Modulation Of Proteins Research Articles

ATR-FTIR spectroscopy to evaluate serum protein expression in a murine cerebral ischemia model

Stroke is a prevalent vascular disease that causes disability and death worldwide. Molecular techniques have been developed to assess serum concentrations of biomarkers associated with this disease, such as some proteins. ATR-FTIR was proposed as an alternative technique to determine protein expression during the early stages of stroke. Serum samples from sham, ischemic, and ischemic treated with estradiol benzoate (EB; as a neuroprotective agent) male rats were evaluated at 0, 2-, 4-, 6-, 12-, and 24-hours post-ischemia. The analysis was developed in the mid-infrared region but mainly focused on the protein region (1500–1700 cm−1), where it was possible to observe the modulation in the absorbance intensity. The peaks at 1545, 1645, 1635, and 1650 cm−1 associated with amide II, amide I, β-sheets, and α-helixes, respectively, were prominent peaks where protein modulation was observed. The results demonstrate that infrared spectroscopy could be a good alternative technique to determine the modulation of protein expression during stroke events.

High-intensity exercise alongside insulin alleviates muscle atrophy in type 1 diabetes mellitus concomitant with modulation of mitophagy-related proteins in skeletal muscle

Background: Diabetes patients’ quality of life can be severely impacted by diabetic muscle atrophy.Aim: This study aimed to explore the impact of high-intensity exercise (HIE) alongside insulin treatment on muscle atrophy in a rat model of type 1 diabetes mellitus (T1DM).Methodology: Fifty rats were allocated into five groups; Group 1, control sedentary (CS), T1DM was elicited in the rest of the groups by giving them Streptozotocin (STZ) (60 mg/kg), where group 2 (DS) remained sedentary, while groups 3,4,5 were treated with insulin after induction of diabetes. Group 4 (DI+MIE) and 5 (DI+ HIE) underwent moderate and high-intensity exercise, respectively.Results: HIE for 14 days combined with insulin treatment significantly restored muscle strength and mass with a significant modification in the mitophagy-related proteins and fibroblast growth factor 21 (FGF 21) compared to other treated groups.Conclusion: This study concluded that there is a therapeutic role for HIE with insulin against T1DM-induced muscle atrophy.

The discovery and structural basis of two distinct state-dependent inhibitors of BamA

BamA is the central component of the essential β-barrel assembly machine (BAM), a conserved multi-subunit complex that dynamically inserts and folds β-barrel proteins into the outer membrane of Gram-negative bacteria. Despite recent advances in our mechanistic and structural understanding of BamA, there are few potent and selective tool molecules that can bind to and modulate BamA activity. Here, we explored in vitro selection methods and different BamA/BAM protein formulations to discover peptide macrocycles that kill Escherichia coli by targeting extreme conformational states of BamA. Our studies show that Peptide Targeting BamA-1 (PTB1) targets an extracellular divalent cation-dependent binding site and locks BamA into a closed lateral gate conformation. By contrast, PTB2 targets a luminal binding site and traps BamA into an open lateral gate conformation. Our results will inform future antibiotic discovery efforts targeting BamA and provide a template to prospectively discover modulators of other dynamic integral membrane proteins.

Patent Foramen Ovale and Oxygenation in Patients with Cystic Fibrosis.

Patent foramen ovale (PFO) affects about 25% of the population. We studied outcomes in cystic fibrosis (CF). We conducted a case-control study of patients with CF (PwCF) and age and sex-matched controls who underwent agitated saline contrast (bubble) echocardiography, 1998-2020. We assessed PFO impacts using linear, logistic, quasipoisson and proportional hazards models. 59 of 64 PwCF and 88 of 93 controls underwent bubble studies to investigate unexplained hypoxemia or dyspnea. PwCF had higher mean pulmonary artery pressure (PAP, 6.9 mm Hg, 95% Confidence Interval [CI] = 2.35-11.4), reduced tricuspid annular plane systolic excursion (TAPSE, -3.78 mm, CI = -5.64 to -1.93) and similar right ventricular diastolic sizes. Absent hypoxemia, PFO incidence was similar between PwCF and controls; with hypoxemia, PFO was more common in CF (Odds Ratio [OR] = 5.00, CI = 1.32-19.0). In CF, oxygen supplementation occurred at a percent predicted forced expiratory volume in 1 s (FEV1%) 22.5 points higher with PFO. Adjusted for FEV1%, PFO was associated with 0.59 more prior year pulmonary exacerbations (CI = 0.20-0.98) and shorter time to next exacerbation (Hazard Ratio = 1.86, CI = 1.06-3.26). Associations between PFO and hypoxemia or exacerbations were insensitive to PAP, TAPSE and CF transmembrane regulator protein modulator treatments. PFO was not associated with CF time to death or lung transplantation (median 1.87 years) adjusted for age, sex, FEV1% and prior year exacerbation counts. PFO in CF is associated with hypoxemia at higher FEV1% and more pulmonary exacerbations but not survival.

