Search Results (216)

Fasciola gigantica (F. gigantica) is a vital parasite that causes fasciolosis. Liver fluke infections affect livestock animals, and the Fasciola species (Fasciola spp.) vaccine has been tested for many types of these diseases. Currently, computer-based vaccine design represents an attractive alternative for constructing vaccines. Thus, this study aimed to design the epitopes of linear B-cells (BCL) and helper T lymphocytes (HTL) using an immunoinformatic approach and to investigate in silico and the mice’s immune response. A non-conserved host region, overlapping F. gigantica cathepsin B proteins (FgCatB), and the highest conserved residue percentages were the criteria used to construct epitopes. The GPGPG linker was used to link epitopes in the multi-epitope Fasciola gigantica cathepsin B (MeFgCatB) peptide. The MeFgCatB peptide has high antigenicity, non-allergenicity, non-toxicity, good solubility, and a high-quality structure. The molecular docking between the MeFgCatB peptide and Toll-like receptor 2 (TLR-2) was evaluated. The IgM, IgG1, and IgG2 levels were elevated in silico. In mice, the MeFgCatB peptide was synthesized and administered as an injection. The MeFgCatB-specific IgG1 and IgG2a levels were elevated after week 2, showing a predominance of IgG1. The rFgCatB1, rFgCatB2, and rFgCatB3 were detected using the MeFgCatB peptide-immunized sera. The MeFgCatB peptide-immunized sera were detected at approximately 28–34 kDa in the whole body. In addition, the MeFgCatB immunized sera can positively signal at the caecal epithelium in the NEJ, 4WKJ, and adult stages. In summary, the MeFgCatB peptide is able to induce mixed Th1/Th2 immune responses with Th2 dominating and to detect the native protein of F. gigantica. The MeFgCatB peptide should help against F. gigantica in future experiments. Full article

Background: Abdominal aortic aneurysm (AAA) is a chronic inflammatory disease characterized by the proteolytic breakdown of the extracellular matrix. A clinical biomarker is needed for risk stratification and prognosis. Methods: In this single-center, 5-year observational study, 452 patients were enrolled: 343 with AAA (≥3 cm), and 109 controls (<3 cm). Plasma levels of six inflammatory proteins (human epididymis protein 4 (HE4), matrix metalloproteinase (MMP) 1 and 3, cathepsin S, chitinase 3 like-1, cathepsin S, and B-cell activating factor (BAFF)) were quantified at baseline. Patients were followed for a total of 5 years (60 months), and major adverse cardiovascular events (MACEs, defined as the composite of myocardial infarction, cerebrovascular attack, and cardiovascular-related death) were recorded. A Cox proportional hazard model was created using biomarker levels, age, sex, hypertension, hypercholesterolemia, diabetes mellitus, smoking status, and coronary artery disease to determine whether the baseline levels of these proteins were associated with MACEs over 5 years. Results: HE4, MMP-3, BAFF, and cathepsin S levels were significantly elevated in AAA patients compared to controls (all p < 0.05). HE4/WFDC2, MMP-3, and Chitinase 3-like 1 were significantly linearly associated with AAA diameter at baseline. With every normalized unit increase in HE4/WFDC2, MMP-3, and Chitinase 3-like 1, there was an increase in abdominal aortic diameter by 0.154 (95% CI: 0.032–0.276, p = 0.013), 0.186 (95% CI: 0.064–0.309, p = 0.003), and 0.231 (0.110–0.353, p < 0.001) centimeters, respectively. Among patients with AAA, elevated HE4 was associated with higher risk of MACEs (adjusted HR 1.249; 95% CI: 1.057–1.476; p = 0.009). Patients with high baseline HE4 (≥9.338 ng/mL) had significantly lower freedom from MACEs at 5 years (76.7% vs. 84.8%, p = 0.022). Conclusions: HE4 may be a potential prognostic biomarker that can be used to risk stratify patients with AAA to better personalize treatment strategies to reduce adverse events. Full article

