Tissue markers may predict treatment response to antitumor necrosis factor-α agents in children with Crohn's disease.

OBJECTIVES: Patients with moderate-severe Crohn's disease (CD) who are treated with antitumor necrosis factor alpha (TNF-α) agents may be subjected to primary nonresponse or partial response. We aimed to identify tissue markers that may predict response to these agents. METHODS: Pediatric patients (6-18 years) with either ileal or ileo-colonic CD who were treated with anti-TNF-α were stratified into three different groups based on their overall response to therapy at the end of induction including clinical and laboratory parameters (group 1-full responders [FR], group 2-partial responders [PR], group 3-nonresponders [NR]). Seven tissue markers (fibronectin, interleukin [IL]-23R, IL-23, TNF-α, collagen-III, IL-13R, and hypoxia-inducible factors [HIF]-1α) were evaluated. Immunofluorescence (IF) analyses were performed on biopsies from the terminal ileum, which were retrieved up to 6 months before treatment initiation. RESULTS: Twenty-six CD patients (16 [61.5%] males; age 13.9 ± 2.9 years), including 8 (30.8%) with ileal disease and 18 (69.2%) with ileo-colonic disease, were enrolled. Terminal ileum biopsies from nine patients from group 1, nine from group 2, and eight from group 3 were evaluated. Three antibodies were found to be significantly different between NR and FR groups; Collagen III and fibronectin stains were significantly more prominent in NR patients, while TNF-α stain was significantly more pronounced in FR, p < 0.05 for each. PR could not have been predicted with neither of markers. CONCLUSIONS: Decreased tissue IF intensity of fibronectin and collagen III and increased intensity of TNF-α may predict response to anti-TNF-α treatment.

Alantolactone Attenuates Renal Fibrosis via Inhibition of Transforming Growth Factor ß/Smad3 Signaling Pathway.

BACKGRUOUND: Renal fibrosis is characterized by the accumulation of extracellular matrix proteins and interstitial fibrosis. Alantolactone is known to exert anticancer, anti-inflammatory, antimicrobial and antifungal effects; however, its effects on renal fibrosis remains unknown. Here, we investigated whether alantolactone attenuates renal fibrosis in mice unilateral ureteral obstruction (UUO) and evaluated the effect of alantolactone on transforming growth factor (TGF) signaling pathway in renal cells. METHODS: To evaluate the therapeutic effect of alantolactone, cell counting kit-8 (CCK-8) assay, histological staining, Western blot analysis, and real-time quantitative polymerase chain reaction were performed in UUO kidneys in vivo and in TGF-ß-treated renal cells in vitro. RESULTS: Alantolactone (0.25 to 4 µM) did not affect the viability of renal cells. Mice orally administered 5 mg/kg of alantolactone daily for 15 days did not show mortality or liver toxicity. Alantolactone decreased UUO-induced blood urea nitrogen and serum creatinine levels. In addition, it significantly alleviated renal tubulointerstitial damage and fibrosis and decreased collagen type I, fibronectin, and α-smooth muscle actin (α-SMA) expression in UUO kidneys. In NRK-49F cells, alantolactone inhibited TGF-ßstimulated expression of fibronectin, collagen type I, plasminogen activator inhibitor-1 (PAI-1), and α-SMA. In HK-2 cells, alantolactone inhibited TGF-ß-stimulated expression of collagen type I and PAI-1. Alantolactone inhibited UUO-induced phosphorylation of Smad3 in UUO kidneys. In addition, it not only decreased TGF-ß secretion but also Smad3 phosphorylation and translocation to nucleus in both kidney cell lines. CONCLUSION: Alantolactone improves renal fibrosis by inhibiting the TGF-ß/Smad3 signaling pathway in obstructive nephropathy. Thus, alantolactone is a potential therapeutic agent for chronic kidney disease.

Predictors of Kidney Function Outcomes and Their Relation to SGLT2 Inhibitor Dapagliflozin in Patients with Type 2 Diabetes Mellitus Who Had Chronic Heart Failure.

