GPCRs and fibroblast heterogeneity in fibroblast-associated diseases.

G protein-coupled receptors (GPCRs) are the largest and most diverse class of signaling receptors. GPCRs regulate many functions in the human body and have earned the title of "most targeted receptors". About one-third of the commercially available drugs for various diseases target the GPCRs. Fibroblasts lay the architectural skeleton of the body, and play a key role in supporting the growth, maintenance, and repair of almost all tissues by responding to the cellular cues via diverse and intricate GPCR signaling pathways. This review discusses the dynamic architecture of the GPCRs and their intertwined signaling in pathological conditions such as idiopathic pulmonary fibrosis, cardiac fibrosis, pancreatic fibrosis, hepatic fibrosis, and cancer as opposed to the GPCR signaling of fibroblasts in physiological conditions. Understanding the dynamics of GPCR signaling in fibroblasts with disease progression can help in the recognition of the complex interplay of different GPCR subtypes in fibroblast-mediated diseases. This review highlights the importance of designing and adaptation of next-generation strategies such as GPCR-omics, focused target identification, polypharmacology, and effective personalized medicine approaches to achieve better therapeutic outcomes for fibrosis and fibrosis associated malignancies.

Pectin: Health-promoting properties as a natural galectin-3 inhibitor.

Galectin-3 has a variety of important pathophysiological significance in the human body. Much evidence shows that the abnormal expression of galectin-3 is related to the formation and development of many diseases. Pectin is mostly obtained from processed citrus fruits and apples and is a known natural inhibitor of galactin-3. A large number of peels produced each year are discarded, and it is necessary to recycle some of the economically valuable active compounds in these by-products to reduce resource waste and environmental pollution. By binding with galectin-3, pectin can directly reduce the expression level of galectin-3 on the one hand, and regulate the expression level of cytokines by regulating certain signaling pathways on the other hand, to achieve the effect of treating diseases. This paper begins by presenting an overview of the basic structure of pectin, subsequently followed by a description of the structure of galectin-3 and its detrimental impact on human health when expressed abnormally. The health effects of pectin as a galectin-3 inhibitor were then summarized from the perspectives of anticancer, anti-inflammatory, ameliorating fibrotic diseases, and anti-diabetes. Finally, the challenges and prospects of future research on pectin are presented, which provide important references for expanding the application of pectin in the pharmaceutical industry or developing functional dietary supplements.

Mesenchymal stem cells in fibrotic diseases-the two sides of the same coin.

Fibrosis is caused by extensive deposition of extracellular matrix (ECM) components, which play a crucial role in injury repair. Fibrosis attributes to ~45% of all deaths worldwide. The molecular pathology of different fibrotic diseases varies, and a number of bioactive factors are involved in the pathogenic process. Mesenchymal stem cells (MSCs) are a type of multipotent stem cells that have promising therapeutic effects in the treatment of different diseases. Current updates of fibrotic pathogenesis reveal that residential MSCs may differentiate into myofibroblasts which lead to the fibrosis development. However, preclinical and clinical trials with autologous or allogeneic MSCs infusion demonstrate that MSCs can relieve the fibrotic diseases by modulating inflammation, regenerating damaged tissues, remodeling the ECMs, and modulating the death of stressed cells after implantation. A variety of animal models were developed to study the mechanisms behind different fibrotic tissues and test the preclinical efficacy of MSC therapy in these diseases. Furthermore, MSCs have been used for treating liver cirrhosis and pulmonary fibrosis patients in several clinical trials, leading to satisfactory clinical efficacy without severe adverse events. This review discusses the two opposite roles of residential MSCs and external MSCs in fibrotic diseases, and summarizes the current perspective of therapeutic mechanism of MSCs in fibrosis, through both laboratory study and clinical trials.

Research progress in effects of microRNA-15a and microRNA-16 on fibrotic diseases. / å¾®RNA-15a和微RNA-16åœ¨çº¤ç»´åŒ–ç–¾ç— ä¸­ä½œç”¨çš„ç ”ç©¶è¿›å±•.

MicroRNA (miR) is a class of highly conserved non-coding single-stranded RNA widely existing in mammals, which can negatively regulate the expression of targeting genes after transcription. As a key regulator, miR negatively regulates the expression of the targeting genes and disrupts important molecular signaling pathways, leading to the imbalance of multiple pathways such as tissue repair and inflammation involved in the fibrotic process. Among them, miR-15a/16 can participate in regulating and controlling the fibrotic process of various organs, including liver, lung, heart, kidney and other fibrotic diseases by acting on cell proliferation and transformation, extracellular matrix proteins production and degradation, inflammation and other important cell functions. It has potential diagnostic and therapeutic value. Clarifying the biological function of miR-15a/16 and its mechanism for action and therapeutic application prospects in various fibrotic lesions are of great significance for the molecular targeted treatment of fibrotic diseases.