Unveiling the impacts of metformin on hepatocellular carcinoma: A bioinformatic exploration in cell lines

The most common type of liver cancer is hepatocellular carcinoma (HCC), accounting for 75–85% of cases. Despite its associated side effects, sorafenib remains the standard treatment for HCC. Given the critical need to improve therapeutic efficacy while minimizing adverse effects, alternative drugs must be thoroughly investigated. Numerous studies indicate that combining sorafenib with metformin results in a more favorable treatment profile. The aim of this study was to employ bioinformatics methodologies to elucidate the molecular pathways and genetic underpinnings of metformin's efficacy in HCC treatment. Genes associated with metformin and its action against HCC (Huh-7 and HepG2 cells) were acquired from the NCBI-GEO data collection by utilizing pre-determined keywords. Subsequently, pathways implicated in metformin-mediated HCC treatment were analyzed through the Kyoto Encyclopedia of Genes and Genomes (KEGG). Our analysis revealed the involvement of multiple pathways, with metabolic pathways implicated in 80% of the total cases. Neurodegenerative pathways were involved in only around 60% of the total cases. These findings align with the multifaceted mechanisms of metformin’s action, encompassing adenosine monophosphate-activated protein kinase activation, apoptosis induction, insulin regulation, anti-inflammatory responses, and modulation of cell proliferation. This comprehensive investigation sheds light on the intricate molecular landscape underpinning metformin's therapeutic efficacy in HCC, thereby informing potential avenues for optimizing treatment strategies.

Knock-Out of IKKepsilon Ameliorates Atherosclerosis and Fatty Liver Disease by Alterations of Lipid Metabolism in the PCSK9 Model in Mice.

The inhibitor-kappaB kinase epsilon (IKKε) represents a non-canonical IκB kinase that modulates NF-κB activity and interferon I responses. Inhibition of this pathway has been linked with atherosclerosis and metabolic dysfunction-associated steatotic liver disease (MASLD), yet the results are contradictory. In this study, we employed a combined model of hepatic PCSK9D377Y overexpression and a high-fat diet for 16 weeks to induce atherosclerosis and liver steatosis. The development of atherosclerotic plaques, serum lipid concentrations, and lipid metabolism in the liver and adipose tissue were compared between wild-type and IKKε knock-out mice. The formation and progression of plaques were markedly reduced in IKKε knockout mice, accompanied by reduced serum cholesterol levels, fat deposition, and macrophage infiltration within the plaque. Additionally, the development of a fatty liver was diminished in these mice, which may be attributed to decreased levels of multiple lipid species, particularly monounsaturated fatty acids, triglycerides, and ceramides in the serum. The modulation of several proteins within the liver and adipose tissue suggests that de novo lipogenesis and the inflammatory response are suppressed as a consequence of IKKε inhibition. In conclusion, our data suggest that the knockout of IKKε is involved in mechanisms of both atherosclerosis and MASLD. Inhibition of this pathway may therefore represent a novel approach to the treatment of cardiovascular and metabolic diseases.

