Diagnostic and prognostic significance of mast cell markers in HIV/AIDS: Current insights and future directions.

Human immunodeficiency virus (HIV) infection continues to pose significant global health challenges, necessitating advancements in diagnostic and prognostic approaches to optimize disease management. While primarily recognized for their roles in allergic responses, mast cells have emerged as potential markers with diagnostic and prognostic significance in the context of HIV/AIDS. This paper aims to synthesize current insights and delineate future directions regarding the utility of mast cell markers in diagnosing HIV infection, predicting disease progression, and guiding therapeutic strategies. Mast cells, equipped with distinct markers such as tryptase, chymase, carboxypeptidase A3, and c-kit/CD117 receptors, exhibit tissue-specific expression patterns that offer potential as diagnostic indicators for HIV infection. Understanding the dynamics of these markers in different tissues and body fluids holds promise for accurate HIV diagnosis, disease staging, and monitoring treatment responses. Moreover, the prognostic significance of mast cell markers in HIV/AIDS lies in their potential to predict disease progression, immune dysregulation, and clinical outcomes. The integration of mast cell markers into clinical applications offers promising avenues for refining diagnostic assays, patient monitoring protocols, and therapeutic strategies in HIV/AIDS. Future research directions involve the development of novel diagnostic tools and targeted therapies based on mast cell-specific markers, potentially revolutionizing clinical practice and enhancing patient care in the management of HIV/AIDS. Continued investigations into mast cell markers' diagnostic and prognostic implications hold immense potential to advance our understanding and improve outcomes in HIV/AIDS management.

Analysis of the mast cell expressed carboxypeptidase A3 and its structural and evolutionary relationship to other vertebrate carboxypeptidases.

Metallo-carboxypeptidases are exopeptidases with diverse expression and function, found in all kingdoms of life from bacteria to mammals. One of them, the carboxypeptidase A3 (CPA3), has become an important component of the mammalian immune system by its expression in mast cells. Mast cells (MCs) are highly specialized sentinel cells, which store large amounts of bioactive mediators, including CPA3, in very abundant cytoplasmic granules. Clinical studies have found an increased CPA3 expression in asthma but the physiological role as well as the evolutionary origin of CPA3 remains largely unexplored. CPA3 belongs to the M14A subfamily of metallo-carboxypeptidases, which among others also includes the digestive enzymes CPA1, CPA2, CPB1 and CPO. To study the appearance of CPA3 during vertebrate evolution, we here performed bioinformatic analyses of homologous genes and gene loci from a broad panel of metazoan animals from invertebrates to mammals. The phylogenetic analysis indicated that CPA3 appeared at the base of tetrapod evolution in a branch closer to CPB1 than to other CPAs. Indeed, CPA3 and CPB1 are also located in the same locus, on chromosome 3 in humans. The presence of CPA3 only in tetrapods and not in fishes, suggested that CPA3 could have appeared by a gene duplication from CPB1 during early tetrapod evolution. However, the apparent loss of CPA3 in several tetrapod lineages, e.g. in birds and monotremes, indicates a complex evolution of the CPA3 gene. Interestingly, in the lack of CPA3 in fishes, zebrafish MCs express instead CPA5 for which the most closely related human carboxypeptidase is CPA1, which has a similar cleavage specificity as CPA3. Collectively, these findings clarify and add to our understanding of the evolution of hematopoietic proteases expressed by mast cells.

Enhanced carboxypeptidase efficacies and differentiation of peptide epimers.

Carboxypeptidases enzymatically cleave the peptide bond of C-terminal amino acids. In humans, it is involved in enzymatic synthesis and maturation of proteins and peptides. Carboxypeptidases A and Y have difficulty hydrolyzing the peptide bond of dipeptides and some other amino acid sequences. Early investigations into different N-blocking groups concluded that larger moieties increased substrate susceptibility to peptide bond hydrolysis with carboxypeptidases. This study conclusively demonstrates that 6-aminoquinoline-N-hydroxysuccimidyl carbamate (AQC) as an N-blocking group greatly enhances substrate hydrolysis with carboxypeptidase. AQC addition to the N-terminus of amino acids and peptides also improves chromatographic peak shapes and sensitivities via mass spectrometry detection. These enzymes have been used for amino acid sequence determination prior to the advent of modern proteomics. However, most modern proteomic methods assume that all peptides are comprised of l-amino acids and therefore cannot distinguish L-from d-amino acids within the peptide sequence. The majority of existing methods that allow for chiral differentiation either require synthetic standards or incur racemization in the process. This study highlights the resistance of d-amino acids within peptides to enzymatic hydrolysis by Carboxypeptidase Y. This stereoselectivity may be advantageous when screening for low abundance peptide stereoisomers.

