Monomethyl fumarate prevents alloimmune rejection in mouse heart transplantation by inducing tolerogenic dendritic cells.

Dendritic cells (DCs) are important targets for eliciting allograft rejection after transplantation. Previous studies have demonstrated that metabolic reprogramming of DCs can transform their immune functions and induce their differentiation into tolerogenic DCs. In this study, we aim to investigate the protective effects and mechanisms of monomethyl fumarate (MMF), a bioactive metabolite of fumaric acid esters, in a mouse model of allogeneic heart transplantation. Bone marrow-derived DCs are harvested and treated with MMF to determine the impact of MMF on the phenotype and immunosuppressive function of DCs by flow cytometry and T-cell proliferation assays. RNA sequencing and Seahorse analyses are performed for mature DCs and MMF-treated DCs (MMF-DCs) to investigate the underlying mechanism. Our results show that MMF prolongs the survival time of heart grafts and inhibits the activation of DCs in vivo. MMF-DCs exhibit a tolerogenic phenotype and function in vitro. RNA sequencing and Seahorse analyses reveal that MMF activates the Nrf2 pathway and mediates metabolic reprogramming. Additionally, MMF-DC infusion prolongs cardiac allograft survival, induces regulatory T cells, and inhibits T-cell activation. MMF prevents allograft rejection in mouse heart transplantation by inducing tolerogenic DCs.

Periosteum-derived mesenchymal stem cell alleviates renal fibrosis through mTOR-mediated Treg differentiation.

BACKGROUND: Mesenchymal stem cells (MSCs) are the hotspots of cellular therapy due to their low immunogenicity, potent immunoregulation, and unique renoprotection. The present study aimed to investigate the effects of periosteum-derived MSCs (PMSCs) in ischemia-reperfusion (IR)-mediated renal fibrosis. METHODS: Using cell proliferation assay, flow cytometry, immunofluorescence, and histologic analysis, the differences in cell characteristics, immunoregulation, and renoprotection of PMSCs were compared to the bone marrow-derived MSCs (BMSCs), the most frequently studied stem cells in cellular therapy. In addition, the mechanism of PMSC renoprotection was investigated by 5' end of the RNA transcript sequencing (SMART-seq) and mTOR knockout mice. RESULTS: The proliferation and differentiation capabilities of PMSCs were stronger than those of BMSCs. Compared with BMSCs, the PMSCs exerted a better effect on alleviating renal fibrosis. Meanwhile, the PMSCs more effectively promote Treg differentiation. Treg exhaustion experiment indicated that Tregs exerted an important effect on inhibiting renal inflammation and acted as a critical mediator in PMSC renoprotection. Additionally, SMART-seq results implied that the PMSCs promoted Treg differentiation, possibly via the mTOR pathway. In vivo and in vitro experiments showed that PMSC inhibited mTOR phosphorylation of Treg. After mTOR knockout, the PMSCs failed to promote Treg differentiation. CONCLUSIONS: Compared with BMSCs, the PMSCs exerted stronger immunoregulation and renoprotection that was mainly attributed to PMSC promotion for Treg differentiation by inhibiting the mTOR pathway.

Integration of transcriptomics and metabolomics reveals pathways involved in MDSC supernatant attenuation of TGF-ß1-induced myofibroblastic differentiation of mesenchymal stem cells.

