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JACS Au Jun 2024This study highlights the novel potential of molecular aggregates as inhibitors of a disease-related protein. Enzyme inhibitors have been studied and developed as...
This study highlights the novel potential of molecular aggregates as inhibitors of a disease-related protein. Enzyme inhibitors have been studied and developed as molecularly targeted drugs and have been applied for cancer, autoimmune diseases, and infections. In many cases, enzyme inhibitors that are used for therapeutic applications interact directly with enzymes in a molecule-to-molecule manner. We found that the aggregates of a small compound, Mn007, inhibited bovine pancreatic DNase I. Once Mn007 molecules formed aggregates, they exhibited inhibitory effects specific to DNases that require divalent metal ions. A DNase secreted by causes streptococcal toxic shock syndrome (STSS). STSS is a severe infectious disease with a fatality rate exceeding 30% in patients, even in this century. disrupts the human barrier system against microbial infections through the secreted DNase. Until now, the discovery/development of a DNase inhibitor has been challenging. Mn007 aggregates were found to inhibit the DNase secreted by , which led to the successful suppression of growth in human whole blood. To date, molecular aggregation has been outside the scope of drug discovery. The present study suggests that molecular aggregation is a vast area to be explored for drug discovery and development because aggregates of small-molecule compounds can inhibit disease-related enzymes.
PubMed: 38938790
DOI: 10.1021/jacsau.4c00210 -
Journal of Extracellular Biology Jan 2024Extracellular vesicles (EVs) contribute to a wide range of pathological processes including cancer progression, yet the molecular mechanisms underlying their biogenesis...
Extracellular vesicles (EVs) contribute to a wide range of pathological processes including cancer progression, yet the molecular mechanisms underlying their biogenesis remain incompletely characterized. The development of tetraspanin-based pHluorin reporters has enabled the real-time analysis of EV release at the plasma membrane. Here, we employed CD81-pHluorin to investigate mechanisms of EV release in ovarian cancer (OC) cells and report a novel role for the Ca-permeable transient receptor potential (TRP) channel TRPC3 in EV-mediated communication. We found that specific activation of TRPC3 increased Ca signalling in SKOV3 cells and stimulated an immediate increase in EV release. Ca-stimulants histamine and ionomycin likewise induced EV release, and imaging analysis revealed distinct stimulation-dependent temporal and spatial release dynamics. Interestingly, inhibition of TRPC3 attenuated histamine-stimulated Ca-entry and EV release, indicating that TRPC3 is likely to act downstream of histamine signalling in EV biogenesis. Furthermore, we found that direct activation of TRPC3 as well as the application of EVs derived from TRPC3-activated cells increased SKOV3 proliferation. Our data provides insights into the molecular mechanisms and dynamics underlying EV release in OC cells, proposing a key role for TRPC3 in EV biogenesis.
PubMed: 38938673
DOI: 10.1002/jex2.132 -
Journal of Extracellular Biology Jan 2024Placental extracellular vesicles (EVs) can be found in the maternal circulation throughout gestation, and their concentration, content and bioactivity are associated...