Structure of Aedes aegypti carboxypeptidase B1-inhibitor complex uncover the disparity between mosquito and non-mosquito insect carboxypeptidase inhibition mechanism.

Metallocarboxypeptidases (MCPs) in the mosquito midgut play crucial roles in infection, as well as in mosquito dietary digestion, reproduction, and development. MCPs are also part of the digestive system of plant-feeding insects, representing key targets for inhibitor development against mosquitoes/mosquito-borne pathogens or as antifeedant molecules against plant-feeding insects. Notably, some non-mosquito insect B-type MCPs are primarily insensitive to plant protease inhibitors (PPIs) such as the potato carboxypeptidase inhibitor (PCI; MW 4 kDa), an inhibitor explored for cancer treatment and insecticide design. Here, we report the crystal structure of Aedes aegypti carboxypeptidase-B1 (CPBAe1)-PCI complex and compared the binding with that of PCI-insensitive CPBs. We show that PCI accommodation is determined by key differences in the active-site regions of MCPs. In particular, the loop regions α6-α7 (Leu242 -Ser250 ) and ß8-α8 (Pro269 -Pro280 ) of CPBAe1 are replaced by α-helices in PCI-insensitive insect Helicoverpa zea CPBHz. These α-helices protrude into the active-site pocket of CPBHz, restricting PCI insertion and rendering the enzyme insensitive. We further compared our structure with the only other PCI complex available, bovine CPA1-PCI. The potency of PCI against CPBAe1 (Ki  = 14.7 nM) is marginally less than that of bovine CPA1 (Ki  = 5 nM). Structurally, the above loop regions that accommodate PCI binding in CPBAe1 are similar to that of bovine CPA1, although observed changes in proteases residues that interact with PCI could account for the differences in affinity. Our findings suggest that PCI sensitivity is largely dictated by structural interference, which broadens our understanding of carboxypeptidase inhibition as a mosquito population/parasite control strategy.

Insufficient ablation promotes the metastasis of residual non-small cell lung cancer (NSCLC) cells via upregulating carboxypeptidase A4.

BACKGROUND: Thermal ablation is a potentially curative therapy for early-stage non-small cell lung cancer (NSCLC). Early recurrence after thermal ablation necessitates our attention. METHODS: The invasion and migration abilities of NSCLC after sublethal heat stimulus were observed in vitro and in vivo. Sublethal thermal stimulus molecular changes were identified by RNA sequencing. A xenograft model of NSCLC with insufficient ablation was established to explore the epithelial-to-mesenchymal transition (EMT) and metastasis-related phenotypes alteration of residual tumors. RESULTS: In vitro, the invasion and migration abilities of NSCLC cells were enhanced 72 h after 44 °C and 46 °C thermal stimulus. Epithelial-mesenchymal transition (EMT) phenotypes were also upregulated under these conditions. RNA sequencing revealed that the expression of carboxypeptidase A4 (CPA4) was significantly upregulated after thermal stimulus. Significant upregulation of CPA4 and EMT phenotypes was also found in the xenograft model of insufficient NSCLC ablation. The EMT process and invasion and migration abilities can be reversed by silencing CPA4. CONCLUSIONS: This study demonstrates that sublethal heat stimulus caused by insufficient ablation can promote EMT and enhance the metastatic capacity of NSCLC. CPA4 plays an important role in these biological processes. Inhibition of CPA4 might be of great significance for improving early-stage NSCLC survival after ablation.

Carboxypeptidase A4 negatively correlates with p53 expression and regulates the stemness of breast cancer cells.

