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1.
Front Immunol ; 15: 1390468, 2024.
Article En | MEDLINE | ID: mdl-38726006

Introduction: Relapsing fever (RF) remains a neglected human disease that is caused by a number of diverse pathogenic Borrelia (B.) species. Characterized by high cell densities in human blood, relapsing fever spirochetes have developed plentiful strategies to avoid recognition by the host defense mechanisms. In this scenario, spirochetal lipoproteins exhibiting multifunctional binding properties in the interaction with host-derived molecules are known to play a key role in adhesion, fibrinolysis and complement activation. Methods: Binding of CihC/FbpC orthologs to different human proteins and conversion of protein-bound plasminogen to proteolytic active plasmin were examined by ELISA. To analyze the inhibitory capacity of CihC/FbpC orthologs on complement activation, a microtiter-based approach was performed. Finally, AlphaFold predictions were utilized to identified the complement-interacting residues. Results and discussion: Here, we elucidate the binding properties of CihC/FbpC-orthologs from distinct RF spirochetes including B. parkeri, B. hermsii, B. turicatae, and B. recurrentis to human fibronectin, plasminogen, and complement component C1r. All CihC/FbpC-orthologs displayed similar binding properties to fibronectin, plasminogen, and C1r, respectively. Functional studies revealed a dose dependent binding of plasminogen to all borrelial proteins and conversion to active plasmin. The proteolytic activity of plasmin was almost completely abrogated by tranexamic acid, indicating that lysine residues are involved in the interaction with this serine protease. In addition, a strong inactivation capacity toward the classical pathway could be demonstrated for the wild-type CihC/FbpC-orthologs as well as for the C-terminal CihC fragment of B. recurrentis. Pre-incubation of human serum with borrelial molecules except CihC/FbpC variants lacking the C-terminal region protected serum-susceptible Borrelia cells from complement-mediated lysis. Utilizing AlphaFold2 predictions and existing crystal structures, we mapped the putative key residues involved in C1r binding on the CihC/FbpC orthologs attempting to explain the relatively small differences in C1r binding affinity despite the substitutions of key residues. Collectively, our data advance the understanding of the multiple binding properties of structural and functional highly similar molecules of relapsing fever spirochetes proposed to be involved in pathogenesis and virulence.


Bacterial Proteins , Borrelia , Fibrinolysis , Plasminogen , Protein Binding , Relapsing Fever , Humans , Borrelia/immunology , Borrelia/metabolism , Relapsing Fever/microbiology , Relapsing Fever/immunology , Relapsing Fever/metabolism , Plasminogen/metabolism , Bacterial Proteins/metabolism , Bacterial Proteins/genetics , Bacterial Proteins/immunology , Complement Activation , Immune Evasion , Bacterial Adhesion , Host-Pathogen Interactions/immunology , Fibronectins/metabolism , Fibrinolysin/metabolism , Complement System Proteins/immunology , Complement System Proteins/metabolism
2.
Sci Rep ; 14(1): 10658, 2024 05 09.
Article En | MEDLINE | ID: mdl-38724553

This study aimed to investigate the effects of exercise on excessive mitochondrial fission, insulin resistance, and inflammation in the muscles of diabetic rats. The role of the irisin/AMPK pathway in regulating exercise effects was also determined. Thirty-two 8-week-old male Wistar rats were randomly divided into four groups (n = 8 per group): one control group (Con) and three experimental groups. Type 2 diabetes mellitus (T2DM) was induced in the experimental groups via a high-fat diet followed by a single intraperitoneal injection of streptozotocin (STZ) at a dosage of 30 mg/kg body weight. After T2DM induction, groups were assigned as sedentary (DM), subjected to 8 weeks of treadmill exercise training (Ex), or exercise training combined with 8-week cycloRGDyk treatment (ExRg). Upon completion of the last training session, all rats were euthanized and samples of fasting blood and soleus muscle were collected for analysis using ELISA, immunofluorescence, RT-qPCR, and Western blotting. Statistical differences between groups were analyzed using one-way ANOVA, and differences between two groups were assessed using t-tests. Our findings demonstrate that exercise training markedly ameliorated hyperglycaemia, hyperlipidaemia, and insulin resistance in diabetic rats (p < 0.05). It also mitigated the disarranged morphology and inflammation of skeletal muscle associated with T2DM (p < 0.05). Crucially, exercise training suppressed muscular excessive mitochondrial fission in the soleus muscle of diabetic rats (p < 0.05), and enhanced irisin and p-AMPK levels significantly (p < 0.05). However, exercise-induced irisin and p-AMPK expression were inhibited by cycloRGDyk treatment (p < 0.05). Furthermore, the administration of CycloRGDyk blocked the effects of exercise training in reducing excessive mitochondrial fission and inflammation in the soleus muscle of diabetic rats, as well as the positive effects of exercise training on improving hyperlipidemia and insulin sensitivity in diabetic rats (p < 0.05). These results indicate that regular exercise training effectively ameliorates insulin resistance and glucolipid metabolic dysfunction, and reduces inflammation in skeletal muscle. These benefits are partially mediated by reductions in mitochondrial fission through the irisin/AMPK signalling pathway.


