Search Results (1,112)

The extensive diversification of flower shape and organs underpins the adaptive success of angiosperms. Despite substantial knowledge of the molecular mechanisms controlling flower induction and development, few studies have quantified the variability in floral traits within species or explored their correlation with other reproductive traits. In cultivated tomato (Solanum lycopersicum L.), human selection has driven fruit diversification in terms of size and shape. In the present study, 48 landraces representing tomato diversity in reproduction-related characteristics were phenotyped for 18 flower structural or dimensional traits. Flower traits exhibited lower coefficients of variation compared to other reproductive traits, though organ numbers showed high heritability values. Flower organ number and size were tightly correlated, but the correlation between dimensional traits was weaker. This likely reflects the selective pressures on pistil traits during domestication, including specific mutations affecting carpel number and ovary morphology. While ovary and fruit size were positively correlated, no relationship was found between ovule and seed size, suggesting that genes related to seed size generally act after fruit set. The collection was genotyped at the Fasciated (Fas) locus, and 13 floral traits were significantly different in fas mutants. The phenotypic variability described in this study could help breeders select for more fertile flowers and assist reproductive biologists in linking genes to flower development. Full article

Low-carbon and highly printable cementitious materials are crucial for the practical application of extrusion-based three-dimensional concrete printing (3DCP). This study develops and optimizes a one-part alkali-activated concrete suitable for 3D printing through an integrated experimental and evaluation approach. An orthogonal experimental design was employed to investigate the effects of precursor ratio (ground granulated blast-furnace slag, GGBFS, to fly ash, FA), water-to-binder ratio, activator dosage, and retarder content on fresh-state properties, rheological behavior, setting characteristics, and mechanical performance. The optimal mixture was determined using the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) multi-criteria decision method. The mixtures exhibited suitable rheology, with a yield stress of 90–141 Pa and a plastic viscosity of 3.5–7.2 Pa·s, a setting time of 40–96 min, and mechanical performance with compressive and flexural strengths of 29–71 MPa and 4.2–6.9 MPa, respectively. The optimal mixture provided a 95-min printing open time and an acceptable pumping pressure of 1.77 MPa, while full-scale tests confirmed stable extrusion and good print quality. Furthermore, within the defined cradle-to-gate, materials-stage boundary and the adopted inventory factors, the optimized alkali-activated mixture exhibited an embodied CO₂ emission of 0.113 kg CO₂/L, which is approximately 61% lower than that of the reference cement-based printable mixture. The proposed approach provides a systematic framework for designing low-carbon, high-performance one-part alkali-activated materials for extrusion-based 3D concrete printing applications. Full article

The widespread occurrence of emerging mycotoxins (EMs) produced by Fusarium, Aspergillus, and Penicillium species has raised increasing concerns regarding food and feed safety. Mitigation strategies currently applied to control regulated mycotoxins in feed may also be effective in reducing contamination by EMs. This study comparatively evaluated the in vitro adsorption efficacy of two leonardites, eight natural smectites, and two modified clays (organoclays) against EMs produced by Fusarium, Aspergillus, and Penicillium spp. All materials were tested at two inclusion levels (0.1 and 0.5% w/v) under two pH conditions (pH 3 and 7), simulating the gastrointestinal environment of monogastric animals. Adsorption performance was strongly influenced by mycotoxin chemistry, adsorbent type, inclusion rate, and medium pH. Organoclays exhibited the highest and most consistent efficacy, achieving near-complete adsorption of beauvericin (BEA) and enniatins (ENNs) (>98–100%) at 0.1% (w/v), as well as high removal of mycophenolic acid (MYC. A.) and citrinin (CIT) (>90%) across both pH conditions. Natural smectites showed high but more selective adsorption, removing >90% of BEA and ENNs at low inclusion rates, while displaying limited efficacy toward fusaric acid (FA) and patulin (PAT). Leonardites demonstrated intermediate and material-dependent performance; leonardite L1 adsorbed approximately 90% of BEA at 0.1% (w/v), whereas ENN adsorption ranged from ~36% to 80% at the same inclusion rate and exceeded 90% only at higher dosages. None of the tested materials effectively adsorbed patulin (PAT) at pH 7; however, at pH 3, four smectites exhibited partial adsorption, and one trioctahedral smectite achieved more than 90% PAT adsorption under acidic conditions. Overall, organoclays displayed the broadest adsorption spectrum across structurally diverse mycotoxins, while smectites exhibited high selectivity driven by surface charge density and interlayer interactions. Leonardite-based materials showed moderate but highly variable adsorption performance, likely influenced by heterogeneity in humic functional groups and physicochemical properties. These findings highlight the need for tailored adsorbent selection or combined mitigation strategies to achieve effective mycotoxin control in the animal feed industry. Full article