Placental extracellular vesicles (EVs) can be found in the maternal circulation throughout gestation, and their concentration, content and bioactivity are associated with pregnancy outcomes, including gestational diabetes mellitus (GDM). However, the effect of changes in the maternal microenvironment on the mechanisms associated with the secretion of EVs from placental cells remains to be fully established. Here, we evaluated the effect of high glucose on proteins associated with the trafficking and release of different populations of EVs from placental cells. BeWo and HTR8/SVneo cells were used as placental models and cultured under 5-mM D-glucose (i.e. control) or 25-mM D-glucose (high glucose). Cell-conditioned media (CCM) and cell lysate were collected after 48 h. Different populations of EVs were isolated from CCM by ultracentrifugation (i.e. pellet 2K-g, pellet 10K-g, and pellet 100K-g) and characterised by Nanoparticle Tracking Analysis. Quantitative proteomic analysis (IDA/SWATH) and multiple reaction monitoring protocols at high resolution (MRM) were developed to quantify 37 proteins related to biogenesis, trafficking/release and recognition/uptake of EVs. High glucose increased the secretion of total EVs across the pellets from BeWo cells, an effect driven mainly by changes in the small EVs concentration in the CCM. Interestingly, no effect of high glucose on HTR8/SVneo cells EVs secretion was observed. High glucose induces changes in proteins associated with vesicle trafficking in BeWo cells, including Heat Shock Protein Family A (Hsp70) Member 9 (HSPA9) and Member 8 (HSPA8). For HTR8/SVneo, altered proteins including prostaglandin F2α receptor regulatory protein (FPRP), RAB5A, RAB35, RAB5B, and RB11B, STAM1 and TSG101. These proteins are associated with the secretion and trafficking of EVs, which could explain in part, changes in the levels of circulating EVs in diabetic pregnancies. Further, we identified that proteins RAB11B, PDCD6IP, STAM, HSPA9, HSPA8, SDCBP, RAB5B, RAB5A, RAB7A and ERAP1 regulate EV release in response to high and low glucose when overexpressed in cells. Interestingly, immunohistochemistry analysis of RAB7A revealed distinct changes in placental tissues obtained from women with normal glucose tolerance (NGT, = 6) and those with GDM ( = 6), influenced by diet or insulin treatment. High glucose regulation of proteins involved in intercellular dynamics and the trafficking of multivesicular bodies to the plasma membrane in placental cells is relevant in the context of GDM pregnancies.
PubMed: 38938672
DOI: 10.1002/jex2.135 -
PeerJ 2024Pyrophosphatases (PPases) are enzymes that catalyze the hydrolysis of pyrophosphate (PPi), a byproduct of the synthesis and degradation of diverse biomolecules. The... (Review)
Review
Pyrophosphatases (PPases) are enzymes that catalyze the hydrolysis of pyrophosphate (PPi), a byproduct of the synthesis and degradation of diverse biomolecules. The accumulation of PPi in the cell can result in cell death. Although the substrate is the same, there are variations in the catalysis and features of these enzymes. Two enzyme forms have been identified in bacteria: cytoplasmic or soluble pyrophosphatases and membrane-bound pyrophosphatases, which play major roles in cell bioenergetics. In eukaryotic cells, cytoplasmic enzymes are the predominant form of PPases (c-PPases), while membrane enzymes (m-PPases) are found only in protists and plants. The study of bacterial cytoplasmic and membrane-bound pyrophosphatases has slowed in recent years. These enzymes are central to cell metabolism and physiology since phospholipid and nucleic acid synthesis release important amounts of PPi that must be removed to allow biosynthesis to continue. In this review, two aims were pursued: first, to provide insight into the structural features of PPases known to date and that are well characterized, and to provide examples of enzymes with novel features. Second, the scientific community should continue studying these enzymes because they have many biotechnological applications. Additionally, in this review, we provide evidence that there are m-PPases present in fungi; to date, no examples have been characterized. Therefore, the diversity of PPase enzymes is still a fruitful field of research. Additionally, we focused on the roles of H/Na pumps and m-PPases in cell bioenergetics. Finally, we provide some examples of the applications of these enzymes in molecular biology and biotechnology, especially in plants. This review is valuable for professionals in the biochemistry field of protein structure-function relationships and experts in other fields, such as chemistry, nanotechnology, and plant sciences.
Topics: Inorganic Pyrophosphatase; Bacteria; Fungi; Diphosphates
PubMed: 38938619
DOI: 10.7717/peerj.17496 -
Animal Bioscience Jun 2024The Hu sheep is a renowned breed known for its high reproductive rate. It is in estrus all year round, and its breeding population is gradually expanding. However, the...
OBJECTIVE
The Hu sheep is a renowned breed known for its high reproductive rate. It is in estrus all year round, and its breeding population is gradually expanding. However, the current techniques for cryopreserving semen have limited effectiveness, which hinders the continuous development of this species. The purpose of this study is to explore the effects of different penetrating cryoprotectants (CPAs) and egg yolk (EY) concentrations on the cryopreservation of Hu ram semen to determine the most effective combination.