Overexposure to transforming growth factor b1 (TGF-ß1) induces myofibroblastic differentiation of mesenchymal stem cells (MSCs), which could be attenuated by myeloid-derived suppressor cell (MDSC) supernatant. However, the promyofibroblastic effects of TGF-ß1 and the antimyofibroblastic effects of MDSC supernatant in MSCs have not been fully elucidated. To further clarify the latent mechanism and identify underlying therapeutic targets, we used an integrative strategy combining transcriptomics and metabolomics. Bone marrow MSCs were collected 24 h following TGF-ß1 and MDSC supernatant treatment for RNA sequencing and untargeted metabolomic analysis. The integrated data were then analyzed to identify significant gene-metabolite correlations. Differentially expressed genes (DEGs) and differentially expressed metabolites (DEMs) were assessed by Gene Ontology (GO) functional annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses for exploring the mechanisms of myofibroblastic differentiation of MSCs. The integration of transcriptomic and metabolomic data highlighted significantly coordinated changes in glycolysis/gluconeogenesis and purine metabolism following TGF-ß1 and MDSC supernatant treatment. By combining transcriptomic and metabolomic analyses, this study showed that glycolysis/gluconeogenesis and purine metabolism were essential for the myofibroblastic differentiation of MSCs and may serve as promising targets for mechanistic research and clinical practice in the treatment of fibrosis by MDSC supernatant.

Liquid-Solid Interfaces under Dynamic Shear Flow: Recent Insights into the Interfacial Slip.

The development of micro/nanofluidic techniques has recently revived interest in dynamic shear flow at liquid-solid interfaces. When the nature of the liquid-solid boundaries was revisited, the slip of the fluids relative to the solid wall was predicted theoretically and confirmed experimentally. This indicates that the molecular-level structures of the liquid-solid interfaces will be influenced by the liquid flow over certain temporal and spatial criteria. However, the fluid flow at the boundary layer still cannot be precisely predicted and effectively controlled, somehow limiting its practical applications. Here, we summarize the recent advances for the microscopic structures at the liquid-solid interfaces upon shear flow. Special attention was given to a second-order nonlinear optical technique, sum frequency generation vibrational spectroscopy, which is a powerful tool for exploring the molecular-level structures and structural dynamics at the liquid-solid interfaces and offering new insights into the molecular mechanisms of the fluid slip at the interfaces. Moreover, we discuss the possible approaches for controlling the interfacial slip at the molecular level and highlight the current challenges and opportunities. Although the theoretical framework of the slip at the liquid-solid interfaces is still incomplete, we hope that this Perspective will complement and enhance our understanding of various interfacial properties and phenomena with respect to practical non-equilibrium dynamic processes happening at the interfaces.

Exploring Interfacial Hydrolysis of Artificial Neutral Lipid Monolayer and Bilayer Catalyzed by Phospholipase C.

Phospholipase C (PLC) represents an important type of enzymes with the feature of hydrolyzing phospholipids at the position of the glycerophosphate bond, among which PLC extracted from Bacillus cereus (BC-PLC) has been extensively studied owing to its similarity to hitherto poorly characterized mammalian analogues. This study focuses on investigating the interfacial hydrolysis mechanism of phosphatidylcholine (PC) monolayer and bilayer membranes catalyzed by BC-PLC using sum frequency generation vibrational spectroscopy (SFG-VS) and laser scanning confocal microscopy (LSCM). We found that, upon interfacial hydrolysis, BC-PLC was adsorbed onto the lipid interface and catalyzed the lipolysis with no net orientation, as evidenced by the silent amide I band, indicating that ordered PLC alignment was not a prerequisite for the enzyme activity, which is very different from what we have reported for phospholipase A1 (PLA1) and phospholipase A2 (PLA2) [Kai, S. Phys. Chem. Chem. Phys. 2018, 20(1), 63-67; Wang, F. Langmuir 2019, 35(39), 12831-12838; Zhang, F. Langmuir 2020, 36(11), 2946-2953]. For the PC monolayer, one of the two hydrolysates, phosphocholine, desorbed from the interface into the aqueous phase, while the other one, diacylglycerol (DG), stayed well packed with high order at the interface. For the PC bilayer, phosphocholine dispersed into the aqueous phase too, similar to the monolayer case; however, DG, presumably formed clusters with the unreacted lipid substrates and desorbed from the interface. With respect to both the monolayer and bilayer cases, mechanistic schematics were presented to illustrate the different interfacial hydrolysis processes. Therefore, this model experimental study in vitro provides significant molecular-level insights and contributes necessary knowledge to reveal the lipolysis kinetics with respect to PLC and lipid membranes with monolayer and bilayer structures.