INTRODUCTION: Sodium-glucose cotransporter 2 inhibitors (SGLT2i) have a favorable impact on the kidney function in patients with heart failure (HF), while there is no clear evidence of what factors predict this effect. The aim of the study was to identify plausible predictors for kidney function outcome among patients with HF and investigate their association with SGLT2i. METHODS: We prospectively enrolled 480 patients with type 2 diabetes mellitus (T2DM) treated with diet and metformin and concomitant chronic HF and followed them for 52 weeks. In the study, we determined kidney outcome as a composite of ≥ 40% reduced estimated glomerular filtration rate from baseline, newly diagnosed end-stage kidney disease or kidney replacement therapy. The relevant medical information and measurement of the biomarkers (N-terminal natriuretic pro-peptide, irisin, apelin, adropin, C-reactive protein, tumor necrosis factor-alpha) were collected at baseline and at the end of the study. RESULTS: The composite kidney outcome was detected in 88 (18.3%) patients of the entire population. All patients received guideline-recommended optimal therapy, which was adjusted to phenotype/severity of HF, cardiovascular risk and comorbidity profiles, and fasting glycemia. Levels of irisin, adropin and apelin significantly increased in patients without clinical endpoint, whereas in those with composite endpoint the biomarker levels exhibited a decrease with borderline statistical significance (p = 0.05). We noticed that irisin ≤ 4.50 ng/ml at baseline and a ≤ 15% increase in irisin serum levels added more valuable predictive information than the reference variable. However, the combination of irisin ≤ 4.50 ng/ml at baseline and ≤ 15% increase in irisin serum levels (area under curve = 0.91; 95% confidence interval = 0.87-0.95) improved the discriminative value of each biomarker alone. CONCLUSION: We suggest that low levels of irisin and its inadequate increase during administration of SGLT2i are promising predictors for unfavorable kidney outcome among patients with T2DM and concomitant HF.

Irisin, a novel metabolic biomarker in hidradenitis suppurativa: correlation with clinical responsivity to anti-TNF-α therapy.

BACKGROUND: Suppurative hidradenitis (HS) is a chronic, inflammatory skin disease of the hair follicle unit. Adalimumab (ADA), an anti-tumor necrosis factor (TNF) alpha, is the only FDA-approved biologic available for the management of HS. TNF-α can also affect glucose and lipid metabolism, promoting insulin resistance and obesity by negatively regulating irisin, a new adipomyokine. METHODS: A total of 17 HS patients were enrolled in the study. Blood samples were collected from all patients at baseline and week-16. Plasma irisin levels were detected by ELISA assay. RESULTS: Plasma irisin levels were significantly increased after 16 weeks of ADA therapy in HS patients compared to baseline. Interestingly, plasma irisin levels correlated with clinical response. CONCLUSIONS: The link between skin inflammatory diseases and metabolic disorders has aroused great interest in order to research new biomarkers able to early identify metabolic comorbidities. Among these emerging biomarkers, irisin is one of the most recently discovered. We examined a group of patients affected by moderate-severe HS treated with anti-TNF-α, demonstrating for the first time how a therapy able to block an inflammatory cytokine can also affect the metabolic profile by modifying levels of irisin.

AKT-driven epithelial-mesenchymal transition is affected by copper bioavailability in HER2 negative breast cancer cells via a LOXL2-independent mechanism.

BACKGROUND: The main mechanism underlying cancer dissemination is the epithelial to mesenchymal transition (EMT). This process is orchestrated by cytokines like TGFß, involving "non-canonical" AKT- or STAT3-driven pathways. Recently, the alteration of copper homeostasis seems involved in the onset and progression of cancer. METHODS: We expose different breast cancer cell lines, including two triple negative (TNBC) ones, an HER2 enriched and one cell line representative of the Luminal A molecular subtype, to short- or long-term copper-chelation by triethylenetetramine (TRIEN). We analyse changes in the expression of EMT markers (E-cadherin, fibronectin, vimentin and αSMA), in the levels and activity of extracellular matrix components (LOXL2, fibronectin and MMP2/9) and of copper homeostasis markers by Western blot analyses, immunofluorescence, enzyme activity assays and RT-qPCR. Boyden Chamber and wound healing assays revealed the impact of copper chelation on cell migration. Additionally, we explored whether perturbation of copper homeostasis affects EMT prompted by TGFß. Metabolomic and lipidomic analyses were applied to search the effects of copper chelation on the metabolism of breast cancer cells. Finally, bioinformatics analysis of data on breast cancer patients obtained from different databases was employed to correlate changes in kinases and copper markers with patients' survival. RESULTS: Remarkably, only HER2 negative breast cancer cells differently responded to short- or long-term exposure to TRIEN, initially becoming more aggressive but, upon prolonged exposure, retrieving epithelial features, reducing their invasiveness. This phenomenon may be related to the different impact of the short and prolonged activation of the AKT kinase and to the repression of STAT3 signalling. Bioinformatics analyses confirmed the positive correlation of breast cancer patients' survival with AKT activation and up-regulation of CCS. Eventually, metabolomics studies demonstrate a prevalence of glycolysis over mitochondrial energetic metabolism and of lipidome changes in TNBC cells upon TRIEN treatment. CONCLUSIONS: We provide evidence of a pivotal role of copper in AKT-driven EMT activation, acting independently of HER2 in TNBC cells and via a profound change in their metabolism. Our results support the use of copper-chelators as an adjuvant therapeutic strategy for TNBC.