Background: Triple-negative breast cancer (TNBC) is an aggressive cancer subtype lacking effective treatment options, and p53 is the most frequently mutated or deleted gene. Carboxypeptidase A4 (CPA4) is an extracellular metallocarboxypeptidase, which was closely associated with aggressiveness. Although a recent study indicated that CPA4 could induce epithelial­mesenchymal transition in breast cancer cells, no studies investigated its stemness-related function and the correlation between CPA4 and p53 in TNBC. In this study, we aimed to investigate the CPA4 levels in breast cancer tissues and analyze its association with p53, and study its roles in cancer stemness maintenance. Methods: CPA4 mRNA level and its prognostic value were analyzed by using online database UALCAN (http://ualcan.path.uab.edu) and Kaplan-Meier plotter (www.kmplot.com), respectively. The expression of CPA4, p53 and ALDH1A1 in breast cancer and adjacent normal tissues were evaluated by IHC using the corresponding primary antibodies on a commercial tissue array (Shanghai Biochip Co., Ltd., Shanghai, China). siRNA knockdown was used to study the function of proliferation, colony formation assay and sphere formation in serum-free medium. Results: Analysis of the UALCAN datasets identified that CPA4 mRNA levels were elevated in TNBC, especially in the TP53-mutant subgroup. Furthermore, high levels of CPA4 mRNA were significantly associated with unfavourable overall survival OS in breast cancer patients. Immunohistochemistical analysis demonstrated that CPA4 levels were elevated in 32.1% of breast cancer samples (45/140), and the positive rates of ALDH1A1 and p53 in the breast cancer tissues were 25% (35/140) and 50% (70/140), respectively. Statistical analysis revealed high levels of CPA4 was significantly associated with TNBC phenotype. Correlation analysis indicated that CPA4 over-expression was positively associated with ALDH1A1 (P<0.01) and negatively correlated with p53 (P<0.05). In Kaplan-Meier survival analysis, either high CPA4 or ALDH1A1 levels was significantly correlated with poor survival in breast cancer patients. Functional studies demonstrated that down-regulation of CPA4 significantly inhibited TNBC cell proliferation, colony-formation assays in soft agar and sphere formation in serum-free medium. Conclusion: This study demonstrated for the first time that CPA4 was negatively correlates with p53 expression and inhibition of CPA4 could reduce the number of breast cancer cells with stemness property. It might be a potential target for the TNBC treatment.

A Francisella tularensis L,D-carboxypeptidase plays important roles in cell morphology, envelope integrity, and virulence.

Francisella tularensis is a Gram-negative, intracellular bacterium that causes the zoonotic disease tularemia. Intracellular pathogens, including F. tularensis, have evolved mechanisms to survive in the harsh environment of macrophages and neutrophils, where they are exposed to cell envelope-damaging molecules. The bacterial cell wall, primarily composed of peptidoglycan (PG), maintains cell morphology, structure, and membrane integrity. Intracellular Gram-negative bacteria protect themselves from macrophage and neutrophil killing by recycling and repairing damaged PG--a process that involves over 50 different PG synthesis and recycling enzymes. Here, we identified a PG recycling enzyme, L,D-carboxypeptidase A (LdcA), of F. tularensis that is responsible for converting PG tetrapeptide stems to tripeptide stems. Unlike E. coli LdcA and most other orthologs, F. tularensis LdcA does not localize to the cytoplasm and also exhibits L,D-endopeptidase activity, converting PG pentapeptide stems to tripeptide stems. Loss of F. tularensis LdcA led to altered cell morphology and membrane integrity, as well as attenuation in a mouse pulmonary infection model and in primary and immortalized macrophages. Finally, an F. tularensis ldcA mutant protected mice against virulent Type A F. tularensis SchuS4 pulmonary challenge.

Reducing Ochratoxin A Content in Grape Pomace by Different Methods.

Grape pomace (GP) is the residue of grapes after wine making and is a valuable source of dietary polyphenol and fiber for health promotion. However, studies found the presence of ochratoxin A (OTA) in GP at very high concentrations, which raises a safety issue in the value-added utilization of GP. This study evaluated the effects of thermal pressure, baking, acid and enzymatic treatments on OTA content in GP. Thermal pressure treatment was conducted with wet GP at 121 °C for 10-30 min in an autoclave; acid treatments were conducted with hydrochloric acid, acetic acid, citric acid, and lactic acid, respectively, at 50 °C for 24 h. Baking was conducted using a cookie model. For enzymatic treatment, purified OTA solution was treated with carboxypeptidase A, alcalase, flavourzyme, pepsin, and lipase, respectively, and the effective enzymes were selected to treat GP. Results show that autoclaving for 10-30 min reduced 19-80% of OTA, varying with treatment time and GP variety. The effectiveness of acid treatment was similar to that of autoclaving and varied with acid type and GP variety. Baking increased the detectable OTA. Among all tested enzymes, carboxypeptidase A was the most effective in reducing OTA, followed by lipase and flavourzyme, but their effects were significantly lower in GP samples.