METHODS
In this study, the effects of glycerol (GLY), ethylene glycol (EG), dimethylacetamide (DMA), dimethyl sulfoxide (DMSO), different proportions of GLY and EG, EY on sperm quality after thawing were investigated by detecting sperm total motility (TM), progressive motility (PM), straight-line velocity (VSL), curvilinear velocity (VCL), average path velocity (VAP), amplitude of lateral head displacement (ALH), wobble movement coefficient (WOB), average motion degree (MAD), functional integrity (plasma membrane integrity, acrosome integrity) and reactive oxygen species (ROS) level.
RESULTS
When GLY and EG were added together, compared to other concentration groups, 6% GLY significantly (p < 0.05) increased TM, PM, plasma membrane integrity, and acrosome integrity of thawed sperm. Additionally, it significantly (p < 0.05) decreased the ROS level of sperm. In this study, the TM, PM and membrane integrity of the 6% EG were significantly (p < 0.05) higher than those of the control, 1% GLY+5% EG and 6% GLY+6% EG groups. Compared to other concentration groups, 20% EY significantly (p < 0.05) improved the TM, PM, and plasma membrane integrity of thawed sperm. However, the integrity of the acrosome increased with the higher concentration of EY.
CONCLUSION
In conclusion, the post-thawed Hu ram semen diluted with a diluent containing 6% GLY and 20% EY exhibited higher quality compared to the other groups.
PubMed: 38938029
DOI: 10.5713/ab.24.0167 -
Slit2-Robo4 signal pathway and tight junction in intestine mediate LPS-induced inflammation in mice.European Journal of Medical Research Jun 2024Sepsis is one of the most common clinical diseases, which is characterized by a serious and uncontrollable inflammatory response. LPS-induced inflammation is a critical...
BACKGROUND
Sepsis is one of the most common clinical diseases, which is characterized by a serious and uncontrollable inflammatory response. LPS-induced inflammation is a critical pathological event in sepsis, but the underlying mechanism has not yet been fully elucidated.
METHODS
The animal model was established for two batches. In the first batch of experiments, Adult C57BL/6J mice were randomly divided into control group and LPS (5 mg/kg, i.p.)group . In the second batch of experiments, mice were randomly divided into control group, LPS group, and LPS+VX765(10 mg/kg, i.p., an inhibitor of NLRP3 inflammasome) group. After 24 hours, mice were anesthetized with isoflurane, blood and intestinal tissue were collected for tissue immunohistochemistry, Western blot analysis and ELISA assays.
RESULTS
The C57BL/6J mice injected with LPS for twenty-four hours could exhibit severe inflammatory reaction including an increased IL-1β, IL-18 in serum and activation of NLRP3 inflammasome in intestine. The injection of VX765 could reverse these effects induced by LPS. These results indicated that the increased level of IL-1β and IL-18 in serum induced by LPS is related to the increased intestinal permeability and activation of NLRP3 inflammasome. In the second batch of experiments, results of western blot and immunohistochemistry showed that Slit2 and Robo4 were significant decreased in intestine of LPS group, while the expression of VEGF was significant increased. Meanwhile, the protein level of tight junction protein ZO-1, occludin, and claudin-5 were significantly lower than in control group, which could also be reversed by VX765 injection.
CONCLUSIONS
In this study, we revealed that Slit2-Robo4 signaling pathway and tight junction in intestine may be involved in LPS-induced inflammation in mice, which may account for the molecular mechanism of sepsis.