Soybean seed quality is defined by an inverse relationship between oil and protein content. Understanding the spatiotemporal regulation of this trade-off is crucial for breeding. This study aims to dissect the transcriptomic networks governing carbon and nitrogen partitioning during seed development. Here, transcriptomic and co-expression network analyses were performed on cotyledon and seedcoat tissues of high-protein (HP) and low-protein (LP) soybean cultivars across three seed developmental stages. We identified 4910 HP/LP-specific differentially expressed genes (DEGs), with striking transcriptional alterations in the early developmental stage. Notably, some important DEGs were enriched in carbon/lipid metabolism, protein folding, and hormone/circadian signaling pathways, among which key gene families (e.g., OLEs, SWEETs, HSPs), core regulators (e.g., LACS, L1L, ABF1), and QTL-localized candidate genes (e.g., FA9) were characterized. Mechanistically, C/VIF1-mediated post-translational inhibition of CWINV1 may restrict carbon flux to oil synthesis in HP seeds; upstream circadian/hormone signaling and L1L-sHSPs jointly promote protein deposition, uncoupling the oil–protein trade-off and enabling HP trait formation. In contrast, LP cultivars upregulated SWEETs, OLEs, and LTPs to facilitate high carbon flux into lipid biosynthesis and storage. These findings provide valuable genetic targets for precision breeding programs aimed at optimizing resource allocation. Full article

Chronic alcohol exposure disrupts blood–brain barrier (BBB) integrity and promotes neuroinflammation, with P2X7 receptor (P2X7R) signaling playing a critical role. Our prior work in male mice linked P2X7R inhibition to reduced extracellular adenosine triphosphate (eATP) release, modulated extracellular vesicle (EV) cargo, and attenuated neuroinflammation in chronic intermittent ethanol (CIE)-exposed mice. However, sex-specific roles of P2X7R signaling and EV-mediated mechanisms in alcohol-induced neuroinflammation remain unclear. Male and female mice were exposed to ethanol vapor for three weeks and treated with Brilliant Blue G (BBG), a P2X7R inhibitor. Compared to their respective CIE-unexposed controls, brain gene expression of tumor necrosis factor–α (Tnf-α), interleukin-1 beta (Il-1b), interleukin-6 (Il-6), monocyte chemoattractant protein-1 (Mcp-1), and Fas ligand (Fasl) significantly increased in CIE-exposed males, while only Il-1b increased in females. P2X7R inhibition significantly reduced these cytokines. Pericyte immunostaining was decreased by CIE (indicating BBB injury) in male mice only and was restored by P2X7R inhibition with no difference between groups in females. Occludin staining (another BBB marker) did not differ between the treatment groups in male and female animals. Circulating cytokines (Macrophage inflammatory protein-1 alpha (MIP-1α), tumor necrosis factor–α (TNF-α), interleukin-1 beta (IL-1β), and interleukin-27 subunit p28/interleukin-30 (IL-27p28/IL-30) were significantly elevated in CIE-exposed males but not in females, with BBG treatment reducing cytokines in males. Circulating eATP, P2X7Rs, P-glycoprotein (P-gp), EVs, and EV-mtDNA, which we identified in our previous study, were increased in both sexes and partially decreased by P2X7R blockade. Spatial memory was impaired by CIE exposure in males but not females, and this deficit was reversed by BBG treatment. Our findings reveal sex differences in CIE-induced circulating cytokines, neuroinflammation, and memory impairment, with a stronger response in males. However, other markers of cell injury associated with CIE exposure were upregulated in both sexes; P2X7R inhibition effectively mitigated these effects, highlighting the functional relevance of targeting the P2X7R in alcohol-induced injury. Full article

