The Role of Cathepsin B in Pathophysiologies of Non-tumor and Tumor tissues: A Systematic Review

NF-kappa-B inhibitor alpha mediates cancer stemness characteristics in oral squamous cell carcinoma by interacting with cathepsin B

The role of NF-kappa-B inhibitor alpha (IκBα), a well-established negative regulator of the NF-κB signalling pathway in cancer is complex, as evidenced by either promoting or suppressing tumourigenesis, depending on the cancer type, however, in oral squamous cell carcinoma (OSCC) remains unelucidated. Here, for the first time, we report that the elevated levels of both NKFBIA mRNA and IκBα protein in OSCC tumour tissues and OSCC cell lines. Meanwhile, IκBα silencing resulted in the suppression of cell proliferation, migration and invasion in OSCC. In addition, we demonstrated that IκBα can mediate the OSCC stemness and epithelial-mesenchymal transition (EMT) characteristics by directly interacting with cathepsin B (CTSB) and thus, facilitating the progression toward carcinogenesis. More importantly, we identified Psammaplin A (PsA), a natural metabolite derived from marine sponges that would disrupt the IκBα-CTSB interaction via competition, thereby reducing oral spheres formation, cell viability and OSCC tumour growth in vivo, clearly demonstrating its potential as an effective therapeutic agent that specifically targets this oncogenic complex. In summary, we have unveiled a novel mechanism underlying the oncogenic role of IκBα-CTSB complex in OSCC, which may offer the therapeutic potential of targeting this complex with PsA for the treatment of OSCC.

Exercise-mediated muscle-hypothalamus crosstalk: Improvement for cognitive dysfunction caused by disrupted circadian rhythm

In contemporary societal evolution, the increasing disruption of the natural sleep-wake cycle, attributable to factors such as shift work and overexposure to artificial light, has been paralleled by a marked escalation in the incidence of cognitive impairments and the prevalence of neurodegenerative diseases. Current management strategies for cognitive impairments include pharmacological and non-pharmacological interventions. Pharmacological interventions for cognitive impairments typically involve medications to manage cognitive symptoms and improve neurological functions. However, these drugs show limited long-term efficacy in slowing disease progression and may cause side effects. Given the widespread occurrence of cognitive dysfunction, it is crucial to develop accessible non-pharmacological interventions. Physical activity and exercise have emerged as pivotal lifestyle determinants known to exert a modulatory effect on the risk profile for cognitive dysfunction caused by disrupted circadian rhythms. The skeletal muscle, a dynamic tissue, undergoes a profound morphological and metabolic reconfiguration in response to physical exertion, along with the secretion of myokines. Additionally, the hypothalamus, particularly the ventromedial nuclei, arcuate nuclei, and the suprachiasmatic nucleus, have crucial functions in regulating physical activity, influencing energy metabolism, and managing circadian cycles. Nevertheless, the communication between the hypothalamus and skeletal muscle during exercise is not fully understood. This narrative review integrates current knowledge on the interaction between the hypothalamus and skeletal muscle during exercise, emphasizing its neuroendocrine effects and potential therapeutic implications for alleviating cognitive dysfunction associated with disrupted circadian rhythms.

Structure-guided virtual screening reveals phytoconstituents as potent cathepsin B inhibitors: Implications for cancer, traumatic brain injury, and Alzheimer's disease

Cathepsin B (CathB) is a lysosomal cysteine protease involved in various pathological and physiological processes and is becoming an attractive target for drug intervention in complex diseases like cancer, traumatic brain injury (TBI) and Alzheimer's disease (AD). The aberrant expression of CathB drives tumor invasiveness and metastasis and exacerbates neurodegeneration and behavioral deficits in AD and TBI. However, current CathB inhibitors lack clinical translation due to poor selectivity, bioavailability, or toxicity, necessitating novel therapeutic candidates. To address this gap, an in silico screening was conducted through the structure-guided virtual screening with the IMPPAT 2 phytochemical library for potential CathB inhibitors. Using the control inhibitor CA-074Me as a benchmark, two phytoconstituents, Nicandrenone and Picrasidine M, emerged with superior binding affinities, ligand efficiency, and robust interactions with the active site residues of CathB. These molecules were further validated through molecular dynamics (MD) simulations, which supported their ability to bind stably to the CathB active pocket and thus likely hold their durable inhibitory activity. Remarkably, these phytoconstituents exhibited favorable pharmacokinetic and ADMET profiles, which validate their potential as lead compounds. The current study showed that these bioactive compounds could be developed as new CathB inhibitors, opening a new frontier for their use in the management of such diseases as cancer, TBI, and AD.

