ADAMTS16 activates latent TGF-β, accentuating fibrosis and dysfunction of the pressure-overloaded heart

Based exploration of the diagnostic value of oxidative stress-related key genes in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) ranks as the third most common contributor to global mortality. Oxidative stress has been recognized as a critical driver of multiple interacting mechanisms in COPD development. This research investigated the potential of oxidative stress-related genes (OSRGs) biomarkers and their potential molecular mechanisms for COPD clinical diagnosis and treatment through bioinformatics analyses. As a result, 5 hub genes, CA3, PPP1R15B, MAPT, MMP9, and ECT2, were yielded by LASSO, Boruta, and SVM-RFE, and the performance of the nomogram constructed based on hub genes was favorable. Correlation analyses between hub genes and oxidative stress biomarkers showed that MMP9 and MAPT genes had a high association with oxidative stress biomarkers. Immune cell infiltration identified follicular helper T cells, Γδ T cells, M0 macrophages, and CD8 T cells as significantly different in COPD. ROC of ECT2 and MMP9 showed a higher capability to discriminate COPD patients from normal samples. In addition, we collected clinical samples and analyzed the core gene expression, which revealed that the hub genes ECT2 and MMP9 had high discriminatory ability in the COPD samples. The epistasis of ECT2 and MMP9 was further verified by constructing animal models, pathological sections, qPCR, immunoblotting, immunohistochemistry, etc. The data indicated the crucial function of MMP9 in CSC-induced oxidative stress injury. Deprivation of MMP9 attenuated CSC-induced injury and promoted macrophage polarisation to M2 macrophages. MMP9 deprivation protected against CSC-induced injury, mainly related to the reduction of cell apoptosis, cell inflammation, and ROS injury in BEAS-2B. It promoted macrophage polarization from M1 to M2. In summary, we found ECT2 and MMP9 are related to oxidative stress in COPD, and MMP9 was related to cell apoptosis, cell inflammation, and ROS injury in BEAS-2B, and the macrophage polarization from M1 to M2.

Progress in the genetics and epigenetics of pelvic floor disorder

Pelvic floor disorder (PFD) is a common gynecological disorder, and with the ageing of the population, PFD has a serious impact on the physical and mental health of patients and their quality of life. The most prominent of these are pelvic organ prolapse (POP) and urinary incontinence (UI), about which the etiology is still unclear, and it is urgent to explore their pathogenesis. Advances in genetics and epigenetics have provided new insights into the pathophysiology of PFD. Candidate genes and genome-wide association studies have identified susceptibility genes for POP and UI. These susceptibility genes typically promote POP by affecting pelvic floor connective tissue. The role of susceptibility genes in UI is multifactorial and includes promoting inflammation, damaging pelvic floor connective tissue, and modulating neurogenic effects. The association of epigenetic changes with POP and UI has also been investigated. DNA methylation studies have identified several important pathways associated with POP. miRNAs play an important role in the development of POP and UI, and this may be an important therapeutic direction for the future. The studies conducted so far have shown that genetic and epigenetic techniques are of great importance in exploring the etiology of PFD and that more in-depth studies are needed in the future.

Cardiac Fibroblasts: Helping or Hurting

Cardiac fibroblasts (CFs) are the essential cell type for heart morphogenesis and homeostasis. In addition to maintaining the structural integrity of the heart tissue, muscle fibroblasts are involved in complex signaling cascades that regulate cardiomyocyte proliferation, migration, and maturation. While CFs serve as the primary source of extracellular matrix proteins (ECM), tissue repair, and paracrine signaling, they are also responsible for adverse pathological changes associated with cardiovascular disease. Following activation, fibroblasts produce excessive ECM components that ultimately lead to fibrosis and cardiac dysfunction. Decades of research have led to a much deeper understanding of the role of CFs in cardiogenesis. Recent studies using the single-cell genomic approach have focused on advancing the role of CFs in cellular interactions, and the mechanistic implications involved during cardiovascular development and disease. Arguably, the unique role of fibroblasts in development, tissue repair, and disease progression categorizes them into the friend or foe category. This brief review summarizes the current understanding of cardiac fibroblast biology and discusses the key findings in the context of development and pathophysiological conditions.

Connexin 43 dephosphorylation mediates the Dchs1/YAP/TEAD signaling pathway to induce cardiac fibrosis

BACKGROUND

The gap junction protein connexin 43 (Cx43) has been implicated in the development of cardiac fibrosis. Our previous findings revealed that Cx43 dephosphorylation at serine 282 (S282) is related to cardiomyocyte apoptosis and arrhythmias in hearts damaged by ischemia/reperfusion. In this study, we investigated the role of Cx43 S282 phosphorylation in cardiac fibrosis.

METHODS

We used angiotensin II (Ang II) intervention in mice to establish an in vivo cardiac fibrosis model and transforming growth factor β-1 (TGF-β1) intervention in cardiac myofibroblasts to establish an in vitro fibrosis model. The expression of Cx43 S282 phosphorylation was examined in the in vivo and in vitro models. To further confirm the effect of Cx43 S282 phosphorylation on cardiac fibrosis, we transfected cardiac myofibroblasts with lentiviral bodies in vitro, and injected myocardium with adenovirus in vivo to establish the over-expression of phosphorylation of Cx43 S282 locus and mutant groups. We sequenced the mRNA of the in vitro group using gene set enrichment analysis (GSEA) and normalized enrichment scoring (NES) to investigate the signaling pathway by which p282-Cx43 affects myocardial fibrosis (MF). The role of the Hippo signaling pathway in phosphorylation at the Cx43 282 site was further validated.

RESULTS

In an in vivo and in vitro model of cardiac fibrosis, the level of phosphorylation of Cx43 S282 was reduced. Mutation of Cx43 S282 to a less phosphorylatable form (S282A) resulted in elevated levels of fibrosis markers, suggesting a critical antifibrotic role for phosphorylated Cx43 S282. Increased phosphorylation of Cx43 S282 produced an inhibitory effect on fibrosis. Enrichment analysis of mRNA sequencing in the mutant model group indicated that the Hippo signaling pathway was involved in the fibrosis process. Cx43 S282 phosphorylation increased the expression of Dchs1 gene, which activates the phosphorylation of yes-associated protein (YAP) and inhibits the YAP/TEAD signaling pathway to inhibit fibrosis development.

CONCLUSIONS

This study suggests that the phosphorylation of Cx43 S282 could be an effective antifibrotic target in cardiac fibroblasts. This indicates a novel mechanism and a molecular target that may hold promise for treating cardiac fibrosis.

miR-207 Suppresses the Progression of SiO2-Induced Pulmonary Fibrosis by Targeting Smad3 to Regulate the TGF-β1/Smad3 Signaling Pathway in C57BL/6 Mice

Silicosis is a worldwide occupational disease characterized by irreversible pulmonary fibrosis. Recent studies have showed that microRNAs (miRNAs) may play a crucial role in silicosis progression by modulating fibrosis-related gene express. In this study, we selected miR-207 as our research subject because we found that miR-207 can be match with Smad3 using bioinformatic techniques, which might silence the key fibrosis-related TGF-β1/Smad3 signal pathway. In this study, the mice were given silica suspension (20 µg/µL, 80 µL) via nostril once a day for 16 days to establish silicosis models, and then were transfected with miR-207 mimic or inhibitor. The mice which were given phosphate-buffered saline (PBS) (80 µL) via nostril were used as control. All mice were killed on Day 45 after the first exposure to dust, after which their lungs were removed for pathological observation and to measure the hydroxyproline content. Then, real-time polymerase chain reaction and Western blot analysis were applied to detect the relative expression levels of TGF-β1/Smad3 signaling pathway indicators (TGF-β1, TGF-βR, and Smad3), and myofibroblast transformation indicators (α-SMA and Fn). Results showed that the lung pathological images of silicosis model group mice showed significant fibrosis, and TGF-β1, TGF-βR, Smad3, α-SMA, and Fn were all highly upregulated compared with the control group mice. Intervention with miR-207 mimics significantly inhibited pulmonary fibrosis in silicosis mice by downregulation of TGF-β1/Smad3 and inhibiting of myofibroblast formation. Whereas these phenomena were not observed in silicosis mice treated with miR-207 inhibitor. The results demonstrated that miR-207 can block the progression of SiO2-induced pulmonary fibrosis by targeting the TGF-β/Smad3 signaling pathway.

The role of the extracellular matrix in cardiac regeneration

The extracellular matrix (ECM) is a complex and dynamic three-dimensional network that functions as an architectural scaffold to maintain cardiac homeostasis. Important biochemical and mechanical signals associated with cell‒cell communication are provided via the reciprocal interaction between cells and the ECM. By converting mechanical cues into biochemical signals, the ECM regulates many cell processes, including migration, adhesion, growth, differentiation, proliferation, and apoptosis. Moreover, the ECM facilitates the replacement of dead cells and preserves the structural integrity of the heart, making it essential in conditions such as myocardial infarction and other pathological states. When excessive ECM deposition or abnormal production of ECM components occurs, the heart undergoes fibrosis, leading to cardiac dysfunction and heart failure. However, emerging evidence suggests that the ECM may contribute to heart regeneration following cardiac injury. The present review offers a complete overview of the existing information and novel discoveries regarding the involvement of the ECM in heart regeneration from both mechanical and biochemical perspectives. Understanding the ECM and its involvement in mechanotransduction holds significant potential for advancing therapeutic approaches in heart repair and regeneration.