Carboxypeptidase A6 was identified and validated as a novel potential biomarker for predicting the occurrence of active ulcerative colitis.

Ulcerative colitis (UC) is a chronic, highly heterogeneous intestinal inflammation with changes in epithelial function and tissue damage. However, the pathogenesis is still unclear between active UC and inactive UC. Herein, weighted gene co-expression network analysis was applied to explore the gene modules related to active UC. Gene set enrichment analysis (GSEA) and gene set variation analysis (GSVA) were used to further investigate the underlying mechanism of selected genes. We found that in the blue module (r = -.72), carboxypeptidase A6 (CPA6) was chosen to validate because of its high intra-modular connectivity and module membership. In the test sets, the expression level of CPA6 was down-regulated in active UC compared with inactive UC and normal colon. Furthermore, CPA6 expression was decreased primarily in the descending colon and only in mucosa affected by active UC. The receiver operating characteristic curve indicated that CPA6 expression had a performed well in diagnosing active UC from inactive UC (area under the curve = 0.99). Importantly, anti-tumour necrosis factor (TNF) treatment (infliximab and golimumab) significantly increased the CPA6 expression. Finally, GSEA and GSVA found that extracellular matrix receptor, inflammatory response and epithelial-mesenchymal transition were highly enriched in active UC with low CPA6 expression. In conclusion, CPA6 was identified and validated as a novel potential biomarker for predicting the occurrence of active UC, probably through regulating extracellular matrix or immune response.

Carboxypeptidase A4 promotes cardiomyocyte hypertrophy through activating PI3K-AKT-mTOR signaling.

Carboxypeptidase A4 (CPA4) is a member of the metallocarboxypeptidase family. Current studies have identified the roles of CPA4 in cancer biology and insulin sensitivity. However, the roles of CPA4 in other diseases are not known. In the present study, we investigated the roles of CPA4 in cardiac hypertrophy. The expression of CPA4 was significantly increased in the hypertrophic heart tissues of human patients and isoproterenol (ISO)-induced hypertrophic heart tissues of mice. We next knocked down Cpa4 with shRNA or overexpressed Cpa4 using adenovirus in neonatal rat cardiomyocytes and induced cardiomyocyte hypertrophy with ISO. We observed that Cpa4 overexpression promoted whereas Cpa4 knockdown reduced ISO-induced growth of cardiomyocyte size and overexpression of hypertrophy marker genes, such as myosin heavy chain ß (ß-Mhc), atrial natriuretic peptide (Anp), and brain natriuretic peptide (Bnp). Our further mechanism study revealed that the mammalian target of rapamycin (mTOR) signaling was activated by Cpa4 in cardiomyocytes, which depended on the phosphoinositide 3-kinase (PI3K)-AKT signaling. Besides, we showed that the PI3K-AKT-mTOR signaling was critically involved in the roles of Cpa4 during cardiomyocyte hypertrophy. Collectively, these results demonstrated that CPA4 is a regulator of cardiac hypertrophy by activating the PI3K-AKT-mTOR signaling, and CPA4 may serve as a promising target for the treatment of hypertrophic cardiac diseases.

Ethanol feeding accelerates pancreatitis progression in CPA1 N256K mutant mice.

Alcoholic pancreatitis is a multifactorial, progressive, inflammatory disorder of the pancreas. Alcohol initiates pancreatitis and promotes its progression in the context of genetic susceptibility and/or other environmental risk factors such as smoking. Genetic mutations can cause digestive enzyme misfolding, which induces endoplasmic reticulum (ER) stress and elicits pancreatitis. Here, we tested the hypothesis that alcohol synergizes with misfolding in promoting ER stress and thereby accelerates chronic pancreatitis progression. To this end, we fed an ethanol-containing diet to CPA1 N256K mice, which carry the human p.N256K CPA1 mutation and develop spontaneous chronic pancreatitis. Inexplicably, CPA1 N256K mice suffered generalized seizures after 2-3 wk of ethanol feeding, which resulted in high mortality and the early termination of the study. Analysis of CPA1 N256K mice euthanized after 3-3.5 wk of ethanol feeding revealed more severe chronic pancreatitis associated with significantly increased Hspa5 [ER chaperone immunoglobulin heavy chain-binding protein (BiP)] mRNA levels when compared with CPA1 N256K mice on a control liquid diet. In contrast, ethanol feeding of C57BL/6N mice for 4 wk increased Hspa5 levels to a lesser degree and caused no pancreatitis. We conclude that ethanol feeding synergizes with the misfolding CPA1 mutant in promoting ER stress and thereby accelerates progression of chronic pancreatitis in CPA1 N256K mice.NEW & NOTEWORTHY Alcoholic pancreatitis is a multifactorial, progressive, inflammatory disorder of the pancreas. This study demonstrates that alcohol synergizes with digestive enzyme misfolding in promoting endoplasmic reticulum stress and thereby accelerates progression of chronic pancreatitis.