Unraveling the Role of Cathepsin B Variants in Polycystic Ovary Syndrome: Insights from a Case-Control Study and Computational Analyses

Polycystic ovary syndrome (PCOS) occurs in women of reproductive age, impairing reproductive and metabolic processes. Variations in the cathepsin B (CTSB) gene can influence the disease prognosis by changing the activity, stability, or expression. These single-nucleotide polymorphisms (SNPs) can affect critical cellular functions like the deposition of extracellular matrix, inflammation, and tissue repair, leading to the development of multifactorial diseases. Our study aims to investigate the association between PCOS risk and CTSB SNPs. In this case-control study, 150 PCOS cases and 150 healthy women were enrolled. Genotyping was conducted using the PCR-RFLP method. Different computational databases were used to predict the impact of variations on the splicing sites. Regarding rs12898, the codominant homozygous (GG vs. AA) and recessive (GG vs. AA + AG) inheritance models reduced PCOS risk by 72% and 71%, respectively. PCOS risk was increased by 2.81, 2.94, 1.62, and 2.20 folds in the codominant (TT vs. CC), recessive (TT vs. CC + CT), T vs. C (rs8898), and T vs. C (rs3779659) modes, respectively. Based on haplotype analysis, Ars12898Trs8898Crs3779659, and Ars12898Crs8898Trs3779659 haplotypes significantly enhance PCOS risk by 1.57 and 3.34 folds, respectively. Furthermore, the interaction analysis indicated that AGrs12898/TTrs8898/CCrs3779659 and AAs12898/TTrs8898/CCrs3779659 genotype combinations strongly correlated with high PCOS risks by 2.59 and 4.20 folds, respectively. The CTSB rs12898 G > A and rs8898 C > T can potentially create or disrupt binding sites for several splicing factors. CTSB rs12898, rs8898, and rs3779659 SNPs were associated with PCOS risk in our population. Larger sample sizes will be necessary to confirm these findings and investigate other potential causal factors involved in PCOS etiology.

Cathepsins and their role in gynecological cancers: Evidence from two-sample Mendelian randomization analysis

Prior studies have reported connections between cathepsins (CTS) and gynecological cancers; however, the exact causal links are yet to be fully understood. Leveraging publicly accessible genome-wide association study summary datasets, we performed a two-sample bidirectional Mendelian randomization (MR) and multivariate MR (MVMR) analysis, with the inverse variance weighted (IVW) method as the primary approach. MR analysis demonstrated inverse associations between CTSB and cervical cancer (IVW: odds ratio [OR] = 0.9995, 95% confidence interval [CI] = 0.9991-0.9999, P = .0418), CTSE and ovarian cancer (IVW: OR = 0.9197, 95% CI = 0.8505-0.9944, P = .0358), CTSZ and ovarian cancer (IVW: OR = 0.9449, 95% CI = 0.8938-0.9990, P = .0459), CTSE and high grade serous ovarian cancer (IVW: OR = 0.8939, 95% CI = 0.8248-0.9689, P = .0063), and CTSZ and high grade serous ovarian cancer (IVW: OR = 0.9269, 95% CI = 0.8667-0.9913, P = .0268). A positive correlation was identified between CTSH and clear cell ovarian cancer (IVW: OR = 1.1496, 95% CI = 1.0368-1.2745, P = .0081). Nevertheless, subsequent adjustment for the false discovery rate revealed that none of the P-values retained statistical significance (PFDR > 0.05). MVMR analysis results elucidated that CTSZ was inversely associated with cervical cancer (IVW: OR = 0.9988, 95% CI = 0.9981-0.9996, P = .0022). Moreover, a positive association was noted between CTSF and cervical cancer (IVW: OR = 1.0007, 95% CI = 1.0000-1.0014, P = .0364), and similarly, between CTSS and cervical cancer (IVW: OR = 1.0005, 95% CI = 1.0000-1.0011, P = .0490). CTSO exhibited a positive association with non-endometrioid endometrial cancer (IVW: OR = 1.4405, 95% CI = 1.1864-1.7490, P < .001), and CTSH was positively associated with clear cell ovarian cancer (IVW: OR = 1.1167, 95% CI = 1.0131-1.2310, P = .0263). The MVMR analysis findings reveal that CTSZ emerges as a protective element against cervical cancer, whereas CTSF and CTSS represent risk factors for this disease. CTSO stands out as a risk factor for non-endometrioid endometrial cancer, and CTSH acts as a risk factor for clear cell ovarian cancer. This study elucidates causative connections between CTS and gynecological cancers, providing innovative insights for diagnostic and therapeutic optimization.