Hydrogen decreases susceptibility to AngII-induced atrial fibrillation and atrial fibrosis via the NOX4/ROS/NLRP3 and TGF-β1/Smad2/3 signaling pathways

Atrial fibrillation (AF) represents the commonly occurring cardiac arrhythmia and the main factor leading to stroke and heart failure. Hydrogen (H2) is a gaseous signaling molecule that has the effects of anti-inflammation and antioxidation. Our study provides evidence that hydrogen decreases susceptibility to AngII-mediated AF together with atrial fibrosis. Following continuous AngII administration for a 28-day period, AngII+H2 treated rats showed decreased susceptibility to AF, a decrease in atrial fibrosis, a decrease in ROS in atrial myocytes, an inhibition of NLRP3 inflammasome activation, an improvement in electrical remodeling, and an inhibition of proliferation and migration of cardiac fibroblasts. We further found that hydrogen regulates the activation of inflammasome and thus improves Ca2+ handling and IKAch and IKur by inhibiting the activity of NOX4 in vivo. In addition, hydrogen was involved in AngII-mediated atrial fibrosis through inhibiting TGF-β1/Smad2/3 pathway through suppressing TGF-β1 activation and secretion in vivo. Our findings suggest that hydrogen is important for preventing and treating AngII-mediated AF and atrial fibrosis, suggesting that hydrogen could be used as the candidate way to prevent and treat AF.

Design, synthesis, and biological evaluation of novel 3-naphthylthiophene derivatives as potent SIRT2 inhibitors for the treatment of myocardial fibrosis

SIRT2 (sirtuin2) is a NAD+-dependent deacetylase implicated in fibrosis and inflammation of the liver, kidney, and heart. In this study, we designed and synthesized a series of 3-naphthylthiophene derivatives and evaluated their inhibitory activity against the SIRT2 enzyme. Among them, Z18 demonstrated outstanding SIRT2 inhibitory activity and selectivity. It significantly inhibited both the proliferation of cardiac fibroblasts (CFs) and the activity and expression of SIRT2 in CFs. Moreover, compound Z18 effectively suppressed TGF-β1-induced increases in α-SMA and CoL-1A1 protein expression, as well as hydroxyproline levels. Pharmacological mechanism tests demonstrated that Z18 inhibited SIRT2, thereby suppressing the TGF-β1-induced autocrine production of TGF-β1 and the phosphorylation of Smad2/3 in CFs. In MTT assays, Z18 exhibited a significant inhibitory effect on the proliferation of CFs induced by TGF-β1. In vivo, Z18 effectively ameliorated TAC- and ISO-induced declines in cardiac function, histopathological morphological changes, and collagen deposition. It also inhibited SIRT2 activity and reduced the expression of α-SMA and p-Smad2/3. In hepatorenal toxicity assays, Z18 exhibited an excellent safety profile. These results support the further development of the selective SIRT2 inhibitor Z18 as a potential lead compound for the treatment of myocardial fibrosis.

Myocardial fibrosis from the perspective of the extracellular matrix: Mechanisms to clinical impact

Fibrosis is defined by the excessive accumulation of extracellular matrix (ECM) and constitutes a central pathophysiological process that underlies tissue dysfunction, across organs, in multiple chronic diseases and during aging. Myocardial fibrosis is a key contributor to dysfunction and failure in numerous diseases of the heart and is a strong predictor of poor clinical outcome and mortality. The excess structural and matricellular ECM proteins deposited by cardiac fibroblasts, is found between cardiomyocytes (interstitial fibrosis), in focal areas where cardiomyocytes have died (replacement fibrosis), and around vessels (perivascular fibrosis). Although myocardial fibrosis has important clinical prognostic value, access to cardiac tissue biopsies for histological evaluation is limited. Despite challenges with sensitivity and specificity, cardiac magnetic resonance imaging (CMR) is the most applicable diagnostic tool in the clinic, and the scientific community is currently actively searching for blood biomarkers reflecting myocardial fibrosis, to complement the imaging techniques. The lack of mechanistic insights into specific pro- and anti-fibrotic molecular pathways has hampered the development of effective treatments to prevent or reverse myocardial fibrosis. Development and implementation of anti-fibrotic therapies is expected to improve patient outcomes and is an urgent medical need. Here, we discuss the importance of the ECM in the heart, the central role of fibrosis in heart disease, and mechanistic pathways likely to impact clinical practice with regards to diagnostics of myocardial fibrosis, risk stratification of patients, and anti-fibrotic therapy.

Discovery and preclinical evaluation of BPB-101: a novel triple functional bispecific antibody targeting GARP-TGF-β complex/SLC, free TGF-β and PD-L1

Background

In the tumor microenvironment (TME), the transforming growth factor-β (TGF-β) and programmed cell death receptor 1 (PD-1)/programmed death ligand 1 (PD-L1) signaling axes are complementary, nonredundant immunosuppressive signaling pathways. Studies have revealed that active TGF-β is mainly released from the glycoprotein A repetitions predominant (GARP)-TGF-β complex on the surface of activated regulatory T cells (Tregs), B cells, natural killer (NK) cells, and tumor cells. The currently available antibodies or fusion proteins that target TGF-β are limited in their abilities to simultaneously block TGF-β release and neutralize active TGF-β in the TME, thus limiting their antitumor effects.

Methods

We designed and constructed a bispecific, trifunctional antibody, namely, BPB-101, that specifically targets the GARP-TGF-β complex and/or small latent complex (SLC), active TGF-β, and PD-L1. The binding ability of BPB-101 to the different antigens was determined by ELISA, FACS, and biolayer interferometry (BLI). The blocking ability of BPB-101 to the TGF-β and PD-1/PD-L1 signaling axes was determined by reporter gene assay (RGA). The antitumor effect and biosafety of BPB-101 were determined in a transgenic mouse tumor model and cynomolgus monkeys, respectively. Stability assessments, including stability in serum, after exposure to light, after repeated freeze-thaw cycles, and after high-temperature stress tests had been completed to evaluate the stability of BPB-101.

Results

BPB-101 bound efficiently to different antigenic proteins: the GARP-TGF-β complex and/or SLC, active TGF-β, and PD-L1. Data showed that BPB-101 not only effectively inhibited the release of TGF-β from human Tregs, but also blocked both the TGF-β and PD-1/PD-L1 signaling pathways. In an MC38-hPD-L1 tumor-bearing C57BL/6-hGARP mouse model, BPB-101 at a dose of 5 mg/kg significantly inhibited tumor growth, with a complete elimination rate of 50%. Stability assessments confirmed the robustness of BPB-101. Furthermore, BPB-101 showed a favorable safety profile in nonhuman primate (NHP) toxicity studies.

Conclusion

BPB-101 is a potentially promising therapeutic candidate that may address unmet clinical needs in cancer immunotherapy, thus, BPB-101 warrants further clinical investigation.

ADAMTS16 drives epithelial-mesenchymal transition and metastasis through a feedback loop upon TGF-β1 activation in lung adenocarcinoma

Lung adenocarcinoma (LUAD) is the major subtype of lung cancer. The poor prognosis of LUAD patients is attributed primarily to metastasis. ADAMTS16 is a crucial member of the ADAMTS family and is involved in tumor progression. However, its role and regulatory mechanism in LUAD remain unexplored. In this study, ADAMTS16 was identified as a crucial oncogene and survival predictor in LUAD via analyses of public datasets. Clinical specimens and tissue microarrays confirmed the differential expression and prognostic value of ADAMTS16 in LUAD patients. Transcriptome data and in vitro experiments demonstrated that ADAMTS16 was positively associated with epithelial-mesenchymal transition (EMT) and the migration abilities of LUAD cells. Knockdown of ADAMTS16 attenuated lung and pleural metastasis in an animal model. Mechanistically, the results of the enzyme-linked immunosorbent assay (ELISA) and western blot (WB) suggested that ADAMTS16 activated the TGF-β signaling pathway by facilitating the conversion of LAP-TGF-β1 to active TGF-β1. Co-Immunoprecipitation (co-IP) indicated an interaction between ADAMTS16 and LAP-TGF-β1. Inhibition of ADAMTS16 impaired EMT and aggressiveness of LUAD cells, while treatment with recombinant TGF-β1 reversed this inhibition. Chromatin immunoprecipitation (ChIP) and dual-luciferase reporter assays indicated that SOX4 acted as a transcriptional activator of ADAMTS16 and that TGF-β1 regulated the expression of ADAMTS16 by increasing the binding of SOX4 to the promoter of ADAMTS16. Suppressing the TGF-β signaling pathway inhibited ADAMTS16 expression, EMT, and lung metastasis, whereas overexpressing SOX4 reversed this inhibition. Therefore, ADAMTS16 forms a positive feedback loop with the TGF-β1/SOX4 axis to regulate EMT and metastasis, and disruption of this feedback loop inhibits tumor progression. These findings underscore the potential of ADAMTS16 as a prognostic biomarker and therapeutic target in LUAD and offer novel insight into the mechanism of EMT and metastasis.