Identifying the “stripe” transcription factors and cooperative binding related to DNA methylation

DNA methylation plays a critical role in gene regulation by modulating the DNA binding of transcription factors (TFs). This study integrates TFs’ ChIP-seq profiles with WGBS profiles to investigate how DNA methylation affects protein interactions. Statistical methods and a 5-letter DNA motif calling model have been developed to characterize DNA sequences bound by proteins, while considering the effects of DNA modifications. By employing these methods, 79 significant universal “stripe” TFs and cofactors (USFs), 2360 co-binding protein pairs, and distinct protein modules associated with various DNA methylation states have been identified. The USFs hint a regulatory hierarchy within these protein interactions. Proteins preferentially bind to non-CpG sites in methylated regions, indicating binding affinity is not solely CpG-dependent. Proteins involved in methylation-specific USFs and cobinding pairs play essential roles in promoting and sustaining DNA methylation through interacting with DNMTs or inhibiting TET binding. These findings underscore the interplay between protein binding and methylation, offering insights into epigenetic regulation in cellular biology.

Identification of novel hub genes and immune infiltration in atopic dermatitis using integrated bioinformatics analysis

The aim of this study was to identify key genes and investigate the immunological mechanisms of atopic dermatitis (AD) at the molecular level via bioinformatics analysis. Gene expression profiles (GSE32924, GSE107361, GSE121212, and GSE230200) were obtained for screening common differentially expressed genes (co-DEGs) from the gene expression omnibus database. Functional enrichment analysis, protein–protein interaction network and module construction, and identification of common hub genes were performed. Hub genes were validated using receiver operating characteristic curve analysis based on GSE130588 and GSE16161. NetworkAnalyst was used to detect microRNAs (miRNAs) and transcription factors (TFs) associated with the hub genes. The immune cell infiltration was analyzed using the CIBERSORT algorithm to further analyze the correlation between hub genes and immune cells. A total of 146 co-DEGs were obtained, showing significant enrichment in cytokine–cytokine receptor interaction and JAK-STAT signaling pathway. Seven hub genes were identified by Cytoscape and validated with external datasets. Subsequent prediction of miRNAs and TFs targeting these hub genes revealed their regulatory roles. Analysis of immune cell infiltration and correlation revealed a significant positive correlation between CCL22 expression and the number of dendritic cells activated. The identified hub genes represent potential diagnostic and therapeutic targets in the immunological pathogenesis of AD.

Identification of function modules in the co-expression protein–protein interaction network of Bombyx mori in response to Beauveria bassiana infection

Beauveria bassiana (B. bassiana) is a common fungal disease in sericulture. Previous research has primarily focused on investigating genes involved in innate immunity. However, the response of Bombyx mori (B. mori) to B. bassiana requires the coordination of other biological processes in addition to the immune system. We measured protein expression profile of B. mori after inoculating B. bassiana using iTRAQ technology in previous. Here we constructed a co-expression protein–protein interaction network of B. mori in response to B. bassiana infection. Subnetworks and modules were analyzed, and the functions of these modules were annotated. The results revealed the identification of numerous proteins associated with cellular immunity, including those involved in phagosomes, lysosomes, mTOR signaling, sugar metabolism, and the ubiquitin–proteasome pathway. Meanwhile, we observed that the pathways involved in protein synthesis were activated, including pyruvate and purine metabolism, RNA transport, ribosome, protein processing in endoplasmic reticulum, and protein export pathways, during B. bassiana infection. Based on this analysis, we selected six candidate genes (shock protein, ribosome, translocon, actin muscle-type A2, peptidoglycan recognition protein, and collagenase) that were found to be related to the response to B. bassiana. Further verification experiments demonstrated significant changes in their expression levels after inoculation with B. bassiana. These research findings provide new insights into the molecular mechanism of insect immune response to fungal infection.

Ultrasound treatment improved gelling and emulsifying properties of myofibrillar proteins from Antarctic krill (Euphausia superba)

Antarctic krill is a promising source of marine proteins with abundant biomass and excellent nutritional profile, but has poor technological properties. Ultrasonic treatment at power levels of 0, 100, 200, 300, 400 and 500 W was applied to improve the technological properties of Antarctic krill meat, and the changes in physicochemical properties of myofibrillar proteins (MPs) were investigated. The results indicated that proper ultrasonic treatment significantly improved the gelling properties of Antarctic krill meat, in terms of a more uniform and stable gel texture and better water holding capacity, which were related to better cross-linking of MPs. Ultrasonic treatment promoted the conversion of MPs’ secondary structures from α-helix and random coil to β-sheet and β-turn, thereby making the molecular structure soft and loose. In addition, at tertiary structure level, ultrasonic treatment exposed the hydrophobic groups and sulfhydryl groups within MPs, thereby improving the emulsifying properties by changing the intermolecular interactions and interface properties. Furthermore, the particle size of MPs decreased and exhibited a more uniform distribution, aligning with the enhanced interactions observed between MPs and oil. These results provide an insight into the efficient development of Antarctic krill by elucidating how the ultrasonic treatment improves the gelling and emulsifying properties based on structure modulation of myofibrillar proteins.

