Authors: Qingzhu Shi, Qicong Shen, Yanfang Liu...

How glucose metabolism remodels pro-tumor functions of tumor-associated macrophages (TAMs) needs further investigation. Here we show that M2-like TAMs bear the highest individual capacity to take up intratumoral glucose. Their increased glucose uptake fuels hexosamine biosynthetic pathway-dependent O-GlcNAcylation to promote cancer metastasis and chemoresistance. Glucose metabolism promotes O-GlcNAcylation of the lysosome-encapsulated protease Cathepsin B at serine 210, mediated by lysosome-localized O-GlcNAc transferase (OGT), elevating mature Cathepsin B in macrophages and its secretion in the tumor microenvironment (TME). Loss of OGT in macrophages reduces O-GlcNAcylation and mature Cathepsin B in the TME and disrupts cancer metastasis and chemoresistance. Human TAMs with high OGT are positively correlated with Cathepsin B expression, and both levels predict chemotherapy response and prognosis of individuals with cancer. Our study reports the biological and potential clinical significance of glucose metabolism in tumor-promoting TAMs and reveals insights into the underlying mechanisms.

Topics: Cathepsin B; Drug Resistance, Neoplasm; Glucose; Hexosamines; Humans; Lysosomes; N-Acetylglucosaminyltransferases; Neoplasms; Serine; Tumor Microenvironment; Tumor-Associated Macrophages

PubMed: 36084651
DOI: 10.1016/j.ccell.2022.08.012

Review

Authors: Zhen Xie, Mengyuan Zhao, Chengxiang Yan...

Cathepsin B (CatB), a cysteine protease, is primarily localized within subcellular endosomal and lysosomal compartments. It is involved in the turnover of intracellular and extracellular proteins. Interest is growing in CatB due to its diverse roles in physiological and pathological processes. In functional defective tissues, programmed cell death (PCD) is one of the regulable fundamental mechanisms mediated by CatB, including apoptosis, pyroptosis, ferroptosis, necroptosis, and autophagic cell death. However, CatB-mediated PCD is responsible for disease progression under pathological conditions. In this review, we provide an overview of the critical roles and regulatory pathways of CatB in different types of PCD, and discuss the possibility of CatB as an attractive target in multiple diseases. We also summarize current gaps in the understanding of the involvement of CatB in PCD to highlight future avenues for research.

Topics: Cathepsin B; Apoptosis; Pyroptosis; Lysosomes

PubMed: 37031185
DOI: 10.1038/s41419-023-05786-0

Authors: Guoliang Deng, Lisha Zhou, Binglin Wang...

BACKGROUND

The loss of tumor antigens and depletion of CD8 T cells caused by the PD-1/PD-L1 pathway are important factors for tumor immune escape. In recent years, there has been increasing research on traditional Chinese medicine in tumor treatment. Cycloastragenol (CAG), an effective active molecule in , has been found to have antiviral, anti-aging, anti-inflammatory, and other functions. However, its antitumor effect and mechanism are not clear.

METHODS

The antitumor effect of CAG was investigated in MC38 and CT26 mouse transplanted tumor models. The antitumor effect of CAG was further analyzed via single-cell multiomics sequencing. Target responsive accessibility profiling technology was used to find the target protein of CAG. Subsequently, the antitumor mechanism of CAG was explored using confocal microscopy, coimmunoprecipitation and transfection of mutant plasmids. Finally, the combined antitumor effect of CAG and PD-1 antibodies in mice or organoids were investigated.

RESULTS

We found that CAG effectively inhibited tumor growth in vivo. Our single-cell multiomics atlas demonstrated that CAG promoted the presentation of tumor cell-surface antigens and was characterized by the enhanced killing function of CD8 T cells. Mechanistically, CAG bound to its target protein cathepsin B, which then inhibited the lysosomal degradation of major histocompatibility complex I (MHC-I) and promoted the aggregation of MHC-I to the cell membrane, boosting the presentation of the tumor antigen. Meanwhile, the combination of CAG with PD-1 antibody effectively enhanced the tumor killing ability of CD8 T cells in xenograft mice and colorectal cancer organoids.

CONCLUSION

Our data reported for the first time that cathepsin B downregulation confers antitumor immunity and explicates the antitumor mechanism of natural product CAG.