Adamts9 is required for the development of primary ovarian follicles and maintenance of female sex in zebrafish†

Previous studies have suggested that adamts9 (a disintegrin and metalloprotease with thrombospondin type-1 motifs, member 9), an extracellular matrix (ECM) metalloprotease, participates in primordial germ cell (PGC) migration and is necessary for female fertility. In this study, we found that adamts9 knockout (KO) led to reduced body size, and female-to-male sex conversion in late juvenile or adult zebrafish; however, primary sex determination was not affected in early juveniles of adamts9 KO. Overfeeding and lowering the rearing density rescued growth defects in female adamts9 KO fish but did not rescue defects in ovarian development in adamts9 KO. Delayed PGC proliferation, significantly reduced number and size of Stage IB follicles (equivalent to primary follicles) in early juveniles of adamts9 KO, and arrested development at Stage IB follicles in mid- or late-juveniles of adamts9 KO are likely causes of female infertility and sex conversion. Via RNAseq, we found significant enrichment of differentially expressed genes involved in ECM organization during sexual maturation in ovaries of wildtype fish; and significant dysregulation of these genes in adamts9 KO ovaries. RNAseq analysis also showed enrichment of inflammatory transcriptomic signatures in adult ovaries of these adamts9 KO. Taken together, our results indicate that adamts9 is critical for development of primary ovarian follicles and maintenance of female sex, and loss of adamts9 leads to defects in ovarian follicle development, female infertility, and sex conversion in late juveniles and mature adults. These results show that the ECM and extracellular metalloproteases play major roles in maintaining ovarian follicle development in zebrafish.

A novel role of ADAMTS16 in renal fibrosis through activating TGF-β/Smad signaling

Chronic Kidney Disease (CKD) has emerged as a global public health concern, with its primary pathological basis being Renal Fibrosis (RF), crucial to halt its progression to End-Stage Renal Disease (ESRD). However, effective treatment options are currently lacking. Therefore, exploring the mechanisms of RF, identifying drug targets and diagnostic biomarkers are important. In this study, we identified ADAMTS16 as a newly expressed regulatory factor highly expressed in renal fibrosis tissue. ADAMTS16 interacts with latency-associated peptide (LAP)-transforming growth factor (TGF)-β, leading to the activation of TGF-β. Loss of ADAMTS16 expression effectively reduces TGF-β-dependent transcription activity. Furthermore, the use of RRFR tetrapeptide derived from ADAMTS16 can activate the TGF-β/Smad signaling axis, promoting RF. In summary, ADAMTS16 is induced in the progression of CKD, interacting with LAP-TGF-β and potentially activating SMAD2/3. Therefore, targeting ADAMTS16 may serve as a crucial new strategy to alleviate RF and treat CKD patients.

Mechanism Actions of Coniferyl Alcohol in Improving Cardiac Dysfunction in Renovascular Hypertension Studied by Experimental Verification and Network Pharmacology

Renovascular hypertension (RH), a secondary hypertension, can significantly impact heart health, resulting in heart damage and dysfunction, thereby elevating the risk of cardiovascular diseases. Coniferol (CA), which has vascular relaxation properties, is expected to be able to treat hypertension-related diseases. However, its potential effects on cardiac function after RH remain unclear. In this study, in combination with network pharmacology, the antihypertensive and cardioprotective effects of CA in a two-kidney, one-clip (2K1C) mice model and its ability to mitigate angiotensin II (Ang II)-induced hypertrophy in H9C2 cells were investigated. The findings revealed that CA effectively reduced blood pressure, myocardial tissue damage, and inflammation after RH. The possible targets of CA for RH treatment were screened by network pharmacology. The interleukin-17 (IL-17) and tumor necrosis factor (TNF) signaling pathways were identified using a Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. The inflammatory response was identified using a Gene Ontology (GO) enrichment analysis. Western blot analysis confirmed that CA reduced the expression of IL-17, matrix metallopeptidase 9 (MMP9), cyclooxygenase 2 (COX2), and TNF α in heart tissues and the H9C2 cells. In summary, CA inhibited cardiac inflammation and fibrohypertrophy following RH. This effect was closely linked to the expression of MMP9/COX2/TNF α/IL-17. This study sheds light on the therapeutic potential of CA for treating RH-induced myocardial hypertrophy and provides insights into its underlying mechanisms, positioning CA as a promising candidate for future drug development.

Biological Age, Chronological Age, and Survival in Pulmonary Fibrosis: A Causal Mediation Analysis

Rationale: Accelerated biological aging has been implicated in the development of interstitial lung disease (ILD) and other diseases of aging but remains poorly understood. Objectives: To identify plasma proteins that mediate the relationship between chronological age and survival association in patients with ILD. Methods: Causal mediation analysis was performed to identify plasma proteins that mediated the chronological age-survival relationship in an idiopathic pulmonary fibrosis discovery cohort. Proteins mediating this relationship after adjustment for false discovery were advanced for testing in an independent ILD validation cohort and explored in a chronic obstructive pulmonary disease cohort. A proteomic-based measure of biological age was constructed and survival analysis performed, assessing the impact of biological age and peripheral blood telomere length on the chronological age-survival relationship. Measurements and Main Results: Twenty-two proteins mediated the chronological age-survival relationship after adjustment for false discovery in the idiopathic pulmonary fibrosis discovery cohort (n = 874), with 19 remaining significant mediators of this relationship in the ILD validation cohort (n = 983) and one mediating this relationship in the chronic obstructive pulmonary disease cohort. Latent transforming growth factor-β binding protein 2 and ectodysplasin A2 receptor showed the strongest mediation across cohorts. A proteomic measure of biological age completely attenuated the chronological age-survival association and better discriminated survival than chronological age. Results were robust to adjustment for peripheral blood telomere length, which did not mediate the chronological age-survival relationship. Conclusions: Molecular measures of aging completely mediate the relationship between chronological age and survival, suggesting that chronological age has no direct effect on ILD survival.

TGF-β signaling: critical nexus of fibrogenesis and cancer

The transforming growth factor-beta (TGF-β) signaling pathway is a vital regulator of cell proliferation, differentiation, apoptosis, and extracellular matrix production. It functions through canonical SMAD-mediated processes and noncanonical pathways involving MAPK cascades, PI3K/AKT, Rho-like GTPases, and NF-κB signaling. This intricate signaling system is finely tuned by interactions between canonical and noncanonical pathways and plays key roles in both physiologic and pathologic conditions including tissue homeostasis, fibrosis, and cancer progression. TGF-β signaling is known to have paradoxical actions. Under normal physiologic conditions, TGF-β signaling promotes cell quiescence and apoptosis, acting as a tumor suppressor. In contrast, in pathological states such as inflammation and cancer, it triggers processes that facilitate cancer progression and tissue remodeling, thus promoting tumor development and fibrosis. Here, we detail the role that TGF-β plays in cancer and fibrosis and highlight the potential for future theranostics targeting this pathway.

Unraveling the Cardiac Matrix: From Diabetes to Heart Failure, Exploring Pathways and Potential Medications

Myocardial infarction (MI) often leads to heart failure (HF) through acute or chronic maladaptive remodeling processes. This establishes coronary artery disease (CAD) and HF as significant contributors to cardiovascular illness and death. Therefore, treatment strategies for patients with CAD primarily focus on preventing MI and lessening the impact of HF after an MI event. Myocardial fibrosis, characterized by abnormal extracellular matrix (ECM) deposition, is central to cardiac remodeling. Understanding these processes is key to identifying new treatment targets. Recent studies highlight SGLT2 inhibitors (SGLT2i) and GLP-1 receptor agonists (GLP1-RAs) as favorable options in managing type 2 diabetes due to their low hypoglycemic risk and cardiovascular benefits. This review explores inflammation's role in cardiac fibrosis and evaluates emerging anti-diabetic medications' effectiveness, such as SGLT2i, GLP1-RAs, and dipeptidyl peptidase-4 inhibitors (DPP4i), in preventing fibrosis in patients with diabetes post-acute MI. Recent studies were analyzed to identify effective medications in reducing fibrosis risk in these patients. By addressing these areas, we can advance our understanding of the potential benefits of anti-diabetic medications in reducing cardiac fibrosis post-MI and improve patient outcomes in individuals with diabetes at risk of HF.

MicroRNA-19a-3p augments TGF-β1-induced cardiac fibroblast activation via targeting BAMBI

The main pathogenic factor leading to cardiac remodeling and heart failure is myocardial fibrosis. Recent research indicates that microRNAs are essential for the progress of cardiac fibrosis. Myocardial fibrosis is considered to be alleviated through the bone morphogenetic protein and activin membrane-bound inhibitor (BAMBI), which does this by blocking the transforming growth factor β1 (TGF-β1) signaling pathway. Here, this study sought to elucidate the post-transcriptional regulation of miR-19a-3p on BAMBI and its role in TGF-β1-induced cardiac fibroblast activation. Transverse aortic constriction (TAC) caused both myocardial interstitial and perivascular collagen deposition. RT-PCR showed that miR-19a-3p was upregulated in the myocardial tissue of cardiac fibrosis, and TGF-β1 induced an increase of miR-19a-3p expression in cardiac fibroblasts. The dual-luciferase reporter test and qRT-PCR confirmed that miR-19a-3p directly combined with BAMBI mRNA 3'UTR, thus reduced BAMBI expression, which diminished the capability of BAMBI to inhibit TGF-β1. Furthermore, miR-19a-3p mimic increased the activation of TGF-β1/SMAD2/3 pathway signaling, which supported cardiac fibroblast activation, which blocked by overexpression of BAMBI. These findings imply that miR-19a-3p enhances the activation of TGF-β1/SMAD2/3 by inhibiting BAMBI, further boosting the activation of cardiac fibroblasts, and may thus offer a novel strategy to tackling myocardial fibrosis.

Differences in Cardiometabolic Proteins in Pregnancy Prioritize Relevant Targets of Preeclampsia

BACKGROUND

Preeclampsia is a hypertensive disorder of pregnancy characterized by widespread vascular inflammation. It occurs frequently in pregnancy, often without known risk factors, and has high rates of maternal and fetal morbidity and mortality. Identification of biomarkers that predict preeclampsia and its cardiovascular sequelae before clinical onset, or even before pregnancy, is a critical unmet need for the prevention of adverse pregnancy outcomes.