AMP-Activated Protein Kinases , Diabetes Mellitus, Experimental , Fibronectins , Inflammation , Insulin Resistance , Mitochondrial Dynamics , Muscle, Skeletal , Physical Conditioning, Animal , Rats, Wistar , Animals , Fibronectins/metabolism , Male , Diabetes Mellitus, Experimental/metabolism , Diabetes Mellitus, Experimental/therapy , Rats , Muscle, Skeletal/metabolism , Inflammation/metabolism , AMP-Activated Protein Kinases/metabolism , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Type 2/therapy , Signal Transduction , Streptozocin
3.
Front Cell Infect Microbiol ; 14: 1391758, 2024.
Article En | MEDLINE | ID: mdl-38716194

Campylobacter jejuni, a Gram-negative bacterium, is one of the most common causes of foodborne illness worldwide. Its adhesion mechanism is mediated by several bacterial factors, including flagellum, protein adhesins, lipooligosaccharides, proteases, and host factors, such as surface glycans on epithelial cells and mucins. Fungal lectins, specialized carbohydrate-binding proteins, can bind to specific glycans on host and bacterial cells and thus influence pathogenesis. In this study, we investigated the effects of fungal lectins and protease inhibitors on the adhesion of C. jejuni to model biotic surfaces (mucin, fibronectin, and collagen) and Caco-2 cells as well as the invasion of Caco-2 cells. The lectins Marasmius oreades agglutinin (MOA) and Laccaria bicolor tectonin 2 (Tec2) showed remarkable efficacy in all experiments. In addition, different pre-incubations of lectins with C. jejuni or Caco-2 cells significantly inhibited the ability of C. jejuni to adhere to and invade Caco-2 cells, but to varying degrees. Pre-incubation of Caco-2 cells with selected lectins reduced the number of invasive C. jejuni cells the most, while simultaneous incubation showed the greatest reduction in adherent C. jejuni cells. These results suggest that fungal lectins are a promising tool for the prevention and treatment of C. jejuni infections. Furthermore, this study highlights the potential of fungi as a rich reservoir for novel anti-adhesive agents.


Bacterial Adhesion , Campylobacter jejuni , Lectins , Protease Inhibitors , Campylobacter jejuni/drug effects , Campylobacter jejuni/physiology , Campylobacter jejuni/metabolism , Humans , Caco-2 Cells , Bacterial Adhesion/drug effects , Lectins/metabolism , Lectins/pharmacology , Protease Inhibitors/pharmacology , Protease Inhibitors/metabolism , Fungi/drug effects , Mucins/metabolism , Epithelial Cells/microbiology , Fibronectins/metabolism
4.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 40(4): 303-310, 2024 Apr.
Article Zh | MEDLINE | ID: mdl-38710514

Objective To clarify the relationship between astrocyte activation patterns and disease progression in epidemic encephalitis B (Japanese encephalitis). Methods First, a mouse model of epidemic encephalitis B was constructed by foot-pad injection of Japanese encephalitis virus (JEV), and the expression of viral protein NS3 in different brain regions was detected by immunofluorescence assay (IFA). Next, IFA, RNA sequencing (RNA-seq) and real-time quantitative PCR (qRT-PCR) were used to clarify the changes in the astrocyte activation patterns at different stages of epidemic encephalitis B. Finally, intracerebroventricular administration of irisin was conducted to regulate the proportion of activation in complement C3-positive A1 astrocytes and S100A10-positive A2 astrocytes, investigating whether it could improve the body mass, behavioral scores, and brain tissue damage in a mouse model. Results NS3 protein was detected by IFA predominantly in the M1/M2 region of the motor cortex and the hippocampus. The number and volume of GFAP-positive astrocytes significantly increased in JEV-infected brain regions, in which the expression of multiple genes associated with A1/A2 astrocyte activation was significantly enhanced. Although intracerebroventricular or intraperitoneal injection of irisin did not improve the prognosis of epidemic encephalitis B, it inhibited the activation of A1 astrocytes and ameliorate neuroinflammation. Conclusion Neurons in the M1/M2 motor cortex and hippocampus are susceptible to JEV infection, in which the abnormal astrocyte activation contributes to the neuroinflammatory injury. Irisin administration may restrain A1 astrocyte activation and alleviate neuroinflammation following JEV infection.


Astrocytes , Disease Models, Animal , Disease Progression , Encephalitis Virus, Japanese , Encephalitis, Japanese , Animals , Astrocytes/metabolism , Astrocytes/virology , Mice , Encephalitis, Japanese/immunology , Encephalitis Virus, Japanese/physiology , Brain/metabolism , Brain/virology , Brain/pathology , Male , Fibronectins/metabolism , Fibronectins/genetics
5.
Nan Fang Yi Ke Da Xue Xue Bao ; 44(4): 675-681, 2024 Apr 20.
Article Zh | MEDLINE | ID: mdl-38708500