Let-7i: A key player and a promising biomarker in diseases. / Let-7iï¼šç–¾ç— ä¸­çš„å ³é”®è°ƒæŽ§åˆ†å­å’Œæœ‰å‰æ™¯çš„ç”Ÿç‰©æ ‡å¿—ç‰©.

MicroRNAs (miRNAs) are endogenous non-coding single-stranded small RNAs that regulate gene expression by recognizing homologous sequences and interfering with transcriptional, translational or epigenetic processes. MiRNAs are involved in a variety of disease processes, and regulate the physiological and pathological status of diseases by modulating target cell activity, migration, invasion, apoptosis, autophagy and other processes. Among them, let-7i is highly expressed in various systems, which participates in the process of tumors, cardiovascular and cerebrovascular diseases, fibrotic diseases, inflammatory diseases, neurodegenerative diseases and other diseases, and plays a positive or negative regulatory role in these diseases through different signal pathways and key molecules. Moreover, it can be used as an early diagnosis and prognostic marker for a variety of diseases and become a potential therapeutic target. As a biomarker, let-7i is frequently tested in combination with other miRNAs to diagnose multiple diseases and evaluate the clinical treatment or prognosis.

Using a peptide-based mass spectrometry approach to quantitate proteolysis of an intact heterogeneous procollagen substrate by BMP1 for antagonistic antibody screening.

Proteases are critical proteins involved in cleaving substrates that may impact biological pathways, cellular processes, or disease progression. In the biopharmaceutical industry, modulating the levels of protease activity is an important strategy for mitigating many types of diseases. While a variety of analytical tools exist for characterizing substrate cleavages, in vitro functional screening for antibody inhibitors of protease activity using physiologically relevant intact protein substrates remains challenging. In addition, detecting such large protein substrates with high heterogeneity using high-throughput mass spectrometry screening has rarely been reported in the literature with concerns for assay robustness and sensitivity. In this study, we established a peptide-based in vitro functional screening assay for antibody inhibitors of mouse bone morphogenic protein 1 (mBMP1) metalloprotease using a heterogeneous recombinant 66-kDa mouse Procollagen I alpha 1 chain (mProcollagen) substrate. We compared several analytical tools including capillary gel electrophoresis Western blot (CE-Western blot), as well as both intact protein and peptide-based mass spectrometry (MS) to quantitate the mBMP1 proteolytic activity and its inhibition by antibodies using this heterogeneous mProcollagen substrate. We concluded that the peptide-based mass spectrometry screening assay was the most suitable approach in terms of throughput, sensitivity, and assay robustness. We then optimized our mBMP1 proteolysis reaction after characterizing the enzyme kinetics using the peptide-based MS assay. This assay resulted in Z' values ranging from 0.6 to 0.8 from the screening campaign. Among over 1200 antibodies screened, IC50 characterization was performed on the top candidate hits, which showed partial or complete inhibitory activities against mBMP1.

Comparative molecular analysis of oral submucous fibrosis and other organ fibrosis based on weighted gene co-expression network analysis. / åŸºäºŽåŠ æƒåŸºå› å ±è¡¨è¾¾ç½‘ç»œåˆ†æžçš„å£è ”é»è†œä¸‹çº¤ç»´åŒ–ä¸Žå ¶ä»–å™¨å®˜çº¤ç»´åŒ–çš„æ¯”è¾ƒåˆ†å­åˆ†æžï¼ˆè‹±æ–‡ï¼‰.