METHODS

We explored differences in cardiovascular proteomics (Olink Explore 384) in 256 diverse pregnant persons across 2 centers (26% Hispanic, 21% Black).

RESULTS

We identified significant differences in plasma abundance of markers associated with angiogenesis, blood pressure, cell adhesion, inflammation, and metabolism between individuals delivering with preeclampsia and controls, some of which have not been widely described previously and are not represented in the preeclampsia placental transcriptome. While we observed a broadly similar pattern in early (<34 weeks) versus late (≥34 weeks) preeclampsia, several proteins related to hemodynamic stress, hemostasis, and immune response appeared to be more highly dysregulated in early preeclampsia relative to late preeclampsia.

CONCLUSIONS

These results demonstrate the value of performing targeted proteomics using a panel of cardiovascular biomarkers to identify biomarkers relevant to preeclampsia pathophysiology and highlight the need for larger multiomic studies to define modifiable pathways of surveillance and intervention upstream to preeclampsia diagnosis.

DUSP22 Ameliorates Endothelial-to-Mesenchymal Transition in HUVECs through Smad2/3 and MAPK Signaling Pathways

Endothelial-to-mesenchymal transition (EndMT) is the process by which endothelial cells lose their endothelial properties and acquire mesenchymal characteristics. Dual-specific protein phosphatase 22 (DUSP22) inactivates various protein kinases and transcription factors by dephosphorylating serine/threonine residues: hence, it plays a key role in many diseases. The aim of this study was to explore the functional role of DUSP22 in EndMT. In the transforming growth factor-β-induced EndMT model in human umbilical vein endothelial cells (HUVECs), we observed a downregulation of DUSP22 expression. This DUSP22 deficiency could aggravate EndMT. Conversely, the overexpression of DUSP22 could ameliorate EndMT. We used signaling pathway inhibitors to verify our results and found that DUSP22 could regulate EndMT through the smad2/3 and the mitogen-activated protein kinase (MAPK) signaling pathways. In summary, DUSP22 ameliorates EndMT in HUVECs in vitro through the smad2/3 and MAPK signaling pathways.

Role of platelet factor 4 in arteriovenous fistula maturation failure: What do we know so far?

The rate of arteriovenous fistula (AVF) maturation failure remains unacceptably high despite continuous efforts on technique improvement and careful pre-surgery planning. In fact, half of all newly created AVFs are unable to be used for hemodialysis (HD) without a salvage procedure. While vascular stenosis in the venous limb of the access is the culprit, the underlying factors leading to vascular narrowing and AVF maturation failure are yet to be determined. We have recently demonstrated that AVF non-maturation is associated with post-operative medial fibrosis and fibrotic stenosis, and post-operative intimal hyperplasia (IH) exacerbates the situation. Multiple pathological processes and signaling pathways are underlying the stenotic remodeling of the AVF. Our group has recently indicated that a pro-inflammatory cytokine platelet factor 4 (PF4/CXCL4) is upregulated in veins that fail to mature after AVF creation. Platelet factor 4 is a fibrosis marker and can be detected in vascular stenosis tissue, suggesting that it may contribute to AVF maturation failure through stimulation of fibrosis and development of fibrotic stenosis. Here, we present an overview of the how PF4-mediated fibrosis determines AVF maturation failure.

Emerging roles for the ADAMTS-like family of matricellular proteins in cardiovascular disease through regulation of the extracellular microenvironment

Dysregulation of the extracellular matrix (ECM) occurs widely across cardiovascular pathologies. Recent work has revealed important roles for the «a disintegrin-like and metalloprotease domain with thrombospondin-type 1 motifs like" (ADAMTSL) family of secreted glycoproteins in cardiovascular tissues during development and disease. Key insights in this regard have come from naturally occurring gene mutations in humans and animals that result in severe diseases with cardiovascular manifestations or aortopathies. Expression of ADAMTSL genes is greatly increased in the myocardium during heart failure. Genetically modified mice recapitulate phenotypes of patients with ADAMTSL mutations and demonstrate important functions in the ECM. The novel functions thus disclosed are intriguing because, while these proteins are neither structural, nor proteases like the related ADAMTS proteases, they appear to act as regulatory, i.e., matricellular proteins. Evidence from genetic variants, genetically engineered mouse mutants, and in vitro investigations have revealed regulatory functions of ADAMTSLs related to fibrillin microfibrils and growth factor signaling. Interestingly, the ability to regulate transforming growth factor (TGF)β signaling may be a shared characteristic of some ADAMTSLs. TGFβ signaling is important in cardiovascular development, health and disease and a central driver of ECM remodeling and cardiac fibrosis. New strategies to target dysregulated TGFβ signaling are warranted in aortopathies and cardiac fibrosis. With their emerging roles in cardiovascular tissues, the ADAMTSL proteins may provide causative genes, diagnostic biomarkers and novel treatment targets in cardiovascular disease. Here, we discuss the relevance of ADAMTSLs to cardiovascular medicine.

Genome-Wide Analysis of DNA Methylation in Pseudomyxoma Peritonei Originated from Appendiceal Neoplasms

INTRODUCTION

Pseudomyxoma peritonei (PMP) is a disease characterized by progressive accumulation of intraperitoneal mucinous ascites produced by neoplasms in the abdominal cavity. Since the prognosis of patients with PMP remains unsatisfactory, the development of effective therapeutic drug(s) is a matter of pressing concern. Genetic analyses of PMP have clarified the frequent activation of GNAS and/or KRAS. However, the involvement of global epigenetic alterations in PMPs has not been reported.

METHODS

To clarify the genetic background of the 15 PMP tumors, we performed genetic analysis using AmpliSeq Cancer HotSpot Panel v2. We further investigated global DNA methylation in the 15 tumors and eight noncancerous colonic epithelial tissues using MethylationEPIC array BeadChip (Infinium 850k) containing a total of 865,918 probes.

RESULTS

This is the first report of comprehensive DNA methylation profiles of PMPs in the world. We clarified that the 15 PMPs could be classified into at least two epigenotypes, unique methylation epigenotype (UME) and normal-like methylation epigenotype (NLME), and that genes associated with neuronal development and synaptic signaling may be involved in the development of PMPs. In addition, we identified a set of hypermethylation marker genes such as HOXD1 and TSPYL5 in the 15 PMPs.

CONCLUSIONS

These findings may help the understanding of the molecular mechanism(s) of PMP and contribute to the development of therapeutic strategies for this life-threatening disease.

The Role of Pro-Inflammatory Cytokines in the Pathogenesis of Cardiovascular Disease

With cardiovascular disease (CVD) being a primary source of global morbidity and mortality, it is crucial that we understand the molecular pathophysiological mechanisms at play. Recently, numerous pro-inflammatory cytokines have been linked to several different CVDs, which are now often considered an adversely pro-inflammatory state. These cytokines most notably include interleukin-6 (IL-6),tumor necrosis factor (TNF)α, and the interleukin-1 (IL-1) family, amongst others. Not only does inflammation have intricate and complex interactions with pathophysiological processes such as oxidative stress and calcium mishandling, but it also plays a role in the balance between tissue repair and destruction. In this regard, pre-clinical and clinical evidence has clearly demonstrated the involvement and dynamic nature of pro-inflammatory cytokines in many heart conditions; however, the clinical utility of the findings so far remains unclear. Whether these cytokines can serve as markers or risk predictors of disease states or act as potential therapeutic targets, further extensive research is needed to fully understand the complex network of interactions that these molecules encompass in the context of heart disease. This review will highlight the significant advances in our understanding of the contributions of pro-inflammatory cytokines in CVDs, including ischemic heart disease (atherosclerosis, thrombosis, acute myocardial infarction, and ischemia-reperfusion injury), cardiac remodeling (hypertension, cardiac hypertrophy, cardiac fibrosis, cardiac apoptosis, and heart failure), different cardiomyopathies as well as ventricular arrhythmias and atrial fibrillation. In addition, this article is focused on discussing the shortcomings in both pathological and therapeutic aspects of pro-inflammatory cytokines in CVD that still need to be addressed by future studies.

Downregulation of B4GALT5 attenuates cardiac fibrosis through Lumican and Akt/GSK-3β/β-catenin pathway

Virtually all forms of cardiac disease exhibit cardiac fibrosis as a common trait, which ultimately leads to adverse ventricular remodeling and heart failure. To improve the prognosis of heart disease, it is crucial to halt the progression of cardiac fibrosis. Protein function is intricately linked with protein glycosylation, a vital post-translational modification. As a fundamental member of the β1,4-galactosyltransferase gene family (B4GALT), β1,4-galactosyltransferase V (B4GALT5) is associated with various disorders. In this study, significant levels of B4GALT5 expression were observed in cardiac fibrosis induced by transverse aortic constriction (TAC) or TGFβ1 and the activation of cardiac fibroblasts (CFs). Subsequently, by administering AAV9-shB4GALT5 injections to TAC animals, we were able to demonstrate that in vivo B4GALT5 knockdown decreased the transformation of CFs into myofibroblasts (myoFBs) and reduced the deposition of cardiac collagen fibers. In vitro tests revealed the same results. Conversely, both in vivo and in vitro experiments indicated that overexpression of B4GALT5 stimulates CFs activation and exacerbates cardiac fibrosis. Initially, we elucidated the primary mechanism by which B4GALT5 regulates the Akt/GSK-3β/β-catenin pathway and directly interacts with laminin, thereby affecting cardiac fibrosis. Our findings demonstrate that B4GALT5 promotes cardiac fibrosis through the Akt/GSK-3β/β-catenin pathway and reveal laminin as the target protein of B4GALT5.

