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Communications Biology Oct 2023Lung cancer, a major contributor to cancer-related fatalities worldwide, involves a complex pathogenesis. Cathepsins, lysosomal cysteine proteases, play roles in various...
Lung cancer, a major contributor to cancer-related fatalities worldwide, involves a complex pathogenesis. Cathepsins, lysosomal cysteine proteases, play roles in various physiological and pathological processes, including tumorigenesis. Observational studies have suggested an association between cathepsins and lung cancer. However, the causal link between the cathepsin family and lung cancer remains undetermined. This study employed Mendelian randomization analyses to investigate this causal association. The univariable Mendelian randomization analysis results indicate that elevated cathepsin H levels increase the overall risk of lung cancer, adenocarcinoma, and lung cancer among smokers. Conversely, reverse Mendelian randomization analyses suggest that squamous carcinoma may lead to increased cathepsin B levels. A multivariable analysis using nine cathepsins as covariates reveals that elevated cathepsin H levels lead to an increased overall risk of lung cancer, adenocarcinoma, and lung cancer in smokers. In conclusion, cathepsin H may serve as a marker for lung cancer, potentially inspiring directions in lung cancer diagnosis and treatment.
Topics: Humans; Cathepsin H; Lung Neoplasms; Mendelian Randomization Analysis; Cathepsin L; Adenocarcinoma
PubMed: 37805623
DOI: 10.1038/s42003-023-05408-7 -
Signal Transduction and Targeted Therapy Oct 2023Patients with chronic obstructive pulmonary disease (COPD) who exhibit elevated blood eosinophil levels often experience worsened lung function and more severe...
Patients with chronic obstructive pulmonary disease (COPD) who exhibit elevated blood eosinophil levels often experience worsened lung function and more severe emphysema. This implies the potential involvement of eosinophils in the development of emphysema. However, the precise mechanisms underlying the development of eosinophil-mediated emphysema remain unclear. In this study, we employed single-cell RNA sequencing to identify eosinophil subgroups in mouse models of asthma and emphysema, followed by functional analyses of these subgroups. Assessment of accumulated eosinophils unveiled distinct transcriptomes in the lungs of mice with elastase-induced emphysema and ovalbumin-induced asthma. Depletion of eosinophils through the use of anti-interleukin-5 antibodies ameliorated elastase-induced emphysema. A particularly noteworthy discovery is that eosinophil-derived cathepsin L contributed to the degradation of the extracellular matrix, thereby leading to emphysema in pulmonary tissue. Inhibition of cathepsin L resulted in a reduction of elastase-induced emphysema in a mouse model. Importantly, eosinophil levels correlated positively with serum cathepsin L levels, which were higher in emphysema patients than those without emphysema. Expression of cathepsin L in eosinophils demonstrated a direct association with lung emphysema in COPD patients. Collectively, these findings underscore the significant role of eosinophil-derived cathepsin L in extracellular matrix degradation and remodeling, and its relevance to emphysema in COPD patients. Consequently, targeting eosinophil-derived cathepsin L could potentially offer a therapeutic avenue for emphysema patients. Further investigations are warranted to explore therapeutic strategies targeting cathepsin L in emphysema patients.
Topics: Animals; Humans; Mice; Asthma; Cathepsin L; Emphysema; Eosinophils; Lung; Pancreatic Elastase; Pulmonary Disease, Chronic Obstructive; Pulmonary Emphysema
PubMed: 37816708
DOI: 10.1038/s41392-023-01634-x -
Acta Pharmacologica Sinica Dec 2016Cathepsin L (CTSL), a lysosomal acid cysteine protease, is known to play important roles in tumor metastasis and chemotherapy resistance. In this study we investigated...
AIM
Cathepsin L (CTSL), a lysosomal acid cysteine protease, is known to play important roles in tumor metastasis and chemotherapy resistance. In this study we investigated the molecular mechanisms underlying the regulation of chemoresistance by CTSL in human lung cancer cells.
