Cyclophilin A in cardiovascular homeostasis and diseases

Hibiscus attenuates renovascular hypertension-induced aortic remodeling dose dependently: the oxidative stress role and Ang II/cyclophilin A/ERK1/2 signaling

Introduction: The high levels of angiotensin II (Ang II) can modify the vascular tone, enhance vascular smooth muscle cells (VSMCs) proliferation and hypertrophy and increase the inflammatory cellular infiltration into the vessel wall. The old herbal nonpharmacological agent, Hibiscus (HS) sabdariffa L has multiple cardioprotective impacts; thus, we investigated the role of HS extract in amelioration of renovascular hypertension (RVH)-induced aortic remodeling. Materials and methods: Thirty-five rats (7/group) were randomly allocated into 5 groups; group: I: Control-sham group, and RVH groups; II, III, IV, and V. The rats in RVH groups were subjected to the modified Goldblatt two-kidneys, one clip (2K1C) for induction of hypertension. In group: II, the rats were left untreated whereas in group III, IV, and V: RVH-rats were treated for 6 weeks with low dose hibiscus (LDH), medium dose hibiscus (MDH), and high dose hibiscus (HDH) respectively. Results: We found that the augmented pro-contractile response of the aortic rings was ameliorated secondary to the in-vivo treatment with HS dose dependently. The cyclophilin A (CyPA) protein levels positively correlated with the vascular adhesion molecule-1 (VCAM-1) and ERK1/2, which, in turn, contribute to the reactive oxygen species (ROS) production. Daily HS intake modified aortic renovation by enhancing the antioxidant capacity, restraining hypertrophy and fibrosis, downregulation of the metastasis associated lung adenocarcinoma transcript (MALAT1), and cyclophilin A (CyPA)/ERK1/2 levels. Discussion: Adding to the multiple beneficial effects, HS aqueous extract was able to inhibit vascular smooth muscle cell proliferation induced by 2K1C model. Thus, adding more privilege for the utilization of the traditional herbal extracts to attenuate RVH-induced aortopathy.

The correlation between serum Cyclophilin A level and severity, prognosis of craniocerebral injury

BACKGROUND

To investigate the value of serum Cyclophilin A(Cyp A) in evaluating the prognosis of patients with different severity of craniocerebral injury.

METHODS

The clinical data of patients with craniocerebral injury treated in the Department of Emergency from July 2014 to August 2017 were collected. The patients were divided into survival group and death group, good neurological function group and poor neurological function group with 28-day prognosis and were divided into mild (13-15) group, moderate (9-12) group, and severe (3-8) group with Glasgow Coma Scale (GCS) score. Clinical parameters such as Cyp A and mortality in groups and the relationship between Cyp A and GCS score were compared and its predictive value for prognosis was analyzed with Binary Logistics regression, Cox proportional hazards model and kaplan-meier survival curve.

RESULTS

In a single-center retrospective study, 503 patients were enrolled, including 365 males and 138 females; serum Cyp A in the survival group was significantly smaller than the death group [18.7 (10.1, 51.5) ng/mL vs. 149.8 (79.5, 194.4) ng/mL, P < 0.005]. There were significant differences in mortality and Cyp A levels between patients with different severity of craniocerebral injury (P < 0.001). Serum Cyp A levels were negatively correlated with GCS scores in all patients with craniocerebral injury, mild, moderate, or severe craniocerebral injury (r = -0.844, r = -0.256, r = -0.540, r = -0.531, P < 0.001). Predictive value of Serum Cyp A level for all patients with craniocerebral injury, mild, moderate, and severe craniocerebral injury is 0.890, 0.789, 0.806, and 0.833, respectively. Logistics regression analysis showed that lactate (OR = 1.260, 95%CI: 1.023-1.551) and Cyp A (OR = 1.021, 95%CI: 1.011-1.031) were positively correlated with death (P < 0.05), Lactic acid (HR 1.115; 95%CI:1.001-1.243; P = 0.048), GCS score (HR 0.888; 95% CI: 0.794-0.993; P = 0.038), Cyp A levels (HR 1.009; 95% CI: 1.004-1.013; P < 0.001) had a significant effect on short-term mortality. Similar results were seen when neurologic function was used as the outcome. Kaplan-meier survival curve analysis found survival rate of patients with Cyp A level below the cut-off value was significantly higher.

CONCLUSION

Serum Cyp A has a certain predictive value for the prognosis of patients with different severity of craniocerebral injury. Among them, patients with severe craniocerebral injury have the highest predictive value and mild craniocerebral injury patients have the least.

Cyclosporin A: A Repurposable Drug in the Treatment of COVID-19?