ADAMTS Proteases: Their Multifaceted Role in the Regulation of Cancer Metastasis

Cancer leads to nearly 10 million deaths worldwide per year. The tumour microenvironment (TME) is fundamental for tumour growth and progression. A key component of the TME, the extracellular matrix (ECM) has recently become a focus of interest in cancer research. Dysregulation of ECM synthesis and proteolysis leads to uncontrolled tumour growth and metastasis. Matrix remodelling enzymes, secreted by cancer cells and stromal cells, modify the overall structure and organisation of ECM proteins, therefore influencing biochemical interactions, tissue integrity and tissue turnover. While A Disintegrin and Metalloproteinases (ADAMs)' and matrix metalloproteinases' role in cancer has been deeply investigated, other proteolytic enzymes, like ADAMs with thrombospondin(-like) motifs (ADAMTSs) have been gaining interest due to their roles in modulating cancer cell-ECM interactions and oncogenic signalling pathways. In this review, we will discuss the dysregulation of ADAMTSs in cancer and their roles in regulating cancer development and progression, via ECM remodelling and cell signalling modulation.

Mesenchymal stem cell-derived exosomes in myocardial infarction: Therapeutic potential and application

Myocardial infarction refers to the irreversible impairment of cardiac function resulting from the permanent loss of numerous cardiomyocytes and the formation of scar tissue. This condition is caused by acute and persistent inadequate blood supply to the heart's arteries. In the treatment of myocardial infarction, Mesenchymal stem cells (MSCs) play a crucial role because of their powerful therapeutic effects. These effects primarily stem from the paracrine secretion of multiple factors by MSCs, with exosome-carried microRNAs being the most effective component in promoting cardiac function recovery after infarction. Exosome therapy has emerged as a promising cell-free treatment for myocardial infarction as a result of its relatively simple composition, low immunogenicity and controlled transplantation dose. Despite these advantages, maintaining the stability of exosomes after transplantation and enhancing their targeting effect remain significant challenges in clinical applications. In recent developments, several approaches have been designed to optimize exosome therapy. These include enhancing exosome retention, improving their ability to target specific effects, pretreating MSC-derived exosomes and employing transgenic MSC-derived exosomes. This review primarily focuses on describing the biological characteristics of exosomes, their therapeutic potential and their application in treating myocardial infarction.

TGF-β as a therapeutic target in the infarcted and failing heart: cellular mechanisms, challenges, and opportunities

INTRODUCTION

Myocardial fibrosis accompanies most cardiac conditions and can be reparative or maladaptive. Transforming Growth Factor (TGF)-β is a potent fibrogenic mediator, involved in repair, remodeling, and fibrosis of the injured heart.

AREAS COVERED

This review manuscript discusses the role of TGF-β in heart failure focusing on cellular mechanisms and therapeutic implications. TGF-β is activated in infarcted, remodeling and failing hearts. In addition to its fibrogenic actions, TGF-β has a broad range of effects on cardiomyocytes, immune, and vascular cells that may have both protective and detrimental consequences. TGF-β-mediated effects on macrophages promote anti-inflammatory transition, whereas actions on fibroblasts mediate reparative scar formation and effects on pericytes are involved in maturation of infarct neovessels. On the other hand, TGF-β actions on cardiomyocytes promote adverse remodeling, and prolonged activation of TGF-β signaling in fibroblasts stimulates progression of fibrosis and heart failure.

EXPERT OPINION

Understanding of the cell-specific actions of TGF-β is necessary to design therapeutic strategies in patients with myocardial disease. Moreover, to implement therapeutic interventions in the heterogeneous population of heart failure patients, mechanism-driven classification of both HFrEF and HFpEF patients is needed. Heart failure patients with prolonged or overactive fibrogenic TGF-β responses may benefit from cautious TGF-β inhibition.

[18 F] -FAPI-42 PET/CT assessment of Progressive right ventricle fibrosis under pressure overload

BACKGROUND

Right heart failure (RHF) is a complication of pulmonary hypertension (PH) and increases the mortality independently of the underlying disease. However, the process of RHF development and progression is not fully understood. We aimed to develop effective approaches for early diagnosis and precise evaluation of RHF.

METHODS

Right ventricle (RV) pressure overload was performed via pulmonary artery banding (PAB) surgery in Sprague-Dawley (SD) rats to induce RHF. Echocardiography, right heart catheterization, histological staining, fibroblast activation protein (FAP) immunofluorescence and 18 F-labelled FAP inhibitor-42 ([18 F] -FAPI-42) positron emission tomography/computed tomography (PET/CT) were performed at day 3, week 1, 2, 4 and 8 after PAB. RNA sequencing was performed to explore molecular alterations between PAB and sham group at week 2 and week 4 after PAB respectively.

RESULTS

RV hemodynamic disorders were aggravated, and RV function was declined based on right heart catheterization and echocardiography at week 2, 4 and 8 after PAB. Progressive cardiac hypertrophy, fibrosis and capillary rarefaction could be observed in RV from 2 to 8 weeks after PAB. RNA sequencing indicated 80 upregulated genes and 43 downregulated genes in the RV at both week 2 and week 4 after PAB; Gene Ontology (GO) analysis revealed that fibrosis as the most significant biological process in the RV under pressure overload. Immunofluorescence indicated that FAP was upregulated in the RV from week 2 to week 8 after PAB; and [18 F] -FAPI-42 PET/CT revealed FAPI uptake was significantly higher in RV at week 2 and further increased at week 4 and 8 after PAB.

CONCLUSION

RV function is progressively declined with fibrosis as the most prominent molecular change after pressure overload, and [18 F] -FAPI-42 PET/CT is as sensitive and accurate as histopathology in RV fibrosis evaluation.

WTAP boosts lipid oxidation and induces diabetic cardiac fibrosis by enhancing AR methylation

Dysregulated lipid metabolism occurs in pathological processes characterized by cell proliferation and migration. Nonetheless, the mechanism of increased mitochondrial lipid oxidation is poorly appreciated in diabetic cardiac fibrosis, which is accompanied by enhanced fibroblast proliferation and migration. Herein, increased WTAP expression promotes cardiac fibroblast proliferation and migration, contributing to diabetic cardiac fibrosis. Knockdown of WTAP suppresses mitochondrial lipid oxidation, fibroblast proliferation and migration to ameliorate diabetic cardiac fibrosis. Mechanistically, WTAP-mediated m6A methylation of AR induced its degradation, dependent on YTHDF2. Additionally, AR directly interacts with mitochondrial lipid oxidation enzyme Decr1; overexpression of AR-suppressed Decr1-mediates mitochondrial lipid oxidation, inhibiting cardiac fibroblast proliferation and migration. Knockdown of AR produced the opposite effect. Clinically, increased WTAP and YTHDF2 levels correlate with decreased AR expression in human DCM heart tissue. We describe a mechanism wherein WTAP boosts higher mitochondrial lipid oxidation, cardiac fibroblast proliferation, and migration by enhancing AR methylation in a YTHDF2-dependent manner.

Myocardial Fibrosis in Hypertrophic Cardiomyopathy: A Perspective from Fibroblasts

Hypertrophic cardiomyopathy (HCM) is the most common inherited heart disease and the leading cause of sudden cardiac death in young people. Mutations in genes that encode structural proteins of the cardiac sarcomere are the more frequent genetic cause of HCM. The disease is characterized by cardiomyocyte hypertrophy and myocardial fibrosis, which is defined as the excessive deposition of extracellular matrix proteins, mainly collagen I and III, in the myocardium. The development of fibrotic tissue in the heart adversely affects cardiac function. In this review, we discuss the latest evidence on how cardiac fibrosis is promoted, the role of cardiac fibroblasts, their interaction with cardiomyocytes, and their activation via the TGF-β pathway, the primary intracellular signalling pathway regulating extracellular matrix turnover. Finally, we summarize new findings on profibrotic genes as well as genetic and non-genetic factors involved in the pathophysiology of HCM.

Isoliensinine Attenuates Renal Fibrosis and Inhibits TGF-β1/Smad2/3 Signaling Pathway in Spontaneously Hypertensive Rats

Purpose

This study aimed to investigate the molecular mechanisms of isoliensinine, a kind of bibenzyl isoquinoline alkaloid which isolated from a TCM named Lotus Plumule (Nelumbo nucifera Gaertn), in treating renal interstitial fibrosis (RIF) by using RNA sequencing, KEGG analysis and in vivo experimental approaches.

Methods

Spontaneous hypertension rats (SHRs) were randomly assigned into five groups, consisting of SHR, SHR+Isoliensinine-L (2.5 mg/kg/day), SHR+Isoliensinine-M (5 mg/kg/day), SHR+Isoliensinine-H (10 mg/kg/day), and SHR+Valsartan (10 mg/kg/day) groups (n = 6 for each group). A control group of Wistar Kyoto rats (n = 6) was also included. Rats were treated intragastrically with isoliensinine, valsartan, or double-distilled water of equal volume for 10 weeks. To examine the therapeutic impact on hypertensive renal injury, fibrosis, and its underlying mechanisms, multiple techniques were employed, including hematoxylin and eosin staining, Masson trichrome staining, RNA sequencing, gene ontology (GO) function and pathway enrichment analysis and immunohistochemistry.

Results

Resultantly, the use of isoliensinine at different concentrations or valsartan showed significant improvement in renal pathological injury in SHRs. RNA sequencing and KEGG analysis uncovered 583 differentially expressed transcripts and pathways enriched in collagen formation and ECM-receptor interaction after treatment with isoliensinine. There was also a reduction in the increase of collagen and upregulation of collagen I & III, TGF-β1, p-Smad2, and p-Smad3 in the renal tissue of SHRs. Thus, isoliensinine ameliorated renal injury and collagen deposition in hypertensive rats, and inhibiting the activation of the TGF-β1/Smad2/3 pathway might be one of the underlying mechanisms.