Transmembrane transport process and endoplasmic reticulum function facilitate the role of gene cel1b in cellulase production of Trichoderma reesei.

BACKGROUND: A total of 11 ß-glucosidases are predicted in the genome of Trichoderma reesei, which are of great importance for regulating cellulase biosynthesis. Nevertheless, the relevant function and regulation mechanism of each ß-glucosidase remained unknown. RESULTS: We evidenced that overexpression of cel1b dramatically decreased cellulase synthesis in T. reesei RUT-C30 both at the protein level and the mRNA level. In contrast, the deletion of cel1b did not noticeably affect cellulase production. Protein CEL1B was identified to be intracellular, being located in vacuole and cell membrane. The overexpression of cel1b reduced the intracellular pNPGase activity and intracellular/extracellular glucose concentration without inducing carbon catabolite repression. On the other hand, RNA-sequencing analysis showed the transmembrane transport process and endoplasmic reticulum function were affected noticeably by overexpressing cel1b. In particular, some important sugar transporters were notably downregulated, leading to a compromised cellular uptake of sugars including glucose and cellobiose. CONCLUSIONS: Our data suggests that the cellulase inhibition by cel1b overexpression was not due to the ß-glucosidase activity, but probably the dysfunction of the cellular transport process (particularly sugar transport) and endoplasmic reticulum (ER). These findings advance the knowledge of regulation mechanism of cellulase synthesis in filamentous fungi, which is the basis for rationally engineering T. reesei strains to improve cellulase production in industry.

Transcriptional profile changes after treatment of ischemia reperfusion injury-induced kidney fibrosis with 18ß-glycyrrhetinic acid.

INTRODUCTION: Chronic kidney disease (CKD) is characterized by renal fibrosis without effective therapy. 18ß-Glycyrrhetinic acid (GA) is reported to have detoxification and anti-inflammatory functions and promotes tissue repair. However, the role of GA in CKD remains unclear. In this study, we investigated whether GA has a potential therapeutic effect in kidney fibrosis. METHODS: A renal fibrosis mouse model was established by ischemia/reperfusion (I/R) injury via clamping unilateral left renal pedicle for 45 min; then, the mice were treated with vehicle or GA. Kidney tissues and blood samples were extracted 14 days after reperfusion and renal function, histopathological staining, quantitative PCR, and western blotting were performed. RNA-seq was performed to explore the changes in the transcriptional profile after GA treatment. RESULTS: Renal function, pathological and molecular analysis displayed that fibrosis was successfully induced in the I/R model. In the GA treatment group, the severity of fibrosis gradually reduced with the best effect seen at a concentration of 25 mg kg -1. A total of 970 differentially expressed genes were identified. Pathway enrichment showed that reduced activation and migration of inflammatory cells and decreased chemokine interaction in significant pathways. Protein-protein interaction networks were constructed and 15 hub genes were selected by degree rank, including chemokines, such as C3, Ccl6, Ccr2, Ptafr, Timp1, and Pf4. CONCLUSIONS: GA may alleviate renal fibrosis by inhibiting the inflammatory response. GA is a promising therapy that may perhaps be used in treating renal fibrosis and CKD.

Interaction between Antimicrobial Peptide CM15 and a Model Cell Membrane Affected by CM15 Terminal Amidation and the Membrane Phase State.