Coronavirus disease 2019 (COVID-19) is now at the forefront of major health challenge faced globally, creating an urgent need for safe and efficient therapeutic strategies. Given the high attrition rates, high costs, and quite slow development of drug discovery, repurposing of known FDA-approved molecules is increasingly becoming an attractive issue in order to quickly find molecules capable of preventing and/or curing COVID-19 patients. Cyclosporin A (CsA), a common anti-rejection drug widely used in transplantation, has recently been shown to exhibit substantial anti-SARS-CoV-2 antiviral activity and anti-COVID-19 effect. Here, we review the molecular mechanisms of action of CsA in order to highlight why this molecule seems to be an interesting candidate for the therapeutic management of COVID-19 patients. We conclude that CsA could have at least three major targets in COVID-19 patients: (i) an anti-inflammatory effect reducing the production of proinflammatory cytokines, (ii) an antiviral effect preventing the formation of the viral RNA synthesis complex, and (iii) an effect on tissue damage and thrombosis by acting against the deleterious action of angiotensin II. Several preliminary CsA clinical trials performed on COVID-19 patients report lower incidence of death and suggest that this strategy should be investigated further in order to assess in which context the benefit/risk ratio of repurposing CsA as first-line therapy in COVID-19 is the most favorable.

The Role of Cyclophilins in Inflammatory Bowel Disease and Colorectal Cancer

Cyclophilins (Cyps) is a kind of ubiquitous protein family in organisms, which has biological functions such as promoting intracellular protein folding and participating in the pathological processes of inflammation and tumor. Inflammatory bowel disease (IBD) and colorectal cancer (CRC) are two common intestinal diseases, but the etiology and pathogenesis of these two diseases are still unclear. IBD and CRC are closely associated, IBD has always been considered as one of the main risks of CRC. However, the role of Cyps in these two related intestinal diseases is rarely studied and reported. In this review, the expression of CypA, CypB and CypD in IBD, especially ulcerative colitis (UC), and CRC, their relationship with the development of these two intestinal diseases, as well as the possible pathogenesis, were briefly summarized, so as to provide modest reference for clinical researches and treatments in future.

Drug discovery focused on novel pathogenic proteins for pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is a fatal disease in which the wall thickening and narrowing of pulmonary microvessels progress due to complicated interactions among processes such as endothelial dysfunction, the proliferation of pulmonary artery smooth muscle cells (PASMCs) and adventitial fibrocytes, and inflammatory cell infiltration. Early diagnosis of patients with PAH is difficult and lung transplantation is the only last choice to save severely ill patients. However, the number of donors is limited. Many patients with PAH show rapid progression and a high degree of pulmonary arterial remodeling characterized by the abnormal proliferation of PASMCs, which makes treatment difficult even with multidrug therapy comprising pulmonary vasodilators. Thus, it is important to develop novel therapy targeting factors other than vasodilation, such as PASMC proliferation. In the development of PAH, inflammation and oxidative stress are deeply involved in its pathogenesis. Excessive proliferation and apoptosis resistance in PASMCs are key mechanisms underlying PAH. Based on those characteristics, we recently screened novel pathogenic proteins and have performed drug discovery targeting those proteins. To confirm the clinical significance of this, we used patient-derived blood samples to evaluate biomarker potential for diagnosis and prognosis. Moreover, we conducted high throughput screening and found several inhibitors of the pathogenic proteins. In this review, we introduce the recent progress on basic and clinical PAH research, focusing on the screening of pathogenic proteins and drug discovery.

Identification of Celastrol as a Novel Therapeutic Agent for Pulmonary Arterial Hypertension and Right Ventricular Failure Through Suppression of Bsg (Basigin)/CyPA (Cyclophilin A)

OBJECTIVE

Pulmonary arterial hypertension is characterized by abnormal proliferation of pulmonary artery smooth muscle cells and vascular remodeling, which leads to right ventricular (RV) failure. Bsg (Basigin) is a transmembrane glycoprotein that promotes myofibroblast differentiation, cell proliferation, and matrix metalloproteinase activation. CyPA (cyclophilin A) binds to its receptor Bsg and promotes pulmonary artery smooth muscle cell proliferation and inflammatory cell recruitment. We previously reported that Bsg promotes cardiac fibrosis and failure in the left ventricle in response to pressure-overload in mice. However, the roles of Bsg and CyPA in RV failure remain to be elucidated. Approach and Results: First, we found that protein levels of Bsg and CyPA were upregulated in the heart of hypoxia-induced pulmonary hypertension (PH) in mice and monocrotaline-induced PH in rats. Furthermore, cardiomyocyte-specific Bsg-overexpressing mice showed exacerbated RV hypertrophy, fibrosis, and dysfunction compared with their littermates under chronic hypoxia and pulmonary artery banding. Treatment with celastrol, which we identified as a suppressor of Bsg and CyPA by drug screening, decreased proliferation, reactive oxygen species, and inflammatory cytokines in pulmonary artery smooth muscle cells. Furthermore, celastrol treatment ameliorated RV systolic pressure, hypertrophy, fibrosis, and dysfunction in hypoxia-induced PH in mice and SU5416/hypoxia-induced PH in rats with reduced Bsg, CyPA, and inflammatory cytokines in the hearts and lungs.

CONCLUSIONS

These results indicate that elevated Bsg in pressure-overloaded RV exacerbates RV dysfunction and that celastrol ameliorates RV dysfunction in PH model animals by suppressing Bsg and its ligand CyPA. Thus, celastrol can be a novel drug for PH and RV failure that targets Bsg and CyPA. Graphic Abstract: A graphic abstract is available for this article.