OBJECTIVE: To investigate the role of irisin in exercise-induced improvement of renal function in type 2 diabetic rats. METHODS: Forty male SD rats aged 4-6 weeks were randomized into normal control group, type 2 diabetes mellitus model group, diabetic exercise (DE) group and diabetic irisin (DI) group (n=8). The rats in DE group were trained with treadmill running for 8 weeks, and those in DI group were given scheduled irisin injections for 8 weeks. After the treatments, blood biochemical parameters of the rats were examined, and renal histopathology was observed with HE, Masson and PAS staining. Western blotting was used to detect the protein expression levels in the rats'kidneys. RESULTS: The diabetic rats showed significantly increased levels of fasting insulin, total cholesterol, triglyceride, serum creatinine and blood urea nitrogen with lowered serum irisin level (all P < 0.05). Compared with those in DM group, total cholesterol, triglyceride, serum creatinine and blood urea nitrogen levels were decreased and serum irisin levels were increased in both DE and DI groups (all P < 0.05). The rats in DM group showed obvious structural disorders and collagen fiber deposition in the kidneys, which were significantly improved in DE group and DI group. Both regular exercises and irisin injections significantly ameliorated the reduction of FNDC5, LC3-II/I, Atg7, Beclin-1, p-AMPK, AMPK and SIRT1 protein expressions and lowered of p62 protein expression in the kidneys of the diabetic rats (all P < 0.05). CONCLUSION: Both exercise and exogenous irisin treatment improve nephropathy in type 2 diabetic rats possibly due to irisin-mediated activation of the AMPK/SIRT1 pathway in the kidneys to promote renal autophagy.


Autophagy , Diabetes Mellitus, Experimental , Diabetes Mellitus, Type 2 , Fibronectins , Kidney , Physical Conditioning, Animal , Rats, Sprague-Dawley , Sirtuin 1 , Animals , Fibronectins/metabolism , Male , Rats , Diabetes Mellitus, Type 2/metabolism , Diabetes Mellitus, Experimental/metabolism , Kidney/metabolism , Sirtuin 1/metabolism , Diabetic Nephropathies/metabolism , Diabetic Nephropathies/therapy , Beclin-1/metabolism , Creatinine/blood , Blood Urea Nitrogen , Insulin , Triglycerides/metabolism , Triglycerides/blood , Cholesterol/blood , AMP-Activated Protein Kinases/metabolism
6.
Nat Commun ; 15(1): 3732, 2024 May 03.
Article En | MEDLINE | ID: mdl-38702309

Immunotherapy with chimeric antigen receptor T cells for pediatric solid and brain tumors is constrained by available targetable antigens. Cancer-specific exons present a promising reservoir of targets; however, these have not been explored and validated systematically in a pan-cancer fashion. To identify cancer specific exon targets, here we analyze 1532 RNA-seq datasets from 16 types of pediatric solid and brain tumors for comparison with normal tissues using a newly developed workflow. We find 2933 exons in 157 genes encoding proteins of the surfaceome or matrisome with high cancer specificity either at the gene (n = 148) or the alternatively spliced isoform (n = 9) level. Expression of selected alternatively spliced targets, including the EDB domain of fibronectin 1, and gene targets, such as COL11A1, are validated in pediatric patient derived xenograft tumors. We generate T cells expressing chimeric antigen receptors specific for the EDB domain or COL11A1 and demonstrate that these have antitumor activity. The full target list, explorable via an interactive web portal ( https://cseminer.stjude.org/ ), provides a rich resource for developing immunotherapy of pediatric solid and brain tumors using gene or AS targets with high expression specificity in cancer.


Brain Neoplasms , Exons , Receptors, Chimeric Antigen , Humans , Brain Neoplasms/immunology , Brain Neoplasms/therapy , Brain Neoplasms/genetics , Animals , Exons/genetics , Child , Receptors, Chimeric Antigen/genetics , Receptors, Chimeric Antigen/immunology , Receptors, Chimeric Antigen/metabolism , Mice , Immunotherapy/methods , Alternative Splicing , Fibronectins/genetics , Fibronectins/metabolism , Fibronectins/immunology , Xenograft Model Antitumor Assays , Gene Expression Regulation, Neoplastic , RNA-Seq , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Cell Line, Tumor , Immunotherapy, Adoptive/methods
7.
Int J Mol Sci ; 25(9)2024 Apr 30.
Article En | MEDLINE | ID: mdl-38732135

Glioblastoma (GBM) is the most lethal and common malignant primary brain tumor in adults. An important feature that supports GBM aggressiveness is the unique composition of its extracellular matrix (ECM). Particularly, fibronectin plays an important role in cancer cell adhesion, differentiation, proliferation, and chemoresistance. Thus, herein, a hydrogel with mechanical properties compatible with the brain and the ability to disrupt the dynamic and reciprocal interaction between fibronectin and tumor cells was produced. High-molecular-weight hyaluronic acid (HMW-HA) functionalized with the inhibitory fibronectin peptide Arg-Gly-Asp-Ser (RGDS) was used to produce the polymeric matrix. Liposomes encapsulating doxorubicin (DOX) were also included in the hydrogel to kill GBM cells. The resulting hydrogel containing liposomes with therapeutic DOX concentrations presented rheological properties like a healthy brain. In vitro assays demonstrated that unmodified HMW-HA hydrogels only caused GBM cell killing after DOX incorporation. Conversely, RGDS-functionalized hydrogels displayed per se cytotoxicity. As GBM cells produce several proteolytic enzymes capable of disrupting the peptide-HA bond, we selected MMP-2 to illustrate this phenomenon. Therefore, RGDS internalization can induce GBM cell apoptosis. Importantly, RGDS-functionalized hydrogel incorporating DOX efficiently damaged GBM cells without affecting astrocyte viability, proving its safety. Overall, the results demonstrate the potential of the RGDS-functionalized hydrogel to develop safe and effective GBM treatments.