Carboxypeptidase A6 Promotes the Proliferation and Migration of Hepatocellular Carcinoma by Up-regulating AKT Signaling Pathway.

Hepatocellular carcinoma (HCC) has a poor treatment prognosis and high mortality worldwide. Understanding the molecular mechanism underlying HCC development would benefit the identification of diagnostic biomarkers and the improvement of the treatment strategies. The expression of carboxypeptidase A6 (CPA6) has been reported in epilepsy and febrile seizures rather than in any type of cancers. However, the function of CPA6 expression in HCC is not yet understood. In this study, we aimed to investigate the clinicopathological significance of the expression of CPA6 in HCC and the underlying mechanisms. We observed that the expression of the CPA6 protein was increased significantly in HCC tissues than in paracancerous tissues. To explore its function in HCC, both gain- and loss-of-function studies demonstrated that CPA6 played a vital role in promoting HCC growth and metastasis. When knocking down CPA6 with shRNA, HCC cell proliferation and migration could be suppressed. Meanwhile, CPA6 overexpression could promote proliferation and migration of HLF cells. Moreover, CPA6 could activate AKT serine/threonine kinase (AKT) signaling pathway as confirmed by Western blotting. In conclusion, our study revealed that CPA6 could promote HCC cell proliferation and migration via AKT-mediated signaling pathway. These findings suggest that CPA6 is a promising diagnostic biomarker and therapeutic target to improve the prognosis of HCC.

circCPA4 acts as a prognostic factor and regulates the proliferation and metastasis of glioma.

Circular RNAs (circRNAs) are reported to play vital roles in tumour process and might be potential prognostic biomarkers and therapeutic targets for tumours. But the expression and function of circRNAs in glioma remain unclear. Here, we performed circRNA microarray analysis of glioma tissues and matched normal brain tissue samples to explore the circRNA profile in glioma. GO analysis, KEGG and Reactom pathway analysis of linear mRNA transcripts corresponding to circRNAs were performed to study the involved biological process and pathways. The clinical significance of the selected circRNA was investigated by Kaplan-Meier survival analysis. Relevant biological function, such as cell proliferation and metastasis, was detected in vitro and in vivo. And possible mechanism of the regulatory function of the selected circRNA in glioma was explored. We found that circCPA4 (hsa_circ_0082374) up-regulated the most in glioma tissues and high levels of circCPA4 were positively related to poor outcome of glioma. And knockdown of circCPA4 suppresses cell proliferation and metastasis in glioma. Moreover, circCPA4 interacts with let-7 and serves as a sponge for let-7. Through the competitive endogenous RNA (ceRNA) mechanism, circCPA4 sponges let-7 to regulate the expression of CPA4 and glioma progression. The circCPA4/let-7/CPA4 axis regulates glioma progression by ceRNA mechanism, and circCPA4 could be a novel prognostic biomarker and target for glioma treatment.

Carboxypeptidase A4 promotes cell growth via activating STAT3 and ERK signaling pathways and predicts a poor prognosis in colorectal cancer.