Cyclophilin 19 secreted in the host cell cytosol by Trypanosoma cruzi promotes ROS production required for parasite growth

Infection by Trypanosoma cruzi, the protozoan parasite that causes Chagas disease, depends on reactive oxygen species (ROS), which has been described to induce parasite proliferation in mammalian host cells. It is unknown how the parasite manages to increase host ROS levels. Here, we found that intracellular T. cruzi forms release in the host cytosol its major cyclophilin of 19 kDa (TcCyp19). Parasites depleted of TcCyp19 by using CRISPR/Cas9 gene replacement proliferate inefficiently and fail to increase ROS, compared to wild type parasites or parasites with restored TcCyp19 gene expression. Expression of TcCyp19 in L6 rat myoblast increased ROS levels and restored the proliferation of TcCyp19 depleted parasites. These events could also be inhibited by cyclosporin A, (a cyclophilin inhibitor), and by polyethylene glycol-linked to antioxidant enzymes. TcCyp19 was found more concentrated in the membrane leading edges of the host cells in regions that also accumulate phosphorylated p47^phox , as observed to the endogenous cyclophilin A, suggesting some mechanisms involved with the translocation process of the regulatory subunit p47^phox in the activation of the NADPH oxidase enzymatic complex. We concluded that cyclophilin released in the host cell cytosol by T. cruzi mediates the increase of ROS, required to boost parasite proliferation in mammalian hosts.

Cyclophilins in Ischemic Heart Disease: Differences Between Acute and Chronic Coronary Artery Disease Patients

Background

Cyclophilins (Cyps) are a family of peptidyl-prolyl cis/trans isomerases consistently involved in cardiovascular diseases through the inflammation pathway. This study aims to investigate the serum levels of Cyps (CypA, CypB, CypC and CypD) in patients with coronary artery disease (CAD) and the correlation with clinical characteristics and inflammation parameters.

Methods

We developed an observational prospective study with a total of 125 subjects: 40 patients with acute CAD, 40 patients with chronic CAD and 45 control volunteers, in whom serum levels of Cyps (CypA, CypB, CypC and CypD), interleukins and metalloproteinases were measured.

Results

CypA levels increased significantly in CAD patients compared with control subjects, but no differences were noted between acute CAD (7.80 ± 1.30 ng/mL) and chronic CAD (5.52 ± 0.76 ng/mL) patients (P = 0.13). No differences in CypB and CypD levels were showed between CAD patients and controls and between acute CAD and chronic CAD patients. In relation with CypC, the levels in CAD patients were significantly higher compared to controls (32.42 ± 3.71 pg/mL vs. 9.38 ± 1.51 pg/mL, P < 0.001), but no differences between acute and chronic CAD groups were obtained (P = 0.62). We analyzed the CypC > 17.5 pg/mL cut-off point, and it was significantly associated with older age, hypertension, dyslipidemia and more extensive CAD in acute and chronic CAD groups.

Conclusions

CypA and CypC levels are increased in CAD patients. High CypC serum levels could be a novel biomarker in CAD patients correlating with a more severe disease.

Perivascular Stem Cell-Derived Cyclophilin A Improves Uterine Environment with Asherman's Syndrome via HIF1α-Dependent Angiogenesis

Asherman's syndrome (AS) is characterized by intrauterine adhesions or fibrosis resulting from scarring inside the endometrium. AS is associated with infertility, recurrent miscarriage, and placental abnormalities. Although mesenchymal stem cells show therapeutic promise for the treatment of AS, the molecular mechanisms underlying its pathophysiology remain unclear. We ascertained that mice with AS, like human patients with AS, suffer from extensive fibrosis, oligo/amenorrhea, and infertility. Human perivascular stem cells (hPVSCs) from umbilical cords repaired uterine damage in mice with AS, regardless of their delivery routes. In mice with AS, embryo implantation is aberrantly deferred, which leads to intrauterine growth restriction followed by no delivery at term. hPVSC administration significantly improved implantation defects and subsequent poor pregnancy outcomes via hypoxia inducible factor 1α (HIF1α)-dependent angiogenesis in a dose-dependent manner. Pharmacologic inhibition of HIF1α activity hindered hPVSC actions on pregnancy outcomes, whereas stabilization of HIF1α activity facilitated such actions. Furthermore, therapeutic effects of hPVSCs were not observed in uterine-specific HIF1α-knockout mice with AS. Secretome analyses of hPVSCs identified cyclophilin-A as the major paracrine factor for hPVSC therapy via HIF1α-dependent angiogenesis. Collectively, we demonstrate that hPVSCs-derived cyclophilin-A facilitates HIF1α-dependent angiogenesis to ameliorate compromised uterine environments in mice with AS, representing the major pathophysiologic features of humans with AS.