Exploring Anticancer Potential of Lactobacillus Strains: Insights into Cytotoxicity and Apoptotic Mechanisms on HCT 115 Cancer Cells.

This study aims to systematically assess the anticancer potential of distinct Lactobacillus strains on Human Colorectal Tumor (HCT) 115 cancer cells, with a primary focus on the apoptotic mechanisms involved. Lactobacillus strains were isolated from sheep milk and underwent a meticulous microbial isolation process. Previous research indicates that certain probiotic bacteria, including Lactobacillus species, may exhibit anticancer properties through mechanisms such as apoptosis induction. However, there is limited understanding of how different Lactobacillus strains exert these effects on cancer cells and the underlying molecular pathways involved. Cytotoxicity was evaluated through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays and exposure durations of Lactobacillus cell-free lyophilized filtrates. Additional apoptotic features were characterized using 4.6-diamidino-2-phenylindole (DAPI) analysis for nuclear fragmentation and Annexin V/PI analysis for apoptosis quantification. Genetic analysis explored the modulation of apoptotic proteins (Bax and Bcl2) in response to Lactobacillus treatment. Whole-genome sequencing (WGS) was performed to understand the genetic makeup of the Lactobacillus strains used in the study. The study demonstrated a significant reduction in HCT 115 cell viability, particularly with L. plantarum, as evidenced by Sulforhodamine B (SRB) and MTT assays. DAPI analysis revealed nuclear fragmentation, emphasizing an apoptotic cell death mechanism. Annexin V/PI analysis supported this, showing a higher percentage of early and late apoptosis in L. plantarum-treated cells. Genetic analysis uncovered up-regulation of pro-apoptotic protein Bax and down-regulation of anti-apoptotic protein Bcl2 in response to Lactobacillus treatment. WGS study revealed a strain reported to NCBI PRJNA439183. L. plantarum emerged as a potent antiproliferative agent against HCT 115 cancer cells, inducing apoptosis through intricate molecular mechanisms. This study underscores the scientific basis for L. plantarum's potential role in cancer therapeutics, highlighting its impact on antiproliferation, adhesion, and gene-protein regulation. Further research is warranted to elucidate the specific molecular pathways involved and to evaluate the therapeutic potential of L. plantarum in preclinical and clinical settings.

Tim-3 Is Required for Regulatory T Cell-Mediated Promotion of T Cell Exhaustion and Viral Persistence during Chronic Lymphocytic Choriomeningitis Virus Infection.

Expression of T cell Ig and mucin domain-containing protein 3 (Tim-3) is upregulated on regulatory T cells (Tregs) during chronic viral infections. In several murine and human chronic infections, the expression of Tim-3 is associated with poor control of viral burden and impaired antiviral immune responses. However, the role of Tim-3+ Tregs during persistent viral infections has not been fully defined. We employed an inducible Treg-specific Tim-3 loss-of-function (Tim-3 Treg knockout) murine model to dissect the role of Tim-3 on Tregs during chronic lymphocytic choriomeningitis virus infection. Tim-3 Treg knockout mice exhibited a decrease in morbidity, a more potent virus-specific T cell response, and a significant decrease in viral burden. These mice also had a reduction in the frequency of PD-1+Tim-3+ and PD-1+Tox+ gp33-specific exhausted CD8+ T cells. Our findings demonstrate that modulation of a single surface protein on Tregs can lead to a reduction in viral burden, limit T cell exhaustion, and enhance gp33-specific T cell response. These studies may help to identify Tim-3-directed therapies for the management of persistent infections and cancer.