Antimicrobial peptides (AMPs) have been proposed as an effective class of antimicrobial agents against microorganisms. In this work, the interaction between an antimicrobial peptide, CM15, and a negatively charged phospholipid bilayer, DPPG, was studied via sum frequency generation (SFG) vibrational spectroscopy. Two structurally correlated characteristic variables were introduced to reveal the interaction mechanism/efficiency, i.e. C-terminal amidation and temperature variation (∼20 °C, room temperature, and ∼35 °C, close to human body temperature). Experimental results indicated that owing to the increased positive charge, C-terminal amidation resulted in rapid adsorption onto the bilayer surface and efficient disruption of the outer layer, exhibiting less ordered insertion orientation. The elevated temperature (from ∼20 °C to ∼35 °C) promoted the penetration of both the outer and inner leaflets by the peptides and finally led to the disruption of the whole bilayer owing to the enhanced fluidity of the bilayer. From the perspective of the interaction mechanism, this experimental study provides two practical cues to understand the disruption process of the negatively charged model biomembranes, which can lay the structural foundation for designing and developing high-efficiency antimicrobial peptides.

Polar Solvents Induce Sum Frequency Generation Activity for Multiwalled Carbon Nanotubes.

Regarding methods of process and use of carbon nanotubes (CNTs), solvents are generally employed to disperse or dissolve CNTs as a pretreatment or intermediate process step. This naturally imposes an essential issue on how CNTs and solvents interact with each other, which seems trivial, comparatively inconsequential, and might often be overlooked from the perspective of engineering scenarios. However, as a matter of fact, it is indeed a fascinating and significant topic. In this article, to investigate the interfacial properties of multiwalled CNTs (MWCNTs) exposed to widely utilized solvents, we applied sum frequency generation vibrational spectroscopy (SFG-VS) to probe solvent-wetted MWCNTs and proved that polar solvents can substantially alter the interfacial optical property of MWCNTs. First, the interfacial optical phonon vibrational modes were detected when MWCNTs were wetted by polar solvents, i.e., water and dimethylformamide (DMF), while such modes were inactive when the solvents were nonpolar, i.e., decalin and air. Second, the interfacial optical phonon vibration frequency displayed distinct dependence on surface defects of MWCNTs. Combining theoretical analysis with experimental verification, a valid conjecture with respect to surface phonon vibration activity for MWCNTs was proposed. This phenomenon of polar solvent-induced SFG activity may have the potential to find applications in optical detection and environmental sensing in the near future.

Revealing Molecular-Level Interaction between a Polymeric Drug and Model Membrane Via Sum Frequency Generation and Microfluidics.

Body fluids flow all over the body and affect the biological processes at biointerfaces. To simulate such a case, sum frequency generation (SFG) vibrational spectroscopy and a self-designed microfluidic chip were combined together to investigate the interaction between a pH-responsive polymeric drug, poly(α-propylacrylic acid) (PPAAc), and the model cell membranes in different liquid environments. By examining the SFG spectra under the static and flowing conditions, the drug-membrane interaction was revealed comprehensively. The interfacial water layer was screened as the key factor affecting the drug-membrane interaction. The interfacial water layer can prevent the side propyl groups on PPAAc from inserting into the model cell membrane but would be disrupted by numerous ions in buffer solutions. Without flowing, at pH 6.6, the interaction between PPAAc and the model cell membrane was strongest; with flowing, at pH 5.8, the interaction was strongest. Flowing was proven to substantially affect the interaction between PPAAc and the model cell membranes, suggesting that the fluid environment was of key significance for biointerfaces. This work demonstrated that, by combining SFG and microfluidics, new information about the molecular-level interaction between macromolecules and the model cell membranes can be acquired, which cannot be obtained by collecting the normal static SFG spectra.

Beneficial factors for biomineralization by ureolytic bacterium Sporosarcina pasteurii.