Association of cyclophilin A level and pulse pressure in predicting recurrence of cerebral infarction

Cyclophilin A (CypA), secreted from vascular smooth muscle cells and inflammatory cells in response to oxidative stress, promotes vascular atherosclerosis and development of carotid stenosis. Increased concentration of plasma CypA in acute cerebral infarction was demonstrated clinically. The primary aim of this study was to investigate the prognostic impact between CypA level and outcome in patients with acute ischemic stroke. Admission serum CypA concentrations were detected in 66 acute cerebral infarction patients and in 52 healthy individuals. Inflammatory biomarkers, including high-sensitivity C-reactive protein, adhesion molecules, interleukins, and matrix-metalloproteases, were also assessed. We also examined the relationship between plasma biomarkers, blood pressure (BP), pulse pressure, the carotid artery velocity, the prognostic assessment with modified Rankin scale, and stroke recurrence. Plasma CypA concentration was higher on the first day of hospitalization in the high BP stroke group than in normal BP stroke group, which was statistically significant, which was observed even in the third month and sixth month follow-up outpatient periods. For stroke recurrence prediction, there was an important association between the higher (>60) pulse pressure on the seventh day of hospitalization and CypA level on the third month and sixth month follow-up outpatient periods. Our study revealed higher circulating serum levels of CypA in the hypertensive stroke group than in the non-hypertensive stroke group. We expect that elevated plasma CypA level and raised pulse pressure during hospitalization to become valuable biomarkers in predicting stroke recurrence in the sixth month assessment of acute cerebral infarction.

Identification of Emetine as a Therapeutic Agent for Pulmonary Arterial Hypertension

Objective:

Excessive proliferation and apoptosis resistance are special characteristics of pulmonary artery smooth muscle cells (PASMCs) in pulmonary arterial hypertension (PAH). However, the drugs in clinical use for PAH target vascular dilatation, which do not exert adequate effects in patients with advanced PAH. Here, we report a novel therapeutic effect of emetine, a principal alkaloid extracted from the root of ipecac clinically used as an emetic and antiprotozoal drug.

Approach and Results:

We performed stepwise screenings for 5562 compounds from original library. First, we performed high-throughput screening with PASMCs from patients with PAH (PAH-PASMCs) and found 80 compounds that effectively inhibited proliferation. Second, we performed the repeatability and counter assay. Finally, we performed a concentration-dependent assay and found that emetine inhibits PAH-PASMC proliferation. Interestingly, emetine significantly reduced protein levels of HIFs (hypoxia-inducible factors; HIF-1α and HIF-2α) and downstream PDK1 (pyruvate dehydrogenase kinase 1). Moreover, emetine significantly reduced the protein levels of RhoA (Ras homolog gene family, member A), Rho-kinases (ROCK1 and ROCK2 [rho-associated coiled-coil containing protein kinases 1 and 2]), and their downstream CyPA (cyclophilin A), and Bsg (basigin) in PAH-PASMCs. Consistently, emetine treatment significantly reduced the secretion of cytokines/chemokines and growth factors from PAH-PASMCs. Interestingly, emetine reduced protein levels of BRD4 (bromodomain-containing protein 4) and downstream survivin, both of which are involved in many cellular functions, such as cell cycle, apoptosis, and inflammation. Finally, emetine treatment ameliorated pulmonary hypertension in 2 experimental rat models, accompanied by reduced inflammatory changes in the lungs and recovered right ventricular functions.

Conclusions:

Emetine is an old but novel drug for PAH that reduces excessive proliferation of PAH-PASMCs and improves right ventricular functions.

Cyclophilin A and matrix metalloproteinase-9: Their relationship, association with, and diagnostic relevance in stable coronary artery disease

Objectives

Data about the circulating levels of cyclophilin A and matrix metalloproteinase-9 in stable coronary artery disease are contradictory. Moreover, their relationship in this disease is not established yet. Thus, this study was designed to assess the relationship between the circulating levels of cyclophilin A and matrix metalloproteinase-9 in coronary artery disease patients with and without type 2 diabetes mellitus (T2DM).

Methods

Serum levels of cyclophilin A, matrix metalloproteinase-9, and high sensitive C-reactive protein (hsCRP) along with fasting blood glucose, glycated hemoglobin, serum lipids, and the anthropometric parameters were measured in 120 participants who were divided equally into four groups (i) normal controls, (ii) T2DM patients, (iii) stable coronary artery disease patients with T2DM, and (iv) stable coronary artery disease patients without T2DM.

Results

Levels of cyclophilin A and matrix metalloproteinase-9 were significantly elevated in sera of coronary artery disease patients with and without T2DM compared to normal controls and T2DM patients. In multiple linear regression models, only cyclophilin A was observed in the final model where it explained the 24.9% variability of matrix metalloproteinase-9. Additionally, high circulating levels of cyclophilin A and matrix metalloproteinase-9 were associated with an increased risk of developing stable coronary artery disease. Finally, the diagnostic efficacy of cyclophilin A and matrix metalloproteinase-9 to discriminate stable coronary artery disease patients with and without T2DM from subjects without coronary artery disease was found to be higher than that of hsCRP.

Conclusion

Serum level of cyclophilin A might be a determinant factor of matrix metalloproteinase-9 level; both may contribute to the pathogenesis of stable coronary artery disease and they appear to be valuable diagnostic biomarkers of stable coronary artery disease with and without T2DM.

ADAMTS8 Promotes the Development of Pulmonary Arterial Hypertension and Right Ventricular Failure: A Possible Novel Therapeutic Target

RATIONALE

Pulmonary arterial hypertension (PAH) is characterized by pulmonary vascular remodeling with aberrant pulmonary artery smooth muscle cells (PASMCs) proliferation, endothelial dysfunction, and extracellular matrix remodeling.

OBJECTIVE

Right ventricular (RV) failure is an important prognostic factor in PAH. Thus, we need to elucidate a novel therapeutic target in both PAH and RV failure.