In silico evaluation of missense SNPs in cancer-associated Cystatin A protein and their potential to disrupt Cathepsin B interaction

Cystatin A (CSTA) functions as a cysteine protease inhibitor by forming tight complexes with the cathepsins. Pathogenic mutations in the CSTA gene can disrupt this interaction, potentially leading to physiological ailments. In this study, eight bioinformatics tools (SIFT, PolyPhen-2, PROVEAN, P-Mut, MutPred2, SNAP2, SNPs & GO, and PHD-SNP) were implemented to analyze non-synonymous SNPs from the dbSNP database. Five mutations (Y43C, Y43N, V48F, Y53H, and E94K) located in the conserved region were found to be highly deleterious and less stabilizing. The protein-protein interaction network found that Cathepsin B (CTSB) interacts highly with CSTA. Mutated CSTAs were created by homology modeling, and their altered binding with CTSB was examined through molecular docking and dynamics simulations. Among these, the Y53H (rs1448459675) and E94K (rs200394711) mutants were recognized as weaker inhibitors because they had 2.5 % and an 8 % lower binding affinity, respectively. Moreover, the E94K-CTSB complex, with a root mean square deviation (RMSD) above 5 Å, was found to be highly unstable during molecular dynamics. The root mean square fluctuation (RMSF) of the E94K mutant showed insufficient flexibility, indicating a reduced capacity to suppress CTSB. These findings suggest that the E94K mutation could affect the protein structure and cathepsin B interaction, potentially leading to pathological consequences as evidenced by colorectal adenocarcinoma patients in the COSMIC (Catalogue of Somatic Mutations in Cancer) database.

Insights on the crosstalk among different cell death mechanisms

The phenomenon of cell death has garnered significant scientific attention in recent years, emerging as a pivotal area of research. Recently, novel modalities of cellular death and the intricate interplay between them have been unveiled, offering insights into the pathogenesis of various diseases. This comprehensive review delves into the intricate molecular mechanisms, inducers, and inhibitors of the underlying prevalent forms of cell death, including apoptosis, autophagy, ferroptosis, necroptosis, mitophagy, and pyroptosis. Moreover, it elucidates the crosstalk and interconnection among the key pathways or molecular entities associated with these pathways, thereby paving the way for the identification of novel therapeutic targets, disease management strategies, and drug repurposing.

Physical activity, cathepsin B, and cognitive health

Regular physical activity (PA) is beneficial for cognitive health, and cathepsin B (CTSB) - a protease released by skeletal muscle during PA - acts as a potential molecular mediator of this association. PA-induced metabolic and mechanical stress appears to increase plasma/serum CTSB levels. CTSB facilitates neurogenesis and synaptic plasticity in brain regions (e.g., hippocampus and prefrontal cortex) that support performance in specific cognitive domains including memory, learning, and executive function. However, the evidence regarding the role of PA-induced changes in CTSB as a mediator of PA-induced cognitive health in humans is mixed. To guide future research, this article identifies key factors that may explain the observed heterogeneity in the findings from human studies and proposes a PA-CTSB-cognition model.

