Search Results (644)

Background: Linagliptin, a potent and highly selective dipeptidyl peptidase-4 (DPP-4) inhibitor approved for the treatment of type 2 diabetes, enhances glucagon-like peptide-1 (GLP-1) signaling. Because GLP-1 receptors are widely expressed in the brain, DPP-4 inhibitors have emerged as potential modulators of central nervous system function. The present study investigated the effects of linagliptin (10 and 20 mg/kg, i.p.) on ketamine- (10 mg/kg, i.p.) and diazepam-induced (2 mg/kg, i.p.) deficits in passive avoidance performance in mice. Behavioral effects were assessed using the passive avoidance test, and brain-derived neurotrophic factor (BDNF) levels in the prefrontal cortex and hippocampus were determined by enzyme-linked immunosorbent assay (ELISA). Linagliptin attenuated ketamine- and diazepam-induced deficits in passive avoidance performance. In addition, both acute and chronic administration of linagliptin increased BDNF levels in the prefrontal cortex but not in the hippocampus. These findings provide preliminary evidence that linagliptin modulates passive avoidance performance in mice and is associated with increased BDNF levels in the prefrontal cortex. Further studies employing complementary behavioral paradigms and additional molecular approaches are required to clarify the neuropharmacological mechanisms underlying these effects. Full article

Processed meat products represent a major challenge for proteomic species identification due to extensive thermal treatment and protein structural changes. In this study, species-specific peptides in pork, chicken, and bovine meat products were identified using a directed fragmentation-assisted de novo sequencing workflow that combines 4-formylbenzene-1,3-disulfonic acid (FBDA) peptide derivatization, dual-polarity data-independent mass spectrometry (DIA-MS), and Protein Acrobat de novo sequencing software. Comparative analysis of non-fractionated and strong cation exchange (SCX)-fractionated pork luncheon samples improved peptide and protein identification after fractionation, with 312 peptides and 115 protein groups detected exclusively in fractionated samples. Species-specific peptides were predominantly assigned to conserved muscle-related proteins, including myosin, troponin, and tropomyosin, while sequence variability enabled reliable species discrimination despite protein conservation across species. To evaluate applicability for food fraud detection, mixed meat samples containing 10% chicken in pork or bovine matrices were analyzed, reflecting potential economically motivated adulteration through substitution with lower-cost meat components. Several chicken-specific peptides remained detectable in both mixtures, demonstrating robustness of the FBDA-assisted peptide sequencing combined with SCX fractionation and DIA-MS for detection of adulteration in complex processed food matrices. These findings establish a mass spectrometry-driven orthogonal method to ELISA testing for fast, reliable and accurate metaproteome analysis of highly processed food. Full article

Melittin (Mel) is a membrane-active peptide with potential anticancer activity, but its direct therapeutic application may be limited by nonspecific toxicity and delivery-related challenges. The study aimed to assess melittin-functionalized magnetic nanoparticles (MNPs-Mel) as a strategy to enhance antitumor activity in Caco-2 cells, with/without magnetic hyperthermia (MH) association. BJ fibroblasts were used as a normal human in vitro cellular model. The effects of free Mel (2.5 µg/mL), MNPs, and MNPs-Mel (50 µg/mL both) + MH (30 min at 355 kHz and 25 kA/m) were assessed using colorimetry (for viability), luminescence (ATP), and spectrophotometry (lactate) following different exposure conditions. The mechanism of apoptosis induction was evaluated by ELISA (caspase 8 and 9 levels). Transmission electron microscopy (TEM) was also used to evaluate nanoparticle morphology and treatment-associated cellular ultrastructural changes. Free Mel reduced viability in both cell lines, with Caco-2 cells showing greater sensitivity at lower concentrations. MNPs (with/without MH) produced limited and less consistent effects, whereas MNPs-Mel significantly reduced Caco-2 viability and ATP levels and increased LDH and caspase 9. MH further enhanced the effects of MNPs-Mel: reduced viability (57–58% of the control at 24 h and 72 h), decreased ATP levels (67% of the control at 24 h and 53% at 72 h), increased LDH levels (206% of the control at 24 h and 301% at 72 h), and induced the mitochondrial apoptotic pathway (caspase 9 increased with 2164% of the control at 72 h). TEM proved the internalization of both MNPs and MNPs-Mel and revealed extensive ultrastructural alterations concerning mitochondria and lysosomes produced by MNPs-Mel, particularly in the Caco-2 cells. These modifications were heavily increased by MNPs-Mel + MH exposure. Overall, these findings demonstrate that Mel functionalization increases the antitumor activity of Mel at lower doses and that MH further potentiates this effect in Caco-2 cells. Full article