Dry eye disease (DED) is a common, multifactorial disorder of the ocular surface. Although DED can affect individuals at any age, its prevalence, clinical manifestations, underlying mechanisms, and optimal management strategies differ considerably across the lifespan. In children, symptoms are frequently associated with atopy and allergic disorders and environmental factors, whereas in young adults, digital device usage and contact lens wear are the predominant contributors. In older adults, systemic diseases and polypharmacy significantly elevate the risk of DED. Across all age groups, tear film instability, decreased tear production, and chronic inflammation are central pathogenic features. Key tear biomarkers, such as pro-inflammatory cytokines, have been widely linked to disease development. Cathepsin S and tumor necrosis factor-alpha have recently been implicated in age-related DED. A nuanced understanding of these age-related differences is crucial for improving diagnostic accuracy and tailoring interventions to specific patient populations. This review synthesizes current evidence on DED across age groups, focusing on prevalence, risk factors, pathophysiology, molecular mechanisms, coexisting conditions, biomarkers, and treatment options. Finally, it highlights critical unmet clinical needs in the management of age-related DED. Full article

Background/Objectives: Glioblastoma represents a particularly aggressive and fatal type of brain tumor. Peptide-drug conjugates, which offer the promise of traversing the blood-brain barrier to selectively accumulate in tumor tissues and precisely target cancer cells, are an active area of research. We present the synthesis and characterization of the T7 peptide (HAIYPRH) as a targeting ligand for the transferrin receptor, which is highly expressed on both the blood-brain barrier and glioma cells. Methods: Using the T7 peptide, the synthesis, characterization, and biological evaluation of a transferrin receptor-targeted, combination SN-38 and rucaparib peptide drug conjugate (T7-SN-38-rucaparib) are described. Results: The T7 peptide drug conjugate readily cleaved in the presence of exogenous cathepsin B, releasing the active drug payloads. In vitro experiments demonstrated potent cytotoxic effects of the T7 peptide drug conjugate on glioblastoma cells (IC₅₀ = 22.27 nM), with reduced toxicity to non-cancerous HEK 293 cells (IC₅₀ = 115.78 nM), indicating selective toxicity toward cancer cells. Further investigations revealed that blocking transferrin receptors with drug-free T7 peptide significantly reduced the conjugate’s cytotoxicity, an effect that could be reversed by introducing exogenous cathepsin B to the cells. Conclusions: These findings highlight the potential of glioblastoma-targeted delivery of SN-38 and rucaparib based on specific recognition of the transferrin receptor for transport across the blood-brain barrier, offering the prospect of reduced toxicity and selective killing of cancer cells. Additionally, since rucaparib does not cross the blood-brain barrier, this work is significant to facilitate the use of rucaparib for the treatment of brain tumors. Full article

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder that is characterized by amyloid-beta (Aβ) accumulation and neuroinflammation. A previous multicenter, phase 2, double-blind, placebo-controlled trial randomized 179 participants into placebo or resveratrol over 52 weeks. Sub-analysis of CSF biomarkers of neuronal damage, inflammation, and microglial activity was performed in a subset of patients treated with a placebo (n = 21) versus resveratrol (n = 30). Markers of neuronal damage, including neuron-specific enolase and hyperphosphorylated neurofilaments, were reduced. Microglial activation was measured via a triggering receptor expressed on myeloid cells (TREM)-2 at baseline and after resveratrol treatment. Resveratrol significantly reduced CSF TREM2 levels and decreased inflammation and tissue damage, including matrix metalloprotease (MMP)-9. Cathepsin D, a lysosomal marker of autophagy, was reduced in the resveratrol group compared with placebo, while angiogenin, a marker of vascular angiogenesis, was increased. These data suggest that resveratrol may exert anti-inflammatory and neuroprotective effects in AD by reducing CSF TREM2 and other markers of neuronal damage. Further research is needed to assess the significance of these biomarker changes on clinical outcomes in patients with neurodegenerative diseases. Full article