Unveiling Cathepsin B inhibition with repurposed drugs for anticancer and anti-Alzheimer's drug discovery

Alzheimer's disease (AD) is characterized by the aggregation of amyloid β (Aβ) peptides and the formation of plaques in the brain, primarily derived from the proteolytic degradation of amyloid precursor protein (APP). Cathepsin B (CatB) is a cysteine protease that plays a pivotal role in this process, making it a potential target for the development of anti-Alzheimer's therapies. Apart from AD, CatB is implicated in various physiological and pathological processes, including cancer. Given the critical role of CatB in these diseases, identifying effective inhibitors is of significant therapeutic interest. In this study, we employed a systematic virtual screening approach using repurposed molecules from the DrugBank database to identify potential CatB inhibitors. Primarily, we focused on binding affinities and selectivity to pinpoint potential hits against CatB. Two repurposed molecules, Lurasidone and Paliperidone, emerged as promising candidates with significant affinity for CatB. These molecules demonstrated favorable drug profiles and exhibited preferential binding to the catalytic pocket of CatB via interacting with functionally significant residues. To further explore the binding mechanism and stability of the CatB-drug complexes, molecular dynamics (MD) simulations were conducted for 500 ns. The results revealed that CatB and Lurasidone, as well as Paliperidone, form stable complexes throughout the simulation. Taken together, the findings suggest that Lurasidone and Paliperidone can act as repurposed CatB inhibitors with potential applications in the development of therapeutics against AD and other CatB-associated diseases after further validation.

Muscle-brain crosstalk mediated by exercise-induced myokines - insights from experimental studies

Over the past couple of decades, it has become apparent that skeletal muscles might be engaged in endocrine signaling, mostly as a result of exercise or physical activity in general. The importance of this phenomenon is currently studied in terms of the impact that exercise- or physical activity -induced signaling factors have, in the interaction of the "muscle-brain crosstalk." So far, skeletal muscle-derived myokines were demonstrated to intercede in the connection between muscles and a plethora of various organs such as adipose tissue, liver, or pancreas. However, the exact mechanism of muscle-brain communication is yet to be determined. It is speculated that, in particular, brain-derived neurotrophic factor (BDNF), irisin, cathepsin B (CTSB), interleukin 6 (IL-6), and insulin-like growth factor-1 (IGF-1) partake in this crosstalk by promoting neuronal proliferation and synaptic plasticity, also resulting in improved cognition and ameliorated behavioral alterations. Researchers suggest that myokines might act directly on the brain parenchyma via crossing the blood-brain barrier (BBB). The following article reviews the information available regarding rodent studies on main myokines determined to cross the BBB, specifically addressing the association between exercise-induced myokine release and central nervous system (CNS) impairments. Although the hypothesis of skeletal muscles being critical sources of myokines seems promising, it should not be forgotten that the origin of these factors might vary, depending on the cell types engaged in their synthesis. Limited amount of research providing information on alterations in myokines expression in various organs at the same time, results in taking them only as circumstantial evidence on the way to determine the actual involvement of skeletal muscles in the overall state of homeostasis. The following article reviews the information available regarding rodent studies on main myokines determined to cross the BBB, specifically addressing the association between exercise-induced myokine release and CNS impairments.

Structure based interaction and molecular dynamics studies of cysteine protease Cathepsin B against curcumin and resveratrol

The lysosomal cysteine peptidase Cathepsin B is identified as a pivotal contributor to cancer development. In the pursuit of discovering less toxic inhibitors for Cathepsin B, various organic compounds have undergone thorough investigation and are being studied at the moment in clinical studies for cancer treatment. Notably, curcumin and resveratrol emerge as prominent candidates. However, the precise molecular mechanism underlying the inhibition of Cathepsin B by these compounds remains elusive. To address this gap, we conducted molecular docking and dynamics studies to unravel the interaction dynamics between Cathepsin B and phytochemicals such as curcumin and resveratrol. Remarkably, Molecular docking studies revealed that curcumin and resveratrol exhibit high binding affinities 7.599 and 6.103 kcal/mol, respectively, positioning them as promising inhibitors for Cathepsin B. Further insights from 150 ns of molecular dynamics simulations, incorporating structural analyses encompassing RMSF, RMSD, Rg, SASA, and H-bond analysis, indicate the superior stability of curcumin compared to resveratrol. Additionally, we assessed their drug-likeness properties using the PreADMET web server, and the MM/BPSA method facilitated the calculation of binding energies for the complexes. On targeting Cathepsin B, this research promises to contribute to the development of drugs that inhibit the progression of cancer.