Conclusion

This study showed that treatment with isoliensinine effectively reduced the renal injury and fibrosis in SHRs. In addition, isoliensinine inhibited the TGF-β1/Smad2/3 signaling in-vivo. These findings provided strong evidence for the therapeutic benefits of isoliensinine in combating renal injury and fibrosis.

Identifying immune cell infiltration and effective diagnostic biomarkers in Crohn's disease by bioinformatics analysis

Background

Crohn's disease (CD) has an increasing incidence and prevalence worldwide. It is currently believed that both the onset and progression of the disease are closely related to immune system imbalance and the infiltration of immune cells. The aim of this study was to investigate the molecular immune mechanisms associated with CD and its fibrosis through bioinformatics analysis.

Methods

Three datasets from the Gene Expression Omnibus data base (GEO) were downloaded for data analysis and validation. Single sample gene enrichment analysis (ssGSEA) was used to evaluate the infiltration of immune cells in CD samples. Immune cell types with significant differences were identified by Wilcoxon test and Least Absolute Shrinkage and Selection Operator (LASSO) regression analysis. Differentially expressed genes (DEGs) were screened and then subjected to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional correlation analysis, as well as protein-protein interaction (PPI) network analysis. The cytoHubba program and the GSE75214 dataset were used to screen for hub genes and plot Receiver operating characteristic (ROC)curves to screen for possible biomarkers of CD based on diagnostic efficacy. The hub genes of CD were correlated with five significantly different immune cells. In addition, validation was performed by real time quantitative PCR (RT-qPCR) experiments in colonic tissue of CD intestinal fibrosis rats to further identify hub genes that are more related to CD intestinal fibrosis.

Results

The DEGs were analyzed separately by 10 algorithms and narrowed down to 9 DEGs after taking the intersection. 4 hub genes were further screened by the GSE75214 validation set, namely COL1A1, CXCL10, MMP2 and FGF2. COL1A1 has the highest specificity and sensitivity for the diagnosis of CD and is considered to have the potential to diagnose CD. Five immune cells with significant differences were screened between CD and health controls (HC). Through the correlation analysis between five kinds of immune cells and four biomarkers, it was found that CXCL10 was positively correlated with activated dendritic cells, effector memory CD8+ T cells. MMP2 was positively correlated with activated dendritic cells, gamma delta T cells (γδ T) and mast cells. MMP2 and COL1A1 were significantly increased in colon tissue of CD fibrosis rats.

Conclusion

MMP2, COL1A1, CXCL10 and FGF2 can be used as hub genes for CD. Among them, COL1A1 can be used as a biomarker for the diagnosis of CD. MMP2 and CXCL10 may be involved in the development and progression of CD by regulating activated dendritic cell, effector memory CD8+ T cell, γδ T cell and mast cell. In addition, MMP2 and COL1A1 may be more closely related to CD intestinal fibrosis.

Activation of XBP1 but not ATF6α rescues heart failure induced by persistent ER stress in medaka fish

The unfolded protein response is triggered in vertebrates by ubiquitously expressed IRE1α/β (although IRE1β is gut-specific in mice), PERK, and ATF6α/β, transmembrane-type sensor proteins in the ER, to cope with ER stress, the accumulation of unfolded and misfolded proteins in the ER. Here, we burdened medaka fish, a vertebrate model organism, with ER stress persistently from fertilization by knocking out the AXER gene encoding an ATP/ADP exchanger in the ER membrane, leading to decreased ATP concentration-mediated impairment of the activity of Hsp70- and Hsp90-type molecular chaperones in the ER lumen. ER stress and apoptosis were evoked from 4 and 6 dpf, respectively, leading to the death of all AXER-KO medaka by 12 dpf because of heart failure (medaka hatch at 7 dpf). Importantly, constitutive activation of IRE1α signaling-but not ATF6α signaling-rescued this heart failure and allowed AXER-KO medaka to survive 3 d longer, likely because of XBP1-mediated transcriptional induction of ER-associated degradation components. Thus, activation of a specific pathway of the unfolded protein response can cure defects in a particular organ.

Therapeutic silencing of lncRNA RMST alleviates cardiac fibrosis and improves heart function after myocardial infarction in mice and swine

Rationale: Cardiac fibrosis is an adverse consequence of aberrant fibroblast activation and extracellular matrix (ECM) deposition following myocardial infarction (MI). Recently, long noncoding RNAs (lncRNAs) have been reported to participate in multiple cardiac diseases. However, the biological functions of lncRNA rhabdomyosarcoma 2-associated transcript (RMST) in cardiac fibrosis remain largely unknown. Methods: The role of RMST in regulating cardiac fibroblast (CF) proliferation, fibroblast-to-myofibroblast transition (FMT), and ECM production, which were induced by transforming growth factor-β1, was evaluated through immunofluorescence staining, cell contraction assay, cell migration assay, qRT-PCR, and western blot. The therapeutic effect of RMST silencing was assessed in murine and porcine MI models. Results: The present study showed that RMST expression was upregulated and associated with cardiac fibrosis in murine and porcine MI models. Further loss-of-function studies demonstrated that RMST silencing in vitro significantly inhibited CF proliferation, FMT, and ECM production. Accordingly, RMST knockdown in vivo alleviated cardiac fibrosis and improved cardiac contractile function in MI mice. Moreover, RMST acted as a competitive endogenous RNA of miR-24-3p. miR-24-3p inhibition abolished, while miR-24-3p agomir reproduced, the RMST knockdown-mediated effects on CF fibrosis by regulating the lysyl oxidase signaling pathway. Finally, the therapeutic potential of RMST knockdown was evaluated in a porcine MI model, and local RMST knockdown significantly inhibited cardiac fibrosis and improved myocardial contractile function in pigs after MI. Conclusion: Our findings identified RMST as a crucial regulator of cardiac fibrosis, and targeting RMST may develop a novel and efficient therapeutic strategy for treating fibrosis-related cardiac diseases.

SIRT3 Deficiency Enhances Ferroptosis and Promotes Cardiac Fibrosis via p53 Acetylation

Cardiac fibrosis plays an essential role in the development of diastolic dysfunction and contributes to heart failure with preserved ejection fraction (HFpEF). Our previous studies suggested Sirtuin 3 (SIRT3) as a potential target for cardiac fibrosis and heart failure. In the present study, we explored the role of SIRT3 in cardiac ferroptosis and its contribution to cardiac fibrosis. Our data showed that knockout of SIRT3 resulted in a significant increase in ferroptosis, with increased levels of 4-hydroxynonenal (4-HNE) and downregulation of glutathione peroxidase 4 (GPX-4) in the mouse hearts. Overexpression of SIRT3 significantly blunted ferroptosis in response to erastin, a known ferroptosis inducer, in H9c2 myofibroblasts. Knockout of SIRT3 resulted in a significant increase in p53 acetylation. Inhibition of p53 acetylation by C646 significantly alleviated ferroptosis in H9c2 myofibroblasts. To further explore the involvement of p53 acetylation in SIRT3-mediated ferroptosis, we crossed acetylated p53 mutant (p534KR) mice, which cannot activate ferroptosis, with SIRT3KO mice. SIRT3KO/p534KR mice exhibited a significant reduction in ferroptosis and less cardiac fibrosis compared to SIRT3KO mice. Furthermore, cardiomyocyte-specific knockout of SIRT3 (SIRT3-cKO) in mice resulted in a significant increase in ferroptosis and cardiac fibrosis. Treatment of SIRT3-cKO mice with the ferroptosis inhibitor ferrostatin-1 (Fer-1) led to a significant reduction in ferroptosis and cardiac fibrosis. We concluded that SIRT3-mediated cardiac fibrosis was partly through a mechanism involving p53 acetylation-induced ferroptosis in myofibroblasts.

Cannabidiol alleviates right ventricular fibrosis by inhibiting the transforming growth factor β pathway in monocrotaline-induced pulmonary hypertension in rats

Cannabidiol (CBD) is a non-intoxicating compound of Cannabis with anti-fibrotic properties. Pulmonary hypertension (PH) is a disease that can lead to right ventricular (RV) failure and premature death. There is evidence that CBD reduces monocrotaline (MCT)-induced PH, including reducing right ventricular systolic pressure (RVSP), vasorelaxant effect on pulmonary arteries, and decreasing expression of profibrotic markers in the lungs. The aim of our study was to investigate the effect of chronic administration of CBD (10 mg/kg daily for 21 days) on profibrotic parameters in the RVs of MCT-induced PH rats. In MCT-induced PH, we found an increase in profibrotic parameters and parameters related to RV dysfunction, i.e. plasma pro-B-type natriuretic peptide (NT-proBNP), cardiomyocyte width, interstitial and perivascular fibrosis area, amount of fibroblasts and fibronectin, as well as overexpression of the transforming growth of factor β1 (TGF-β1), galectin-3 (Gal-3), suppressor of mothers against decapentaplegic 2 (SMAD2), phosphorylated SMAD2 (pSMAD2) and alpha-smooth muscle actin (α-SMA). In contrast, vascular endothelial cadherin (VE-cadherin) levels were decreased in the RVs of MCT-induced PH rats. Administration of CBD reduced the amount of plasma NT-proBNP, the width of cardiomyocytes, the amount of fibrosis area, fibronectin and fibroblast expression, as well as decreased the expression of TGF-β1, Gal-3, SMAD2, pSMAD2, and increased the level of VE-cadherin. Overall, CBD has been found to have the anti-fibrotic potential in MCT-induced PH. As such, CBD may act as an adjuvant therapy for PH, however, further detailed investigations are recommended to confirm our promising results.