Angiostrongyliasis, the primary cause of eosinophilic meningitis, represents an emerging disease caused by Angiostrongylus cantonensis larvae, inadvertently transmitted to humans. The diagnosis of human angiostrongyliasis relies on epidemiological features, clinical symptoms, medical history, and laboratory findings, notably hyper eosinophilia in blood and cerebrospinal fluid. Consequently, accurate diagnosis is challenging and prone to confusion with other parasitic diseases. The quest for an early, rapid, and specific diagnostic test for angiostrongyliasis persists, driven by the imperative for enhanced test specificity. This study focused on mapping IgM epitopes on galectin-1 (Gal-1) and galectin-2 (Gal-2) proteins derived from A. cantonensis. The specificity of the epitopes was assessed using database homology analysis. After selecting specific epitopes, researchers chemically synthesized 12 individual multi-antigen peptides (MAPs4) and one chimeric polypeptide that is 65 amino acids long. The effectiveness of these synthesized peptides was subsequently evaluated using enzyme-linked immunoassay (ELISA). A total of twelve unique IgM epitopes were discovered; five were linked to Gal-1, while seven were linked to Gal-2. An ELISA-peptide method confirmed the twelve epitopes, and then the chimeric polypeptide was employed as an antigen to coat ELISA plates. This setup was evaluated with patients’ sera to diagnose strongyloidiasis in vitro. This study provides a comprehensive representation of the IgM epitopes of Gal-1 and Gal-2 from A. cantonensis. ELISA data utilizing the chimeric polypeptide demonstrate that the selected sequences hold promise for the development of a specific immunological assay tailored for the acute diagnosis of angiostrongyliasis infections. Full article

Brucellosis is a globally prevalent zoonotic disease affecting both humans and animals. Its nonspecific clinical manifestations often complicate diagnosis, underscoring the need for reliable laboratory confirmation. Traditional serological assays, though widely used, suffer from limitations such as inconsistent sensitivity and false-positive results. To address these challenges, this study mapped IgM and IgG epitopes of the Brucella Omp-2a protein using sera from infected patients. Epitope identification was performed through SPOT synthesis on cellulose membranes, followed by assessment of potential cross-reactivity using peptide database analysis and ELISA validation. Three major IgM and seven IgG linear B-cell epitopes were identified, six of which demonstrated strong reactivity in peptide-ELISA. Importantly, no significant cross-reactivity with proteins from other human pathogens was detected. Two chimeric multi-epitope peptides, composed of 50 and 60 amino acids and integrating Brucella-specific IgM and IgG epitopes, exhibited excellent diagnostic performance in ELISA, achieving near 100% sensitivity and specificity. These findings support the potential of synthetic peptides as reliable and cost-effective alternatives to native antigens in serological assays. Further validation in larger, geographically diverse cohorts will be essential to confirm their diagnostic robustness and facilitate their integration into routine brucellosis diagnostics. Full article