Doxorubicin , Fibronectins , Glioblastoma , Hyaluronic Acid , Hydrogels , Oligopeptides , Glioblastoma/drug therapy , Glioblastoma/metabolism , Glioblastoma/pathology , Humans , Doxorubicin/pharmacology , Doxorubicin/chemistry , Oligopeptides/chemistry , Oligopeptides/pharmacology , Fibronectins/metabolism , Fibronectins/antagonists & inhibitors , Hydrogels/chemistry , Cell Line, Tumor , Hyaluronic Acid/chemistry , Brain Neoplasms/drug therapy , Brain Neoplasms/metabolism , Brain Neoplasms/pathology , Liposomes/chemistry , Apoptosis/drug effects , Matrix Metalloproteinase 2/metabolism
8.
J Cell Biochem ; 125(5): e30565, 2024 May.
Article En | MEDLINE | ID: mdl-38591469

Mammals exhibit two distinct types of adipose depots: white adipose tissue (WAT) and brown adipose tissue (BAT). While WAT primarily functions as a site for energy storage, BAT serves as a thermogenic tissue that utilizes energy and glucose consumption to regulate core body temperature. Under specific stimuli such as exercise, cold exposure, and drug treatment, white adipocytes possess a remarkable ability to undergo transdifferentiation into brown-like cells known as beige adipocytes. This transformation process, known as the "browning of WAT," leads to the acquisition of new morphological and physiological characteristics by white adipocytes. We investigated the potential role of Irisin, a 12 kDa myokine that is secreted in mice and humans by skeletal muscle after physical activity, in inducing the browning process in mesenchymal stromal cells (MSCs). A subset of the MSCs possesses the remarkable capability to differentiate into different cell types such as adipocytes, osteocytes, and chondrocytes. Consequently, comprehending the effects of Irisin on MSC biology becomes a crucial factor in investigating antiobesity medications. In our study, the primary objective is to evaluate the impact of Irisin on various cell types engaged in distinct stages of the differentiation process, including stem cells, committed precursors, and preadipocytes. By analyzing the effects of Irisin on these specific cell populations, our aim is to gain a comprehensive understanding of its influence throughout the entire differentiation process, rather than solely concentrating on the final differentiated cells. This approach enables us to obtain insights into the broader effects of Irisin on the cellular dynamics and mechanisms involved in adipogenesis.


Adipogenesis , Cell Differentiation , Fibronectins , Mesenchymal Stem Cells , Humans , Mesenchymal Stem Cells/metabolism , Mesenchymal Stem Cells/cytology , Mesenchymal Stem Cells/drug effects , Fibronectins/metabolism , Fibronectins/pharmacology , Cell Differentiation/drug effects , Cells, Cultured
9.
Int J Mol Sci ; 25(7)2024 Mar 31.
Article En | MEDLINE | ID: mdl-38612728

Interaction with the environment appears necessary for the maturation of sensorimotor and cognitive functions in early life. In rats, a model of sensorimotor restriction (SMR) from postnatal day 1 (P1) to P28 has shown that low and atypical sensorimotor activities induced the perturbation of motor behavior due to muscle weakness and the functional disorganization of the primary somatosensory and motor cortices. In the present study, our objective was to understand how SMR affects the muscle-brain dialogue. We focused on irisin, a myokine secreted by skeletal muscles in response to exercise. FNDC5/irisin expression was determined in hindlimb muscles and brain structures by Western blotting, and irisin expression in blood and cerebrospinal fluid was determined using an ELISA assay at P8, P15, P21 and P28. Since irisin is known to regulate its expression, Brain-Derived Neurotrophic Factor (BDNF) levels were also measured in the same brain structures. We demonstrated that SMR increases FNDC5/irisin levels specifically in the soleus muscle (from P21) and also affects this protein expression in several brain structures (as early as P15). The BDNF level was increased in the hippocampus at P8. To conclude, SMR affects FNDC5/irisin levels in a postural muscle and in several brain regions and has limited effects on BDNF expression in the brain.


Brain-Derived Neurotrophic Factor , Fibronectins , Animals , Rats , Brain , Muscle, Skeletal , Cognition
10.
Trends Immunol ; 45(5): 327-328, 2024 May.
Article En | MEDLINE | ID: mdl-38664101

Lawrence et al. report that fetal cortical boundaries are susceptible to morphogenetic stress that regulates a microglia state resembling postnatal, axon-tract associated microglia (ATM). This state performs a newfound function at these boundaries by preventing the formation of cavitary lesions, mediated in part by Spp1-regulated phagocytosis of fibronectin 1.