As a lysosomal cysteine protease of the papain subfamily, cathepsin B (CTSB) is characterized by its innate immune functions and hydrolytic activity. However, the functions of CTSB in the immune responses of teleosts remain to be clarified. In this study, two CTSB genes in S. schlegelii, SsCTSBa and SsCTSBb, were identified. Both SsCTSBa and SsCTSBb are composed of a 993 bp ORF encoding 330 amino acids. It was found in a phylogeny analysis that both genes form monophyletic clades with their orthologous counterparts of Honeycomb rockfish (Sebastes umbrosus). A synteny analysis indicated that the CTSB homologues were comparatively conserved during vertebrate evolution. Additionally, quantitative real-time PCR revealed the ubiquitous mRNA expression of SsCTSBa and SsCTSBb in all of the examined tissues, and substantially differential expression patterns could be observed following Aeromonas salmonicida infection. A subcellular localization analysis demonstrated that the distribution of SsCTSBa and SsCTSBb was mainly in the cytoplasm. Moreover, rSsCTSBa and rSsCTSBb showed strong binding to Poly(I:C) and exhibited diverse agglutination effects on different bacteria. Overall, these findings suggest that the CTSB genes in black rockfish might show essential functions in the host defense of teleosts against bacterial infections, providing valuable insights for further investigations into the immune mechanism of teleost CTSB. Full article

Excessive iron accumulation poses a significant threat to liver health, primarily through oxidative stress and autophagy dysregulation. α-Lipoic acid (ALA), a natural antioxidant with hepatoprotective properties, may alleviate iron-induced liver damage, but its underlying mechanisms are not fully understood. This study utilized male Sprague Dawley rats and BRL-3A cells to explore the protective effects of ALA against iron overload in vivo and in vitro, respectively. ALA treatment significantly reduced hepatic iron accumulation, improved liver morphology, and alleviated iron-induced ultrastructural damage in rats. ALA also improved liver function markers in plasma, including alkaline phosphatase (ALP), gamma-glutamyltransferase (GGT), total bilirubin (TBIL), and the AST/ALT ratio. Furthermore, ALA mitigated iron-induced oxidative stress by lowering hepatic reactive oxygen species (ROS) and malondialdehyde (MDA), while increasing the antioxidant enzyme activities of glutathione peroxidase (GSH-Px) and catalase (CAT). In BRL-3A cells, ALA improved cell viability, decreased intracellular ROS, and reduced iron levels. Proteomics analysis indicates that NAD(P)H: quinone oxidoreductase 1 (NQO1) may play a critical role in the protective effects of ALA against iron overload-induced hepatic damage in rats. Mechanistically, ALA upregulated NQO1 expression while downregulating autophagy-related proteins, including light chain 3B (LC3B), lysosomal-associated membrane protein 1 (LAMP1), and cathepsin D (CTSD). Inhibition or knockdown of NQO1 abolished ALA’s protective effects, confirming its role in reducing oxidative stress and excessive autophagy. These findings highlight the potential of ALA as a therapeutic agent for managing hepatic iron toxicity through iron chelation and activation of NQO1. Full article

Dysfunction of the lysosome and autophagy–lysosome pathway is closely associated with various diseases, such as neurodegenerative diseases, non-alcoholic fatty liver disease (NAFLD), etc. Additionally, chloroquine is a clinically widely used drug for treating malaria and autoimmune diseases, but long-term or high-dose administration may lead to significant toxic side effects. Attapulgite (ATT), a natural nanomaterial with excellent adsorption capacity and biocompatibility, herein demonstrated a novel biological function in regulating the lysosomal and autophagy–lysosome pathway. ATT could be effectively internalized into lysosome-related acidic compartments. Further study revealed that ATT could restore lysosomal pH, activate cathepsin D, alleviate autophagy blockage in chloroquine-treated cells, and reduce chloroquine-elicited cell death. In a cell model related to Huntington’s disease, treatment with ATT reinforced the degradation of the mutant huntingtin proteins by increasing cathepsin D maturation and autophagy flux. ATT could also promote lipid droplet clearance in hepatocytes with palmitic acid-induced steatosis, reduce hepatic lipid accumulation, and improve fasting blood glucose in high-fat-diet-induced NAFLD mice. These findings establish ATT as a lysosomal modulator, providing a foundation for its therapeutic potential in mitigating the adverse effects associated with long-term chloroquine use, especially improving neurodegenerative and metabolic disorders. Full article