METHODS AND RESULTS

We performed microarray analysis in PASMCs from patients with PAH (PAH-PASMCs) and controls. We found a ADAMTS8 (disintegrin and metalloproteinase with thrombospondin motifs 8), a secreted protein specifically expressed in the lung and the heart, was upregulated in PAH-PASMCs and the lung in hypoxia-induced pulmonary hypertension (PH) in mice. To elucidate the role of ADAMTS8 in PH, we used vascular smooth muscle cell-specific ADAMTS8-knockout mice (ADAMTS^ΔSM22). Hypoxia-induced PH was attenuated in ADAMTS^ΔSM22 mice compared with controls. ADAMTS8 overexpression increased PASMC proliferation with downregulation of AMPK (AMP-activated protein kinase). In contrast, deletion of ADAMTS8 reduced PASMC proliferation with AMPK upregulation. Moreover, deletion of ADAMTS8 reduced mitochondrial fragmentation under hypoxia in vivo and in vitro. Indeed, PASMCs harvested from ADAMTS^ΔSM22 mice demonstrated that phosphorylated DRP-1 (dynamin-related protein 1) at Ser637 was significantly upregulated with higher expression of profusion genes (Mfn1 and Mfn2) and improved mitochondrial function. Moreover, recombinant ADAMTS8 induced endothelial dysfunction and matrix metalloproteinase activation in an autocrine/paracrine manner. Next, to elucidate the role of ADAMTS8 in RV function, we developed a cardiomyocyte-specific ADAMTS8 knockout mice (ADAMTS8^ΔαMHC). ADAMTS8^ΔαMHC mice showed ameliorated RV failure in response to chronic hypoxia. In addition, ADAMTS8^ΔαMHC mice showed enhanced angiogenesis and reduced RV ischemia and fibrosis. Finally, high-throughput screening revealed that mebendazole, which is used for treatment of parasite infections, reduced ADAMTS8 expression and cell proliferation in PAH-PASMCs and ameliorated PH and RV failure in PH rodent models.

CONCLUSIONS

These results indicate that ADAMTS8 is a novel therapeutic target in PAH.

Discovery of potential plasma protein biomarkers for acute myocardial infarction via proteomics

Background

Acute myocardial infarction (AMI) is an acute disease with high mortality and seriously threatens human health. The identification of new effective biological markers for AMI is a prerequisite for treatment. Most proteomic studies have focused on atherosclerotic plaques, vascular cells, monocytes and platelets in the blood; however, the concentration of these factors in plasma is low, making it difficult to measure the complexity of plasma components. Moreover, some studies have examined the plasma protein of patients with acute coronary syndrome with histochemistry; however, the results are not consistent. Therefore, it is necessary to further investigate the differential proteins in the plasma of patients with AMI via proteomics to identify new biomarkers of AMI.

Methods

In this study, immunodepletion of high-abundance plasma proteins followed by an isobaric tagging for relative and absolute quantitation (iTRAQ)-based quantitative proteomic approach was used to analyze plasma samples from 5 control individuals and 10 AMI patients.

Results

Four hundred sixty-eight proteins were identified from two samples, and 33 proteins were differentially expressed in AMI patients compared to the controls. Among the 33 proteins, 12 proteins showed a ≥1.5-fold change between AMI and control samples. These proteins included fatty acid binding protein 3 (FABP3, ratio =6.36), creatine kinase-MB (CK-MB ratio =4.89), adenylate kinase1 (AK1 ratio =4.16), pro-platelet basic protein (PPBP ratio =3.29), creatine kinase (CK ratio =2.88), platelet factor 4 (PF4 ratio =2.62), peptidyl prolyl isomerase Cyclophilin A (PPIA ratio =2.05), Cofilin-1 (CFL1 ratio =1.81), coronin1A (CORO1A ratio =1.71), protein kinase M (PKM ratio =1.63), ribonuclease inhibitor (RNH1, ratio =1.67), and triose phosphate isomerase (TPI1 ratio =1.56). By contrast, there was a decrease of 19 proteins, such as adiponectin (ADIPOQ ratio =0.70), insulin-like growth factor binding protein6 (IGFBP6 ratio =0.70), Dickkopf-related protein 3 (DKK3 ratio =0.70) and complement 4B (C4B ratio =0.68). The most over-represented term was regulation of cell proliferation in the cellular component category of Gene Ontology (GO). The top 3 biological process terms were regulation of cell proliferation, response to wounding and wound healing. These proteins included immune proteins, blood coagulation proteins, lipid metabolism proteins, cytoskeleton proteins, energy metabolism proteins, gene regulation proteins, myocutaneous proteins, and myocardial remodeling proteins and were highly connected with each other, which indicates that the functional network of these processes contribute to the pathophysiology of AMI.

Conclusions

In conclusion, the present quantitative proteomic study identified novel AMI biomarker candidates and might provide fundamental information for the development of an AMI biomarker.