Association between peripheral biomarkers and clinical response to IV ketamine for unipolar treatment-resistant depression: An open label study.

BACKGROUND: Major Depression is the leading cause of disability worldwide. A cohort of patients do not respond adequately to available antidepressants, leading to treatment-resistant depression (TRD). We evaluated the antidepressant efficacy of an acute intravenous ketamine treatment (0.5 mg/kg) for patients with unipolar TRD, and measured peripheral blood-based biomarkers associated with response to treatment. METHODS: Fifteen adults diagnosed with TRD completed an open label study of ten infusions of subanesthetic ketamine over four weeks. Out of fifteen patients, blood was collected from eleven patients at three timepoints to analyze peripheral biomarkers in isolated plasma, including IL-6, IL-10, TNF-α, BDNF, and irisin. Irisin analysis was completed using an ELISA assay, and the remaining biomarkers were analyzed together simultaneously using a multiplex immunoassay. RESULTS: Repeated ketamine infusions produced a significant decrease in total average depressive symptoms (MADRS) at all timepoints. Improvements in depressive symptoms were significant at one week, and continued to significantly decrease until two weeks, where it was maintained. Ketamine was generally well tolerated, and we observed improvements in functional impairment, anhedonia, and psychiatric symptoms, with no increases in manic symptoms. Levels of BDNF throughout treatment inversely correlated to decreases in MADRS scores, and higher levels of baseline BDNF predicted mood responses at one- and four weeks. LIMITATIONS: The study was observational and uncontrolled, with a sample size of 15. Outpatients remained on their course of medications, unless they were pharmacological agents that have previously been identified to block ketamine's effects. CONCLUSIONS: Ketamine may be an efficacious and safe pharmacological option for the acute treatment of patients suffering from severe TRD. BDNF has the potential to function as a prognostic biomarker for predicting response to ketamine treatments.

Cascade Drug Delivery through Tumor Barriers of Pancreatic Cancer via Ultrasound in Combination with Functional Microbubbles.

The abundant desmoplastic stroma and the lack of sufficient targets on pancreatic cancer cells render poor drug penetration and cellular uptake, which significantly compromise the chemotherapy efficacy. Herein, we reported a three-step cascade delivery strategy for selective delivery of paclitaxel (PTX) to achieve a targeted therapy for pancreatic cancer. cRGD and cCLT1 peptides, which could target the integrin and fibronectin, respectively, overexpressed in pancreatic cancer cells and stroma, were decorated on PTX-loaded microbubbles, resulting in the formation of dual-targeting PTX-RCMBs. In this strategy, ultrasound in combination with PTX-RCMBs first enhanced the permeability of tumor vessels via cavitation effects and simultaneously helped the generated PTX-RCNPs penetrate into the stroma. Then, the cCLT1 peptide modified on PTX-RCNPs selectively bound the fibronectin highly expressed in the stroma and later targeted the integrin (α5ß1) on the cell surface. Finally, another targeting cRGD peptide modified on PTX-RCNPs would further promote PTX uptake via targeting the integrin (αvß3) on the cell surface. This strategy significantly increased the delivery of PTX into tumor tissues. Moreover, the in vivo effective accumulation of PTX was monitored by ultrasound and fluorescence bimodal imaging. The tumor growth inhibition was investigated on subcutaneous tumor mouse models with 89.8% growth inhibition rate during 21 days of treatment, showing great potential for improving pancreatic cancer therapy.

MAP/Microtubule Affinity Regulating Kinase 4 Inhibitory Potential of Irisin: A New Therapeutic Strategy to Combat Cancer and Alzheimer's Disease.