While most cowpea cultivars are susceptible to parasitism by the root parasitic weed Striga gesnerioides (Willd.) Vatke, cultivar B301 is resistant to all Striga races except for SG4z. Resistance to Striga parasitism is manifested by the elicitation of a hypersensitive response (HR) at the site of parasite attachment on the host root followed by rapid death of the attached parasite. We isolated a papain-like cysteine protease (PLCP) designated SGCP1 that is highly expressed in the haustoria of S. gesnerioides race SG3 at the time of parasite attachment to the host root. SGCP1 contains an apoplast-targeting signal peptide, a Cathepsin pro-peptide inhibitory domain, a papain family cysteine protease domain, and a granulin domain. Full-length SGCP1 and a variant lacking the signal peptide (SGCP∆SP) were expressed in the roots of composite B301 plants. Expression of SGCP1 and SGCP∆SP resulted in activation of host innate immune responses exemplified by increased frequency of HR and decreased levels of parasite cotyledon expansion (CE), indicative of successful host parasitism, in transgenic compared to wild-type B301 roots parasitized by SG4z. These data indicate that SGCP1 functions as an avirulence factor capable of activating host innate immunity and furthers our understanding of how compatible and incompatible host–parasite interactions are controlled. Full article

The SARS-CoV-2 proteases M^pro and PL^pro are critical targets for antiviral drug development for the treatment of COVID-19. The 1,2,4-thiadiazole functional group is an inhibitor of cysteine proteases, such as papain and cathepsins. This chemical moiety is also present in ceftaroline fosamil (CF), an FDA-approved fifth-generation cephalosporin antibiotic. This study investigates the interactions between CF, its primary metabolites (M1 is dephosphorylated CF and M2 is an opened β-lactam ring) and derivatives (protonated M1H and M2H), and its open 1,2,4-thiadiazole rings derivatives (open-M1H and open-M2H) with SARS-CoV-2 proteases and evaluates CF’s effects on in vitro viral replication. In silico analyses (molecular docking and molecular dynamics (MD) simulations) demonstrated that CF and its metabolites are potential inhibitors of PL^pro and M^pro. Docking analysis indicated that the majority of the ligands were more stable with M^pro than PL^pro; however, in vitro biochemical analysis indicated PL^pro as the preferred target for CF. CF inhibited viral replication in the human Calu-3 cell model at submicromolar concentrations when added to cell culture medium at 12 h. Our results suggest that CF should be evaluated as a potential repurposing agent for COVID-19, considering not only viral proteases but also other viral targets and relevant cellular pathways. Additionally, the reactivity of sulfur in the 1,2,4-thiadiazole moiety warrants further exploration for the development of viral protease inhibitors. Full article

The impact of dietary lipid sources on nutrient metabolism and reproductive development is a critical focus in aquaculture broodstock nutrition. Previous studies have demonstrated that fish oil supplementation modulates the expression of genes involved in steroid hormone synthesis, glucose, and lipid metabolism promoting ovarian development in female Scatophagus argus (spotted scat). However, the effects of fish oil on hepatic function at the protein level remain poorly characterized. In this study, female S. argus were fed diets containing 8% fish oil (FO, experimental group) or 8% soybean oil (SO, control group) for 60 days. Comparative proteomic analysis of liver tissue identified significant differential protein expression between groups. The FO group exhibited upregulation of lipid metabolism-related proteins, including COMM domain-containing protein 1 (Commd1), tetraspanin 8 (Tspan8), myoglobin (Mb), transmembrane protein 41B (Tmem41b), stromal cell-derived factor 2-like protein 1 (Sdf2l1), and peroxisomal biogenesis factor 5 (Pex5). Additionally, glucose metabolism-associated proteins, such as Sdf2l1 and non-POU domain-containing octamer-binding protein (Nono), were elevated in the FO group. Moreover, proteins linked to inflammation and antioxidant responses, including G protein-coupled receptor 108 (Gpr108), protein tyrosine phosphatase non-receptor type 2 (Ptpn2), Pex5, p120 catenin (Ctnnd1), tripartite motif-containing protein 16 (Trim16), and aquaporin 11 (Aqp11), were elevated in the FO group, while proteins involved in oxidative stress, such as reactive oxygen species modulator 1 (Romo1), cathepsin A (Ctsa), and Cullin 4A (Cul4a), were downregulated. These proteomic findings align with prior transcriptomic data, indicating that dietary fish oil enhances hepatic lipid metabolism, mitigates oxidative stress, and strengthens antioxidant capacity. Furthermore, these hepatic adaptations may synergistically support ovarian maturation in S. argus. This study provides novel proteomic-level evidence supporting the role of fish oil in modulating hepatic lipid and energy metabolism, thereby elucidating the role of fish oil in optimizing hepatic energy metabolism and redox homeostasis to influence reproductive processes, advancing our understanding of n-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA) in teleost liver physiology. Full article