High Serum Cyclophilin C levels as a risk factor marker for Coronary Artery Disease

Cyclophilins (Cyps) are ubiquitous proteins that belong to the immunophilins family consistently associated with inflammatory and cardiovascular diseases. While levels of CypA have been extensively studied, less data are available for other Cyps. The purpose of this case-control study was to determine the relationship of Cyps (A, B, C and D) with coronary artery disease (CAD) and eight inflammation markers. Serum levels of Cyps, interleukins and metalloproteinases were measured in serum collected from 84 subjects. Participants were divided into two sub-groups based on CAD diagnosis: 40 CAD patients and 44 control volunteers. Serum levels of CypA, CypB and CypC, IL-1β and IL-6 were significantly higher in CAD patients. Bivariate correlation analysis revealed a significant positive correlation between Cyps and several blood and biochemical parameters. When the ability of Cyps levels for CAD diagnosis was evaluated, higher sensitivity and selectivity values were obtained with CypC (c-statistic 0.891, p < 0.001) indicating that it is a good marker of CAD disease, while less conclusive results were obtained with CypA (c-statistic 0.748, p < 0.001) and CypB (c-statistic 0.655, p < 0.014). In addition, significant correlations of traditional CAD risk factors and CypC were observed. In summary, high levels of CypC are a risk factor for CAD and therefore it can be proposed as a new biomarker for this disease.

Cyclophilin A in Arrhythmogenic Cardiomyopathy Cardiac Remodeling

Arrhythmogenic cardiomyopathy (ACM) is a genetic disorder characterized by the progressive substitution of functional myocardium with noncontractile fibro-fatty tissue contributing to ventricular arrhythmias and sudden cardiac death. Cyclophilin A (CyPA) is a ubiquitous protein involved in several pathological mechanisms, which also characterize ACM (i.e., fibrosis, inflammation, and adipogenesis). Nevertheless, the involvement of CyPA in ACM cardiac remodeling has not been investigated yet. Thus, we first evaluated CyPA expression levels in the right ventricle (RV) tissue specimens obtained from ACM patients and healthy controls (HC) by immunohistochemistry. Then, we took advantage of ACM- and HC-derived cardiac mesenchymal stromal cells (C-MSC) to assess CyPA modulation during adipogenic differentiation. Interestingly, CyPA was more expressed in the RV sections obtained from ACM vs. HC subjects and positively correlated with the adipose replacement extent. Moreover, CyPA was upregulated at early stages of C-MSC adipogenic differentiation and was secreted at higher level over time in ACM- derived C-MSC. Our study provides novel ex vivo and in vitro information on CyPA expression in ACM remodeling paving the way for future C-MSC-based mechanistic and therapeutic investigations.

Exosomal cyclophilin A as a novel noninvasive biomarker for Epstein-Barr virus associated nasopharyngeal carcinoma

Exosomes have emerged as novel vehicles for proteins and other contents in cancer progression. Cyclophilin A (CYPA) is a pivotal member of immunophilin family. Whether CYPA can be detected in sera of nasopharyngeal carcinoma (NPC) patients remains to be explored. Epstein-Barr virus (EBV) is the first identified human tumor virus and is a causative agent of NPC. The antibody of EBV capsid antigen immunoglobulin A (EBV-VCA-IgA) is a known biomarker of NPC, with a proportion of no more than 70% being detected positively. Hence, novel biomarkers need to be discovered for early diagnosis, prognosis, and monitoring of EBV-associated NPC. A total of 110 NPC and 36 normal control serum samples were collected. Exosomes from these samples were extracted. The mRNA and protein expression levels of the above samples were validated by reverse transcription -quantitative polymerase chain reaction, Western blotting, or enzyme-linked immunosorbent assay (ELISA). Finally, the results demonstrated that both the serum and exosomal CYPA levels of NPC patients were significantly higher than that of normal cases. In addition, exosomal CYPA had a much higher level than that in the whole sera. The positive rate of EBV-VCA-IgA antibody was 68.2% in NPC sera, and noticeably, among the cases with EBV-VCA-IgA negative, 80% of them presented high levels of CYPA above the standard (cutoff value). In particular, CYPA in exosomes was uniformly with higher significance than that in whole sera. Combined analysis of CYPA protein and EBV-VCA-IgA antibody showed a greatly higher discriminatory ability in diagnosis of NPC. Moreover, exosomal CYPA level had a positive correlation with that of the EBV-encoded latent membrane protein 1 (LMP1) in exosomes. EBV-positive cancer cells secreted significantly higher levels of exosomal CYPA. This study established the utility of circulating exosomal CYPA as a potential noninvasive diagnostic biomarker for EBV-associated NPC.

Simplified immunosuppressive and neuroprotective agents based on gracilin A

The architecture and bioactivity of natural products frequently serve as embarkation points for the exploration of biologically relevant chemical space. Total synthesis followed by derivative synthesis has historically enabled a deeper understanding of structure-activity relationships. However, synthetic strategies towards a natural product are not always guided by hypotheses regarding the structural features required for bioactivity. Here, we report an approach to natural product total synthesis that we term 'pharmacophore-directed retrosynthesis'. A hypothesized, pharmacophore of a natural product is selected as an early synthetic target and this dictates the retrosynthetic analysis. In an ideal application, sequential increases in the structural complexity of this minimal structure enable development of a structure-activity relationship profile throughout the course of the total synthesis effort. This approach enables the identification of simpler congeners retaining bioactivity at a much earlier stage of a synthetic effort, as demonstrated here for the spongiane diterpenoid, gracilin A, leading to simplified derivatives with potent neuroprotective and immunosuppressive activity.