Background/Objectives: Osmotic demyelination syndrome (ODS) causes marked myelin loss with relative axonal preservation. We used diffusion tensor imaging (DTI) to longitudinally assess white matter (WM) changes, hypothesizing that radial diffusivity (RD) would show dynamic recovery alongside clinical improvement. Methods: A 40-year-old woman with ODS and five age-matched female controls underwent DTI at 7 weeks and 6 months post-onset. Metrics were extracted from 27 WM tract categories using atlas-based regions of interest. Lesions were defined by directional dual thresholds (RD_d ≥ 2.0, axial diffusivity [AD] ≤ −2.0, or fractional anisotropy [FA] ≤ −2.0) and confirmed using the Crawford–Howell test with Benjamini–Hochberg FDR correction (q ≤ 0.05). Longitudinal percent change (Δ%) was compared using the Friedman test with Bonferroni-corrected Wilcoxon post hoc tests (α = 0.017). Results: Serum sodium increased from 126 to 138 mmol/L within 24 h, followed by a severe neurological deficit; near-complete recovery by 6 months. At 7 weeks, RD-defined lesions were detected in 10/27 tracts (37.0%)—1/6 brainstem-related and 9/21 non-brainstem—indicating widespread myelin-predominant injury. No AD- or FA-based lesions met criteria, although AD increase in the cingulate gyrus was significant. From 7 weeks to 6 months, the mean Δ% was −0.40 ± 9.38% (AD), −4.73 ± 9.73% (RD), and +7.94 ± 7.53% (FA). Changes differed across metrics (χ²(2) = 24.07, p = 5.92 × 10⁻⁶), with greater RD and FA changes than AD. Conclusions: Early RD-predominant abnormalities preceded RD reduction and FA increase during recovery, consistent with restoration of myelin-related microstructure. Larger studies are warranted. Full article

Persistent corpus luteum (PCL) and ovarian quiescence (OQ) are key manifestations of ovarian dysfunction (OD) that lead to reduced reproductive capacity in beef cattle, posing a serious challenge to the industry. Anthocyanins (ACNs) are known for their antioxidant properties. This study aimed to investigate the regulatory effects of ACNs on PCL and OQ and to explore the underlying mechanisms. Forty-eight beef cows diagnosed with both OQ and PCL were selected and continuously fed ACNs for 60 days. The results showed that the regulatory effects of ACNs were dose-dependent. A high dose of ACNs (ACNH) significantly increased the number of large follicles and reduced the occurrence of PCL. ACNH treatment significantly decreased serum progesterone (P4) levels and increased estradiol (E2) levels. Furthermore, ACNH reduced microbial diversity in OD cows but significantly increased the abundance of Patescibacteria, Actinobacteriota, Proteobacteria, and Chloroflexi, while decreasing the abundance of Desulfobactera, indicating that ACNs may affect ovarian function by regulating the gut microbial environment. In an ovarian granulosa cell model of oxidative damage, ACN intervention could reduce oxidative stress levels and mitigate oxidative damage. ACNs downregulated various pro-apoptotic genes, such as P53, Fas, and Bax, while upregulating anti-apoptotic genes Bcl-2 and Bcl-xL, suggesting that ACNs significantly inhibit cell apoptosis. To conclude, these results demonstrate that ACNs improve the ovarian function of beef cows by regulating gut microbiota and reducing oxidative stress-induced apoptosis in ovarian granulosa cells, thereby enhancing the reproductive capacity of beef cattle that show reproductive disorders. These findings provide a theoretical basis for the application of ACNs in the cattle industry and showcase their potential value as natural antioxidants. Full article

Obesity is well-known as a major risk factor for metabolic disorders, and natural compounds are being explored as alternatives to conventional therapies. While Centella asiatica is well known for its medicinal and dietary benefits, the biological activities of Giant Centella asiatica (GCA), especially when extracted with mineral-rich lava seawater, remain poorly characterized. This study aimed to evaluate the anti-adipogenic and lipid-metabolism-regulating effects of a novel GCA extract (GCA-LS-90) and its ability to stimulate GLP-1 secretion in vitro. GCA-LS-90 significantly inhibited lipid accumulation in 3T3-L1 adipocytes by up to 24.3% at 200 µg/mL (p < 0.001). It downregulated adipogenic transcription factors (C/EBPβ, C/EBPα, PPARγ) and lipogenic regulators (SREBP1c, FAS, G6PD, ME), while upregulating KLF2 (all p < 0.001). Western blotting confirmed reduced SREBP1c and SREBP2 protein expression, increased phosphorylation of AMPKα/ACC, and enhanced HSL activity (p < 0.05–0.001). In STC-1 cells, GCA-LS-90 increased GLP-1 secretion (53.5 pmol/L at 90 µg/mL vs. 41.3 pmol/L in control, p < 0.001). The major compounds, 3,5- and 4,5-di-O-caffeoylquinic acids, reproduced these effects. In conclusion, GCA-LS-90 modulated adipogenesis-, lipid-metabolism-, and GLP-1 secretion-related pathways in vitro, suggesting its potential as a functional ingredient for obesity management. Further in vivo studies are needed to confirm efficacy and translational relevance. Full article