Dysregulation of lipid metabolism in the liver of Tspo knockout mice

The translocator protein, TSPO, has been implicated in a wide range of cellular processes exerted from its position in the outer mitochondrial membrane from where it influences lipid metabolism and mitochondrial oxidative activity. Understanding how this protein regulates a profusion of processes requires further elucidation and to that end we have examined lipid metabolism and used an RNAseq strategy to compare transcript abundance in wildtype and Tspo knockout (KO) mouse liver. The levels of cholesterol, triglyceride and phospholipid were significantly elevated in the KO mouse liver. The expression of cholesterol homeostasis genes was markedly downregulated. Determination of the differential expression revealed that many genes were either up- or downregulated in the KO animals. However, a striking observation within the results was a decrease of transcripts for protein degradation proteins in KO animals while protease inhibitors were enriched. When the entire abundance data-set was analysed with CEMiTool, and revealed a module of proteins that were under-represented in the KO animals. These could subsequently be formed into a network comprising three interlinked clusters at the centre of which were proteins of cytoplasmic ribosomes with gene ontology terms suggesting impairment to translation. The largest cluster was dominated by proteins of lipid metabolism but also contained disparate systems of iron metabolism and behaviour. The third cluster was dominated by proteins of the electron transport chain and oxidative phosphorylation. These findings suggest that TSPO contributes to lipid metabolism, detoxification of active oxygen species and oxidative phosphorylation, and regulates mitochondrial retrograde signalling.

A temperature-inducible protein module for control of mammalian cell fate.

Inducible protein switches allow on-demand control of proteins in response to inputs including chemicals or light. However, these inputs either cannot be controlled with precision in space and time or cannot be applied in optically dense settings, limiting their application in tissues and organisms. Here we introduce a protein module whose active state can be reversibly toggled with a small change in temperature, a stimulus that is both penetrant and dynamic. This protein, called Melt (Membrane localization through temperature), exists as a monomer in the cytoplasm at elevated temperatures but both oligomerizes and translocates to the plasma membrane when temperature is lowered. The original Melt variant switched states between 28-32°C, and state changes could be observed within minutes of temperature change. Melt was highly modular, permitting thermal control over diverse processes including signaling, proteolysis, nuclear shuttling, cytoskeletal rearrangements, and cell death, all through straightforward end-to-end fusions. Melt was also highly tunable, giving rise to a library of variants with switch point temperatures ranging from 30-40°C. The variants with higher switch points allowed control of molecular circuits between 37°C-41°C, a well-tolerated range for mammalian cells. Finally, Melt permitted thermal control of cell death in a mouse model of human cancer, demonstrating its potential for use in animals. Thus Melt represents a versatile thermogenetic module for straightforward, non-invasive, spatiotemporally-defined control of mammalian cells with broad potential for biotechnology and biomedicine.

Enhanced feature matching in single-cell proteomics characterizes IFN-γ response and co-existence of cell states

Proteome analysis by data-independent acquisition (DIA) has become a powerful approach to obtain deep proteome coverage, and has gained recent traction for label-free analysis of single cells. However, optimal experimental design for DIA-based single-cell proteomics has not been fully explored, and performance metrics of subsequent data analysis tools remain to be evaluated. Therefore, we here formalize and comprehensively evaluate a DIA data analysis strategy that exploits the co-analysis of low-input samples with a so-called matching enhancer (ME) of higher input, to increase sensitivity, proteome coverage, and data completeness. We assess the matching specificity of DIA-ME by a two-proteome model, and demonstrate that false discovery and false transfer are maintained at low levels when using DIA-NN software, while preserving quantification accuracy. We apply DIA-ME to investigate the proteome response of U-2 OS cells to interferon gamma (IFN-γ) in single cells, and recapitulate the time-resolved induction of IFN-γ response proteins as observed in bulk material. Moreover, we uncover co- and anti-correlating patterns of protein expression within the same cell, indicating mutually exclusive protein modules and the co-existence of different cell states. Collectively our data show that DIA-ME is a powerful, scalable, and easy-to-implement strategy for single-cell proteomics.