Background: There is an urgent need to identify new biomarkers for early diagnosis and development of therapeutic strategies for diabetes mellitus (DM) patients who have invasive breast cancer (BC). We previously reported the increased activated form of 70 kDa ribosomal protein S6 kinase 1 (phospho-p70S6K1) in a triple-negative BC (TNBC) cell line MDA-MB-231 exposed to glycated albumin (GA) and in invasive ductal carcinoma tissues from T2DM patients, compared to untreated cells and their non-diabetic counterparts, respectively. Objective: We aimed to explore the function of p70S6K1 in GA-promoted TNBC progression. Methods: By employing small interference (si)RNA technology or blocking its kinase activity using its specific pharmacological inhibitor, we monitored cell invasion using Transwell^® inserts and the expression levels of activated signaling proteins and cancer-related proteins using Western blot. Results: In silico analysis revealed that high mRNA levels of p70S6K1 were associated with an unfavorable prognosis and progression to advanced stages of TNBC in DM patients. The downregulation/blockade of p70S6K1 inhibited GA-promoted MDA-MB-231 cell invasion and the phosphorylation of protein S6 and ERK1/2, the p70S6K1 downstream effector, and the key oncogenic signaling protein, respectively. The suppression of the expression of GA-upregulated cancer proteins, including enolase-2, capping protein CapG, galectin-3, and cathepsin D, was observed after p70S6K1 downregulation/blockade. Further in silico validation analyses revealed increased gene expression of galectin-3 in DM TNBC patients, resulting in poor overall survival and disease-free survival. Conclusions: Targeting p70S6K1 may present a valuable therapeutic strategy, while galectin-3 could serve as a potential prognostic biomarker for invasive BC progression in DM patients. Full article

Background: Chronic wounds, such as diabetic ulcers, often fail to progress through healing due to persistent inflammation, infections, and extracellular matrix (ECM) imbalances. Cathepsin D, an aspartate protease active in acidic environments, plays a pivotal role in wound healing by mediating inflammatory responses, ECM remodeling, and macrophage phenotype transitions. Its dysregulation, however, can impair healing, highlighting the need for targeted modulation of its activity. The aim of this study was to investigate the molecular interaction between Fe²⁺ and cathepsin D’s catalytic core and ionic zipper under physiological and acidic conditions to identify strategies to enhance tissue repair and accelerate the healing of chronic wounds. Methods: The molecular structure of active cathepsin D was obtained from the Protein Data Bank (PDB) and analyzed using UCSF Chimera. Molecular interactions between cathepsin D and ferrous ions (Fe²⁺) were studied, focusing on key residues (D33 and D231) and ionic zipper residues (E5, E180, and D187). Results: Our results showed that the active form of cathepsin D, a 96 kDa dimer, consisted of heterodimers with distinct amino acid chains, where residues D33 and D231 formed the active site, and E5, E180, and D187 constituted the ionic zipper. A functional pocket containing the conserved residues D33 and D231, essential for proteolytic activity, was identified. At physiological pH (~7.5), D33 exhibited the most potent interactions with Fe²⁺, with interaction energies of −7 × 10¹⁷ J at oxygen atoms of the carboxylate group (OD1) and α-carbon (CA) atoms, whereas D231 showed slightly lower energies of −6 × 10¹⁷ J at γ-carbon atom (CG) and CA atoms. At acidic pH (~4), E5 was the primary interacting residue, with the shortest distance to Fe²⁺ (2.69 Å), and showed stable interactions across several atoms, emphasizing its role in metal binding. Conclusions: pH conditions strongly influence the interaction of cathepsin D with Fe². At physiological pH, residues D33 and D231 demonstrate robust and energetically efficient binding with Fe²⁺. At the same time, under acidic conditions, E5 emerges as the primary residue involved, potentially affecting the ionic zipper of cathepsin D. These insights provide a molecular foundation for targeting specific residues to modulate cathepsin D activity, presenting promising opportunities for therapeutic strategies aimed at improving chronic wound healing. Full article