METHODS
Human lung cancer A549 cells, A549/PTX (paclitaxel-resistant) cells and A549/DDP (cisplatin-resistant) cells were tested. The resistance to cisplatin or paclitaxel was detected using MTT and the colony-formation assays. Actin remodeling was observed with FITC-Phalloidin fluorescent staining or immunofluorescence. A wound-healing assay or Transwell assay was used to assess the migration or invasion ability. The expression of CTSL and epithelial and mesenchymal markers was analyzed with Western blotting and immunofluorescence. The expression of EMT-associated transcription factors was measured with Western blotting or q-PCR. BALB/c nude mice were implanted subcutaneously with A549 cells overexpressing CTSL, and the mice were administered paclitaxel (10, 15 mg/kg, ip) every 3 d for 5 times.
RESULTS
Cisplatin or paclitaxel treatment (10-80 ng/mL) induced CTSL expression in A549 cells. CTSL levels were much higher in A549/PTX and A549/DDP cells than in A549 cells. Silencing of CTSL reversed the chemoresistance in A549/DDP and A549/TAX cells, whereas overexpression of CTSL attenuated the sensitivity of A549 cells to cisplatin or paclitaxel. Furthermore, A549/DDP and A549/TAX cells underwent morphological and cytoskeletal changes with increased cell invasion and migration abilities, accompanied by decreased expression of epithelial markers (E-cadherin and cytokeratin-18) and increased expression of mesenchymal markers (N-cadherin and vimentin), as well as upregulation of EMT-associated transcription factors Snail, Slug, ZEB1 and ZEB2. Silencing of CTSL reversed EMT in A549/DDP and A549/TAX cells; In contrast, overexpression of CTSL induced EMT in A549 cells. In xenograft nude mouse model, the mice implanted with A549 cells overexpressing CTSL exhibited significantly reduced sensitivity to paclitaxel treatment, and increased expression of EMT-associated proteins and transcription factors in tumor tissues.
CONCLUSION
Cisplatin and paclitaxel resistance is associated with CTSL upregulation-induced EMT in A549 cells. Thus, CTSL-mediated EMT may be exploited as a target to enhance the efficacy of cisplatin or paclitaxel against lung cancer and other types of malignancies.
Topics: A549 Cells; Animals; Antineoplastic Agents; Cathepsin L; Cisplatin; Drug Resistance, Neoplasm; Humans; Male; Mice; Mice, Inbred BALB C; Paclitaxel; Up-Regulation
PubMed: 27840408
DOI: 10.1038/aps.2016.93 -
Gastroenterology Feb 2018Acute pancreatitis is characterized by premature intracellular activation of digestive proteases within pancreatic acini and a consecutive systemic inflammatory...
BACKGROUND & AIMS
Acute pancreatitis is characterized by premature intracellular activation of digestive proteases within pancreatic acini and a consecutive systemic inflammatory response. We investigated how these processes interact during severe pancreatitis in mice.
METHODS
Pancreatitis was induced in C57Bl/6 wild-type (control), cathepsin B (CTSB)-knockout, and cathepsin L-knockout mice by partial pancreatic duct ligation with supramaximal caerulein injection, or by repetitive supramaximal caerulein injections alone. Immune cells that infiltrated the pancreas were characterized by immunofluorescence detection of Ly6g, CD206, and CD68. Macrophages were isolated from bone marrow and incubated with bovine trypsinogen or isolated acinar cells; the macrophages were then transferred into pancreatitis control or cathepsin-knockout mice. Activities of proteases and nuclear factor (NF)-κB were determined using fluorogenic substrates and trypsin activity was blocked by nafamostat. Cytokine levels were measured using a cytometric bead array. We performed immunohistochemical analyses to detect trypsinogen, CD206, and CD68 in human chronic pancreatitis (n = 13) and acute necrotizing pancreatitis (n = 15) specimens.