AGGF1 therapy inhibits thoracic aortic aneurysms by enhancing integrin α7-mediated inhibition of TGF-β1 maturation and ERK1/2 signaling

Thoracic aortic aneurysm (TAA) is a localized or diffuse dilatation of the thoracic aortas, and causes many sudden deaths each year worldwide. However, there is no effective pharmacologic therapy. Here, we show that AGGF1 effectively blocks TAA-associated arterial inflammation and remodeling in three different mouse models (mice with transverse aortic constriction, Fbn1^C1041G/+ mice, and β-aminopropionitrile-treated mice). AGGF1 expression is reduced in the ascending aortas from the three models and human TAA patients. Aggf1^+/- mice and vascular smooth muscle cell (VSMC)-specific Aggf1^smcKO knockout mice show aggravated TAA phenotypes. Mechanistically, AGGF1 enhances the interaction between its receptor integrin α7 and latency-associated peptide (LAP)-TGF-β1, blocks the cleavage of LAP-TGF-β1 to form mature TGF-β1, and inhibits Smad2/3 and ERK1/2 phosphorylation in VSMCs. Pirfenidone, a treatment agent for idiopathic pulmonary fibrosis, inhibits TAA-associated vascular inflammation and remodeling in wild type mice, but not in Aggf1^+/- mice. In conclusion, we identify an innovative AGGF1 protein therapeutic strategy to block TAA-associated vascular inflammation and remodeling, and show that efficacy of TGF-β inhibition therapies require AGGF1.

Aerobic Exercise Ameliorates Myocardial Fibrosis via Affecting Vitamin D Receptor and Transforming Growth Factor-β1 Signaling in Vitamin D-Deficient Mice

Myocardial fibrosis is a pathological phenomenon associated with cardiovascular disease (CVD) that plays a crucial role in the development of heart diseases. Vitamin D deficiency can promote the development of CVD and exercise plays a role in the treatment of CVD. This study aimed to explore the effects of 12-week aerobic exercise training on myocardial fibrosis in vitamin D-deficient mice. A vitamin D-deficient mouse model was induced by a vitamin D-deficient (0 IU Vitamin D₃/kg) diet. Twenty-four C57BL/6J male mice were randomly divided into three groups: a control sedentary group (CONS, n = 8), a vitamin D-deficient sedentary group (VDDS, n = 8), and a vitamin D-deficient exercise group (VDDE, n = 8) which was aerobically trained for 12 weeks. The results showed that the serum 25-hydroxyvitamin D [25(OH)D] levels of the VDDS group were <50 nmol/L, which was significantly lower than that of the CONS group. Compared with the CONS group, the VDDS group showed cardiac dysfunction and significant fibrosis, together with lower vitamin D receptor (VDR) mRNA and protein expression levels, higher mRNA expression levels of profibrotic and inflammatory factors, and higher transforming growth factor-β1 (TGF-β1) and phospho-Smad2/3 (P-Smad2/3) protein expression levels. Serum 25(OH)D levels in the VDDE group were significantly higher than those in the VDDS group. Compared with the VDDS group, the VDDE group showed improved cardiac function and alleviated myocardial fibrosis. Meanwhile, the VDDE group had significantly higher VDR mRNA and protein expression levels; lower mRNA expression levels of profibrotic and inflammatory factors; and lower TGF-β1 and P-Smad2/3 protein expression levels. In conclusion, aerobic exercise training remains a promising intervention for treating myocardial fibrosis in vitamin D deficiency.

Protein therapy of skeletal muscle atrophy and mechanism by angiogenic factor AGGF1

BACKGROUND

Skeletal muscle atrophy is a common condition without a pharmacologic therapy. AGGF1 encodes an angiogenic factor that regulates cell differentiation, proliferation, migration, apoptosis, autophagy and endoplasmic reticulum stress, promotes vasculogenesis and angiogenesis and successfully treats cardiovascular diseases. Here, we report the important role of AGGF1 in the pathogenesis of skeletal muscle atrophy and attenuation of muscle atrophy by AGGF1.

METHODS

In vivo studies were carried out in impaired leg muscles from patients with lumbar disc herniation, two mouse models for skeletal muscle atrophy (denervation and cancer cachexia) and heterozygous Aggf1^+/- mice. Mouse muscle atrophy phenotypes were characterized by body weight and myotube cross-sectional areas (CSA) using H&E staining and immunostaining for dystrophin. Molecular mechanistic studies include co-immunoprecipitation (Co-IP), western blotting, quantitative real-time PCR analysis and immunostaining analysis.

RESULTS

Heterozygous Aggf1^+/- mice showed exacerbated phenotypes of reduced muscle mass, myotube CSA, MyHC (myosin heavy chain) and α-actin, increased inflammation (macrophage infiltration), apoptosis and fibrosis after denervation and cachexia. Intramuscular and intraperitoneal injection of recombinant AGGF1 protein attenuates atrophy phenotypes in mice with denervation (gastrocnemius weight 81.3 ± 5.7 mg vs. 67.3 ± 5.1 mg for AGGF1 vs. buffer; P < 0.05) and cachexia (133.7 ± 4.7 vs. 124.3 ± 3.2; P < 0.05). AGGF1 expression undergoes remodelling and is up-regulated in gastrocnemius and soleus muscles from atrophy mice and impaired leg muscles from patients with lumbar disc herniation by 50-60% (P < 0.01). Mechanistically, AGGF1 interacts with TWEAK (tumour necrosis factor-like weak inducer of apoptosis), which reduces interaction between TWEAK and its receptor Fn14 (fibroblast growth factor-inducing protein 14). This leads to inhibition of Fn14-induced NF-kappa B (NF-κB) p65 phosphorylation, which reduces expression of muscle-specific E3 ubiquitin ligase MuRF1 (muscle RING finger 1), resulting in increased MyHC and α-actin and partial reversal of atrophy phenotypes. Autophagy is reduced in Aggf1^+/- mice due to inhibition of JNK (c-Jun N-terminal kinase) activation in denervated and cachectic muscles, and AGGF1 treatment enhances autophagy in two atrophy models by activating JNK. In impaired leg muscles of patients with lumbar disc herniation, MuRF1 is up-regulated and MyHC and α-actin are down-regulated; these effects are reversed by AGGF1 by 50% (P < 0.01).

CONCLUSIONS

These results indicate that AGGF1 is a novel regulator for the pathogenesis of skeletal muscle atrophy and attenuates skeletal muscle atrophy by promoting autophagy and inhibiting MuRF1 expression through a molecular signalling pathway of AGGF1-TWEAK/Fn14-NF-κB. More importantly, the results indicate that AGGF1 protein therapy may be a novel approach to treat patients with skeletal muscle atrophy.

Signaling Pathways and Potential Therapeutic Strategies in Cardiac Fibrosis

Cardiac fibrosis constitutes irreversible necrosis of the heart muscle as a consequence of different acute (myocardial infarction) or chronic (diabetes, hypertension, …) diseases but also due to genetic alterations or aging. Currently, there is no curative treatment that is able to prevent or attenuate this phenomenon that leads to progressive cardiac dysfunction and life-threatening outcomes. This review summarizes the different targets identified and the new strategies proposed to fight cardiac fibrosis. Future directions, including the use of exosomes or nanoparticles, will also be discussed.

Inhibition of CEMIP potentiates the effect of sorafenib on metastatic hepatocellular carcinoma by reducing the stiffness of lung metastases

Hepatocellular carcinoma (HCC) with lung metastasis is associated with poor prognosis and poor therapeutic outcomes. Studies have demonstrated that stiffened stroma can promote metastasis in various tumors. However, how the lung mechanical microenvironment favors circulating tumor cells remains unclear in metastatic HCC. Here, we found that the expression of cell migration-inducing hyaluronan-binding protein (CEMIP) was closely associated with lung metastasis and can promote pre-metastatic niche formation by increasing lung matrix stiffness. Furthermore, upregulated serum CEMIP was indicative of lung fibrotic changes severity in patients with HCC lung metastasis. By directly targeting CEMIP, pirfenidone can inhibit CEMIP/TGF-β1/Smad signaling pathway and reduce lung metastases stiffening, demonstrating promising antitumor activity. Pirfenidone in combination with sorafenib can more effectively suppress the incidence of lung metastasis compared with sorafenib alone. This study is the first attempt to modulate the mechanical microenvironment for HCC therapy and highlights CEMIP as a potential target for the prevention and treatment of HCC lung metastasis. CEMIP mediating an HCC-permissive microenvironment through controlling matrix stiffness. Meanwhile, Pirfenidone could reduce metastasis stiffness and increases the anti-angiogenic effect of Sorafenib by directly targeting CEMIP.