Topics: Humans; Mice; Animals; CD8-Positive T-Lymphocytes; Programmed Cell Death 1 Receptor; Cathepsin B; Mice, Inbred C57BL; Cell Line, Tumor; Antibodies; Antigens, Neoplasm; Proteins; Major Histocompatibility Complex

PubMed: 36307151
DOI: 10.1136/jitc-2022-004874

Authors: Meng-Yuan Li, Ying Wu, Hao-Lan Tang...

Embryo implantation and decidualization are crucial for a successful pregnancy. How the inflammatory response is regulated during these processes is undefined. Pyroptosis is an inflammatory form of cell death mediated by gasdermin D (GSDMD). Through in vivo, cultured epithelial cells and organoids, it is shown that pyroptosis occurs in epithelial cells at the implantation site. Compared with those on day 4 of pseudopregnancy and delayed implantation, pyroptosis-related protein levels are significantly increased on day 4 of pregnancy and activated implantation, suggesting that blastocysts are involved in regulating pyroptosis. Blastocyst-derived cathepsin B (CTSB) is stimulated by preimplantation estradiol-17β and induces pyroptosis in epithelial cells. Pyroptosis-induced IL-18 secretion from epithelial cells activates a disintegrin and metalloprotease 12 (ADAM12) to process the epiregulin precursor into mature epiregulin. Epiregulin (EREG) enhances in vitro decidualization in mice. Pyroptosis-related proteins are detected in the mid-secretory human endometrium and are elevated in the recurrent implantation failure endometrium. Lipopolysaccharide treatment in pregnant mice causes implantation failure and increases pyroptosis-related protein levels. Therefore, the data suggest that modest pyroptosis is beneficial for embryo implantation and decidualization. Excessive pyroptosis can be harmful and lead to pregnancy failure.

Topics: Pyroptosis; Cathepsin B; Embryo Implantation; Animals; Female; Mice; Pregnancy; Humans; Decidua

PubMed: 39316370
DOI: 10.1002/advs.202402299

Randomized Controlled Trial

Authors: Hyo Youl Moon, Andreas Becke, David Berron...

Peripheral processes that mediate beneficial effects of exercise on the brain remain sparsely explored. Here, we show that a muscle secretory factor, cathepsin B (CTSB) protein, is important for the cognitive and neurogenic benefits of running. Proteomic analysis revealed elevated levels of CTSB in conditioned medium derived from skeletal muscle cell cultures treated with AMP-kinase agonist AICAR. Consistently, running increased CTSB levels in mouse gastrocnemius muscle and plasma. Furthermore, recombinant CTSB application enhanced expression of brain-derived neurotrophic factor (BDNF) and doublecortin (DCX) in adult hippocampal progenitor cells through a mechanism dependent on the multifunctional protein P11. In vivo, in CTSB knockout (KO) mice, running did not enhance adult hippocampal neurogenesis and spatial memory function. Interestingly, in Rhesus monkeys and humans, treadmill exercise elevated CTSB in plasma. In humans, changes in CTSB levels correlated with fitness and hippocampus-dependent memory function. Our findings suggest CTSB as a mediator of effects of exercise on cognition.

Topics: Adult; Affect; Aging; Animals; Behavior, Animal; Brain-Derived Neurotrophic Factor; Cathepsin B; Cognition; Doublecortin Domain Proteins; Doublecortin Protein; Exercise Test; Female; Hippocampus; Humans; Macaca mulatta; Male; Memory; Mice, Inbred C57BL; Mice, Knockout; Microtubule-Associated Proteins; Motor Activity; Neurogenesis; Neurons; Neuropeptides; Physical Conditioning, Animal; Reproducibility of Results; Running; Sedentary Behavior; Young Adult

PubMed: 27345423
DOI: 10.1016/j.cmet.2016.05.025

Authors: Zhe Lin, Shuang Zhao, Xuesong Li...