Cyclophilin A and CD147 associate with progression of diabetic nephropathy

To find the associations of circulating cyclophilin A (CyP A) and CD147/EMMPRIN with renal outcomes in type 2 diabetes patients and possible pathogenesis involved. Total 131 patients were recruited since 2004. Glycated hemoglobin, blood glucose and urine albumin-creatinine ratio levels at baseline and every 3 months were measured. Plasma CyP A and CD147 were also measured at baseline. Patients were divided into two groups based upon the median level of the baseline plasma CyP A value: < 93.64 ng/mL (group A, n = 65), ≥ 93.64 ng/mL (group B, n = 66). The estimated glomerular filtration rate was calculated at each follow-up visit. Besides, mitochondrial function assay by cellular mitochondrial energy utility was studied when cells were exposed to glucose or exogenous CyP A or both. Multivariate analysis, using median level (93.64) ng/mL as the cut-off value, revealed that circulating CyP A and CD147 levels at baseline were associated with the baseline estimated glomerular filtration rate (eGFR) (p = .042 and p = .001 separately) in cross-sectional analysis. Longitudinally, higher baseline plasma CyP A level was also correlated to a rapid decline in eGFR (p = .016). The results were also significant when using the continuous plasma CyP A level (p = .003). In cells exposed to glucose, results of oxygen consumption rate (OCR) showed a significant reduction in basal respiration, maximal respiration and ATP production. Depressed OCR further occurred when incubated with both of CyP A and glucose. Plasma CyP A and CD147 can serve as indicators of renal disease progression in type 2 diabetes patients.

Identification of Novel Therapeutic Targets for Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) and chronic thromboembolic pulmonary hypertension (CTEPH) are fatal diseases; however, their pathogenesis still remains to be elucidated. We have recently screened novel pathogenic molecules and have performed drug discovery targeting those molecules. Pulmonary artery smooth muscle cells (PASMCs) in patients with PAH (PAH-PASMCs) have high proliferative properties like cancer cells, which leads to thickening and narrowing of distal pulmonary arteries. Thus, we conducted a comprehensive analysis of PAH-PASMCs and lung tissues to search for novel pathogenic proteins. We validated the pathogenic role of the selected proteins by using tissue-specific knockout mice. To confirm its clinical significance, we used patient-derived blood samples to evaluate the potential as a biomarker for diagnosis and prognosis. Finally, we conducted a high throughput screening and found inhibitors for the pathogenic proteins.

Different roles of myocardial ROCK1 and ROCK2 in cardiac dysfunction and postcapillary pulmonary hypertension in mice

Although postcapillary pulmonary hypertension (PH) is an important prognostic factor for patients with heart failure (HF), its pathogenesis remains to be fully elucidated. To elucidate the different roles of Rho-kinase isoforms, ROCK1 and ROCK2, in cardiomyocytes in response to chronic pressure overload, we performed transverse aortic constriction (TAC) in cardiac-specific ROCK1-deficient (cROCK1^-/-) and ROCK2-deficient (cROCK2^-/-) mice. Cardiomyocyte-specific ROCK1 deficiency promoted pressure-overload-induced cardiac dysfunction and postcapillary PH, whereas cardiomyocyte-specific ROCK2 deficiency showed opposite results. Histological analysis showed that pressure-overload-induced cardiac hypertrophy and fibrosis were enhanced in cROCK1^-/- mice compared with controls, whereas cardiac hypertrophy was attenuated in cROCK2^-/- mice after TAC. Consistently, the levels of oxidative stress were up-regulated in cROCK1^-/- hearts and down-regulated in cROCK2^-/- hearts compared with controls after TAC. Furthermore, cyclophilin A (CyPA) and basigin (Bsg), both of which augment oxidative stress, enhanced cardiac dysfunction and postcapillary PH in cROCK1^-/- mice, whereas their expressions were significantly lower in cROCK2^-/- mice. In clinical studies, plasma levels of CyPA were significantly increased in HF patients and were higher in patients with postcapillary PH compared with those without it. Finally, high-throughput screening demonstrated that celastrol, an antioxidant and antiinflammatory agent, reduced the expressions of CyPA and Bsg in the heart and the lung, ameliorating cardiac dysfunction and postcapillary PH induced by TAC. Thus, by differentially affecting CyPA and Bsg expressions, ROCK1 protects and ROCK2 jeopardizes the heart from pressure-overload HF with postcapillary PH, for which celastrol may be a promising agent.