Elderberry (Sambucus nigra L.) and linden (Tilia cordata Mill.) flower extracts are known for their pro-healthy properties. Various extraction methods, both conventional (Soxhlet) and advanced (ultrasound assisted extraction, UAE, accelerated solvent extraction, ASE, and matrix solid phase dispersion, MSPD), were applied to obtain ethanol–water extracts from the plants. The biological profiles, the total polyphenol content (TPC) and total flavonoid content (TFC) in the extracts were determined spectrophotometrically. Almost 40 compounds were identified in extracts by means of HPLC-MS/MS. The contents of the chosen phenolic acids (chlorogenic, p-coumaric, protocatechuic, and gallic) and flavonoids (rutin, catechin, quercetin, kaempferol, apigenin, and naringenin) were determined by HPLC-DAD. It was observed that the elderflower extracts contained higher levels of the compounds investigated than did the linden extracts. Chlorogenic acid was the main phenolic acid in the majority of extracts form the elderberry flower, whereas in the linden extracts, it was protocatechuic acid. Nevertheless, rutin was the main component of both plant extracts. The cytotoxicity of the elderberry and linden flower extracts against VERO, FaDu, H1HeLa, and RKO cell lines were subsequently examined. The elderflower extracts exerted no cytotoxicity, whereas linden extracts showed selective cytotoxicity against FaDu and RKO cells with CC₅₀ of 54.35 and 46.27 µg/mL, respectively. The antiviral potential of the extracts against HHV-1, CVB3, and HRV14 were also examined. The results demonstrate antiviral activity against HHV-1, particularly for linden flower extract in concentration of 62.5 µg/mL. Full article

The rising environmental burden of Portland cement production has intensified the demand for eco-friendly binders that support sustainable construction. This study investigates the development and performance of eco-friendly self-compacting geopolymer concrete (SCGC) produced from industrial by-products, including fly ash (FA), ground granulated blast furnace slag (GGBFS), silica fume (SF), metakaolin (MK), and glass waste powder (GWP). Twenty-one binder formulations were evaluated for fresh-state workability, mechanical performance, durability, and microstructural characteristics under different curing regimes. Fresh properties were assessed using slump flow, V-funnel, L-box, and J-ring tests, while hardened-state evaluations included compressive and flexural strength, Young’s modulus, and water absorption. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis were performed on selected mixes to examine microstructural features and crystalline phase development. Results highlight a strong dependency of SCGC performance on binder composition and curing conditions. Mixes rich in GGBFS and SF demonstrated superior mechanical and durability performance, achieving compressive strengths of up to 102.4 MPa under water curing and 107.6 MPa under heat curing, along with negligible water absorption, reflecting a dense and well-developed gel matrix. SEM micrographs confirmed homogeneous, compact microstructures in high-performing mixes, while XRD analysis revealed broad amorphous humps indicative of well-formed N-A-S-H and C-A-S-H gel phases with minimal crystalline residues. In contrast, FA-dominant mixes displayed delayed strength development, and MK-GWP-rich systems exhibited higher porosity and reduced strength. This study underscores the significance of precursor synergy, optimized curing strategies, and microstructural refinement in tailoring SCGC for high-performance, durable, and low-carbon applications in sustainable construction with values ranged from 38.64 GPa (Mix 21) to 25.04 GPa (Mix 19) at 28 days. Stiffer mixes corresponded to denser matrices containing GGBFS and silica fume, whereas lower values were linked to weaker bonding and higher porosity. Full article