Genetic information is generally transferred from RNA to protein according to the classic "Central Dogma". Here, we made a striking discovery that post-translational modification of a protein specifically regulates the editing of its own mRNA. We show that S-nitrosylation of cathepsin B (CTSB) exclusively alters the adenosine-to-inosine (A-to-I) editing of its own mRNA. Mechanistically, CTSB S-nitrosylation promotes the dephosphorylation and nuclear translocation of ADD1, leading to the recruitment of MATR3 and ADAR1 to CTSB mRNA. ADAR1-mediated A-to-I RNA editing enables the binding of HuR to CTSB mRNA, resulting in increased CTSB mRNA stability and subsequently higher steady-state levels of CTSB protein. Together, we uncovered a unique feedforward mechanism of protein expression regulation mediated by the ADD1/MATR3/ADAR1 regulatory axis. Our study demonstrates a novel reverse flow of information from the post-translational modification of a protein back to the post-transcriptional regulation of its own mRNA precursor. We coined this process as "Protein-directed EDiting of its Own mRNA by ADAR1 (PEDORA)" and suggest that this constitutes an additional layer of protein expression control. "PEDORA" could represent a currently hidden mechanism in eukaryotic gene expression regulation.

Topics: RNA Editing; RNA, Messenger; Cathepsin B; Gene Expression Regulation; RNA Precursors; RNA; Adenosine Deaminase

PubMed: 37156877
DOI: 10.1038/s41422-023-00812-4

Review

Authors: Veronika Stoka, Olga Vasiljeva, Hiroshi Nakanishi...

Papain-like cysteine proteases are composed of 11 human cysteine cathepsins, originally located in the lysosomes. They exhibit broad specificity and act as endopeptidases and/or exopeptidases. Among them, only cathepsins B, H, C, and X/Z exhibit exopeptidase activity. Recently, cysteine cathepsins have been found to be present outside the lysosomes and often participate in various pathological processes. Hence, they have been considered key signalling molecules. Their potentially hazardous proteolytic activities are tightly regulated. This review aims to discuss recent advances in understanding the structural aspects of these four cathepsins, mechanisms of their zymogen activation, regulation of their activities, and functional aspects of these enzymes in neurodegeneration and cancer. Neurodegenerative effects have been evaluated, particularly in Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, multiple sclerosis, and neuropsychiatric disorders. Cysteine cathepsins also participate in tumour progression and metastasis through the overexpression and secretion of proteases, which trigger extracellular matrix degradation. To our knowledge, this is the first review to provide an in-depth analysis regarding the roles of cysteine cathepsins B, H, C, and X in neurodegenerative diseases and cancer. Further advances in understanding the functions of cysteine cathepsins in these conditions will result in the development of novel, targeted therapeutic strategies.

Topics: Humans; Cysteine Proteases; Neurodegenerative Diseases; Cysteine; Cathepsin B; Neoplasms; Lysosomes

PubMed: 37958596
DOI: 10.3390/ijms242115613

Toxoplasma gondii Induces Pyroptosis in Human Placental Trophoblast and Amniotic Cells by Inducing ROS Production and Activation of Cathepsin B and NLRP1/NLRP3/NLRC4/AIM2 Inflammasome.

Authors: Juan-Hua Quan, Fei Fei Gao, Tian-Zhong Ma...

Toxoplasma gondii infection in pregnant women may cause fetal anomalies; however, the underlying mechanisms remain unclear. The current study investigated whether T. gondii induces pyroptosis in human placental cells and the underlying mechanisms. Human placental trophoblast (BeWo and HTR-8/SVneo) and amniotic (WISH) cells were infected with T. gondii, and then reactive oxygen species (ROS) production, cathepsin B (CatB) release, inflammasome activation, and pyroptosis induction were evaluated. The molecular mechanisms of these effects were investigated by treating the cells with ROS scavengers, a CatB inhibitor, or inflammasome-specific siRNA. T. gondii infection induced ROS generation and CatB release into the cytosol in placental cells but decreased mitochondrial membrane potential. T. gondii-infected human placental cells and villi exhibited NLRP1, NLRP3, NLRC4, and AIM2 inflammasome activation and subsequent pyroptosis induction, as evidenced by increased expression of ASC, cleaved caspase-1, and mature IL-1β and gasdermin D cleavage. In addition to inflammasome activation and pyroptosis induction, adverse pregnancy outcome was shown in a T. gondii-infected pregnant mouse model. Administration of ROS scavengers, CatB inhibitor, or inflammasome-specific siRNA into T. gondii-infected cells reversed these effects. Collectively, these findings show that T. gondii induces NLRP1/NLRP3/NLRC4/AIM2 inflammasome-dependent caspase-1-mediated pyroptosis via induction of ROS production and CatB activation in placental cells. This mechanism may play an important role in inducing cell injury in congenital toxoplasmosis.