Microglia , Microglia/physiology , Animals , Humans , Phagocytosis , Cerebral Cortex/embryology , Cerebral Cortex/cytology , Brain/embryology , Brain/physiology , Fibronectins/metabolism
11.
Biomolecules ; 14(4)2024 Apr 11.
Article En | MEDLINE | ID: mdl-38672483

The X-chromosome-linked cell adhesion molecule L1 (L1CAM), a glycoprotein mainly expressed by neurons in the central and peripheral nervous systems, has been implicated in many neural processes, including neuronal migration and survival, neuritogenesis, synapse formation, synaptic plasticity and regeneration. L1 consists of extracellular, transmembrane and cytoplasmic domains. Proteolytic cleavage of L1's extracellular and transmembrane domains by different proteases generates several L1 fragments with different functions. We found that myelin basic protein (MBP) cleaves L1's extracellular domain, leading to enhanced neuritogenesis and neuronal survival in vitro. To investigate in vivo the importance of the MBP-generated 70 kDa fragment (L1-70), we generated mice with an arginine to alanine substitution at position 687 (L1/687), thereby disrupting L1's MBP cleavage site and obliterating L1-70. Young adult L1/687 males showed normal anxiety and circadian rhythm activities but enhanced locomotion, while females showed altered social interactions. Older L1/687 males were impaired in motor coordination. Furthermore, L1/687 male and female mice had a larger hippocampus, with more neurons in the dentate gyrus and more proliferating cells in the subgranular layer, while the thickness of the corpus callosum and the size of lateral ventricles were normal. In summary, subtle mutant morphological changes result in subtle behavioral changes.


Brain , Neural Cell Adhesion Molecule L1 , Animals , Neural Cell Adhesion Molecule L1/genetics , Neural Cell Adhesion Molecule L1/metabolism , Mice , Male , Female , Brain/metabolism , Fibronectins/metabolism , Fibronectins/genetics , Mutation , Behavior, Animal , Protein Domains , Neurons/metabolism , Hippocampus/metabolism , Mice, Inbred C57BL
12.
Proc Natl Acad Sci U S A ; 121(19): e2313590121, 2024 May 07.
Article En | MEDLINE | ID: mdl-38683978

Myokines and exosomes, originating from skeletal muscle, are shown to play a significant role in maintaining brain homeostasis. While exercise has been reported to promote muscle secretion, little is known about the effects of neuronal innervation and activity on the yield and molecular composition of biologically active molecules from muscle. As neuromuscular diseases and disabilities associated with denervation impact muscle metabolism, we hypothesize that neuronal innervation and firing may play a pivotal role in regulating secretion activities of skeletal muscles. We examined this hypothesis using an engineered neuromuscular tissue model consisting of skeletal muscles innervated by motor neurons. The innervated muscles displayed elevated expression of mRNAs encoding neurotrophic myokines, such as interleukin-6, brain-derived neurotrophic factor, and FDNC5, as well as the mRNA of peroxisome-proliferator-activated receptor γ coactivator 1α, a key regulator of muscle metabolism. Upon glutamate stimulation, the innervated muscles secreted higher levels of irisin and exosomes containing more diverse neurotrophic microRNAs than neuron-free muscles. Consequently, biological factors secreted by innervated muscles enhanced branching, axonal transport, and, ultimately, spontaneous network activities of primary hippocampal neurons in vitro. Overall, these results reveal the importance of neuronal innervation in modulating muscle-derived factors that promote neuronal function and suggest that the engineered neuromuscular tissue model holds significant promise as a platform for producing neurotrophic molecules.


Brain-Derived Neurotrophic Factor , Exosomes , Muscle, Skeletal , Exosomes/metabolism , Animals , Muscle, Skeletal/metabolism , Muscle, Skeletal/innervation , Brain-Derived Neurotrophic Factor/metabolism , Mice , Fibronectins/metabolism , Motor Neurons/metabolism , Interleukin-6/metabolism , MicroRNAs/metabolism , MicroRNAs/genetics , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/metabolism , Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha/genetics , Neurons/metabolism , Nerve Growth Factors/metabolism , Myokines
13.
Int Immunopharmacol ; 133: 112029, 2024 May 30.
Article En | MEDLINE | ID: mdl-38640715

Corneal wound healing requires epithelial reorganization and stromal extracellular matrix (ECM) remodeling, with ECM proteins such as Tenascin C (TnC) regulating and maintaining corneal homeostasis. The N-terminal globular domain and C-terminal fibrinogen-related domains of TnC are separated by epidermal growth factor (EGF)-like repeats, and upto fifteen fibronectin type III domains (Tn fn). Overexpression of Tn fn 1-5 and its splice variants occurs in varied pathologies. We have previously used Tn64 (a single chain variable fragment antibody cognate to Tn fn 1-5) to establish roles of Tn fn 1-5 in fibrotic pathologies such as rheumatoid arthritis and posterior capsular opacification. Here, we show that Tn64 binds to Tn fn repeats 3-5 (which constitute the major site for binding of soluble fibronectin within TnC). Unlike other Tn fn domains, Tn fn 3-5 displays no inhibition of fibronectin matrix assembly. Rather, the Tn fn 3-5 construct is pro-fibrotic and elicits increased expression of fibronectin. We examined corneal epithelial as well as stromal wound healing through Tn64 binding to Tn fn 3-5, using a human corneal epithelial cell (HCEC) line, primary cultures of human corneal fibroblasts (HCFs), and an ex-vivo corneal organ culture model. Tn64 enhanced proliferation and adhesion of corneal epithelial cells, while inhibiting the migration of corneal fibroblasts and myofibroblasts. Tn64 appears to attenuate inflammation through downregulation of TNF-α, prevent corneal fibrosis by limiting fibronectin polymerization, and promote regeneration of corneal epithelia and stroma, suggesting that it could be developed as a therapeutic agent for effective anti-fibrotic corneal wound healing.