Advances in multimodal therapy for high-risk neuroblastomas (NBs) have plateaued, prompting therapeutic initiatives to harness the immune system. NBs, however, are immunologically “cold” and a significant challenge to immunotherapy. Here, in a Jurkat lymphocyte cytotoxicity model, we describe an antigen-independent, cell-mediated mechanism for eliminating NB cells, first detected in PMA-activated low pcDNA-SH-SY5Y and high TrkAIII-SH-SY5Y TrkAIII-expressing cells, which are resistant to Jurkat elimination under normal conditions. Characterization of this mechanism through live cell imaging, adhesion assays, RT-PCR, Western blotting and indirect IF, employing a variety of inhibitors, indicates that it initiates with PMA-induced NB cell CCL2 expression. This results in CCL2 promotion of Jurkat CCR2b expression, CCL2/CCR2b-mediated Jurkat LFA-1 activation and the formation of cytotoxic lipid-raft LFA1/ICAM-1 immune synapses, through which Jurkat m-TRAIL combines with PMA-enhanced NB cell DR5/TRAIL-R2 expression to induce NB cell apoptosis. This mechanism is enhanced by the NB-associated oncoprotein TrkAIII through Shp/Src-regulated c-FLIP sequester and is PD-L1/PD-1-independent and resistant to osteoprotegerin. It eliminates both non-MYCN-amplified (SH-SY5Y and SK-N-SH) and MYCN-amplified (SMS-KCNR) NB cells that exhibit PMA-inducible CCL2 expression but not MYCN-amplified NB cells (IMR-32 and NB-1) that exhibit CCL2 repression, and is offset by reciprocal NB cell-induced Fas-mediated Jurkat cell apoptosis. These findings form a solid foundation for further pre-clinical development aimed at identifying clinically relevant physiological immune cell equivalents and alternative PKC activators, with the ultimate goal of translating this mechanism into an effective immune-therapeutic approach for the treatment of high-risk non-immunogenic NBs, especially NBs that exhibit CCL2 and TrkAIII expression. Full article

Background: Liver cancer is a complex malignant tumor; gambogic acid (GA) has significant anti-cancer potential, but poor water solubility and low bioavailability limit its clinical application. In this paper, by integrating nanocrystal (NC) technology and an active targeting strategy, a new nanoagent—folic acid-modified phospholipid–gambogic acid nanocrystals (GA-NCs@FA)—was developed to improve the delivery efficiency and therapeutic effect of GA in the treatment of liver cancer. Methods: GA-NCs@FA was prepared by the CO₂-assisted precipitation method and the thin-film hydration method. The in vitro anti-tumor activity of GA-NCs@FA was evaluated by cytotoxicity, as well as a scratch and uptake test. A HepG2 tumor-bearing nude mouse model was established to investigate the in vivo distribution and tumor targeting of GA. The in vivo anti-tumor activity was evaluated by the tumor inhibition rate, and the pathological changes of organs in each group were observed by H&E staining. Results: GA-NCs@FA significantly reduced HepG2 cell viability (IC₅₀: 0.50 μg·mL⁻¹) and migration ability (48 h healing rate: 11.50%) and enhanced intracellular fluorescence intensity. In vivo analysis showed that GA-NCs@FA significantly increased the accumulation of drugs in tumor tissues by active targeting and achieved a tumor growth inhibition rate of 70.9%. Histopathology confirmed that GA-NCs@FA induced the most obvious nuclear pyknosis and necrosis in tumor tissues while maintaining good biosafety. Conclusions: GA-NCs@FA significantly prolongs the systemic circulation time of the drug and enhances intratumoral accumulation; therefore, it is a method that can be considered for active targeting and treatment of liver cancer. Full article

Proanthocyanidins (PACs) are a key group of bioactive phytochemicals known to provide health benefits. Most PACs are non-bioavailable polymeric molecules that need to be biotransformed by colonic microbes into simple metabolites to exert their pharmacological effects. In this study, six previously unexamined PAC metabolites from Saccharomyces cerevisiae, 3-aminophenol (3-AMP), 3-aminosalicylic acid, 2,4-dihydroxy-6-methylbenzaldehyde, 4-hydroxyphenylacetamide (4-HPA), 3-phenyllactic acid, and 2,4,6-trihydroxyacetophenone, were tested for their antiadipogenic activity using an insulin-dependent 3T3-L1 preadipocyte differentiation model. Lipid accumulation in differentiating preadipocytes was visualized and measured with the Oil Red O assay. Only 3-AMP and 4-HPA significantly reduced lipid accumulation at a concentration of 25 µM. To understand the cellular mechanisms, protein levels of key regulators of adipogenesis and lipid metabolism were analyzed using Western blotting. 3-AMP and 4-HPA may attenuate lipid accumulation by suppressing de novo lipogenesis, with 3-AMP downregulating the peroxisome proliferator-activated receptor (PPAR)-γ/acetyl-CoA carboxylase (ACC)/fatty acid synthase (FAS) axis and 4-HPA primarily inhibiting ACC/FAS signaling. Molecular docking studies indicated that 3-AMP may downregulate PPAR-γ expression through competitive inhibition of insulin receptors. These preliminary findings suggest that 3-AMP and 4-HPA exhibit potential antiadipogenic effects, highlighting PAC-derived postbiotics as promising nutraceuticals for mitigating obesity risk. Full article