Topics: Mice; Animals; Humans; Female; Pregnancy; Inflammasomes; NLR Family, Pyrin Domain-Containing 3 Protein; Toxoplasma; Reactive Oxygen Species; Pyroptosis; Trophoblasts; Cathepsin B; Placenta; RNA, Small Interfering; Caspases; Calcium-Binding Proteins; CARD Signaling Adaptor Proteins; NLR Proteins

PubMed: 37741453
DOI: 10.1016/j.ajpath.2023.08.016

Authors: Tingxiu Liu, Yuehan Ren, Junning Zhang...

Emerging evidence suggests a tentative association between cathepsins and uterine leiomyoma (UL). Previous investigations have predominantly focused on the role of cathepsins in the metastasis and colonization of gynecological malignancies. Still, observational studies may lead to confounding and biases. We employed a bidirectional Mendelian randomization (MR) analysis to elucidate the causative links between various cathepsins and UL. Instrumental variables (IVs) of cathepsins and UL within the European cohort were from extant genome-wide association study datasets. Sensitivity assessments was executed, and the heterogeneity of the findings was meticulously dissected to affirm the solidity of the outcomes. Our findings reveal the association between cathepsin B (CTSB) and an elevated risk of developing UL (all cancers excluded) [Inverse Variance Weighted (IVW) method]: OR = 1.06, 95%CI [1.02, 1.11], P = 0.008895711. Although the association does not persist after multiple testing or Steiger filtering, this finding adds to our understanding of the causal relationship between CTSB of various cathepsins and UL (all cancers excluded) and may herald new therapeutic avenues for individuals affected by this condition.

Topics: Humans; Female; Leiomyoma; Mendelian Randomization Analysis; Uterine Neoplasms; Cathepsin B; Cathepsins; Genome-Wide Association Study; Polymorphism, Single Nucleotide; Genetic Predisposition to Disease

PubMed: 39264885
DOI: 10.1371/journal.pone.0310292

Authors: Barbara Breznik, Clara Limbaeck Stokin, Janko Kos...

Glioblastoma (GBM) is the most lethal brain tumor also due to malignant and therapy-resistant GBM stem cells (GSCs) that are localized in protecting hypoxic GSC niches. Some members of the cysteine cathepsin family of proteases have been found to be upregulated in GBM. Cathepsin K gene expression is highly elevated in GBM tissue versus normal brain and it has been suggested to regulate GSC migration out of the niches. Here, we investigated the cellular distribution of cathepsins B, X and K in GBM tissue and whether these cathepsins are co-localized in GSC niches. Therefore, we determined expression of these cathepsins in serial paraffin sections of 14 human GBM samples and serial cryostat sections of two samples using immunohistochemistry and metabolic mapping of cathepsin activity using selective fluorogenic substrates. We detected cathepsins B, X and K in peri-arteriolar GSC niches in 9 out of 16 GBM samples, which were defined by co-expression of the GSC marker CD133, the niche marker stromal-derived factor-1α (SDF-1α) and smooth muscle actin as a marker for arterioles. The expression of cathepsin B and X was detected in stromal cells and cancer cells throughout the GBM sections, whereas cathepsin K expression was more restricted to arteriole-rich regions in the GBM sections. Metabolic mapping showed that cathepsin B, but not cathepsin K is active in GSC niches. On the basis of these findings, it is concluded that cathepsins B, X and K have distinct functions in GBM and that cathepsin K is the most likely GSC niche-related cathepsin of the three cathepsins investigated.

Topics: Adult; Aged; Aged, 80 and over; Arterioles; Cathepsin B; Cathepsin K; Cathepsin Z; Cathepsins; Glioblastoma; Humans; Immunohistochemistry; Middle Aged; Proteolysis; Stem Cell Niche

PubMed: 30046941
DOI: 10.1007/s10735-018-9787-y