RESULTS
Macrophages were the predominant immune cell population that migrated into the pancreas during induction of pancreatitis in control mice. CD68-positive macrophages were found to phagocytose acinar cell components, including zymogen-containing vesicles, in pancreata from mice with pancreatitis, as well as human necrotic pancreatic tissues. Trypsinogen became activated in macrophages cultured with purified trypsinogen or co-cultured with pancreatic acini and in pancreata of mice with pancreatitis; trypsinogen activation required macrophage endocytosis and expression and activity of CTSB, and was sensitive to pH. Activation of trypsinogen in macrophages resulted in translocation of NF-kB and production of inflammatory cytokines; mice without trypsinogen activation (CTSB-knockout mice) in macrophages developed less severe pancreatitis compared with control mice. Transfer of macrophage from control mice to CTSB-knockout mice increased the severity of pancreatitis. Inhibition of trypsin activity in macrophages prevented translocation of NF-κB and production of inflammatory cytokines.
CONCLUSIONS
Studying pancreatitis in mice, we found activation of digestive proteases to occur not only in acinar cells but also in macrophages that infiltrate pancreatic tissue. Activation of the proteases in macrophage occurs during endocytosis of zymogen-containing vesicles, and depends on pH and CTSB. This process involves macrophage activation via NF-κB-translocation, and contributes to systemic inflammation and severity of pancreatitis.
Topics: Adoptive Transfer; Animals; Cathepsin B; Cathepsin L; Cells, Cultured; Ceruletide; Coculture Techniques; Cytokines; Disease Models, Animal; Endocytosis; Enzyme Activation; Genetic Predisposition to Disease; Humans; Hydrogen-Ion Concentration; Inflammation Mediators; Macrophages; Mice, Inbred C57BL; Mice, Knockout; NF-kappa B; NLR Family, Pyrin Domain-Containing 3 Protein; Necrosis; Pancreas; Pancreatectomy; Pancreatitis, Acute Necrotizing; Phagocytosis; Phenotype; Severity of Illness Index; Time Factors; Trypsinogen
PubMed: 29079517
DOI: 10.1053/j.gastro.2017.10.018 -
Immunity Dec 2013Complement is viewed as a critical serum-operative component of innate immunity, with processing of its key component, C3, into activation fragments C3a and C3b confined...
Complement is viewed as a critical serum-operative component of innate immunity, with processing of its key component, C3, into activation fragments C3a and C3b confined to the extracellular space. We report here that C3 activation also occurred intracellularly. We found that the T cell-expressed protease cathepsin L (CTSL) processed C3 into biologically active C3a and C3b. Resting T cells contained stores of endosomal and lysosomal C3 and CTSL and substantial amounts of CTSL-generated C3a. While "tonic" intracellular C3a generation was required for homeostatic T cell survival, shuttling of this intracellular C3-activation-system to the cell surface upon T cell stimulation induced autocrine proinflammatory cytokine production. Furthermore, T cells from patients with autoimmune arthritis demonstrated hyperactive intracellular complement activation and interferon-γ production and CTSL inhibition corrected this deregulated phenotype. Importantly, intracellular C3a was observed in all examined cell populations, suggesting that intracellular complement activation might be of broad physiological significance.