This study investigated the effects of different doses of ranolazine in a middle cerebral artery occlusion/reperfusion (MCAO-I/R) model by evaluating histopathological changes and serum Sirtuin 1 (SIRT1), Apela peptide (APELA), and Apelin-13 (APL13) levels. A total of 47 male Sprague Dawley rats (250 ± 20 g) were randomly assigned to five groups: Sham (n = 7), MCAO (n = 10), MCAO+RAN10 (n = 10), MCAO+RAN30 (n = 10), and MCAO+RAN50 (n = 10). MCAO-I/R was induced by transient filament occlusion of the right middle cerebral artery for 90 min followed by reperfusion. Ranolazine was administered intraperitoneally once daily for 21 days in the treatment groups. Serum SIRT1, APELA, and APL13 levels were measured using enzyme-linked immunosorbent assay (ELISA), and brain tissues were evaluated histopathologically for neuronal degeneration and apoptotic cell counts. Histopathological analysis revealed significant neuronal degeneration and increased apoptosis in the MCAO group compared with the Sham group. Ranolazine treatment did not demonstrate significant histopathological improvement compared with the untreated MCAO group. Among the treatment groups, the MCAO+RAN50 group showed higher apoptotic cell counts and lower serum biomarker levels than the other ranolazine-treated groups. Serum SIRT1, APELA, and APL13 levels were lowest in the MCAO+RAN50 group, with selected pairwise differences reaching statistical significance. Under the present experimental conditions, clear evidence of neuroprotection could not be demonstrated. None of the ranolazine-treated groups showed significant histopathological improvement compared with the untreated MCAO group. These findings indicate that higher-dose ranolazine was not associated with neuroprotection under the conditions of this study. However, given the limited sample size, absence of infarct volume analysis, lack of neurological functional assessment, and absence of tissue-level molecular validation, further studies are required to clarify the biological significance and potential clinical relevance of the observed biomarker changes. Full article

Post-exercise release of cardiac biomarkers reflects physiological adaptations of the myocardium to exercise; however, data on their kinetics after exhaustive exercise under hypoxia remain scarce. We determined the kinetics of cardiac biomarker changes following a single bout of exercise to volitional exhaustion under normoxia and moderate normobaric hypoxia (2000 m and 3000 m a.s.l.) in trained (n = 12; VO_2max 64.2 ± 2.9 mL·kg⁻¹·min⁻¹) and untrained (n = 12; VO_2max 44.1 ± 7.4 mL·kg⁻¹·min⁻¹) men. Participants performed a graded exercise test (GXT) followed by a constant-workload exercise test (CXT) at the lactate threshold under three conditions (FiO₂ = 20.9%, 16.5%, 14.4%). Venous blood was sampled at rest, immediately post-exercise, and at 2, 6, and 24 h of recovery for determination of cardiac troponin T (cTnT) and I (cTnI), myoglobin (Mb), creatine kinase MB isoform (CK-MB), heart-type fatty acid-binding protein (H-FABP), ischemia-modified albumin (IMA), and N-terminal pro-B-type natriuretic peptide (NT-proBNP) by ELISA. Exhaustive exercise induced significant elevations in all biomarkers, peaking at 2–6 h post-exercise and largely returning to resting values by 24 h. Moderate normobaric hypoxia did not augment the cardiac biomarker response; rather, it attenuated the increases in Mb, NT-proBNP, and IMA, likely due to earlier peripheral fatigue and lower absolute mechanical work. The inhibitory effect of hypoxia on cTnI release was observed exclusively in trained men, suggesting an interaction between training-related cardiac adaptations and the hypoxic stimulus. These findings support the safety of high-intensity exercise at simulated altitudes of 2000–3000 m a.s.l. Full article

Background: N-terminal pro-B-type natriuretic peptide (NT-proBNP) is released in response to increased cardiac wall stress and is used as a biomarker for volume overload and heart failure (HF). It is also elevated in atrial fibrillation (AF) and inflammation. However, in hemodialysis (HD) patients, its interpretation is complicated by reduced renal clearance, large fluid shifts between dialysis sessions, and chronic inflammation. Methods: In 123 HD patients, we examined the relationship between NT-proBNP and interdialytic weight gain, HF with preserved ejection fraction (HFpEF), left ventricular systolic dysfunction (LVSD), and AF, as well as the impact of inflammation. Clinical characteristics, laboratory data, and echocardiography (within three months) were evaluated, while serum NT-proBNP and calprotectin levels were measured by ELISA. Results: NT-proBNP showed no association with interdialytic weight gain and did not identify HFpEF. Inflammatory markers (C-reactive protein and calprotectin) correlated positively with NT-proBNP. Multivariable analysis demonstrated that LVSD, AF, and inflammation remained independent predictors of NT-proBNP levels. Although NT-proBNP levels were higher in LVSD, its diagnostic performance was poor (AUC 0.627). In contrast, NT-proBNP was significantly elevated in patients with AF and showed good diagnostic performance (AUC 0.801). Conclusions: In HD patients, NT-proBNP is not correlated with interdialytic weight gain, performs poorly as a marker of LVSD, but may serve as a useful marker of AF. Full article