ADAMTS6 cleaves the large latent TGFβ complex and increases the mechanotension of cells to activate TGFβ

The ADAMTS superfamily is composed of secreted metalloproteases and structurally related non-catalytic ADAMTS-like proteins. A subset of this superfamily, including ADAMTS6, ADAMTS10 and ADAMTSL2, are involved in elastic fiber assembly and bind to fibrillin and other matrix molecules that regulate the extracellular bioavailability of the potent growth factor TGFβ. Fibrillinopathies, that can also result from mutation of these ADAMTS/L proteins, have been linked to disrupted TGFβ homeostasis. ADAMTS6 and ADAMTS10 are homologous metalloproteases with poorly characterized substrates where ADAMTS10 is thought to process fibrillin-2 and ADAMTS6 latent TGFβ-binding protein (LTBP)-1. In order to understand the contribution of ADAMTS6, and these other members of the ADAMTS/L family, to TGFβ homeostasis, we have analyzed the effects of ADAMTS6, ADAMTS10 and ADAMTSL2 expression on TGFβ activation. We found that their expression increases TGFβ activation in a dose dependent manner, following stimulation with mature TGFβ1. For ADAMTS6, the catalytically active protease is required for effective TGFβ activation, where ADAMTS6 cleaves LTBP3 as well as LTBP1, and binds to the large latent TGFβ complexes of LTBP1 and LTBP3. Furthermore, ADAMTS6 expression increases the mechanotension of cells which results in inactivation of the Hippo Pathway, resulting in an increased translocation of YAP/TAZ complex to the nucleus. Together these findings suggest that when the balance of TGFβ is perturbed ADAMTS6 can influence TGFβ activation via two mechanisms. It directly cleaves the latent TGFβ complexes and also acts indirectly, along with ADAMTS10 and ADAMTSL2, by altering the mechanotension of cells. Together this increases activation of TGFβ from large latent complexes which may contribute to disease pathogenesis.

[Serum levels of endothelin-1 and connective tissue growth factor are elevated in patients with atrial fibrillation and correlated with relapse following radiofrequency ablation]

OBJECTIVE

To investigate the changes in serum levels of endothelin-1 (ET-1) and connective tissue growth factor (CTGF) in patients with atrial fibrillation (AF) and their value for predicting recurrence of AF after radiofrequency ablation (RFCA).

METHODS

Sixty-six patients with paroxysmal AF (PaAF) and 72 with persistent AF (PaAF) admitted in our hospital were recruited as AF group and 80 patients with sinus rhythm as the control group, and in all the participants, serum levels of ET-1 and CTGF were measured using ELISA and Western blotting. From 6 patients with AF and 6 with sinus rhythm undergoing cardiac surgery in our hospital, tissue samples of the right atrial appendage were taken intraoperatively for observation of structural changes of the cardiomyocytes, myocardial fibrosis and expression of ET-1 and CTGF protein. In AF group, the patients receiving RFCA were followed up for 6 months following the procedure for assessment of the outcomes.

RESULTS

Compared with the control patients, the patients with AF showed obvious damages of the cardiomyocyte structure and myocardial fibrosis. Serum levels of ET-1 and CTGF levels were significantly higher in PaAF and PeAF groups than in the control group, and were higher in PeAF group than in PaAF group. In the patients with AF, serum ET-1 and CTGF levels were positively correlated with left atrial diameter (LAD) (P < 0.05), and ET-1 was positively correlated with CTGF levels (P < 0.05). In patients with postoperative AF recurrence, the serum levels of ET-1 and CTGF were significantly higher than those in patients without recurrence; serum ET-1 and CTGF levels before and after the operation were positively correlated with the recurrence of PeAF, and elevated serum levels of ET- 1 and CTGF were identified by logistic regression analysis as independent risk factors for postoperative recurrence of PeAF.

CONCLUSION

Serum levels of ET-1 and CTGF are significantly elevated in AF patients in positive correlation with AF duration. ET-1 and CTGF levels are higher in AF patients with postoperative recurrence, and they both have predictive value for recurrence of PeAF following RFCA.

Optic neuropathy associated with TGFβ dysregulation in mice with a glaucoma-causative mutation of ADAMTS10

Glaucoma is a neurodegenerative disease that causes irreversible blindness due to loss of retinal ganglion cells (RGCs) and their axons. We previously identified a G661R mutation of ADAMTS10 (A Disintegrin And Metalloproteinase with ThromboSpondin type 1 motif 10) as the disease-causing mutation in a beagle model of glaucoma. ADAMTS10 is a secreted matrix metalloproteinase that belongs to the ADAMTS family which is involved in extracellular matrix (ECM) turnover. Previous studies have shown that ADAMTS10 binds fibrillin microfibrils, promotes their formation, and influences their fibrillin isoform composition. Here, we established a mouse model carrying the G661R mutation of ADAMTS10 (ADAMTS10G661R/G661R) to investigate its ocular phenotypes related to glaucoma and to explore possible functions of ADAMTS10. We found that ADAMTS10 was expressed in the inner retina and along RGC axons in the optic nerve. However, ADAMTS10 was not colocalized with fibrillin microfibrils in these tissues, suggesting fibrillin-independent function for ADAMTS10. In electroretinogram experiments, we found that ADAMTS10G661R/G661R mice had reduced amplitude of retinal responses to dim light stimulus, indicating RGC dysfunction. The reduced RGC function coincided with RGC axon structural changes manifested as smaller optic nerves and fewer optic nerve axons, which may contribute to glaucoma. The reduced number of optic nerve axons found for ADAMTS10G661R/G661R mice occurred early, suggesting developmental deficits. Subsequent experiments found increased apoptosis in the retina of ADAMTS10G661R/G661R mice during postnatal development, which could result in fewer RGCs produced, accounting for fewer optic nerve axons in adulthood. Consistent with a protective effect of transforming growth factor β (TGFβ) signaling against apoptosis during retinal development as shown previously by others, we found increased apoptosis accompanied by decreased TGFβ signaling in the developing retina of ADAMTS10G661R/G661R mice, suggesting a novel role for ADAMTS10 in regulating TGFβ signaling which could involve direct interaction between ADAMTS10 and latent TGFβ.

Effect of TGF-β1-Mediated Exercise Analgesia in Spared Nerve Injury Mice

Peripheral nerve injury leads to severe neuropathic pain. Previous studies have highlighted the beneficial effects of physical exercise on alleviating neuropathic pain. Exercise regulating transforming growth factor-β1 (TGF-β1) can improve several diseases and relieve neuropathic pain induced by peripheral nerve injury. Here, we investigated whether exercise could alleviate neuropathic pain by modulating TGF-β1 expression. We assessed mechanical and cold pain behavior and conducted molecular evaluation of the spinal cord. We found that spared nerve injury (SNI) led to mechanical and cold allodynia in the hind paw, elevated the expression of latency-associated peptide- (LAP-) TGF-β1, and activated astroglial in the spinal cord. Exercise decreases allodynia, astroglial activation, and LAP-TGF-β1 in SNI mice. Intrathecal injection of a TGF-type I receptor inhibitor attenuated exercise analgesia and enhanced astroglial activation. These findings demonstrate that exercise induces analgesia by promoting TGF-β1 activation and inhibiting astrogliosis. Our study reveals a new underlying mechanism for exercise-attenuated neuropathic pain in the maintenance stage of neuropathic pain after nerve injury.

A pan-cancer analysis of matrisome proteins reveals CTHRC1 and a related network as major ECM regulators across cancers

The extracellular matrix in the tumour microenvironment can regulate cancer cell growth and progression. A pan-cancer analysis of TCGA data from 30 cancer types, identified the top 5% of matrisome genes with amplifications or deletions in their copy number, that affect their expression and cancer survival. A similar analysis of matrisome genes in individual cancers identified CTHRC1 to be significantly altered. CTHRC1, a regulator of collagen synthesis, was identified as the most prominently upregulated matrisome gene of interest across cancers. Differential gene expression analysis identified 19 genes whose expression is increased with CTHRC1. STRING analysis of these genes classified them as ‘extracellular’, involved most prominently in ECM organization and cell adhesion. KEGG analysis showed their involvement in ECM-receptor and growth factor signalling. Cytohubba analysis of these genes revealed 13 hub genes, of which MMP13, POSTN, SFRP4, ADAMTS16 and FNDC1 were significantly altered in their expression with CTHRC1 and seen to affect survival across cancers. This could in part be mediated by their overlapping roles in regulating ECM (collagen or fibronectin) expression and organisation. In breast cancer tumour samples CTHRC1 protein levels are significantly upregulated with POSTN and MMP13, further supporting the need to evaluate their crosstalk in cancers.

Comprehensive characterization of the postoperative pericardial inflammatory response: Potential implications for clinical outcomes

Objective

There is a paucity of data on the inflammatory response that takes place in the pericardial space after cardiac surgery. This study provides a comprehensive assessment of the local postoperative inflammatory response.

Methods

Forty-three patients underwent cardiotomy, where native pericardial fluid was aspirated and compared with postoperative pericardial effluent collected at 4, 24, and 48 hours' postcardiopulmonary bypass. Flow cytometry was used to define the levels and proportions of specific immune cells. Samples were also probed for concentrations of inflammatory cytokines, matrix metalloproteinases (MMPs), and tissue inhibitors of metalloproteinases (TIMPs).

Results

Preoperatively, the pericardial space mainly contains macrophages and T cells. However, the postsurgical pericardial space was populated predominately by neutrophils, which constituted almost 80% of immune cells present, and peaked at 24 hours. When surgical approaches were compared, minimally invasive surgery was associated with fewer neutrophils in the pericardial space at 4 hours' postsurgery. Analysis of the intrapericardial concentrations of inflammatory mediators showed interleukin-6, MMP-9, and TIMP-1 to be highest postsurgery. Over time, MMP-9 concentrations decreased significantly, whereas TIMP-1 levels increased, resulting in a significant reduction of the ratio of MMP:TIMP after surgery, suggesting that active inflammatory processes may influence extracellular matrix remodeling.

Conclusions

These results show that cardiac surgery elicits profound alterations in the immune cell profile in the pericardial space. Defining the cellular and molecular mediators that drive pericardial-specific postoperative inflammatory processes may allow for targeted therapies to reduce immune-mediated complications.