Irisin is a clinically significant protein playing a valuable role in regulating various diseases. Irisin attenuates synaptic and memory dysfunction, highlighting its importance in Alzheimer's disease. On the other hand, Microtubule Affinity Regulating Kinase 4 (MARK4) is associated with various cancer types, uncontrolled neuronal migrations, and disrupted microtubule dynamics. In addition, MARK4 has been explored as a potential drug target for cancer and Alzheimer's disease therapy. Here, we studied the binding and subsequent inhibition of MARK4 by irisin. Irisin binds to MARK4 with an admirable affinity (K = 0.8 × 107 M-1), subsequently inhibiting its activity (IC50 = 2.71 µm). In vitro studies were further validated by docking and simulations. Molecular docking revealed several hydrogen bonds between irisin and MARK4, including critical residues, Lys38, Val40, and Ser134. Furthermore, the molecular dynamic simulation showed that the binding of irisin resulted in enhanced stability of MARK4. This study provides a rationale to use irisin as a therapeutic agent to treat MARK4-associated diseases.

Fibronectin plays a major role in hypoxia-induced lenvatinib resistance in hepatocellular carcinoma PLC/PRF/5 cells.

Resistance to lenvatinib mesylate (LEN), a systemic chemotherapy that can be administered orally, has been a major issue for treatment of hepatocellular carcinoma (HCC). Although HCC is the tumor that most exhibits intratumoral hypoxia, which has been shown to be involved in the development of treatment resistance, there are no reports of LEN resistance in HCC treatment under hypoxia. The purpose of our study was to elucidate the mechanism of treatment resistance to LEN under hypoxia using HCC cell lines. We confirmed LEN resistance under hypoxic conditions in HCC cell lines. There was a significant increase in the IC50 value of PLC/PRF/5 cells from 13.0±0.8 µM in normoxia to 21.3±1.1 µM in hypoxia, but in HepG2 cells, the increase was not significant. To elucidate the LEN resistance mechanism of PLC/PRF/5 cells under hypoxia, we performed microarray analysis and extracted genes that are thought to be related to this mechanism. Furthermore, in-silico analysis confirmed significant changes in the extracellular matrix, and among them, FN1 encoding fibronectin was determined as the hub of the gene cluster. The expression of fibronectin in PLC/PRF/5 cells examined with immunofluorescence staining was significantly elevated in and outside of cells under hypoxia, and tended to decrease when cells were exposed to LEN under normoxia. Furthermore, the fibronectin concentration in the culture solution of PLC/PRF/5 cells examined by ELISA was 2.3 times higher under hypoxia than under normoxia under LEN(-) conditions, and 1.6 times higher under hypoxia than under normoxia under LEN(+) conditions. It is assumed that in PLC/PRF/5 cells, fibronectin is probably suppressed as an indirect effect of LEN under normoxia, but transcription factors such as HIF-1α are induced under hypoxia, thus enhancing the production of fibronectin and attenuating the effect of LEN, resulting in drug resistance. This behavior of fibronectin with LEN exposure under hypoxia is probably specific to PLC/PRF/5 cells. Further studies should verify the combined effective inhibition of fibronectin and the MAPK pathway as a promising therapeutic strategy to enhance the value of LEN in HCC treatment.

Effect of Irisin on Pressure Overload-Induced Cardiac Remodeling.

BACKGROUND: Irisin has been considered a prognostic factor in several cardiovascular diseases. Nevertheless, no data are available on the role of irisin in cardiac remodeling. AIM OF THE STUDY: This study aimed to determine the potential role of irisin in cardiac remodeling and explore potential mechanisms. METHODS: A total of 40 rats that underwent transverse abdominal aortic constriction (TAC) surgery or sham operation were divided into four groups: sham + saline (NS), sham + irisin, TAC + NS, and TAC + irisin. After 6 weeks of treatment, echocardiography was performed to assess in vivo cardiac morphology. The left ventricular myocardium was prepared and observed by pathological examination. The effect of irisin on cardiomyocyte apoptosis and the expression of oxidative stress and cardiac hypertrophy markers were observed. Then, the effect of irisin on the Akt signaling system was also detected. RESULTS: The rats in the TAC group displayed obvious signs of cardiac dysfunction and cardiac hypertrophy, and irisin treatment could reverse these changes. Irisin could inhibit the expression of nicotinamide adenine dinucleotide phosphate oxidase 2 and xanthine oxidase in TAC rats and increase the expression of antioxidant enzymes. Furthermore, the expression of phosphorylated protein kinase B (p-Akt), phosphorylated mammalian target of rapamycin (p-mTOR), and phosphorylated glycogen synthase kinase 3ß (p-GSK3ß) was much higher in the cardiac remodeling groups (p <0.05 vs. sham rats). Irisin could relieve the inhibition effect and reduce the expression level of these three proteins. CONCLUSIONS: Irisin treatment could significantly improve cardiac remodeling by inhibiting oxidative stress via attenuating the Akt signaling activation.