Background/Objectives: Canine papillomavirus (CPV) is an important viral pathogen associated with papillomatosis in dogs, with canine papillomavirus type 1 (CPV1) and type 2 (CPV2) among the most prevalent and clinically relevant genotypes. The L1 capsid protein is a major immunogenic antigen of papillomaviruses; however, conserved linear B-cell epitopes shared between CPV genotypes remain poorly defined. This study aimed to identify conserved cross-reactive B-cell epitopes within CPV1 and CPV2 L1 proteins and to evaluate their preliminary immunoreactivity. Methods: Conserved linear B-cell epitopes were predicted through integrated bioinformatic and structural analyses based on sequence conservation and surface accessibility. Three candidate epitopes were selected. Recombinant CPV1 and CPV2 L1 proteins were expressed in Escherichia coli (E. coli), purified, used as recombinant L1 antigens, together with BSA-conjugated synthetic epitope peptides for mouse immunization. Antigen-specific IgG responses were assessed by ELISA, antigen-associated IFN-γ responses were evaluated by ELISpot, and cross-reactive antibody recognition was assessed by Western blot. Results: Recombinant L1 proteins induced strong antigen-specific IgG responses in mice. The selected peptides induced detectable but weaker humoral responses compared with the recombinant L1 proteins. Among the three epitopes, TPSGSLV and TVVDNTR elicited antibodies that recognized both CPV1 and CPV2 L1 proteins, while the epitope VIVPKVS showed minimal or no detectable immunoreactivity. ELISpot analysis showed only modest antigen-associated IFN-γ responses, particularly in peptide-immunized groups. Conclusions: This study identified conserved cross-reactive linear B-cell epitope candidates within CPV1 and CPV2 L1 proteins and provided preliminary immunological evidence supporting their potential relevance for CPV antigen design. However, peptide-induced responses were weaker than those induced by recombinant L1 proteins, and VLP formation, antibody neutralizing activity, and protective efficacy were not evaluated. Further studies in dogs, including optimized antigen-display platforms, neutralization assays, and protection studies, are required to determine the practical value of these epitopes for CPV vaccine development. Full article

Background/Objective: Phoenixin (PNX), a recently identified neuropeptide, has been shown to regulate the hypothalamic–pituitary–gonadal axis and play a role in folliculogenesis and oocyte maturation. However, its clinical relevance in ovarian reserve remains unclear. This study aimed to evaluate the association between serum PNX-14 and PNX-20 levels and ovarian reserve and to determine whether these peptides provide additional information regarding ovarian reserve status in women with diminished ovarian reserve (DOR). Methods: This prospective case–control study included 160 women of reproductive age. Participants were categorized according to anti-Müllerian hormone (AMH) levels and antral follicle count (AFC). Serum PNX-14 and PNX-20 levels were measured using ELISA. Statistical analyses included group comparisons, Spearman correlation, receiver operating characteristic (ROC) analysis, and logistic regression. Results: PNX-14 levels differed significantly across AMH-defined groups (p < 0.001), with higher levels observed in women with DOR. In contrast, PNX-20 levels showed no significant differences (p = 0.305). PNX-14 demonstrated excellent diagnostic performance for identifying DOR (AUC = 0.921), with a sensitivity of 78.7% and a specificity of 95.3% at a cut-off value of 183 pg/mL. A significant negative correlation was found between AMH and PNX-14 (r = −0.639, p < 0.001), whereas PNX-20 showed no significant correlation. In logistic regression analysis, PNX-14 was significantly associated with DOR in unadjusted and partially adjusted models; however, this association was attenuated after adjustment for AFC. Conclusions: PNX-14 is significantly associated with ovarian reserve status and may provide complementary information regarding DOR when interpreted alongside established ovarian reserve markers. In contrast, PNX-20 does not appear to have clinical utility in this context. Full article