Topics: Animals; Lipopolysaccharides; Mice; Signal Transduction; Nerve Tissue Proteins; Inflammation; Intercellular Signaling Peptides and Proteins; Tight Junctions; Mice, Inbred C57BL; Male; Receptors, Cell Surface; Receptors, Immunologic; Intestinal Mucosa; NLR Family, Pyrin Domain-Containing 3 Protein; Intestines; Disease Models, Animal; Inflammasomes
PubMed: 38937814
DOI: 10.1186/s40001-024-01894-5 -
Cell & Bioscience Jun 2024Microvascular destabilization is the primary cause of the inner blood-retinal barrier (iBRB) breakdown and increased vascular leakage in diabetic retinopathy (DR).... (Review)
Review
Microvascular destabilization is the primary cause of the inner blood-retinal barrier (iBRB) breakdown and increased vascular leakage in diabetic retinopathy (DR). Microvascular destabilization results from the combinational effects of increased levels of growth factors and cytokines, involvement of inflammation, and the changed cell-to-cell interactions, especially the loss of endothelial cells and pericytes, due to hyperglycemia and hypoxia. As the manifestation of microvascular destabilization, the fluid transports via paracellular and transcellular routes increase due to the disruption of endothelial intercellular junctional complexes and/or the altered caveolar transcellular transport across the retinal vascular endothelium. With diabetes progression, the functional and the structural changes of the iBRB components, including the cellular and noncellular components, further facilitate and aggravate microvascular destabilization, resulting in macular edema, the neuroretinal damage and the dysfunction of retinal inner neurovascular unit (iNVU). Although there have been considerable recent advances towards a better understanding of the complex cellular and molecular network underlying the microvascular destabilization, some still remain to be fully elucidated. Recent data indicate that targeting the intricate signaling pathways may allow to against the microvascular destabilization. Therefore, efforts have been made to better clarify the cellular and molecular mechanisms that are involved in the microvascular destabilization in DR. In this review, we discuss: (1) the brief introduction of DR and microvascular destabilization; (2) the cellular and molecular components of iBRB and iNVU, and the breakdown of iBRB; (3) the matrix and cell-to-cell contacts to maintain microvascular stabilization, including the endothelial glycocalyx, basement membrane, and various cell-cell interactions; (4) the molecular mechanisms mediated cell-cell contacts and vascular cell death; (5) the altered cytokines and signaling pathways as well as the intricate network of the cytokines involved in microvascular destabilization. This comprehensive review aimed to provide the insights for microvascular destabilization by targeting the key molecules or specific iBRB cells, thus restoring the function and structure of iBRB and iNVU, to treat DR.
PubMed: 38937783
DOI: 10.1186/s13578-024-01269-7 -
BMC Nephrology Jun 2024To investigate the expression and significance of Fractalkine (CX3CL1, FKN) in serum and renal tissue of myeloperoxidase and anti-neutrophil cytoplasmic antibody...
OBJECTIVE
To investigate the expression and significance of Fractalkine (CX3CL1, FKN) in serum and renal tissue of myeloperoxidase and anti-neutrophil cytoplasmic antibody associated vasculitis (MPO-AAV) rats.
METHODS
Thirty Wistar-Kyoto (WKY) rats were randomly divided into: Control group, MPO-AAV group (400 µg/kg MPO mixed with Freund's complete adjuvant i.p), MPO-AAV + Anti-FKN group (400 µg/kg MPO mixed with Freund's complete adjuvant i.p), anti-FKN group (1 µg/ rat /day, i.p) after 6 weeks. MPO-AAV associated glomerulonephritis model was established by intraperitoneal injection of MPO + Freund's complete adjuvant with 10 mice in each group. The concentration of MPO-ANCA and FKN in serum was detected by Enzyme-linked immunosorbent assay (ELISA). Hematoxylin-eosin (HE) staining was used to detect pathological changes of kidney tissue. Western blot and immunofluorescence staining were used to detect the expression and localization of FKN protein in kidney tissue. Renal function test indicators: 24-hour urinary protein (UAER), blood urea nitrogen (BUN), serum creatinine (Scr). The expression levels of p65NF-κB and IL-6 was detected by Immunohistochemical assays.
RESULTS
Compared with the control group, the serum MPO-ANCA antibody expression level in the MPO-AAV group was significantly increased (P < 0.01), and the contents of UAER, BUN and Scr were significantly up-regulated at 24 h (P < 0.01). Compared with the control group, the glomeruli in the MPO-AAV group had different degrees of damage, infiltration of inflammatory cell, and membrane cell hyperplasia and renal tubule edema. Compared with the control group, rats in the MPO-AAV group had significantly higher levels of FKN in serum and renal tissues (P < 0.01), and high expression of p65NF-κB and IL-6 in renal tissues (P < 0.01) (P < 0.05), whereas anti-FKN reversed the expression of the above factors. In MPO-AAV renal tissue, FKN was mainly expressed in the cytoplasm of renal tubular epithelial cells and glomerular podocytes. In addition, the contents of 24 h UAER, BUN and Scr of renal function in MPO-AAV rats were significantly decreased (P < 0.01) and the damage of renal tissue was significantly ameliorated after the administration of antagonistic FKN.