Topics: Adult; Arthritis, Rheumatoid; B-Lymphocyte Subsets; CD4-Positive T-Lymphocytes; Cathepsin L; Cell Differentiation; Cell Line; Cell Survival; Child; Complement Activation; Complement C3; Complement C3a; Complement C3b; Gene Expression Regulation; Homeostasis; Humans
PubMed: 24315997
DOI: 10.1016/j.immuni.2013.10.018 -
Nature Medicine Mar 2021Angiotensin-converting enzyme 2 (ACE2) and accessory proteases (TMPRSS2 and CTSL) are needed for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cellular... (Meta-Analysis)
Meta-Analysis
Angiotensin-converting enzyme 2 (ACE2) and accessory proteases (TMPRSS2 and CTSL) are needed for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cellular entry, and their expression may shed light on viral tropism and impact across the body. We assessed the cell-type-specific expression of ACE2, TMPRSS2 and CTSL across 107 single-cell RNA-sequencing studies from different tissues. ACE2, TMPRSS2 and CTSL are coexpressed in specific subsets of respiratory epithelial cells in the nasal passages, airways and alveoli, and in cells from other organs associated with coronavirus disease 2019 (COVID-19) transmission or pathology. We performed a meta-analysis of 31 lung single-cell RNA-sequencing studies with 1,320,896 cells from 377 nasal, airway and lung parenchyma samples from 228 individuals. This revealed cell-type-specific associations of age, sex and smoking with expression levels of ACE2, TMPRSS2 and CTSL. Expression of entry factors increased with age and in males, including in airway secretory cells and alveolar type 2 cells. Expression programs shared by ACE2TMPRSS2 cells in nasal, lung and gut tissues included genes that may mediate viral entry, key immune functions and epithelial-macrophage cross-talk, such as genes involved in the interleukin-6, interleukin-1, tumor necrosis factor and complement pathways. Cell-type-specific expression patterns may contribute to the pathogenesis of COVID-19, and our work highlights putative molecular pathways for therapeutic intervention.
Topics: Adult; Aged; Aged, 80 and over; Alveolar Epithelial Cells; Angiotensin-Converting Enzyme 2; COVID-19; Cathepsin L; Datasets as Topic; Demography; Female; Gene Expression Profiling; Host-Pathogen Interactions; Humans; Lung; Male; Middle Aged; Organ Specificity; Respiratory System; SARS-CoV-2; Sequence Analysis, RNA; Serine Endopeptidases; Single-Cell Analysis; Virus Internalization
PubMed: 33654293
DOI: 10.1038/s41591-020-01227-z -
Cell Research Apr 2021The upcoming flu season in the Northern Hemisphere merging with the current COVID-19 pandemic raises a potentially severe threat to public health. Through experimental...
The upcoming flu season in the Northern Hemisphere merging with the current COVID-19 pandemic raises a potentially severe threat to public health. Through experimental coinfection with influenza A virus (IAV) and either pseudotyped or live SARS-CoV-2 virus, we found that IAV preinfection significantly promoted the infectivity of SARS-CoV-2 in a broad range of cell types. Remarkably, in vivo, increased SARS-CoV-2 viral load and more severe lung damage were observed in mice coinfected with IAV. Moreover, such enhancement of SARS-CoV-2 infectivity was not observed with several other respiratory viruses, likely due to a unique feature of IAV to elevate ACE2 expression. This study illustrates that IAV has a unique ability to aggravate SARS-CoV-2 infection, and thus, prevention of IAV infection is of great significance during the COVID-19 pandemic.
Topics: Angiotensin-Converting Enzyme 2; Animals; COVID-19; Cathepsin L; Cell Line; Coinfection; Humans; Influenza A virus; Lung; Mice; Mice, Transgenic; Orthomyxoviridae Infections; SARS-CoV-2; Serine Endopeptidases; Severity of Illness Index; Viral Load; Virus Internalization
PubMed: 33603116
DOI: 10.1038/s41422-021-00473-1 -
Veterinary Research Jun 2022Cathepsin L is an important cysteine protease, but its function in T. spiralis remains unclear. The aim of this research was to explore the biological characteristics of...