Anti-EGFR Fibronectin Bispecific Chemically Self-Assembling Nanorings (CSANs) Induce Potent T Cell-Mediated Antitumor Responses and Downregulation of EGFR Signaling and PD-1/PD-L1 Expression.

Overexpression of the epidermal growth factor receptor (EGFR) on various cancers makes it an important target for cancer immunotherapy. We recently demonstrated that single-chain variable fragment-based bispecific chemically self-assembled nanorings (CSANs) can successfully modify T cell surfaces and function as prosthetic antigen receptors (PARs) allowing selective targeting of tumor antigens while incorporating a dissociation mechanism of the rings. Here, we report the generation of anti-EGFR fibronectin (FN3)-based PARs with high yield, rapid protein production, predicted low immunogenicity, and increased protein stability. We demonstrated the cytotoxicity of FN3-PARs successfully while evaluating FN3 affinities, CSAN valencies, and antigen expression levels. Using an orthotopic breast cancer model, we showed that FN3-PARs can suppress tumor growth with no adverse effects and FN3-PARs reduced immunosuppressive programmed cell death ligand-1 (PD-L1) expression by downregulating EGFR signaling. These results demonstrate the potential of FN3-PARs to direct selective T cell-targeted tumor killing and to enhance antitumor T cell efficacy by modulating the tumor microenvironment.

Involvement of Integrin-Activating Peptides Derived from Tenascin-C in Cancer Aggression and New Anticancer Strategy Using the Fibronectin-Derived Integrin-Inactivating Peptide.

Matricellular proteins, which exist in association with the extracellular matrix (ECM) and ECM protein molecules, harbor functional sites within their molecular structures. These functional sites are released through proteolytic cleavage by inflammatory proteinases, such as matrix metalloproteinases (MMPs) and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS), and the peptides containing these functional sites have unique biological activities that are often not detected in the parent molecules. We previously showed that tenascin-C (TNC) and plasma fibronectin (pFN), examples of matricellular proteins, have cryptic bioactive sites that have opposite effects on cell adhesion to the ECM. A peptide containing the bioactive site of TNC, termed TNIIIA2, which is highly released at sites of inflammation and in the tumor microenvironment (TME), has the ability to potently and persistently activate ß1-integrins. In the opposite manner, the peptide FNIII14 containing the bioactive site of pFN has the ability to inactivate ß1-integrins. This review highlights that peptide TNIIIA2 can act as a procancer factor and peptide FNIII14 can act as an anticancer agent, based on the regulation on ß1-integrin activation. Notably, the detrimental effects of TNIIIA2 can be inhibited by FNIII14. These findings open the possibility for new therapeutic strategies based on the inactivation of ß1-integrin by FNIII14.

The role of cryoprecipitate in massively transfused patients: Results from the Trauma Quality Improvement Program database may change your mind.