Objective: Diabetes mellitus is closely associated with mitochondrial dysfunction, which disrupts cellular energy metabolism and perturbs hormonal homeostasis. Humanin (HN), a 24-amino acid peptide encoded within the mitochondrial genome, has attracted considerable attention due to its cytoprotective and metabolic regulatory properties. Despite its recognized biological potential, the role of HN in coordinating key metabolic hormone networks under diabetic conditions remains poorly understood. This study aimed to investigate the integrative effects of repeated humanin administration on key metabolic hormones leptin, ghrelin, irisin, and asprosin and its potential role in restoring hormonal homeostasis in a streptozotocin (STZ)-induced diabetic mouse model. Materials and Methods: Forty male mice were randomly assigned to four groups (n = 10 for each group): control, HN (4 mg/kg/day), STZ (150 mg/kg), and STZ + HN. Humanin was administered intraperitoneally for 15 consecutive days. Serum levels of leptin, asprosin, irisin, and ghrelin were measured using enzyme-linked immunosorbent assay (ELISA), and data were analyzed using one-way ANOVA followed by Tukey’s post hoc test. Results: STZ-induced diabetes markedly disrupted metabolic hormone balance, as indicated by decreased leptin and irisin levels and increased asprosin concentrations. Repeated HN treatment effectively restored leptin levels and suppressed asprosin concentrations, while irisin levels showed a relative increase compared to the STZ animals. In addition, ghrelin levels were significantly elevated in HN-treated diabetic mice compared to untreated STZ animals. Conclusions: These findings indicate that humanin exerts an integrative, multi-hormonal regulatory effect, supporting the restoration of metabolic and endocrine homeostasis under diabetic conditions. Full article

The Getah virus (GETV) is a mosquito-borne pathogen that infects diverse hosts, including pigs, horses, and humans, which can cause swine reproductive disorders such as abortion and stillbirth, posing a potential threat to animal and public health. Therefore, there is an urgent need for efficient and accurate serological diagnostic methods for surveillance and control of GETV. However, commercial diagnostic kits for swine GETV infection remain unavailable. In this study, we developed a novel enzyme-linked immunosorbent assay (ELISA) based on a GETV-specific epitope peptide (E2EP3) for serological detection. The N-terminally biotinylated E2EP3 peptide was synthesized, and the reaction conditions were systematically optimized, resulting in a cut-off value of 0.363. The assay exhibited no cross-reactivity with Japanese encephalitis virus (JEV), porcine circovirus type 2 (PCV2), porcine circovirus type 3 (PCV3), pseudorabies virus (PRV), or classical swine fever virus (CSFV). It demonstrated good reproducibility and high sensitivity, detecting GETV-positive serum diluted up to 1:640. The overall agreement rate reached 95%, consistent with a conventional recombinant GETV E2 protein-based ELISA. Benefiting from the biotin–streptavidin system, this assay achieved strong signal amplification and low background. Moreover, the procedure is simple, cost-effective, and stable, making it suitable for GETV large-scale serological surveillance and vaccine evaluation. Full article