Carboxypeptidase A4 (CPA4) is a novel cancer-related gene that is aberrantly expressed in various malignant tumors. However, the roles and mechanisms of CPA4 have not been explored in colorectal cancer (CRC). In this study, we investigated the functions and mechanisms by which CPA4 promotes CRC progression. Quantitative real-time PCR (qRT-PCR) and western blot showed that CPA4 mRNA and CPA4 protein levels were up-regulated in CRC compared to levels in adjacent normal tissue. Immunohistochemistry (IHC) results indicating high CPA4 levels were positively associated with poor prognoses. In addition, Cell Counting Kit-8 (CCK-8), colony formation, flow cytometry, and transwell assays demonstrated that CPA4 overexpression facilitated the growth of CRC cells, whereas CPA4 knockdown resulted in decreased proliferation, G1/S phase transition arrest, and apoptosis. Subcutaneous tumorigenesis was performed in nude mice to confirm the tumor-promoting effects of CPA4 in vivo. Western blot revealed that activation of the STAT3 and ERK pathways is one of the oncogenic functions of CPA4 in CRC. Accordingly, CPA4 promotes CRC cell growth via activating the STAT3 and ERK pathways and may be a prognostic factor or therapeutic target for CRC.

Diagnostic and Prognostic Significance of Carboxypeptidase A4 (CPA4) in Breast Cancer.

Recent research focused on prolonged survival has suggested that carboxypeptidase A4 (CPA4) plays a role in both tumor microenvironment formation and distant metastasis in cancer. In some patients, serum and expression (mRNA) levels of CPA4 have been found to be correlated with the aggressiveness and progression of the disease. Accordingly, we conducted a first study to investigate the diagnostic and prognostic significance of CPA4 in the case of breast cancer (BC), the most common form of malignancy in women. The study included a total of 50 patients with BC and 20 healthy women as the control group. The participants' serum CPA4 levels were determined by the ELISA test, and, for assessment of CPA4 mRNA, we used the PCR method. The serum CPA4 (p = 0.001) and CPA4 mRNA (p = 0.015) levels were found to be statistically significantly higher in the controls, compared to the patient group. When the results of patient group were statistically analyzed based on subgrouping by tumor characteristics, the measured CPA4 mRNA levels showed significant difference with respect to the molecular subtype (p = 0.006), pN status (p = 0.023), and pathological stage (p = 0.039), while the serum CPA4 measurements differed significantly in terms of pathological type only (p = 0.024). We conclude that CPA4 is diagnostically and prognostically not futile when used in combination with the other considerations and measurements in breast cancer.

Synthesis and Structural/Functional Characterization of Selective M14 Metallocarboxypeptidase Inhibitors Based on Phosphinic Pseudopeptide Scaffold: Implications on the Design of Specific Optical Probes.

Metallocarboxypeptidases (MCPs) of the M14 family are Zn2+-dependent exoproteases present in almost every tissue or fluid in mammals. These enzymes perform a large variety of physiological functions and are involved in several pathologies, such as pancreatic diseases, inflammation, fibrinolysis, and cancer. Here, we describe the synthesis and functional/structural characterization of a series of reversible tight-binding phosphinic pseudopeptide inhibitors that show high specificity and potency toward these proteases. Characterization of their inhibitory potential against a large variety of MCPs, combined with high-resolution crystal structures of three selected candidates in complex with human carboxypeptidase A (CPA)1, allowed to decipher the structural determinants governing selectivity for type-A of the M14A MCP family. Further, the phosphinic pseudopeptide framework was exploited to generate an optical probe selectively targeting human CPAs. The phosphinic pseudopeptides presented here constitute the first example of chemical probes useful to selectively report on type-A MCPs activity in complex media.

Carboxypeptidase A4 accumulation is associated with an aggressive phenotype and poor prognosis in triple-negative breast cancer.

Using whole transcriptome analysis and a lentiviral short hairpin RNA screening library, carboxypeptidase A4 (CPA4) was identified as a novel marker in breast cancer and a therapeutic target in triple­negative breast cancer (TNBC) in the present study. Immunohistochemistry was used to evaluate the presence of CPA4, estrogen receptor, progesterone receptor, human epidermal growth factor receptor 2, Ki67, epidermal growth factor receptor, cytokeratin 5/6, aldehyde dehydrogenase 1, cluster of differentiation (CD)44, CD24, claudins, E­cadherin, vimentin and androgen receptor in 221 cases of breast cancer, including 68 TNBC cases. The effects of CPA4 on the viability and migration ability of TNBC cells were analyzed using RNA interference methods. Increased CPA4 expression, specifically in the cytoplasm of cancer tissue cells, was detected. Furthermore, high CPA4 expression in TNBC cases was associated with low expression of E­cadherin and with the expression of cancer stem cell markers (high CD44/low CD24). Patients with TNBC and high levels of CPA4 expression had a significantly poorer prognosis compared with those with low CPA4 expression. Notably, viability and migration were reduced, but E­cadherin expression was upregulated in CPA4­suppressed TNBC cells. The present data suggested that CPA4 may be a novel inducer for epithelial­mesenchymal transition, which is characterized by the downregulation of E­cadherin and mesenchymal phenotypes. To conclude, CPA4 may be a marker for poor prognosis and a promising therapeutic target in TNBC with aggressive phenotypes.