BACKGROUND: The ureolytic bacterium Sporosarcina pasteurii is well-known for its capability of microbially induced calcite precipitation (MICP), representing a great potential in constructional engineering and material applications. However, the molecular mechanism for its biomineralization remains unresolved, as few studies were carried out. RESULTS: The addition of urea into the culture medium provided an alkaline environment that is suitable for S. pasteurii. As compared to S. pasteurii cultivated without urea, S. pasteurii grown with urea showed faster growth and urease production, better shape, more negative surface charge and higher biomineralization ability. To survive the unfavorable growth environment due to the absence of urea, S. pasteurii up-regulated the expression of genes involved in urease production, ATPase synthesis and flagella, possibly occupying resources that can be deployed for MICP. As compared to non-mineralizing bacteria, S. pasteurii exhibited more negative cell surface charge for binding calcium ions and more robust cell structure as nucleation sites. During MICP process, the genes for ATPase synthesis in S. pasteurii was up-regulated while genes for urease production were unchanged. Interestingly, genes involved in flagella were down-regulated during MICP, which might lead to poor mobility of S. pasteurii. Meanwhile, genes in fatty acid degradation pathway were inhibited to maintain the intact cell structure found in calcite precipitation. Both weak mobility and intact cell structure are advantageous for S. pasteurii to serve as nucleation sites during MICP. CONCLUSIONS: Four factors are demonstrated to benefit the super performance of S. pasteurii in MICP. First, the good correlation of biomass growth and urease production of S. pasteurii provides sufficient biomass and urease simultaneously for improved biomineralization. Second, the highly negative cell surface charge of S. pasteurii is good for binding calcium ions. Third, the robust cell structure and fourth, the weak mobility, are key for S. pasteurii to be nucleation sites during MICP.

Correlation between miR-21 and miR-145 and the incidence and prognosis of colorectal cancer.

PURPOSE: The purpose of this study was to investigate the expression of microRNA (miR)-21 and miR-145 in serum and tumor tissues of patients with colorectal cancer (CRC), and to explore the correlation between the expression of these miRs and the clinicopathological parameters and prognosis of CRC patients. METHODS: Serum specimens, frozen tumor tissue and adjacent normal tissue of 50 CRC patients who were hospitalized in our hospital from February 2009 to February 2011 were collected, along with serum specimens of 30 healthy people (control). The expression levels of miR-21 and miR-145 in serum, tumor tissues and adjacent normal tissues were detected by quantitative real time polymerase chain reaction (qRT-PCR). The correlation between the expression of the two miRs in serum was analyzed by Spearman method. The relationship between the expression of miR- 21 and miR-145 in serum and the pathological parameters and prognosis of patients with CRC were analyzed using clinical data. RESULTS: The expression level of miR-21 in CRC tissue was significantly higher than that in adjacent normal tissues, while the expression of miR-145 in CRC tissue was significantly lower than that in adjacent normal tissues. The expression level of miR-21 in the serum of CRC patients was significantly higher compared with healthy people, while the expression of miR-145 in the serum of CRC patients was significantly lower than that in healthy people. The expression of miR-21 and miR-145 in the serum was positively correlated with their expression in tumor tissue. High expression level of miR-21 in the serum was correlated with tumor size, grade of differentiation, invasion, metastasis and clinical stage, and low expression level of miR-145 in the serum was correlated with tumor size, grade of differentiation, invasion, metastasis and clinical stage. The 5-year overall survival (OS) was 52% (26/50). Single factor survival analysis showed that miR-21 and miR-145 were the influencing factors of OS of patients with CRC. CONCLUSIONS: High expression of miR-21 and low expression of miR-145 are closely related to the development and progression of CRC, especially with the grade of differentiation, invasion, metastasis and clinical stage. MiR-21 and miR-145 in the serum can be used as markers for early screening of CRC and indicators for prognosis prediction.

Correlation of cTfh cells and memory B cells with AMR after renal transplantation.