Development of Novel Therapies for Cardiovascular Diseases by Clinical Application of Basic Research

Cyclophilin A (CyPA) is secreted from vascular smooth muscle cells, inflammatory cells, activated platelets, and cardiac fibroblasts in response to oxidative stress. Excessive and continuous activation of the RhoA/Rho-kinase system promotes the secretion of CyPA, resulting in the development of multiple cardiovascular diseases. Basigin (Bsg), a transmembrane glycoprotein that activates matrix metalloproteinases, is an extracellular receptor for CyPA that promotes cell proliferation and inflammation. Thus, the CyPA/Bsg system is potentially a novel therapeutic target for cardiovascular diseases. Importantly, plasma CyPA levels are increased in patients with coronary artery disease, abdominal aortic aneurysms, pulmonary hypertension, and heart failure. Moreover, plasma CyPA levels can predict all-cause death in patients with coronary artery disease and pulmonary hypertension. Additionally, plasma soluble Bsg levels are increased and predict all-cause death in patients with heart failure, suggesting that CyPA and Bsg are novel biomarkers for cardiovascular diseases. To discover further novel molecules targeting the CyPA/Bsg system, high-throughput screening of compounds found molecules that ameliorate the development of cardiovascular diseases. In addition to CyPA and Bsg, novel therapeutic targets and their inhibitors for patients with pulmonary arterial hypertension have been recently screened and identified. Ultimately, the final goal is to develop novel biomarkers and medications that will be useful for improving the prognosis and quality of life in patients with cardiovascular diseases.

Comparative proteomic analysis reveals heart toxicity induced by chronic arsenic exposure in rats

Arsenic is a widespread metalloid in the environment, which poses a broad spectrum of adverse effects on human health. However, a global view of arsenic-induced heart toxicity is still lacking, and the underlying molecular mechanisms remain unclear. By performing a comparative quantitative proteomic analysis, the present study aims to investigate the alterations of proteome profile in rat heart after long-term exposure to arsenic. As a result, we found that the abundance of 81 proteins were significantly altered by arsenic treatment (35 up-regulated and 46 down-regulated). Among these, 33 proteins were specifically associated with cardiovascular system development and function, including heart development, heart morphology, cardiac contraction and dilation, and other cardiovascular functions. It is further proposed that the aberrant regulation of 14 proteins induced by arsenic would disturb cardiac contraction and relaxation, impair heart morphogenesis and development, and induce thrombosis in rats, which is mediated by the Akt/p38 MAPK signaling pathway. Overall, these findings will augment our knowledge of the involved mechanisms and develop useful biomarkers for cardiotoxicity induced by environmental arsenic exposure.

Prognostic Impacts of Plasma Levels of Cyclophilin A in Patients With Coronary Artery Disease

Objective—

Cyclophilin A (CyPA) is secreted from vascular smooth muscle cells, inflammatory cells, and activated platelets in response to oxidative stress. We have recently demonstrated that plasma CyPA level is a novel biomarker for diagnosing coronary artery disease. However, it remains to be elucidated whether plasma CyPA levels also have a prognostic impact in such patients.

Approach and Results—

In 511 consecutive patients undergoing diagnostic coronary angiography, we measured the plasma levels of CyPA, high-sensitivity C-reactive protein (hsCRP), and brain natriuretic peptide and evaluated their prognostic impacts during the follow-up (42 months, interquartile range: 25–55 months). Higher CyPA levels (≥12 ng/mL) were significantly associated with all-cause death, rehospitalization, and coronary revascularization. Higher hsCRP levels (≥1 mg/L) were also significantly correlated with the primary end point and all-cause death, but not with rehospitalization or coronary revascularization. Similarly, higher brain natriuretic peptide levels (≥100 pg/mL) were significantly associated with all-cause death and rehospitalization, but not with coronary revascularization. Importantly, the combination of CyPA (≥12 ng/mL) and hsCRP (≥1 mg/L) was more significantly associated with all-cause death (hazard ratio, 21.2; 95% confidence interval, 4.9–92.3,; P <0.001) than CyPA (≥12 ng/mL) or hsCRP (≥1 mg/L) alone.

Conclusions—

The results indicate that plasma CyPA levels can be used to predict all-cause death, rehospitalization, and coronary revascularization in patients with coronary artery disease and that when combined with other biomarkers (hsCRP and brain natriuretic peptide levels), the CyPA levels have further enhanced prognostic impacts in those patients.

RhoA/Rho-Kinase in the Cardiovascular System

Twenty years ago, Rho-kinase was identified as an important downstream effector of the small GTP-binding protein, RhoA. Thereafter, a series of studies demonstrated the important roles of Rho-kinase in the cardiovascular system. The RhoA/Rho-kinase pathway is now widely known to play important roles in many cellular functions, including contraction, motility, proliferation, and apoptosis, and its excessive activity induces oxidative stress and promotes the development of cardiovascular diseases. Furthermore, the important role of Rho-kinase has been demonstrated in the pathogenesis of vasospasm, arteriosclerosis, ischemia/reperfusion injury, hypertension, pulmonary hypertension, and heart failure. Cyclophilin A is secreted by vascular smooth muscle cells and inflammatory cells and activated platelets in a Rho-kinase-dependent manner, playing important roles in a wide range of cardiovascular diseases. Thus, the RhoA/Rho-kinase pathway plays crucial roles under both physiological and pathological conditions and is an important therapeutic target in cardiovascular medicine. Recently, functional differences between ROCK1 and ROCK2 have been reported in vitro. ROCK1 is specifically cleaved by caspase-3, whereas granzyme B cleaves ROCK2. However, limited information is available on the functional differences and interactions between ROCK1 and ROCK2 in the cardiovascular system in vivo. Herein, we will review the recent advances about the importance of RhoA/Rho-kinase in the cardiovascular system.