Unraveling modulation effects on albumin synthesis and inflammation by Striatin, a bioactive protein fraction isolated from Channa striata: In silico proteomics and in vitro approaches

Hypoalbuminemia, associated with inflammation in severely ill patients, can emerge due to decreased albumin production. Transforming growth factor-beta (TGF-β) and nuclear factor-kappa B (NF-κB) are critical signaling pathways responsible for decreased albumin expression. This study explores the protein content and modulation effects of Striatin on albumin synthesis and inflammation, employing in silico proteomics and in vitro investigations. In the in silico proteomics realm, LC/MS-MS protein sequencing, 3D modeling, protein-protein docking simulations, 100 ns molecular dynamics (MD) simulations, and MM/PBSA binding free energy calculations were carried out. Complementing this, in vitro studies examined Albumin gene expression and extracellular secretion in HepG2 cells subjected to lipopolysaccharides-induced hypoalbuminemia. Furthermore, the study probed Striatin's influence on the NF-ᴋB expression, given albumin's role as a negative acute-phase protein. The results unveiled nucleoside diphosphate kinase (NdK) and parvalbumin (PV) as the prominent constituents within Striatin. Notably, NdK and PV exhibited the ability to disrupt hydrogen bonds with specific residues in both TGF-β and NF-κB complexes, thereby enhancing their flexibility, akin to the action of the FKBP12 complex (antagonist complex). In the in vitro experiments, Striatin demonstrated a dose and time-dependent inhibition of hypoalbuminemia, with peak efficacy observed at a concentration of 20 μg/mL. At this concentration, Striatin also suppressed NF-κB expression when co-incubated with lipopolysaccharides. While these findings suggest potential inhibitory effects of Striatin on TGF-β and NF-κB activities, they are preliminary and warrant further investigation. This study highlights Striatin's potential as a therapeutic agent for inflammation-related hypoalbuminemia, though additional research is needed to fully validate these results.

Chem-CRISPR/dCas9FCPF: a platform for chemically induced epigenome editing.

Epigenetic aberration is one of the major driving factors in human cancer, often leading to acquired resistance to chemotherapies. Various small molecule epigenetic modulators have been reported. Nonetheless, outcomes from animal models and clinical trials have underscored the substantial setbacks attributed to pronounced on- and off-target toxicities. To address these challenges, CRISPR/dCas9 technology is emerging as a potent tool for precise modulation of epigenetic mechanism. However, this technology involves co-expressing exogenous epigenetic modulator proteins, which presents technical challenges in preparation and delivery with potential undesirable side effects. Recently, our research demonstrated that Cas9 tagged with the Phe-Cys-Pro-Phe (FCPF)-peptide motif can be specifically targeted by perfluorobiphenyl (PFB) derivatives. Here, we integrated the FCPF-tag into dCas9 and established a chemically inducible platform for epigenome editing, called Chem-CRISPR/dCas9FCPF. We designed a series of chemical inhibitor-PFB conjugates targeting various epigenetic modulator proteins. Focusing on JQ1, a panBET inhibitor, we demonstrate that c-MYC-sgRNA-guided JQ1-PFB specifically inhibits BRD4 in close proximity to the c-MYC promoter/enhancer, thereby effectively repressing the intricate transcription networks orchestrated by c-MYC as compared with JQ1 alone. In conclusion, our Chem-CRISPR/dCas9FCPF platform significantly increased target specificity of chemical epigenetic inhibitors, offering a viable alternative to conventional fusion protein systems for epigenome editing.

Receptor activity-modifying protein modulation of parathyroid hormone-1 receptor function and signaling.