Renal transplantation is the preferred treatment option for patients with end-stage renal disease (ESRD) in a clinical setting. Antibody mediated rejection (AMR) is one of the leading causes of graft dysfunction. To address the current shortcomings in the early diagnosis and treatment of AMR in clinical practice, this article analyzes the distribution of different circulating T follicular helper (cTfh) cell subtypes and B cell subpopulations in peripheral blood and detects the cytokine levels of chemokine ligand 13 (CXCL13), interleukin-21 (IL-21), and interleukin-4 (IL-4) related to cTfh cells in peripheral blood of kidney transplant recipients. Moreover, we also explore the correlation between cTfh cells, peripheral blood memory B cells, and AMR, their value as early predictive indicators of AMR, and explore potential therapeutic targets for AMR patients. Our results indicate that the proportion of cTfh cells increased at the onset of AMR, which plays an important role in antigen-specific B-cell immune regulation. Activation of cTfh cells in AMR patients correlates with phenotypes of memory B cells and plasma blasts. cTfh cells and memory B cells have promising diagnostic efficacies and predictive values for AMR. The proportion of cTfh cells to CD4+ T cells and the proportion of memory B cells to CD19+ B cells are correlated with serum creatinine levels, indicating that cTfh cells and memory B cells may be involved in the progression of AMR. In addition, the CXCL13, IL-21, and IL-4, which were associated with cTfh cells, may be involved in the onset of AMR.

A multicenter, open-label, parallel-group, randomized controlled trial of Tongluo-Qutong rubber plaster for the treatment of cervical spondylotic radiculopathy.

BACKGROUND: In China, Tongluo-Qutong rubber plaster (TQRP) is commonly used for cervical spondylotic radiculopathy, but lacks high-quality trials. OBJECTIVE: This study aimed to conduct a multicenter, open-label, parallel-group, randomized controlled trial in China to investigate the practical efficacy and safety of TQRP in the treatment of CSR. METHODS: A total of 240 patients diagnosed with CSR were recruited for the investigation from multiple hospitals in Gansu province, China. The patients were randomly assigned to either an experimental or a control group. The experimental group received treatment with TQRP, whereas the control group was administered a diclofenac sodium patch (DSP) for a maximum duration of 21 days. The visual analogue scale (VAS) score for pain, the proportion of patients experiencing 50% or more pain relief, the neck disability index (NDI), changes as per the Eaton trial, and recurrence during the follow-up period were evaluated for both groups. The safety and adverse events associated with the concurrent drug therapy were also evaluated. RESULTS: At each time point, the mean VAS and NDI scores of both groups demonstrated a downward trend. The experimental group exhibited a greater decline in VAS score at each time point compared to the control group (P< 0.01). In the Eaton trial, both the percentage of patients experiencing pain relief of 50% or more and the number of abnormal results exhibited improvement. However, the outcomes in the 21 ± 3d experimental group were significantly superior to those in the control group (P< 0.01). During the follow-up period, the recurrence events in the experimental group were reduced compared to the control group. The difference between the two groups was statistically significant (P< 0.05). The incidence of adverse reactions was 1.74% for TQRP and 3.54% for DSP. CONCLUSION: TQRP is effective and safe in the treatment of CSR.

Protein multi-level structure feature-integrated deep learning method for mutational effect prediction.

Through iterative rounds of mutation and selection, proteins can be engineered to enhance their desired biological functions. Nevertheless, identifying optimal mutation sites for directed evolution remains challenging due to the vastness of the protein sequence landscape and the epistatic mutational effects across residues. To address this challenge, we introduce MLSmut, a deep learning-based approach that leverages multi-level structural features of proteins. MLSmut extracts salient information from protein co-evolution, sequence semantics, and geometric features to predict the mutational effect. Extensive benchmark evaluations on 10 single-site and two multi-site deep mutation scanning datasets demonstrate that MLSmut surpasses existing methods in predicting mutational outcomes. To overcome the limited training data availability, we employ a two-stage training strategy: initial coarse-tuning on a large corpus of unlabeled protein data followed by fine-tuning on a curated dataset of 40-100 experimental measurements. This approach enables our model to achieve satisfactory performance on downstream protein prediction tasks. Importantly, our model holds the potential to predict the mutational effects of any protein sequence. Collectively, these findings suggest that our approach can substantially reduce the reliance on laborious wet lab experiments and deepen our understanding of the intricate relationships between mutations and protein function.