Background/Objectives: Exploiting the metabolic properties of postbiotics is a novel strategy for managing metabolic disorders, including diabetes. Inactivated microorganisms, a major class of postbiotics, improve glycemic control in preclinical and clinical studies. Here, we examined whether heat-killed (HK) Mycobacterium aurum (M. aurum) exerts prophylactic or therapeutic anti-hyperglycemic effects in diabetic mice. Methods: Diabetes was induced in male BALB/c mice by streptozotocin (STZ; 150 mg/kg) injection. HK M. aurum (1 mg) was given orally (three prophylactic doses before STZ) or intradermally (six weekly therapeutic doses after STZ). We assessed glycemic parameters, serum C-peptide/insulin (ELISA), and tissue protein expression (Western blot). Results: Neither route altered body weight or glucose homeostasis in non-diabetic mice. In STZ-diabetic mice, oral prophylactic treatment significantly attenuated hyperglycemia (39–60% reduction weeks 5–8 post-STZ) and showed a trend toward improved serum C-peptide, but did not affect dysregulated expression of skeletal muscle (SM), hepatic, pancreatic and renal proteins involved in glucose transport (GLUT2, GLUT4, and SGLT2), glycolysis (α-LDH), mitochondrial uncoupling (UCP2 and UCP3), and antioxidant defense (CAT). Therapeutic intradermal administration significantly decreased blood glucose (~30% at week 5, ~40% at week 6) and modestly enhanced insulin secretion. Hepatic UCP2 and α-LDH and SM UCP3 protein levels were normalized toward non-diabetic levels, whereas hepatic GLUT2 and SM GLUT4 remained largely unchanged. These correlative findings suggest effects independent of insulin-dependent glucose transport, but do not demonstrate direct functional improvement in mitochondrial or redox status. Conclusions: HK M. aurum exerts partial anti-hyperglycemic effects in STZ-induced diabetic mice, but the associated protein changes require functional validation before its role as a postbiotic in β-cell dysfunction can be established. Full article

Background/Objectives: This study aimed to clarify the cardioprotective effects of combined empagliflozin and sacubitril/valsartan therapy in an experimental rat model of heart failure (HF). The main research question was whether dual treatment provides greater functional and molecular benefit than either monotherapy, with particular emphasis on oxidative stress, inflammation, apoptosis, and JAK2/STAT3 signaling. Methods: HF was induced in rats by 7-day isoproterenol administration and confirmed four weeks later by echocardiographic evidence of reduced ejection fraction (<55%). The animals were then assigned to healthy control, untreated HF, empagliflozin, sacubitril/valsartan, and combined empagliflozin/sacubitril/valsartan groups. Following four weeks of treatment, ex vivo cardiac function was evaluated using the Langendorff technique. Serum cardiospecific markers and natriuretic peptides were measured by ELISA. Oxidative stress parameters were determined in coronary venous effluent, while myocardial gene expression of selected (anti)oxidative, (anti)inflammatory, (anti)apoptotic, and signaling markers was assessed by RT-PCR. Myocardial collagen content was evaluated using Picrosirius red staining. Results: HF rats exhibited impaired ex vivo myocardial function, elevated cardiac injury markers, increased oxidative stress, upregulation of pro-inflammatory and pro-apoptotic genes, activation of JAK2/STAT3 signaling, and increased myocardial collagen content. Both monotherapies produced partial benefit. In contrast, combined treatment achieved the most pronounced improvement in contractile performance, attenuated oxidative stress more consistently, reduced expression of TNF-α, IL-1β, IL-6, IL-17, Bax, CASP-3, and CASP-9, favorably modulated JAK2, STAT3, mTOR, and PPARγ expression, and decreased myocardial collagen content. Conclusions: Dual empagliflozin and sacubitril/valsartan therapy exerted broader cardioprotective effects than either monotherapy, likely through coordinated antioxidant, anti-inflammatory, anti-apoptotic, and signaling-related mechanisms. Full article

Antibody treatment for Alzheimer’s disease is an evolving therapeutic strategy that ensures high affinity and specificity to the target antigen; however, current approaches have proven only partially successful. A 14-mer peptide, T14, is twice as high in Alzheimer’s brains and has been identified as a primary driver in the neurodegenerative process. Previously, the polyclonal antibody Ab-19 was shown to be as effective as the T14 receptor blocker (NBP-14) in reducing the toxic calcium influx in PC12 cells. The aim of this study was to establish a thorough validation process in order to evaluate the efficacy of respective anti-T14 monoclonal antibodies in T14 detection and rescuing potential from T14-induced toxicity in PC12 cells. Subsequently, we assessed the binding affinity of the most promising antibody, THK-117, via quantitative indirect conjugated T14 ELISA assays. The level of efficacy shown proved to be comparable to the polyclonal antibody, yet with the additional advantage of robust manufacturing reproducibility and high binding specificity toward the T14 epitope. With a notably low EC50, THK-117 can be viewed as a promising candidate for humanization, offering a strong potential as a therapeutic monoclonal antibody for the treatment and prevention of Alzheimer’s disease. Full article