Melittin treatment suppressed malignant NSCLC progression through enhancing CTSB-mediated hyperautophagy

Melittin is preclinically investigated as anticancer agent in multiple tumor types. But its regulation role and regulatory mechanism regarding NSCLC is unknown. In our investigation, Proteomic test was employed to identify proteins that expressed abnormally in cancer cells and that with Melittin treatmented. The results showed CTSB was one of the Top proteins with different expression levels in the lysosomes of Melittin-treatmented cancer cells and showed an up-regulation trend. CTSB expression was increased in NSCLC cancer tissues compared to adjacent normal tissues, as demonstrated in lung cancer tissue chips experiment. However, Melittin treatment increased the CTSB level in lysosomes, which inhibited the malignant progression of NSCLC. We hypothesized that the relative homeostasis of CTSB in cancer cells was destroyed, and CTSB exerts its hydrolytic effect excessively, resulting in excessive autophagy of cancer cells, thus inhibiting the malignant progression of cancer cells. The direct combination of Melittin and CTSB was proposed by molecular docking technique, LiP-SMap was used to analyze the target genes and active components extracted from high-throughput sequencing proteomic data, and successfully verified that melittin was successfully demonstrated to directly target CTSB-binding. In vivo and in vitro studies have shown that Melittin treatment inhibits the malignant progression of A549 and HCC1833 cells and animal tumors, namely non-small cell lung cancer, by promoting CTSB-mediated hyperautophagy. CTSB-specific inhibitor CA-074 Me and autophagy inhibitor 3-MA treatment reversed the inhibit effect of Melittin to the malignant progression of NSCLC. Taken together, Melittin treatment inhibited malignant progression regarding NSCLC through enhancing CTSB-mediated hyperautophagy.

Nano revolution of DNA nanostructures redefining cancer therapeutics-A comprehensive review

DNA nanostructures are a promising tool in cancer treatment, offering an innovative way to improve the effectiveness of therapies. These nanostructures can be made solely from DNA or combined with other materials to overcome the limitations of traditional single-drug treatments. There is growing interest in developing nanosystems capable of delivering multiple drugs simultaneously, addressing challenges such as drug resistance. Engineered DNA nanostructures are designed to precisely deliver different drugs to specific locations, enhancing therapeutic effects. By attaching targeting molecules, these nanostructures can recognize and bind to cancer cells, increasing treatment precision. This approach offers tailored solutions for targeted drug delivery, enabling the delivery of multiple drugs in a coordinated manner. This review explores the advancements and applications of DNA nanostructures in cancer treatment, with a focus on targeted drug delivery and multi-drug therapy. It discusses the benefits and current limitations of nanoscale formulations in cancer therapy, categorizing DNA nanostructures into pure forms and hybrid versions optimized for drug delivery. Furthermore, the review examines ongoing research efforts and translational possibilities, along with challenges in clinical integration. By highlighting the advancements in DNA nanostructures, this review aims to underscore their potential in improving cancer treatment outcomes.

Modular Development of Enzyme-Activatable Proteolysis Targeting Chimeras for Selective Protein Degradation and Cancer Targeting

As an emerging therapeutic modality, proteolysis targeting chimeras (PROTACs) indiscriminately degrade proteins in both healthy and diseased cells, posing a risk of on-target off-site toxicity in normal tissues. Herein, we present the modular development of enzyme-activatable PROTACs, which utilize enzyme-recognition moieties to block protein degradation activities and can be specifically activated by elevated enzymes in cancer cells to enable cell-selective protein degradation and cancer targeting. We identified the methylene alkoxy carbamate (MAC) unit as an optimal self-immolative linker, possessing high stability and release efficiency for conjugating enzyme-recognition moieties with PROTACs. Leveraging the MAC linker, we developed a series of enzyme-activatable PROTACs, harnessing distinct enzymes for cancer-cell-selective protein degradation. Significantly, we introduced the first dual-enzyme-activatable PROTAC that requires the presence of two cancer-associated enzymes for activation, demonstrating highly selective protein degradation in cancer cells over nonmalignant cells, potent in vivo antitumor efficacy, and no off-tumor toxicity to normal tissues. The broad applicability of enzyme-activatable PROTACs was further demonstrated by caging other PROTACs via the MAC linker to target different proteins and E3 ligases. Our work underscores the substantial potential of enzyme-activatable PROTACs in overcoming the off-site toxicity associated with conventional PROTACs and offers new opportunities for targeted cancer treatment.