BACKGROUND: Cryoprecipitate was developed for the treatment of inherited and acquired coagulopathies. The role of cryoprecipitate in hemorrhaging trauma patients is still speculative. The aim of our study was to assess the role of cryoprecipitate as an adjunct to transfusion in trauma patients. METHODS: We performed a 2-year (2015-2016) analysis of the American College of Surgeons-Trauma Quality Improvement Program data set and included all adult trauma patients who received 4 or greater packed red blood cells (pRBCs)/4 hours. Patients were stratified based on receipt of cryoprecipitate within the first 24 hours (cryoprecipitate vs. no-cryoprecipitate). Outcomes were blood products transfused, in-hospital complications, and mortality. Regression analyses were performed. RESULTS: A total of 19,643 (cryoprecipitate, 4,945; no-cryoprecipitate, 14,698) were included. Mean age was 40 ± 22 years, median Injury Severity Score was 27 [18-40], and Glasgow Coma Scale score was 9 [3-14]. The overall complication rate was 45%, mortality was 47%, and 29% of the patients died in the first 24 hours. Patients in the cryoprecipitate group received a lower volume of plasma (p < 0.01), and pRBCs (p < 0.01). Additionally, patients who received cryoprecipitate had lower rates of 24-hour mortality (p < 0.01) and in-hospital mortality (p < 0.01). However, there was no difference between the two groups regarding complications (p = 0.36) or volume of platelet transfused (p = 0.22). On multivariate logistic regression, the use of cryoprecipitate was associated with decreased (odds ratio [OR], 0.78 [0.63-0.84]; p = 0.02), in-hospital mortality (OR, 0.79 [0.77-0.87]; p = 0.01), but had no association with in-hospital complications (OR, 1.48 [0.71-1.99]; p = 0.31). On linear regression analysis, the use of cryoprecipitate was not associated with 24-hour pRBCs (ß = -0.12 [-0.28 to 0.27], p = 0.47), 24-hour plasma (ß = -0.06 [-0.21 to 0.43], p = 0.29), and 24-hour platelets (ß = -0.24 [-0.09 to 0.33], p = 0.17) transfusion requirements. CONCLUSION: The adjunctive use of cryoprecipitate in hemorrhaging trauma patients may reduce mortality without affecting in-hospital complications and transfusion requirements. Further studies are needed to better understand its potentially beneficial effects. LEVEL OF EVIDENCE: Therapeutic, level IV.

A dual-functional Embolization-Visualization System for Fluorescence image-guided Tumor Resection.

Rationale: Intraoperative bleeding impairs physicians' ability to visualize the surgical field, leading to increased risk of surgical complications and reduced outcomes. Bleeding is particularly challenging during endoscopic-assisted surgical resection of hypervascular tumors in the head and neck. A tool that controls bleeding while marking tumor margins has the potential to improve gross tumor resection, reduce surgical morbidity, decrease blood loss, shorten procedure time, prevent damage to surrounding tissues, and limit postoperative pain. Herein, we develop and characterize a new system that combines pre-surgical embolization with improved visualization for endoscopic fluorescence image-guided tumor resection. Methods: Silk-elastinlike protein (SELP) polymers were employed as liquid embolic vehicles for delivery of a clinically used near-infrared dye, indocyanine green (ICG). The biophysical properties of SELP, including gelation kinetics, modulus of elasticity, and viscosity, in response to ICG incorporation using rheology, were characterized. ICG release from embolic SELP was modeled in tissue phantoms and via fluorescence imaging. The embolic capability of the SELP-ICG system was then tested in a microfluidic model of tumor vasculature. Lastly, the cytotoxicity of the SELP-ICG system in L-929 fibroblasts and human umbilical vein endothelial cells (HUVEC) was assessed. Results: ICG incorporation into SELP accelerated gelation and increased its modulus of elasticity. The SELP embolic system released 83 ± 8% of the total ICG within 24 hours, matching clinical practice for pre-surgical embolization procedures. Adding ICG to SELP did not reduce injectability, but did improve the gelation kinetics. After simulated embolization, ICG released from SELP in tissue phantoms diffused a sufficient distance to deliver dye throughout a tumor. ICG-loaded SELP was injectable through a clinical 2.3 Fr microcatheter and demonstrated deep penetration into 50-µm microfluidic-simulated blood vessels with durable occlusion. Incorporation of ICG into SELP improved biocompatibility with HUVECs, but had no effect on L-929 cell viability. Principle Conclusions: We report the development and characterization of a new, dual-functional embolization-visualization system for improving fluorescence-imaged endoscopic surgical resection of hypervascular tumors.

Irisin ameliorates the postoperative depressive-like behavior by reducing the surface expression of epidermal growth factor receptor in mice.

Postoperative depression is a serious problem with under-optimized treatment. Our previous result demonstrated that single dose of propofol exposure in mice could cause depressive-like behavior. In the present study, we explored the possible preventive strategy that could ameliorate the depressive-like behavior in mice. Irisin was used for co-treatment with propofol in mice to test whether irisin could prevent the depressive-like behavior in mice. We found irisin could significantly reduce the immobility time in tail suspension and forced swimming tests in mice with propofol. We also found irisin was able to protect neurons against high concentration propofol treatment induced cell death in cultures. Meanwhile, irisin could significantly inhibit the increase of cytokines in astrocyte cultures exposed to propofol. These in vitro results suggested that interaction between astrocyte and neuron may be involved in the action mechanism that irisin prevented the mice from developing of depressive-like behavior. Last, we revealed that propofol caused increased surface expression of epidermal growth factor receptor (EGFR) but irisin could reduce the expression level of EGFR on cell surface.