Receptor activity-modifying proteins (RAMPs) are known to modulate the pharmacology and function of several G-protein-coupled receptors (GPCRs), including the parathyroid hormone 1 receptor (PTH1R). However, the precise effects of different RAMPs on PTH1R signalling and trafficking remain poorly understood. This study investigated the impact of RAMP2 and RAMP3 on PTH1R function using a range of PTH and PTH-related protein (PTHrP)-derived ligands. We employed FRET imaging to assess PTH1R interactions with RAMPs. Cell surface expression of PTH1R was evaluated in the presence of RAMPs. PTH1R-mediated cAMP accumulation, β-arrestin recruitment, and calcium signalling were measured in response to various ligands. Antibody-capture scintillation proximity assays were used to examine G-protein activation patterns. PTH1R preferentially interacted with RAMP2 and, to a lesser extent, RAMP3, but not with RAMP1. RAMP3 co-expression reduced cell surface expression of PTH1R. RAMP2 significantly enhanced PTH1R-mediated signalling responses to PTH (1-34), PTHrP (1-34), PTH (1-84), and PTH (1-17) analogue ZP2307, while RAMP3 co-expression attenuated or abolished these responses. Full-length PTHrP analogues exhibited lower potency and efficacy than PTHrP (1-34) in activating PTH1R. RAMP2 increased the potency and/or efficacy of these analogues, whereas RAMP3 reduced these responses. RAMP2 differentially modulated G-protein activation by PTH1R in a ligand-dependent manner, with PTH (1-34) and PTHrP (1-34) inducing distinct patterns of G-protein subtype activation. These findings highlight the complex role of RAMPs in regulating PTH1R signalling and trafficking, revealing differential effects of RAMP2 and RAMP3 on receptor function. The data suggest that targeting the PTH1R/RAMP2 complex may be a promising strategy for developing novel bone anabolic therapies by leveraging biased agonism and functional selectivity. Further research using physiologically relevant models is needed to elucidate the therapeutic potential of this approach.

Recent advances in the understanding of the peritoneal membrane.

The efficiency of peritoneal dialysis (PD) as a life-sustaining replacement therapy for patients with kidney failure relies on the integrity and function of the peritoneal membrane. Here, we review the most recent advances in the understanding of the peritoneal membrane and its role in PD. A recent update of the ISPD guidelines proposed a revised definition of membrane dysfunction, emphasizing the importance of fluid balance in patients treated with PD and identified three main mechanisms leading to insufficient peritoneal ultrafiltration (UF). The Bio-PD study, the first genomewide association study in PD, demonstrated that 20% of the interindividual variability in the peritoneal solute transfer rate is genetically determined, and identified several loci of potential relevance for peritoneal transport. A candidate-gene approach identified and characterized a common and functional variant in the promoter of the AQP1 gene associated with water transport and clinical outcomes in PD. Innovative strategies to preserve the integrity of the peritoneal membrane and to enhance UF are also discussed, including the use of gliflozins; steady glucose concentration PD; modulation of GLUT proteins; and cytoprotective additives. A comprehensive understanding of the peritoneal membrane and of the mechanisms driving UF may help individualizing PD prescription and improving outcomes in patients treated with PD.

Enhanced anti-tumor efficacy of S3I-201 in breast cancer mouse model through Wharton jelly- exosome

ObjectiveExosomes, membrane-enveloped vesicles found in various cell types, including Wharton’s jelly mesenchymal stem cells, play a crucial role in intercellular communication and regulation. Their use as a cell-free nanotechnology and drug delivery system has attracted attention. Triple-negative breast cancer (TNBC) is a major global health problem and is characterized by a high mortality rate. This study investigates the potential of Wharton’s Jelly mesenchymal stem cell-derived exosomes (WJ-Exo) as carriers of S3I-201 and their effects on STAT3 expression in breast cancer cell lines, and evaluates whether these exosomes can enhance the anti-tumor effect of S3I-201.MethodsThe filtered WJ-Exos were analyzed by Transmission Electron Microscopy (TEM), Scanning electron microscopy (SEM), Dynamic Light Scattering (DLS), flow cytometry, and Western blotting. These exosomes were then used for loading with S3I-201, resulting in the nano-formulation WJ-Exo(S3I-201). The effect of WJ-Exo(S3I-201) on 4T1 cancer cells was investigated in vitro using MTT assay, flow cytometry, wound healing assay, Western blotting and Quantitative Real-Time Polymerase chain reaction (qPCR) analysis. Finally, the therapeutic efficacy of the nano-formulation was investigated in vivo using a tumor-bearing mouse model.ResultsIn vitro experiments showed that co-incubation of 4T1 cells with the nano-formulation resulted in a significant reduction in p-STAT3 levels, induction of apoptosis, modulation of Bcl-2, Bax and caspase-3 protein and gene expression, and inhibition of migration. In vivo, treatment of tumor-bearing mice with WJ-Exo(S3I-201) showed a strong antitumor effect that exceeded the efficacy observed in the S3I-201 group.ConclusionOur results demonstrate that WJ-Exo is an effective carrier for targeting S3I-201 to tumor cells and enhances the therapeutic efficacy of S3I-201 in tumor-bearing mice.