Fibroblasts , Fibrosis , Single-Chain Antibodies , Tenascin , Wound Healing , Humans , Wound Healing/drug effects , Single-Chain Antibodies/pharmacology , Single-Chain Antibodies/genetics , Tenascin/metabolism , Tenascin/genetics , Tenascin/immunology , Fibronectins/metabolism , Fibronectins/genetics , Animals , Cornea/pathology , Cornea/metabolism , Cells, Cultured , Fibronectin Type III Domain , Cell Line
14.
Medicine (Baltimore) ; 103(15): e37473, 2024 Apr 12.
Article En | MEDLINE | ID: mdl-38608120

Chronic renal failure (CRF) causes a reduction in glomerular filtration rate and damage to renal parenchyma. Fushengong decoction (FSGD) showed improvement in renal function in CRF rats. This study aims to analyze the differentially expressed proteins in CRF patients treated with Western medicine alone or in combination with FSGD. Sixty patients with CRF recruited from Yongchuan Traditional Chinese Medicine Hospital affiliated to Chongqing Medical University were randomly assigned into control (treated with Western medicine alone) and observation groups (received additional FSGD treatment thrice daily for 8 weeks). The clinical efficacy and changes in serum Bun, serum creatinine, Cystatin C, and transforming growth factor beta 1 (TGF-ß1) before and after treatment were observed. We employed isotope relative labeling absolute quantification labeling and liquid chromatography-mass spectrometry to identify differentially expressed proteins and carried out bioinformatics Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses. Patients in the observation group showed greater clinical improvement and lower levels of serum Bun, serum creatinine, Cyc-c, and TGF-ß1 than the control group. We identified 32 differentially up-regulated and 52 down-regulated proteins in the observation group. These proteins are involved in the blood coagulation system, protein serine/threonine kinase activity, and TGF-ß, which are closely related to the pathogenesis of CRF. Protein-protein-interaction network analysis indicated that candidate proteins fibronectin 1, fibrinogen alpha chain, vitronectin, and Serpin Family C Member 1 were in the key nodes. This study provided an experimental basis suggesting that FSGD combined with Western medicine could significantly improve renal function and renal fibrosis of CRF patients, which may be through the regulation of fibronectin 1, fibrinogen alpha chain, vitronectin, Serpin Family C Member 1, TGF-ß, and the complement coagulation pathway (see Graphical abstract S1, Supplemental Digital Content, http://links.lww.com/MD/L947).


Kidney Failure, Chronic , Renal Insufficiency, Chronic , Serpins , Animals , Humans , Rats , Creatinine , Extracellular Matrix Proteins , Fibrinogen , Fibronectins , Kidney Failure, Chronic/drug therapy , Renal Insufficiency, Chronic/drug therapy , Transforming Growth Factor beta , Transforming Growth Factor beta1 , Vitronectin
15.
J Cell Mol Med ; 28(9): e18259, 2024 May.
Article En | MEDLINE | ID: mdl-38676364

Mechanical ventilation (MV) is an essential life-saving technique, but prolonged MV can cause significant diaphragmatic dysfunction due to atrophy and decreased contractility of the diaphragm fibres, called ventilator-induced diaphragmatic dysfunction (VIDD). It is not clear about the mechanism of occurrence and prevention measures of VIDD. Irisin is a newly discovered muscle factor that regulates energy metabolism. Studies have shown that irisin can exhibit protective effects by downregulating endoplasmic reticulum (ER) stress in a variety of diseases; whether irisin plays a protective role in VIDD has not been reported. Sprague-Dawley rats were mechanically ventilated to construct a VIDD model, and intervention was performed by intravenous administration of irisin. Diaphragm contractility, degree of atrophy, cross-sectional areas (CSAs), ER stress markers, AMPK protein expression, oxidative stress indicators and apoptotic cell levels were measured at the end of the experiment.Our findings showed that as the duration of ventilation increased, the more severe the VIDD was, the degree of ER stress increased, and the expression of irisin decreased.ER stress may be one of the causes of VIDD. Intervention with irisin ameliorated VIDD by reducing the degree of ER stress, attenuating oxidative stress, and decreasing the apoptotic index. MV decreases the expression of phosphorylated AMPK in the diaphragm, whereas the use of irisin increases the expression of phosphorylated AMPK. Irisin may exert its protective effect by activating the phosphorylated AMPK pathway.