Obesity is a complex metabolic disorder characterized by excessive accumulation of adipose tissue, resulting from an imbalance between energy intake and expenditure. It is associated with an increased risk of chronic diseases such as type 2 diabetes, cardiovascular disease, and cancer. Kefiran is a water-soluble exopolysaccharide produced by lactic acid bacteria, Lactobacillus kefiranofaciens, in kefir grains, composed primarily of glucose and galactose. It has garnered scientific interest due to its antioxidant, anti-inflammatory, and antimicrobial properties. Rice Kefiran (RK) is a functional food made with culturing L. kefiranofaciens in a medium containing rice. It is standardized to contain at least 5 mg/g of kefiran. This study investigated the anti-obesity effect of RK on a high-fat diet (HFD)-induced obese mouse model. HFD-fed mice exhibited marked increases in body weight gain (10.3 g vs. 2.0 g in controls) and adipose tissue mass (2.4 g vs. 0.4 g in controls). RK administration significantly attenuated weight gain to 8.3 g and 6.0 g at doses of 10 and 50 mg/kg, respectively, and reduced adipose tissue mass to 2.2 g (RK10) and 1.7 g (RK50). Oral glucose tolerance testing revealed impaired glucose clearance in HFD-fed mice, with blood glucose levels of 403.5 mg/dL at 15 min and 314.6 mg/dL at 120 min, compared with 348.8 mg/dL and 232.2 mg/dL in controls. RK treatment improved glucose tolerance, particularly at 50 mg/kg, reducing glucose levels to 359.0 mg/dL at 15 min and 263.8 mg/dL at 120 min. Biochemical analyses demonstrated that RK significantly reduced serum total cholesterol (213.6 mg/dL in HFD vs. 178.0 and 184.0 mg/dL in RK10 and RK50), triglycerides (379.0 mg/dL in HFD vs. 228.8 and 234.6 mg/dL), and non-esterified fatty acids (0.89 mEq/mL in HFD vs. 0.54 and 0.35 mEq/mL), while phospholipid levels remained unchanged. Furthermore, RK increased serum nicotinamide phosphoribosyltransferase (NAMPT) levels from 15.8 ng/mL in HFD-fed mice to 30.0 and 50.0 ng/mL in the RK10 and RK50 groups, respectively, and restored hepatic NAD⁺/NADH ratios toward control levels (1.78 µmol/L in HFD vs. 1.90 µmol/L and 2.07 µmol/L in RK10 and RK50). Gene expression analysis showed that RK increased Nampt mRNA expression and decreased the mRNA expression of adipogenic and lipogenic genes, including Srebp-1c, Acc-1, and Fas. These findings suggest that RK may ameliorate obesity-related metabolic disturbances and its associated metabolic dysfunctions by modulating lipid metabolism, glucose tolerance, and NAD⁺ biosynthesis pathways. Full article

This prospective, single-center, case-control study investigated circulating autoantibodies (AAbs) targeting G protein-coupled receptors (GPCRs) in Long COVID (LC) patients to identify potential diagnostic biomarkers and therapeutic targets. Fifteen participants were enrolled at the LC clinic in Rome: eleven with severe LC—defined as >4 persistent symptoms (fatigue, cognitive impairment, poor exercise tolerance, dyspnea, arthralgia, or dysautonomic manifestations) >3 months post-infection—and four asymptomatic post-COVID (APC) individuals. Fatigue was assessed using the Fatigue Assessment Scale (FAS ≥ 22; severe ≥ 35). Auto-Abs against AT1R, endothelin receptor A, adrenergic (α1, α2, β1, β2), and muscarinic (M1–M5) receptors were quantified, along with blood cortisol and ACTH levels. SARS-CoV-2-specific T-cell responses to Spike and Nucleocapsid proteins were evaluated by ELISpot assay. In our small cohort, LC patients were younger, had fewer comorbidities (p = 0.03), fewer vaccine doses (p = 0.03), and higher FAS scores (33 vs. 12; p = 0.001). Mean GPCR AAbs levels were higher in LC than in APC (8.88 vs. 5.45 Units/mL; p = 0.17), indicating a coherent autoimmune signature in LC that correlates with symptom development. Morning cortisol was lower in LC (12.7 vs. 17 mg/dL; p = 0.01), and T-cell responses tended to be weaker. These findings suggest GPCR AAbs may serve as biomarkers and therapeutic targets for a subset of patients, guiding diagnosis and treatments with IV immunoglobulin or immunoadsorption. Full article