DSS-induced colitis produces inflammation-induced bone loss while irisin treatment mitigates the inflammatory state in both gut and bone.

Chronic pediatric inflammatory bowel disease (IBD) leads to lack of bone accrual, bone loss, and increased fractures. Presently there is no cure, and many IBD treatments incur negative side effects. We previously discovered treatment with exogenous irisin resolved inflammatory changes in the colon, gut lymphatics, and bone in a mild IBD rodent model. Here we assess irisin treatment in severe IBD induced via dextran sodium sulfate (DSS). Male Sprague Dawley rats (2-mo-old) were untreated (Con) or given 2% DSS in drinking water. In week two, half of each group (Con + Ir and DSS + Ir) received injections of recombinant irisin (i.p., 2x/wk). After 4 weeks, gut inflammation was associated with declines in bone mineral density and cancellous bone volume. Furthermore, elevated osteocyte TNF-α, interleukin-6, RANKL, OPG, and sclerostin corresponded with higher osteoclast surfaces and lower bone formation rate in DSS animals as well as lower ultimate load. While irisin treatment improved colon inflammation, there were no improvements in bone density or bone mechanical properties; however, irisin elevated bone formation rate, decreased osteoclast surfaces, and reduced osteocyte pro-inflammatory factors. These data highlight the negative impact of chronic gut inflammation on bone as well as the therapeutic potential of irisin as an anti-inflammatory treatment.

Irisin alleviates pulmonary epithelial barrier dysfunction in sepsis-induced acute lung injury via activation of AMPK/SIRT1 pathways.

OBJECTIVE: Alveolar epithelial barrier dysfunction in response to inflammatory reaction contributes to pulmonary edema in acute lung injury(ALI).Irisin,a newly-found myokine,exerts the anti-inflammatory effects. This study aims to investigate the protective effects of irisin on lipopolysaccharide (LPS)-induced ALIin vivo and in vitro, and to explore its underlying mechanism. METHODS: Male SD rats and A549 cells were divided into 4 groups: control group, LPS group, Irisin pretreated group, and Irisin/Compound C(a special inhibitor of AMPK)-treated group. The ALI model was established by intravenous injection of LPS in rats, and LPS challenge in A549 cells. Pulmonary specimens were harvested for microscopic examination of the pathological changes, and the expression of AMPK,SIRT1,NF-κB, p66Shc and caspase-3 in lung tissues. The pulmonary permeability were examined by wet/dry lung weight ratio(W/D) and lung permeability index(LPI). The apoptotic index, and the expression of tumor necrosis factor-α(TNF-α), interleukin-1ß(IL-1ß), monocyte chemoattractant activating protein-1 (MCP-1), tight junctions (occludin,ZO-1) were determined both in lung tissue and A549 cells. RESULTS: Irisin alleviated lung histological changes and decreased pulmonary microvascular permeability in LPS-induced rats. Irisin up-regulated the expression of occludin, ZO-1,AMPK,SIRT1, down-regulated the expression of TNF-α,IL-1ß,MCP-1,NF-κB, p66Shc caspase-3, and decreased the apoptotic index in LPS-induced rats and A549 cells. All these protective effects of irisin could be reversed by Compound C. CONCLUSION: Irisin improved LPS-induced alveolar epithelial barrier dysfunction via suppressing inflammation and apoptosis, and this protective effect might be mediated by activating AMPK/SIRT1 pathways.

Irisin pretreatment ameliorates intestinal ischemia/reperfusion injury in mice through activation of the Nrf2 pathway.