CONCLUSION
FKN may play a key role in the pathogenesis of MPO-AAV associated glomerulonephritis.
Topics: Animals; Chemokine CX3CL1; Glomerulonephritis; Rats; Peroxidase; Rats, Inbred WKY; Male; Anti-Neutrophil Cytoplasmic Antibody-Associated Vasculitis; Kidney; Antibodies, Antineutrophil Cytoplasmic; Transcription Factor RelA
PubMed: 38937701
DOI: 10.1186/s12882-024-03565-3 -
Scientific Reports Jun 2024In this study, polymer-coated anisotropic inorganic nanowires dispersed in PBI matrix were introduced to construct 1D proton conducting channels within PBI. Ionic-liquid...
In this study, polymer-coated anisotropic inorganic nanowires dispersed in PBI matrix were introduced to construct 1D proton conducting channels within PBI. Ionic-liquid and solvothermal methods were used for the synthesis of ZrO and WO NWs, which were coated with PVPA and PDDA polymers to increase their proton conductivity. Our results showed that, prepared membranes have amorphous nature due to the dominating presence of PBI. SEM analysis revealed the average thickness of membrane of about 36 µm. TG/DTA analysis detected lower weight loss of WO NWs (total 2.8%) compared to ZrO NWs (18%). Proton conductivity analysis showed that, PDDA/WO NWs possess relatively 4 times higher proton conductivity (4 10 Scm) compared to PDDA/ZrO NWs (1 10 Scm) at 80 ℃. In addition, PDDA-coated WO NWs dispersed PBI membranes showed the highest fuel cell current density (1.2 A/cm) and power density (215 mW/cm) at 150 ℃ after 24 h which is nearly 2.5 times higher than pure PBI membrane. In addition, they exhibited the lowest in-situ proton resistance of about (0.47 Ω) compared with that of pure PBI membrane (0.8 Ω). Our results are introducing new concepts towards the development of thin and efficient polymer electrolyte membranes for PEM fuel cells.
PubMed: 38937620
DOI: 10.1038/s41598-024-65955-9 -
Signal Transduction and Targeted Therapy Jun 2024Epidermal growth factor receptor (EGFR) is reportedly overexpressed in most esophageal squamous cell carcinoma (ESCC) patients, but anti-EGFR treatments offer limited...
Epidermal growth factor receptor (EGFR) is reportedly overexpressed in most esophageal squamous cell carcinoma (ESCC) patients, but anti-EGFR treatments offer limited survival benefits. Our preclinical data showed the promising antitumor activity of afatinib in EGFR-overexpressing ESCC. This proof-of-concept, phase II trial assessed the efficacy and safety of afatinib in pretreated metastatic ESCC patients (n = 41) with EGFR overexpression (NCT03940976). The study met its primary endpoint, with a confirmed objective response rate (ORR) of 39% in 38 efficacy-evaluable patients and a median overall survival of 7.8 months, with a manageable toxicity profile. Transcriptome analysis of pretreatment tumors revealed that neurotrophic receptor tyrosine kinase 2 (NTRK2) was negatively associated with afatinib sensitivity and might serve as a predictive biomarker, irrespective of EGFR expression. Notably, knocking down or inhibiting NTRK2 sensitized ESCC cells to afatinib treatment. Our study provides novel findings on the molecular factors underlying afatinib resistance and indicates that afatinib has the potential to become an important treatment for metastatic ESCC patients.
Topics: Humans; Afatinib; ErbB Receptors; Esophageal Squamous Cell Carcinoma; Drug Resistance, Neoplasm; Female; Male; Middle Aged; Aged; Esophageal Neoplasms; Protein Kinase Inhibitors; Receptor, trkB; Cell Line, Tumor; Adult; Gene Expression Regulation, Neoplastic; Tyrosine Kinase Inhibitors; Membrane Glycoproteins
PubMed: 38937446
DOI: 10.1038/s41392-024-01875-4