Identification of the Subtypes of Renal Ischemia-Reperfusion Injury Based on Pyroptosis-Related Genes.

Ischemia-reperfusion injury (IRI) often occurs in the process of kidney transplantation, which significantly impacts the subsequent treatment and prognosis of patients. The prognosis of patients with different subtypes of IRI is quite different. Therefore, in this paper, the gene expression data of multiple IRI samples were downloaded from the GEO database, and a double Laplacian orthogonal non-negative matrix factorization (DL-ONMF) algorithm was proposed to classify them. In this algorithm, various regularization constraints are added based on the non-negative matrix factorization algorithm, and the prior information is fused into the algorithm from different perspectives. The connectivity information between different samples and features is added to the algorithm by Laplacian regularization constraints on samples and features. In addition, orthogonality constraints on the basis matrix and coefficient matrix obtained by the algorithm decomposition are added to reduce the influence of redundant samples and redundant features on the results. Based on the DL-ONMF algorithm for clustering, two PRGs-related IRI isoforms were obtained in this paper. The results of immunoassays showed that the immune microenvironment was different among PRGS-related IRI types. Based on the differentially expressed PRGs between subtypes, we used LASSO and SVM-RFE algorithms to construct a diagnostic model related to renal transplantation. ROC analysis showed that the diagnostic model could predict the outcome of renal transplant patients with high accuracy. In conclusion, this paper presents an algorithm, DL-ONMF, which can identify subtypes with different disease characteristics. Comprehensive bioinformatic analysis showed that pyroptosis might affect the outcome of kidney transplantation by participating in the immune response of IRI.

Demonstrating the Interfacial Polymer Thermal Transition from Coil-to-Globule to Coil-to-Stretch under Shear Flow Using SFG and MD Simulation.

Revealing interfacial shear-induced structural responsiveness has long been an important topic in that most fluids in nature and human life are in motion and cause interesting boundary phenomena. It is amazing how the polymer chain conformation or local structural features at a boundary change under the effective shear condition. In this study, microfluidic-assisted sum frequency generation (SFG) vibrational spectroscopy and all-atom molecular dynamics (MD) simulation are combined to reveal that the shear flow can effectively block the so-called thermal coil-to-globule transition of the poly(N-isopropylacrylamide) (PNIPAM) brushes on the solid substrate, and the normal coil-to-globule transition transfers to a coil-to-stretch one under shear flow with increasing ambient temperature. Such findings are attributed to the balance between the shear flow and the molecular interaction with respect to the polymer chains and adjacent water molecules, thus demonstrating the significant effect of the shear flow on the structural and dynamic behaviors of the polymer chains at the boundaries from the molecular level.

Monocytic Myeloid-Derived Suppressor Cells Inhibit Myofibroblastic Differentiation in Mesenchymal Stem Cells Through IL-15 Secretion.