Intestinal ischemia/reperfusion (I/R) injury is a serious clinical event that may induce intestinal mucosal injury, whose major underlying mechanisms include reactive oxygen species (ROS) generation, release of inflammatory mediators and induction of apoptosis. Irisin is considered an agent with potent protection against many pathological injures. The aim of this study was to investigate the protective effect of irisin pretreatment on intestinal injury and explore its underlying mechanisms in a mouse model of intestinal I/R injury as well as a cell model (IEC-6 cell) of hypoxia/reoxygenation (H/R). The results showed that irisin pretreatment ameliorated I/R and H/R-induced injury in vivo and in vitro. In addition, irisin reduced the levels of tumor necrosis factor (TNF)-α, interleukin(IL)-1ß and interleukin(IL)-6 in the intestine. Compared with the I/R group, irisin pretreatment effectively reduced malondialdehyde (MDA) and myeloperoxidase (MPO) levels, but increased superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities in the intestine, and significantly reduced oxidative stress. Furthermore, irisin pretreatment downregulated Bax and cleaved Caspase-3 at the protein level, and increased Bcl-2 protein amounts, significantly reducing apoptosis in the intestine of I/R mice. Moreover, both in vivo and in vitro results showed that irisin pretreatment significantly upregulated nuclear factor (erythroid-derived 2)-like 2 (Nrf2) protein. Meanwhile, Nrf2 siRNA treatment partially abrogated the protective effects of irisin pretreatment on H/R induced cellular damage, inflammatory response, oxidative stress, and apoptosis in IEC-6 cells. These findings suggest that irisin pretreatment improves I/R-induced intestinal inflammatory response, reduces oxidative stress and inhibits apoptosis, which could be, at least partially, associated with Nrf2 pathway activation.

Synthetic α5ß1 integrin ligand PHSRN is proangiogenic and neuroprotective in cerebral ischemic stroke.

Ischemic stroke is the leading cause of disability and death worldwide. An effective therapeutic approach is urgently needed. Stroke-induced angiogenesis and neurogenesis are essential mechanisms in the long-term repair. Extracellular matrix proteins are also involved in tissue self-repair. Recently, a PHSRN (Pro-His-Ser-Arg-Asn) peptide from the fibronectin synergistic motif that can promote wound healing in epithelia and induce endothelial proliferation and cancer cell migration was identified. The therapeutic potential of this peptide in stroke is unknown. Here, we examined the potential of PHSRN in stroke therapy using an ischemic rat model of middle cerebral artery occlusion (MCAO). PHSRN reduced the infarct volume in MCAO rats, improved neurological function, and alleviated motor function impairment. PHSRN targeted the damaged brain region and distributed to endothelial cells after intraperitoneal injection. PHSRN significantly promoted angiogenesis and vascular endothelial growth factor secretion through activation of integrin α5ß1 and its downstream intracellular signals, e.g., focal adhesion kinase, Ras, cRaf, and extracellular-signal-regulated kinase. PHSRN treatment also stimulated neurogenesis in MCAO rats, and maintained neuronal survival and neuronal morphologic complexity via induction of VEGF secretion. Together, these results provide insights into the role of integrin α5ß1 following ischemia and support the feasibility of using PHSRN peptide in stroke therapy.

Irisin Peptide Protects Brain Against Ischemic Injury Through Reducing Apoptosis and Enhancing BDNF in a Rodent Model of Stroke.

Evidence has shown therapeutic potential of irisin in cerebral stroke. The present study aimed to assess the effects of recombinant irisin on the infarct size, neurological outcomes, blood-brain barrier (BBB) permeability, apoptosis and brain-derived neurotrophic factor (BDNF) expression in a mouse model of stroke. Transient focal cerebral ischemia was established by middle cerebral artery occlusion (MCAO) for 45 min and followed reperfusion for 23 h in mice. Recombinant irisin was administrated at doses of 0.1, 0.5, 2.5, 7.5, and 15 µg/kg, intracerebroventricularly (ICV), on the MCAO beginning. Neurological outcomes, infarct size, brain edema and BBB permeability were evaluated by modified neurological severity score (mNSS), 2,3,5-triphenyltetrazolium chloride (TTC) staining and Evans blue (EB) extravasation methods, respectively, at 24 h after ischemia. Apoptotic cells and BDNF protein were detected by TUNEL assay and immunohistochemistry techniques. The levels of Bcl-2, Bax and caspase-3 proteins were measured by immunoblotting technique. ICV irisin administration at doses of 0.5, 2.5, 7.5 and 15 µg/kg, significantly reduced infarct size, whereas only in 7.5 and 15 µg/kg improved neurological outcome (P < 0.001). Treatment with irisin (7.5 µg/kg) reduced brain edema (P < 0.001) without changing BBB permeability (P > 0.05). Additionally, irisin (7.5 µg/kg) significantly diminished apoptotic cells and increased BDNF immunoreactivity in the ischemic brain cortex (P < 0.004). Irisin administration significantly downregulated the Bax and caspase-3 expression and upregulated the Bcl-2 protein. The present study indicated that irisin attenuates brain damage via reducing apoptosis and increasing BDNF protein of brain cortex in the experimental model of stroke in mice.