Identification of ferroptosis-related gene signature for tuberculosis diagnosis and therapy efficacy

Diagnosis of tuberculosis remains a challenge when microbiological tests are negative. Immune cell atlas of patients with tuberculosis and healthy controls were established by single-cell transcriptome. Through integrated analysis of scRNA-seq with microarray and bulk RNA sequencing data, a ferroptosis-related gene signature containing ACSL4, CTSB, and TLR4 genes that were associated with tuberculosis disease was identified. Four gene expression datasets from blood samples of patients with tuberculosis, latent tuberculosis infection, and healthy controls were used to assess the diagnostic value of the gene signature. The areas under the ROC curve for the combined gene signature were 1.000, 0.866, 0.912, and 0.786, respectively, in differentiating active tuberculosis from latent infection. During anti-tuberculosis treatment, the expression of the gene signature decreased significantly in cured patients with tuberculosis. In conclusion, the ferroptosis-related gene signature was associated with tuberculosis treatment efficacy and was a promising biomarker for differentiating active tuberculosis from latent infection.

Milk Fat Globule Membrane-Containing Protein Powder Promotes Fitness in Caenorhabditis elegans

Milk-derived peptides and milk fat globule membrane (MFGM) have gained interest as health-promoting food ingredients. However, the mechanisms by which these nutraceuticals modulate the function of biological systems often remain unclear. We utilized Caenorhabditis elegans to elucidate how MFGM-containing protein powder (MProPow), previously used in a clinical trial, affect the physiology of this model organism. Our results demonstrate that MProPow does not affect lifespan but promotes the fitness of the animals. Surprisingly, gene expression analysis revealed that MProPow decreases the expression of genes functioning on innate immunity, which also translates into reduced survival on pathogenic bacteria. One of the innate immunity-associated genes showing reduced expression upon MProPow supplementation is cpr-3, the homolog of human cathepsin B. Interestingly, knockdown of cpr-3 enhances fitness, but not in MProPow-treated animals, suggesting that MProPow contributes to fitness by downregulating the expression of this gene. In summary, this research highlights the value of C. elegans in testing the biological activity of food supplements and nutraceuticals. Furthermore, this study should encourage investigations into whether milk-derived peptides and MFGM mediate their beneficial effects through the modulation of cathepsin B expression in humans.

Association of Serum Proteases and Acute Phase Factors Levels with Survival Outcomes in Patients with Colorectal Cancer

Colorectal cancer (CRC) represents a substantial burden on global healthcare, contributing to significant morbidity and mortality worldwide. Despite advances in screening methodologies, its incidence remains high, necessitating continued efforts in early detection and treatment. Neoplastic invasion and metastasis are primary determinants of CRC lethality, emphasizing the urgency of understanding underlying mechanisms to develop effective therapeutic strategies. This study aimed to explore the potential of serum biomarkers in predicting survival outcomes in CRC patients, with a focus on cathepsin B (CB), leukocytic elastase (LE), total sialic acid (TSA), lipid-associated sialic acid (LASA), antitrypsin activity (ATA), C-reactive protein (CRP), and cystatin C (CC). We recruited 185 CRC patients and 35 healthy controls, assessing demographic variables, tumor characteristics, and 7 serum biomarker levels, including (1) CB, (2) LE, (3) TSA, (4) LASA, (5) ATA, (6) CRP, and (7) CC. Statistical analyses included ANOVA with Tukey's post hoc tests and MANOVA for continuous variables. Student's t-test was used for dependent samples, while non-parametric tests like Mann-Whitney U and Wilcoxon signed-rank tests were applied for variables deviating from the normal distribution. Categorical variables were assessed using chi-square and Kruskal-Wallis tests. Spearman's rank correlation coefficient was utilized to examine variable correlations. Survival analysis employed the Kaplan-Meier method with a log-rank test for comparing survival times between groups. Significant associations were observed between CB (p = 0.04), LE (p = 0.01), and TSA (p = 0.008) levels and survival outcomes in CRC patients. Dukes' classification stages also showed a significant correlation with survival (p = 0.001). However, no significant associations were found for LASA, ATA, CRP, and CC. Multivariate analysis of LE, TSA, and ATA demonstrated a notable correlation with survival (p = 0.041), notwithstanding ATA's lack of significance in univariate analysis (p = 0.13). CB, LE, and TSA emerged as promising diagnostic markers with prognostic value in CRC, potentially aiding in early diagnosis and treatment planning. Further research is needed to validate these findings and explore additional prognostic indicators.