Background: Accumulating evidence indicates that mesenchymal stem cells (MSCs) are precursors of myofibroblasts, which play a vital role in renal fibrosis. The close interaction between MSCs and other immune cells regulates the development of multiple fibrosis-related diseases. However, the effect of myeloid-derived suppressor cells (MDSCs) on MSCs remains unexplored. Here, we investigated the effect of MDSCs on the myofibroblastic differentiation of MSCs. Methods: MSCs were induced to undergo myofibroblastic differentiation with transforming growth factor beta 1 (TGF-ß1). M-MDSCs and G-MDSCs were sorted by flow cytometry. Supernatants derived from MDSCs were administered to cultured bone marrow MSCs (BM-MSCs) undergoing TGF-ß1-induced myofibroblastic differentiation. Myofibroblastic differentiation was evaluated by immunostaining. The expression of fibrosis-related genes was determined by quantitative PCR and western blot analysis. In vitro, M-MDSC supernatant or M-MDSC supernatant with interleukin (IL)-15 mAbs was administered following unilateral renal ischemia-reperfusion injury (IRI) to observe the myofibroblast differentiation of renal resident MSCs (RRMSCs) in a murine model. Results: Myofibroblastic differentiation of MSCs was hindered when the cells were treated with MDSC-derived supernatants, especially that from M-MDSCs. The inhibitory effect of M-MDSC supernatant on the myofibroblastic differentiation of MSCs was partially mediated by IL-15-Ras-Erk1/2-Smad2/3 signaling. Treatment with M-MDSC supernatant ameliorated renal fibrosis and myofibroblastic differentiation in RRMSCs through IL-15. Additionally, M-MDSC supernatant increased M-MDSC infiltration in the kidney in a mouse IRI model. M-MDSC supernatant downregulated the adhesion and migration marker CD44 on the cell membrane of MSCs via IL-15. Conclusion: M-MDSC-derived supernatant inhibited the TGF-ß1-induced myofibroblastic differentiation of MSCs through IL-15. Our findings shed new light on the effect of MDSCs on myofibroblastic differentiation and adhesion of MSCs, which might provide a new perspective in the development of treatment strategies for renal fibrosis.

Bone marrow mesenchymal stem cell-derived exosomal miR-21a-5p alleviates renal fibrosis by attenuating glycolysis by targeting PFKM.

Renal fibrosis is a common pathological feature and outcome of almost all chronic kidney diseases, and it is characterized by metabolic reprogramming toward aerobic glycolysis. Mesenchymal stem cell-derived exosomes (MSC-Exos) have been proposed as a promising therapeutic approach for renal fibrosis. In this study, we investigated the effect of MSC-Exos on glycolysis and the underlying mechanisms. We demonstrated that MSC-Exos significantly ameliorated unilateral ureter obstruction (UUO)-induced renal fibrosis by inhibiting glycolysis in tubular epithelial cells (TECs). miRNA sequencing showed that miR-21a-5p was highly enriched in MSC-Exos. Mechanistically, miR-21a-5p repressed the expression of phosphofructokinase muscle isoform (PFKM), a rate-limiting enzyme of glycolysis, thereby attenuating glycolysis in TECs. Additionally, knockdown of miR-21a-5p abolished the renoprotective effect of MSC-Exos. These findings revealed a novel role for MSC-Exos in the suppression of glycolysis, providing a new insight into the treatment of renal fibrosis.

Clinical Outcome of Day-3 Cleavage Slow-Growing Embryos at Different Cleavage Rates after Overnight Culture: A Cohort Retrospective Study.

INTRODUCTION: We explored the association between clinical outcomes and the cleavage rate of day-3 cleavage slow-growing embryos after overnight culture. METHODS: The data collected from 303 frozen embryo transfer (FET) cycles with 606 4-cell or 5-cell embryos cultured overnight (18-22 h) after thawing were analyzed. Based on the growth rate after the overnight culture, the embryos were divided into three groups: no embryo reaching eight cells (Group I), either one of the two embryos reaching eight cells (Group II), and both two embryos reaching eight cells or more (Group III). A statistical analysis of the different clinical outcomes from the three groups was performed. RESULTS: Biochemical pregnancy rate (OR 3.22; p = 0.001), implantation rate (OR 2.44; p = 0.002), clinical pregnancy rate (OR 3.04; p = 0.001), ongoing pregnancy rate (OR 3.14; p = 0.001), and live birth rate (OR 2.78; p = 0.004) were significantly higher in Group III as compared to Group I. Group II had a significantly higher biochemical pregnancy rate (OR 2.02; p = 0.013) and implantation rate (OR 1.77; p = 0.019) than Group I. CONCLUSIONS: The capability of day-3 cleavage slow-growing embryos to reach eight cells, especially that of two embryos reaching eight cells by overnight culture, appear to result in a better pregnancy outcome.