AMP-Activated Protein Kinases , Apoptosis , Diaphragm , Endoplasmic Reticulum Stress , Fibronectins , Rats, Sprague-Dawley , Animals , Fibronectins/metabolism , Diaphragm/metabolism , AMP-Activated Protein Kinases/metabolism , Male , Respiration, Artificial/adverse effects , Rats , Oxidative Stress , Muscle Contraction
16.
Medicine (Baltimore) ; 103(15): e37716, 2024 Apr 12.
Article En | MEDLINE | ID: mdl-38608067

Nonalcoholic fatty liver disease (NAFLD) is considered one of the most important causes of chronic liver disorders in the world. Dietary pattern is a modifiable risk factor that represents the main target for the prevention and treatment of NAFLD. The aim of this cross-sectional study was to assess the impact of low-fat diet on anthropometric measurements, biochemical, and inflammatory parameters in individuals with obesity/overweight and NAFLD. A total of 108 individuals (n = 59 males and n = 49 females) aged between 19 and 65 years participated in the 12-week weight loss program. Dietary treatment plans including low-fat diets were randomly prescribed for each individual. Anthropometric measurements were collected by a trained dietitian at baseline and 12-week follow-up. Blood samples were collected for each individual at baseline and 3rd month for biochemical measurements and enzyme-linked immunosorbent assay analysis for tumor necrosis factor-α (TNF-α), interleukin (IL)-6, fibroblast growth factor-21 (FGF-21), chemerin, and irisin levels in plasma. At the end of the study, body weight, body mass index, body fat % body fat mass (kg) reduced significantly in females and males (P < .05). Moreover, reductions in waist, hip, and neck circumferences were significant in both groups. Changes in alanine aminotransferase and aspartate aminotransferase levels were significant in 3rd month. After 3 months, reductions in TNF-α, IL-6, and FGF-21 levels were significant in individuals with obesity/overweight and NAFLD. While no significant change in chemerin and irisin levels was found. These results show that low-fat diet over a 12-week period led to improvements in both anthropometric measurements and biochemical parameters in individuals with obesity/overweight and NAFLD.


Non-alcoholic Fatty Liver Disease , Overweight , Female , Male , Humans , Infant , Overweight/complications , Diet, Fat-Restricted , Cross-Sectional Studies , Fibronectins , Tumor Necrosis Factor-alpha , Obesity/complications , Interleukin-6
17.
Carbohydr Polym ; 336: 122122, 2024 Jul 15.
Article En | MEDLINE | ID: mdl-38670769

Pectin interacts with fibronectin (FN), a modular protein in the extracellular matrix. This interaction is significant as FN plays a pivotal role by binding to the receptor integrin α5ß1. However, the molecular mechanism underlying the pectin-FN interaction and its impact on integrin binding remains unknown. In this study, water-soluble pectins (WSPs) were extracted from three different pectin sources and subsequently characterized. These included Citrus WSP, which primarily comprises the homogalacturonan region, and Kaki and Yuzu WSPs, both of which are rich in rhamnogalacturonan regions. We investigated the molecular interactions between these WSPs and two FN fragments, Anastellin and RetroNectin, using surface plasmon resonance analysis. Citrus WSP exhibited a notable binding affinity to FN, with a dissociation constant (KD) of approximately 10-7 M. In contrast, Kaki and Yuzu WSPs displayed comparatively weaker or negligible binding affinities. The binding reactivity of Citrus WSP with FN was notably diminished following the enzymatic removal of its methyl-ester groups. Additionally, Citrus WSP disrupted the binding of integrin ß1 to RetroNectin without altering the affinity, despite its minimal direct binding to integrin itself. This study furthers our understanding of the intricate pectin-FN interaction and sheds light on their potential physiological relevance and impact on cellular responses.


Fibronectins , Integrin beta1 , Pectins , Protein Binding , Pectins/metabolism , Pectins/chemistry , Fibronectins/metabolism , Fibronectins/chemistry , Integrin beta1/metabolism , Citrus/chemistry , Citrus/metabolism , Humans , Surface Plasmon Resonance
18.
Int J Pharm ; 656: 124096, 2024 May 10.
Article En | MEDLINE | ID: mdl-38583821

Pulmonary fibrosis (PF) is a chronic, progressive and irreversible interstitial lung disease that seriously threatens human life and health. Our previous study demonstrated the unique superiority of traditional Chinese medicine cryptotanshinone (CTS) combined with sustained pulmonary drug delivery for treating PF. In this study, we aimed to enhance the selectivity, targeting efficiency and sustained-release capability based on this delivery system. To this end, we developed and evaluated CTS-loaded modified liposomes-chitosan (CS) microspheres SM(CT-lipo) and liposome-exosome hybrid bionic vesicles-CS microspheres SM(LE). The prepared nano-in-micro particles system integrates the advantages of the carriers and complements each other. SM(CT-lipo) and SM(LE) achieved lung myofibroblast-specific targeting through CREKA peptide binding specifically to fibronectin (FN) and the homing effect of exosomes on parent cells, respectively, facilitating efficient delivery of anti-fibrosis drugs to lung lesions. Furthermore, compared with daily administration of conventional microspheres SM(NC) and positive control drug pirfenidone (PFD), inhaled administration of SM(CT-lipo) and SM(LE) every two days still attained similar efficacy, exhibiting excellent sustained drug release ability. In summary, our findings suggest that the developed SM(CT-lipo) and SM(LE) delivery strategies could achieve more accurate, efficient and safe therapy, providing novel insights into the treatment of chronic PF.