Autophagic-lysosomal damage induced by swainsonine is protected by trehalose through activation of TFEB-regulated pathway in renal tubular epithelial cells

Swainsonine (SW) is the main toxic component of locoweed. Previous studies have shown that kidney damage is an early pathologic change in locoweed poisoning in animals. Trehalose induces autophagy and alleviates lysosomal damage, while its protective effect and mechanism against the toxic injury induced by SW is not clear. Based on the published literature, we hypothesize that transcription factor EB(TFEB) -regulated is targeted by SW and activating TFEB by trehalose would reverse the toxic effects. In this study, we investigate the mechanism of protective effects of trehalose using renal tubular epithelial cells. The results showed that SW induced an increase in the expression level of microtubule-associated protein light chain 3-II and p62 proteins and a decrease in the expression level of ATPase H+ transporting V1 Subunit A, Cathepsin B, Cathepsin D, lysosome-associated membrane protein 2 and TFEB proteins in renal tubular epithelial cells in a time and dose-dependent manner suggesting TFEB-regulated lysosomal pathway is adversely affected by SW. Conversely, treatment with trehalose, a known activator of TFEB promote TFEB nuclear translocation suggesting that TFEB plays an important role in protection against SW toxicity. We demonstrated in lysosome staining that SW reduced the number of lysosomes and increased the luminal pH, while trehalose could counteract these SW-induced effects. In summary, our results demonstrated for the first time that trehalose could alleviate the autophagy degradation disorder and lysosomal damage induced by SW. Our results provide an interesting method for reversion of SW-induced toxicity in farm animals and furthermore, activation of TFEB by trehalose suggesting novel mechanism of treating lysosomal storage diseases.

Role of Cathepsin B Expression in Oral Squamous Cell Carcinoma: A Comprehensive Review

This comprehensive review delves into the intricate landscape of oral squamous cell carcinoma (OSCC) by examining the role of cathepsin B expression in its pathogenesis. OSCC, a prevalent and clinically significant oral malignancy, poses a considerable global health burden, necessitating a thorough exploration of its underlying molecular mechanisms. Cathepsin B, a lysosomal cysteine protease, emerges as a critical player in OSCC, influencing tumour initiation, invasion, and metastasis. The review begins with a brief overview of OSCC, emphasizing its epidemiological and clinical features, followed by exploring the significance of studying cathepsin B expression in this context. In the manuscript, the structure and function of cathepsin B are elucidated, providing a foundation for understanding its aberrant expression in OSCC. Clinical studies revealing correlations with tumour grade and stage, along with prognostic significance, are scrutinized, offering insights into the potential diagnostic and prognostic utility of cathepsin B. The biological functions of cathepsin B in OSCC, including its impact on tumour invasion and modulation of apoptosis, are comprehensively discussed. The Therapeutic Implications section explores targeting cathepsin B as a potential strategy, emphasizing the need for future research to overcome associated challenges. In the Conclusion section, the review synthesizes key findings, delineates implications for future research, and highlights the potential impact of cathepsin B on OSCC diagnosis and treatment, contributing to the ongoing efforts to advance our understanding of this complex malignancy, which is associated with a high mortality rate and improve clinical outcomes.

Development of a Novel Biomarker for the Progression of Idiopathic Pulmonary Fibrosis

