantly spherical with an average size of 67.28 nm. In vitro release studies showed 97.78% release at 8 h, with an EE% of 96.97%. Ethanol-induced gastric ulcers were associated with oxidative stress, characterized by elevated levels of NADPH, ROS, MDA, and NO, while the level of SOD was reduced. It was accompanied by increased inflammatory markers HMGB1, which subsequently increased TLR-2, MyD88, NF-κBp56, NLRP3, TNF-α, IL-1β, and IL-6 levels; conversely, a significant decrease in Nrf2/PPAR-γ/SIRT1 levels was observed. In contrast, OMP-NS administration significantly reduced oxidative stress and inflammatory markers, restored SOD activity, and upregulated protective pathways Nrf2/PPAR-γ/SIRT1 more effectively than conventional OMP therapy. In conclusion, OMP-NS represents a promising therapeutic strategy with notable anti-inflammatory and anti-ulcerogenic effects in ethanol-induced gastric ulcers. Full article

Background: Sepsis-induced acute lung injury (ALI) is a serious disease constituting a heavy burden on society due to high mortality and morbidity. Inflammation and oxidative stress constitute key pathological mechanisms in ALI caused by sepsis. LL-37 can improve the survival of septic mice. Nevertheless, its function and underlying mechanism in sepsis-evoked ALI is elusive. Methods: The human A549 alveolar epithelial cell line was treated with LL-37 or ZBP1 recombinant vector under LPS exposure. Then, the effects on cell oxidative stress injury, inflammatory response, and autophagy were analyzed. RNA-seq analysis was performed to detect the differentially expressed genes (DEGs) between the LPS and LPS/LL-37 groups. Furthermore, the effects of LL-37 on cecal ligation and the puncture (CLP)-constructed ALI model were explored. Results: LL-37 attenuated LPS-evoked oxidative injury in human alveolar epithelial cells by increasing cell viability and suppressing ROS, malondialdehyde, and lactate dehydrogenase levels and apoptosis. Moreover, LPS-induced releases of pro-inflammatory IL-18, TNF-α, and IL-1β were suppressed by LL-37. Furthermore, LPS’s impairment of autophagy was reversed by LL-37. RNA-seq analysis substantiated 1350 differentially expressed genes between the LPS and LPS/LL-37 groups. Among them was ZBP1, a significantly down-regulated gene with the largest fold change. Moreover, LL-37 suppressed LPS-increased ZBP1 expression. Importantly, ZBP1 elevation restrained LL-37-induced autophagy in LPS-treated cells and abrogated LL-37-mediated protection against LPS-evoked oxidative injury and inflammation. LL-37 ameliorated abnormal histopathological changes, tissue edema, the lung injury score, oxygenation index (PaO2/FiO2), and glycemia contents in the CLP-constructed ALI model, which were offset through ZBP1 elevation via its activator CBL0137. Additionally, LL-37 suppressed inflammation and oxidative stress in lung tissues, concomitant with autophagy elevation and ZBP1 down-regulation. Conclusions: LL-37 may alleviate the progression of sepsis-evoked ALI by attenuating pulmonary epithelial cell oxidative injury and inflammatory response via ZBP1-mediated autophagy activation, indicating a promising approach for the therapy of ALI patients. Full article

Controlling low ambient temperatures and ammonia levels is critical for effective environmental management in poultry houses during winter, as both represent persistent stressors affecting bird health and productivity. However, evidence regarding their combined long-term effects on the physiological responses of laying hens remains limited. In this study, 576 eighteen-week-old Hy-Line Brown hens were randomly assigned to six treatments (8 replicates with 12 birds per replicate each treatment) and housed in environmentally controlled chambers for 20 weeks: T1 (8 °C, ≤5 ppm ammonia), T2 (8 °C, 20 ppm ammonia), T3 (8 °C, 45 ppm ammonia), T4 (20 °C, ≤5 ppm ammonia; control), T5 (20 °C, 20 ppm ammonia), and T6 (20 °C, 45 ppm ammonia). Plasma samples were collected at 22, 26, 30, 34, and 38 weeks to evaluate physiological stress biomarkers (corticosterone, CORT; total antioxidant capacity, T-AOC), immunoglobulins (IgG, IgM, and IgA), and reproductive hormones (luteinizing hormone, LH; follicle-stimulating hormone, FSH; estradiol, E2). At 38 weeks, hypothalamus, pituitary, and spleen tissues were collected to assess the relative mRNA expression of gonadotropin-releasing hormone (GnRH), FSH, tumor necrosis factor-α (TNF-α), and interleukins (IL-1β, IL-6, and IL-10). Results showed that both cold and ammonia stress reduced antioxidant capacity, disrupted immune homeostasis, and altered reproductive hormone profiles. Cold exposure induced acute immunoendocrine alterations with partial physiological adaptation over time, whereas ammonia exerted progressive and cumulative damage, including elevated immunoglobulins (IgG and IgM) and downregulation of GnRH and FSH expression. Combined exposure significantly upregulated TNF-α and IL-1β expression, suggesting a synergistic inflammatory response. These results highlight complex, parameter-specific interactions between cold and ammonia stressors, emphasizing the need for targeted environmental strategies. Stage-specific interventions—thermal regulation in early laying and ammonia control in later phases—are recommended to safeguard hen health and optimize productivity under winter conditions. Full article