Chitosan , Exosomes , Fibronectins , Liposomes , Pulmonary Fibrosis , Pyridones , Animals , Fibronectins/administration & dosage , Pulmonary Fibrosis/drug therapy , Exosomes/chemistry , Chitosan/chemistry , Chitosan/administration & dosage , Administration, Inhalation , Microspheres , Drug Liberation , Male , Delayed-Action Preparations , Phenanthrenes/administration & dosage , Phenanthrenes/chemistry , Phenanthrenes/pharmacokinetics , Mice , Drug Delivery Systems/methods , Humans , Lung/metabolism , Lung/drug effects , Rats, Sprague-Dawley , Antifibrotic Agents/administration & dosage , Antifibrotic Agents/chemistry
19.
Vet Immunol Immunopathol ; 271: 110753, 2024 May.
Article En | MEDLINE | ID: mdl-38608406

Porcine epidemic diarrhea virus (PEDV) causes immensely large economic losses worldwide in the swine industry. PEDV attacks the intestine, disrupts intestinal epithelium morphology and barrier integrity, and results in profound diarrhea and high mortality. A commercially available isotonic protein solution (IPS) (Tonisity Px) has anecdotally been reported to be effective in supportive treatment of piglets with active PEDV infections. This study evaluated the effects of supplementing (or not) the drinking water of 14 day old PEDV-infected piglets with the IPS on the content of E-cadherin, fibronectin, interferon-alpha (IFN-α), and matrix metalloproteinase 9 (MMP-9) in duodenal tissue. The content of PEDV DNA in feces was also measured. Though both groups had similar PEDV shedding at day 1, IPS piglets had significantly lower PEDV shedding at day 5, 14 and 21. The IPS group also had a shorter duration of PEDV virus shedding. Levels of E-cadherin and fibronectin, both of which are structural proteins in the intestine, remained unchanged from baseline in the IPS group, whereas the same molecules decreased significantly in the control group. IFN-α, an antiviral cytokine, and MMP-9, an enzyme that aids in tissue remodeling, were increased at days 5 and 14 post infection, and then decreased at day 21 post-infection in the IPS group compared to control. Overall, the IPS used in this study enhanced epithelial intercellular adhesion (E-cadherin) and extracellular matrix structure (fibronectin), resulted in significantand favorable changes in MMP-9 activity, and favorably modulated IFN-α production. This is the first report of this panel of biomarkers, especially MMP-9 and IFN-α, in the face of in vivo PEDV infection. This is also the first report to investigate a commercially available swine product that does not need to be administered in solid feed, and that is already registered for use throughout Asia, Europe, South America, and North America. Overall, the results of this study serve to clarify the behavior of 4 key biomarkers in the presence of in vivo PEDV infection. The results also indicate that IPS (Tonisity Px) supplementation is a viable intervention to modulate the porcine intestinal immune response with favorable effects on the intestine.


Coronavirus Infections , Porcine epidemic diarrhea virus , Swine Diseases , Virus Shedding , Animals , Swine , Porcine epidemic diarrhea virus/physiology , Porcine epidemic diarrhea virus/immunology , Coronavirus Infections/veterinary , Coronavirus Infections/immunology , Coronavirus Infections/virology , Swine Diseases/virology , Swine Diseases/immunology , Fibronectins/metabolism , Matrix Metalloproteinase 9/metabolism , Cadherins/metabolism , Intestines/immunology , Intestines/virology , Interferon-alpha/immunology , Cell Adhesion , Intestinal Mucosa/immunology
20.
Aging Clin Exp Res ; 36(1): 90, 2024 Apr 10.
Article En | MEDLINE | ID: mdl-38598000

BACKGROUND: Skeletal muscle is the main source of circulating irisin, both at rest and during physical activity. Previous studies have suggested that irisin can improve cognitive abilities. AIMS: We explored whether six months of Tai Chi (TC) practice can modulate such a relationship in healthy older persons. METHODS: This is a prospective clinical study to evaluate the effects of TC practice as compared with low intensity exercise (LI) and no exercise (NE) control groups on plasmatic irisin levels and cognitive performance. Forty-two healthy older persons were stratified into three groups according to physical activities. Biochemical assay and cognitive functions were assessed at the baseline and after six months. RESULTS: A significant change was found in circulating irisin levels in TC as compared with NE group (p = 0.050) across time. At six months in TC group irisin levels significantly correlated with a verbal memory test (p = 0.013) controlled by age and education. CONCLUSION: Our results suggest the potential benefits for cognitive health of TC practice by irisin levels modulation.


Fibronectins , Tai Ji , Humans , Aged , Aged, 80 and over , Prospective Studies , Cognition , Educational Status
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