The progression of idiopathic pulmonary fibrosis (IPF) is diverse and unpredictable. We identified and validated a new biomarker for IPF progression. To identify a candidate gene to predict progression, we assessed differentially expressed genes in patients with advanced IPF compared with early IPF and controls in three lung sample cohorts. Candidate gene expression was confirmed using immunohistochemistry and Western blotting of lung tissue samples from an independent IPF clinical cohort. Biomarker potential was assessed using an enzyme-linked immunosorbent assay of serum samples from the retrospective validation cohort. We verified that the final candidate gene reflected the progression of IPF in a prospective validation cohort. In the RNA-seq comparative analysis of lung tissues, CD276, COL7A1, CTSB, GLI2, PIK3R2, PRAF2, IGF2BP3, and NUPR1 were up-regulated, and ADAMTS8 was down-regulated in the samples of advanced IPF. Only CTSB showed significant differences in expression based on Western blotting (n = 12; p < 0.001) and immunohistochemistry between the three groups of the independent IPF cohort. In the retrospective validation cohort (n = 78), serum CTSB levels were higher in the progressive group (n = 25) than in the control (n = 29, mean 7.37 ng/mL vs. 2.70 ng/mL, p < 0.001) and nonprogressive groups (n = 24, mean 7.37 ng/mL vs. 2.56 ng/mL, p < 0.001). In the prospective validation cohort (n = 129), serum CTSB levels were higher in the progressive group than in the nonprogressive group (mean 8.30 ng/mL vs. 3.00 ng/mL, p < 0.001). After adjusting for baseline FVC, we found that CTSB was independently associated with IPF progression (adjusted OR = 2.61, p < 0.001). Serum CTSB levels significantly predicted IPF progression (AUC = 0.944, p < 0.001). Serum CTSB level significantly distinguished the progression of IPF from the non-progression of IPF or healthy control.

The Significance of Cathepsin B in Mediating Radiation Resistance in Colon Carcinoma Cell Line (Caco-2)

Cathepsins (Caths) are lysosomal proteases that participate in various physiological and pathological processes. Accumulating evidence suggests that caths play a multifaceted role in cancer progression and radiotherapy resistance responses. Their proteolytic activity influences the tumor's response to radiation by affecting oxygenation, nutrient availability, and immune cell infiltration within the tumor microenvironment. Cathepsin-mediated DNA repair mechanisms can promote radioresistance in cancer cells, limiting the efficacy of radiotherapy. Additionally, caths have been associated with the activation of prosurvival signaling pathways, such as PI3K/Akt and NF-κB, which can confer resistance to radiation-induced cell death. However, the effectiveness of radiotherapy can be limited by intrinsic or acquired resistance mechanisms in cancer cells. In this study, the regulation and expression of cathepsin B (cath B) in the colon carcinoma cell line (caco-2) before and after exposure to radiation were investigated. Cells were exposed to escalating ionizing radiation doses (2 Gy, 4 Gy, 6 Gy, 8 Gy, and 10 Gy). Analysis of protein expression, in vitro labeling using activity-based probes DCG04, and cath B pull-down revealed a radiation-induced up-regulation of cathepsin B in a dose-independent manner. Proteolytic inhibition of cathepsin B by cathepsin B specific inhibitor CA074 has increased the cytotoxic effect and cell death due to ionizing irradiation treatment in caco-2 cells. Similar results were also obtained after cathepsin B knockout by CRISPR CAS9. Furthermore, upon exposure to radiation treatment, the inhibition of cath B led to a significant upregulation in the expression of the proapoptotic protein BAX, while it induced a significant reduction in the expression of the antiapoptotic protein BCL-2. These results showed that cathepsin B could contribute to ionizing radiation resistance, and the abolishment of cathepsin B, either by inhibition of its proteolytic activity or expression, has increased the caco-2 cells susceptibility to ionizing irradiation.

Cathepsin-facilitated invasion of BMI1-high hepatocellular carcinoma cells drives bile duct tumor thrombi formation

Bile duct tumor thrombosis (BDTT) is a complication mostly observed in patients with advanced hepatocellular carcinoma (HCC), causing jaundice and associated with poor clinical outcome. However, its underlying molecular mechanism is unclear. Here, we develop spontaneous preclinical HCC animal models with BDTT to identify the role of BMI1 expressing tumor initiating cells (BMI1high TICs) in inducing BDTT. BMI1 overexpression transforms liver progenitor cells into BMI1high TICs, which possess strong tumorigenicity and increased trans-intrahepatic biliary epithelial migration ability by secreting lysosomal cathepsin B (CTSB). Orthotopic liver implantation of BMI1high TICs into mice generates tumors and triggers CTSB mediated bile duct invasion to form tumor thrombus, while CTSB inhibitor treatment prohibits BDTT and extends mouse survival. Clinically, the elevated serum CTSB level determines BDTT incidence in HCC patients. Mechanistically, BMI1 epigenetically up-regulates CTSB secretion in TICs by repressing miR-218-1-3p expression. These findings identify a potential diagnostic and therapeutic target for HCC patients with BDTT.