Phenotypes, endotypes and biomarkers in anaphylaxis: current insights.

PURPOSE OF REVIEW: The aim of the review is to describe the different clinical pictures of anaphylaxis (phenotypes), in relation to the underlying mechanisms and potential biomarkers, to describe anaphylaxis endotypes. This may aid in achieving a better understanding, management and outcomes of such severe reactions. RECENT FINDINGS: Different anaphylaxis phenotypes have been outlined, ranging from the classical type-I-like to those suggestive of cytokine-storm-like or complement-mediated reactions. Underlying mechanisms differ and biomarkers of cells and systems involved are being identified (tryptase, IL-6, bradykinin etc.) SUMMARY: Identifying specific phenotypes/endotypes will allow the application of precision medicine in patients with anaphylaxis, providing insights to the most appropriate approach in each case.

Mutations in the pancreatic secretory enzymes CPA1 and CPB1 are associated with pancreatic cancer.

To evaluate whether germline variants in genes encoding pancreatic secretory enzymes contribute to pancreatic cancer susceptibility, we sequenced the coding regions of CPB1 and other genes encoding pancreatic secretory enzymes and known pancreatitis susceptibility genes (PRSS1, CPA1, CTRC, and SPINK1) in a hospital series of pancreatic cancer cases and controls. Variants in CPB1, CPA1 (encoding carboxypeptidase B1 and A1), and CTRC were evaluated in a second set of cases with familial pancreatic cancer and controls. More deleterious CPB1 variants, defined as having impaired protein secretion and induction of endoplasmic reticulum (ER) stress in transfected HEK 293T cells, were found in the hospital series of pancreatic cancer cases (5/986, 0.5%) than in controls (0/1,045, P = 0.027). Among familial pancreatic cancer cases, ER stress-inducing CPB1 variants were found in 4 of 593 (0.67%) vs. 0 of 967 additional controls (P = 0.020), with a combined prevalence in pancreatic cancer cases of 9/1,579 vs. 0/2,012 controls (P < 0.01). More ER stress-inducing CPA1 variants were also found in the combined set of hospital and familial cases with pancreatic cancer than in controls [7/1,546 vs. 1/2,012; P = 0.025; odds ratio, 9.36 (95% CI, 1.15-76.02)]. Overall, 16 (1%) of 1,579 pancreatic cancer cases had an ER stress-inducing CPA1 or CPB1 variant, compared with 1 of 2,068 controls (P < 0.00001). No other candidate genes had statistically significant differences in variant prevalence between cases and controls. Our study indicates ER stress-inducing variants in CPB1 and CPA1 are associated with pancreatic cancer susceptibility and implicate ER stress in pancreatic acinar cells in pancreatic cancer development.

Mast cells signal their importance in health and disease.

FcεRI is the primary receptor in mast cells that mediates allergic reactions by inducing rapid release of mediators, an adaptive immune response that might have evolved as a host defense against parasites and venoms. Yet it is apparent that mast cells are also activated through non-IgE receptors, the significance of which is just beginning to be understood. This includes the Mas-related G protein-coupled receptor X2, which might contribute to reactions to diverse antimicrobials and polybasic compounds, and the adhesion G protein-coupled receptor E2, variants of which are associated with familial vibratory urticaria and are activated by mechanical vibration. Similarly, mast cells have long been recognized as the main repository for histamine, heparin, and proteases. Recent evidence also points to new functions, modes of delivery, and mechanisms of action of mast cell proteases that add new dimensions to the roles of mast cells in human biology. In addition, exposure of mast cells to environmental cues can quantitatively and qualitatively modulate their responses and thus their effect on allergic inflammation. Illustrating this paradigm, we summarize a number of recent studies implicating the injury/tissue damage cytokine IL-33 as a modulator of allergen-induced mast cell responses. We also discuss the discovery of markers associated with transformed mast cells and new potential directions in suppressing mast cell activity.