Background: Metastatic prostate cancer (mPCa) is marked by heterogeneity and therapy resistance, which arise from prolonged therapy regimens. This heterogeneity is reflected in various morphologic and genetic characteristics, biomarker expression, and other molecular mechanisms, thereby contributing to the complexity of the disease. Methods: To investigate tumor heterogeneity, the effects of androgen targeting therapy (ADT) on single-cell PSA secretion was assessed by analyzing the prostate cancer cell lines using a modified ELISpot platform. The FACS and cytospin techniques were employed to understand the influence of the cell cycle on PSA secretion patterns. Additionally, a proteome array was used to identify potential biomarkers from different PCa cell lines with varying metastatic potential. Results: Among the various PCa cell lines examined, PSA expression and secretion could be visualized only from the LNCaPs. PSA secretion from circulating tumor cells (CTCs) further confirmed the validity of this assay. These LNCaPs exhibited heterogeneity in single-cell intracellular and extracellular PSA expression and in their ADT responses. LNCaPs in the G1 phase showed higher PSA secretion than in the S or G2/M phase. Apart from PSA, Cathepsin D, Progranulin, IL-8, Serpin E1, and Enolase 2 were identified as secretome markers from the metastatic PCa cell lines. Conclusions: We observed variability in PSA secretion in LNCaP in response to anti-androgen treatment and a cell cycle-dependent secretion pattern. The notable presence of Progranulin and Cathepsin D in metastatic cell lines makes them promising candidates for use in multiplexing and single-cell platforms, potentially advancing our understanding and treatment of this disease. Full article

Parkinson’s disease (PD) is characterized by widespread distribution of Lewy bodies, which are composed of phosphorylated and aggregated forms of α-Synuclein (α-Syn), in the brain. Although the accumulation and propagation of α-Syn contribute to the development of PD, the involvement of the blood–brain barrier (BBB) in these processes remains unknown. Pericytes, one of the cell types that constitute the BBB, degrade various forms of α-Syn. However, the detailed mechanisms involved in α-Syn degradation by pericytes remain poorly understood. Therefore, in this study, we aimed to determine the ability of the BBB-constituting cells, particularly primary cultures of rat pericytes, brain endothelial cells, and astrocytes, to degrade α-Syn. After α-Syn uptake by the cells, intracellular α-Syn decreased only in pericytes. This pericyte-specific α-Syn decrease was inhibited by an autophagy inhibitor, bafilomycin A1, and a proteasome inhibitor, MG132. siRNA-mediated knockdown of degradation enzymes or familial PD-associated genes, including cathepsin D, DJ-1, and LRRK2, did not affect α-Syn clearance in pericytes. However, pharmacological inhibitors of Akt, ERK, and p38 MAPK inhibited α-Syn degradation by pericytes. In conclusion, our results suggest that α-Syn degradation by pericytes is mediated by an autophagy–lysosome system and a ubiquitin–proteasome system via α-Syn-activated Akt, ERK, and p38 MAPK signaling pathways. Full article