Cathepsin L is an important cysteine protease, but its function in T. spiralis remains unclear. The aim of this research was to explore the biological characteristics of T. spiralis cathepsin L (TsCatL) and its role in T. spiralis-host interactions. Bioinformatic analysis revealed the presence of the cysteine protease active site residues Gln, Cys, His and Asn in mature TsCatL, as well as specific motifs of cathepsin L similar to ERFNIN and GYLND in the prepeptide of TsCatL. Molecular docking of mature TsCatL and E64 revealed hydrophobic effects and hydrogen bonding interactions. Two domains of TsCatL (TsCatL2) were cloned and expressed, and recombinant TsCatL2 (rTsCatL2) was autocatalytically cleaved under acidic conditions to form mature TsCatL. TsCatL was transcribed and expressed in larvae and adults and located in the stichosome, gut and embryo. Enzyme kinetic tests showed that rTsCatL2 degraded the substrate Z-Phe-Arg-AMC under acidic conditions, which was inhibited by E64 and PMSF and enhanced by EDTA, L-cysteine and DTT. The kinetic parameters of rTsCatL2 were a Km value of 48.82 μM and Vmax of 374.4 nM/min at pH 4.5, 37 °C and 5 mM DTT. In addition, it was shown that rTsCatL2 degraded haemoglobin, serum albumin, immunoglobulins (mouse IgG, human IgG and IgM) and extracellular matrix components (fibronectin, collagen I and laminin). The proteolytic activity of rTsCatL2 was host specific and significantly inhibited by E64. rTsCatL2 possesses the natural activity of a sulfhydryl-containing cysteine protease, and TsCatL is an important digestive enzyme that seems to be important for the nutrient acquisition, immune evasion and invasion of Trichinella in the host.
Topics: Animals; Cathepsin L; Cysteine Proteases; Immunoglobulin G; Mice; Molecular Docking Simulation; Trichinella spiralis
PubMed: 35739604
DOI: 10.1186/s13567-022-01065-6 -
International Journal of Molecular... Jun 2022Wheat gliadins contain a large amount of glutamine- and proline-rich peptides which are not hydrolyzed by human digestive peptidases and can cause autoimmune celiac...
Wheat gliadins contain a large amount of glutamine- and proline-rich peptides which are not hydrolyzed by human digestive peptidases and can cause autoimmune celiac disease and other forms of gluten intolerance in predisposed people. Peptidases that efficiently cleave such immunogenic peptides can be used in enzyme therapy. The stored product insect pest efficiently hydrolyzes gliadins. The main digestive peptidase of is cathepsin L, which is from the papain C1 family with post-glutamine cleavage activity. We describe the isolation and characterization of recombinant procathepsin L (rpTcCathL1, NP_001164001), which was expressed in cells. The activation of the proenzyme was conducted by autocatalytic processing. The effects of pH and proenzyme concentration in the reaction mixture on the processing were studied. The mature enzyme retained high activity in the pH range from 5.0 to 9.0 and displayed high pH-stability from 4.0 to 8.0 at 20 °C. The enzyme was characterized according to electrophoretic mobility under native conditions, activity and stability at various pH values, a sensitivity to various inhibitors, and substrate specificity, and its hydrolytic effect on 8-, 10-, 26-, and 33-mer immunogenic gliadins peptides was demonstrated. Our results show that rTcCathL1 is an effective peptidase that can be used to develop a drug for the enzyme therapy of various types of gluten intolerance.
Topics: Animals; Cathepsin L; Celiac Disease; Enzyme Precursors; Gliadin; Glutamine; Humans; Hydrolysis; Peptide Hydrolases; Peptides; Tribolium
PubMed: 35806001
DOI: 10.3390/ijms23137001 -
Pharmacology & Therapeutics Nov 2015Proteolytic enzymes may serve as promising targets for novel therapeutic treatment strategies seeking to impede cancer progression and metastasis. One such enzyme is... (Review)
Review
Proteolytic enzymes may serve as promising targets for novel therapeutic treatment strategies seeking to impede cancer progression and metastasis. One such enzyme is cathepsin L (CTSL), a lysosomal cysteine protease. CTSL upregulation, a common occurrence in a variety of human cancers, has been widely correlated with metastatic aggressiveness and poor patient prognosis. In addition, CTSL has been implicated to contribute to cancer-associated osteolysis, a debilitating morbidity affecting both life expectancy and the quality of life. In this review, we highlight the mechanisms by which CTSL contributes to tumor progression and dissemination and discuss the therapeutic utility of CTSL intervention strategies aimed at impeding metastatic progression and bone resorption.
Topics: Animals; Cathepsin L; Cysteine Proteinase Inhibitors; Humans; Neoplasms
PubMed: 26299995
DOI: 10.1016/j.pharmthera.2015.08.007