OBJECTIVES: There is currently a lack of economic and suitable animal models that can accurately recapitulate the oral submucous fibrosis (OSF) disease state for indepth study. This is one of the primary reasons for the limited therapeutic methods available for OSF. Based on the underlying logic of pan-cancer analysis, this study systematically compares OSF and the other four types of organ fibrosis from the aspects of molecules, signaling pathways, biological processes, etc. A comprehensive analysis of the similarities and differences between OSF and other organ fibrosis is helpful for researchers to discover some general rules of fibrosis disease and may provide new ideas for studying OSF. METHODS: Microarray data of the GSE64216, GSE76882, GSE171294, GSE92592, and GSE90051 datasets were downloaded from GEO. Differentially expressed mRNAs (DEmRNAs) of each type of fibrosis were identified by Limma package. Weighted gene co-expression network analysis (WGCNA) was used to identify each type of fibrosis-related module. The similarities and differences of each fibrosis-related-module genes were analyzed by function and pathway enrichment analysis. RESULTS: A total of 6 057, 10 910, 27 990, 10 480, and 4 801 DEmRNAs were identified in OSF, kidney intestinal fibrosis (KIF), liver fibrosis (LF), idiopathic pulmonary fibrosis (IPF), and skin fibrosis (SF), respectively. By using WGCNA, each type of fibrosis-related module was identified. The co-expression networks for each type of fibrosis were constructed respectively. Except that KIF and LF have 5 common hub genes, other fibrotic diseases have no common hub genes with each other. The common pathways of OSF, KIF, LF, IPF, and SF mainly focus on immune-related pathways. CONCLUSIONS: OSF and the other 4 types of fibrotic diseases are tissue- and organ-specific at the molecular level, but they share many common signaling pathways and biological processes, mainly in inflammation and immunity.

Keloid disorder: Fibroblast differentiation and gene expression profile in fibrotic skin diseases.

Keloid disorder, a group of fibroproliferative skin diseases, is characterized by unremitting accumulation of the extracellular matrix (ECM) of connective tissue, primarily collagen, to develop cutaneous tumors on the predilection sites of skin. There is a strong genetic predisposition for keloid formation, and individuals of African and Asian ancestry are particularly prone. The principal cell type responsible for ECM accumulation is the myofibroblast derived from quiescent resident skin fibroblasts either through trans-differentiation or from keloid progenitor stem cells with capacity for multi-lineage differentiation and self-renewal. The biosynthetic pathways leading to ECM accumulation are activated by several cytokines, but particularly by TGF-ß signalling. The mechanical properties of the cellular microenvironment also play a critical role in the cell's response to TGF-ß, as demonstrated by culturing of fibroblasts derived from keloids and control skin on substrata with different degrees of stiffness. These studies also demonstrated that culturing of fibroblasts on tissue culture plastic in vitro does not reflect their biosynthetic capacity in vivo. Collectively, our current understanding of the pathogenesis of keloids suggests a complex network of interacting cellular, molecular and mechanical factors, with distinct pathways leading to myofibroblast differentiation and activation. Keloids can serve as a model system of fibrotic diseases, a group of currently intractable disorders, and deciphering of the critical pathogenetic steps leading to ECM accumulation is expected to identify targets for pharmacologic intervention, not only for keloids but also for a number of other, both genetic and acquired, fibrotic diseases.

Emerging role of Twist1 in fibrotic diseases.

Epithelial-mesenchymal transition (EMT) is a pathological process that occurs in a variety of diseases, including organ fibrosis. Twist1, a basic helix-loop-helix transcription factor, is involved in EMT and plays significant roles in various fibrotic diseases. Suppression of the EMT process represents a promising approach for the treatment of fibrotic diseases. In this review, we discuss the roles and the underlying molecular mechanisms of Twist1 in fibrotic diseases, including those affecting kidney, lung, skin, oral submucosa and other tissues. We aim at providing new insight into the pathogenesis of various fibrotic diseases and facilitating the development of novel diagnostic and therapeutic methods for their treatment.

Connexins, Pannexins, and Their Channels in Fibroproliferative Diseases.

Cellular and molecular mechanisms of wound healing, tissue repair, and fibrogenesis are established in different organs and are essential for the maintenance of function and tissue integrity after cell injury. These mechanisms are also involved in a plethora of fibroproliferative diseases or organ-specific fibrotic disorders, all of which are associated with the excessive deposition of extracellular matrix components. Fibroblasts, which are key cells in tissue repair and fibrogenesis, rely on communicative cellular networks to ensure efficient control of these processes and to prevent abnormal accumulation of extracellular matrix into the tissue. Despite the significant impact on human health, and thus the epidemiologic relevance, there is still no effective treatment for most fibrosis-related diseases. This paper provides an overview of current concepts and mechanisms involved in the participation of cellular communication via connexin-based pores as well as pannexin-based channels in the processes of tissue repair and fibrogenesis in chronic diseases. Understanding these mechanisms may contribute to the development of new therapeutic strategies to clinically manage fibroproliferative diseases and organ-specific fibrotic disorders.