Mitofilin in cardiovascular diseases: Insights into the pathogenesis and potential pharmacological interventions.

The impact of mitochondrial dysfunction on the pathogenesis of cardiovascular disease is increasing. However, the precise underlying mechanism remains unclear. Mitochondria produce cellular energy through oxidative phosphorylation while regulating calcium homeostasis, cellular respiration, and the production of biosynthetic chemicals. Nevertheless, problems related to cardiac energy metabolism, defective mitochondrial proteins, mitophagy, and structural changes in mitochondrial membranes can cause cardiovascular diseases via mitochondrial dysfunction. Mitofilin is a critical inner mitochondrial membrane protein that maintains cristae structure and facilitates protein transport while linking the inner mitochondrial membrane, outer mitochondrial membrane, and mitochondrial DNA transcription. Researchers believe that mitofilin may be a therapeutic target for treating cardiovascular diseases, particularly cardiac mitochondrial dysfunctions. In this review, we highlight current findings regarding the role of mitofilin in the pathogenesis of cardiovascular diseases and potential therapeutic compounds targeting mitofilin.

Response to programmed cell death protein 1 antibody in patients with Epstein-Barr virus-associated intrahepatic cholangiocarcinoma.

AIM: Epstein-Barr virus-associated intrahepatic cholangiocarcinoma (EBVaICC) has a distinct genomic profile and increased CD3+ and CD8+ T cells infiltration. However, the efficacy of immunotherapy in EBVaICC remains largely unknown. This study aimed to assess the efficacy of programmed cell death protein 1 (PD-1) antibody therapy in EBVaICC. METHODS: Patients with metastatic biliary tract cancer (BTC) diagnosed at Sun Yat-sen University Cancer Center from January 2016 to December 2021 were identified. In situ hybridisation was performed to detect EBV. Overall survival (OS) and progression-free survival (PFS) were measured. RESULTS: A total of 698 patients with metastatic BTC were identified, of whom 39 (5.6%) had EBVaICC. Among the 136 patients who were not administered PD-1 antibody, the OS was similar between patients with EBVaICC and EBV-negative ICC (median OS 12.5 versus 9.5 months, respectively; P = 0.692). For the 205 patients who were administered PD-1 antibody, patients with EBVaICC had significantly longer OS than patients with EBV-negative ICC (median OS 24.9 versus 11.9 months, respectively; P = 0.004). Seventeen patients with EBVaICC were administered PD-1 antibody. Eight patients (47%) achieved a partial response, and 17 patients achieved disease control. The median PFS was 17.5 months. CONCLUSIONS: This study identified a clinically actionable subset of patients with EBVaICC with a promising response to the PD-1 antibody.

Iron homeostasis in the heart: Molecular mechanisms and pharmacological implications.

Iron is necessary for the life of practically all living things, yet it may also harm people toxically. Accordingly, humans and other mammals have evolved an effective and tightly regulatory system to maintain iron homeostasis in healthy tissues, including the heart. Iron deficiency is common in patients with heart failure, and is associated with worse prognosis in this population; while the prevalence of iron overload-related cardiovascular disorders is also increasing. Therefore, enhancing the therapy of patients with cardiovascular disorders requires a thorough understanding of iron homeostasis. Here, we give readers an overview of the fundamental mechanisms governing systemic iron homeostasis as well as the most recent knowledge about the intake, storage, use, and export of iron from the heart. Genetic mouse models used for investigation of iron metabolism in various in vivo scenarios are summarized and highlighted. We also go through different clinical conditions and therapeutic approaches that target cardiac iron dyshomeostasis. Finally, we conclude the review by outlining the present knowledge gaps and important open questions in this field in order to guide future research on cardiac iron metabolism.

Research progress on effects of traditional Chinese medicine on myocardial ischemia-reperfusion injury: A review.

Ischemic heart disease (IHD) is a high-risk disease in the middle-aged and elderly population. The ischemic heart may be further damaged after reperfusion therapy with percutaneous coronary intervention (PCI) and other methods, namely, myocardial ischemia-reperfusion injury (MIRI), which further affects revascularization and hinders patient rehabilitation. Therefore, the investigation of new therapies against MIRI has drawn great global attention. Within the long history of the prevention and treatment of MIRI, traditional Chinese medicine (TCM) has increasingly been recognized by the scientific community for its multi-component and multi-target effects. These multi-target effects provide a conspicuous advantage to the anti-MIRI of TCM to overcome the shortcomings of single-component drugs, thereby pointing toward a novel avenue for the treatment of MIRI. However, very few reviews have summarized the currently available anti-MIRI of TCM. Therefore, a systematic data mining of TCM for protecting against MIRI will certainly accelerate the processes of drug discovery and help to identify safe candidates with synergistic formulations. The present review aims to describe TCM-based research in MIRI treatment through electronic retrieval of articles, patents, and ethnopharmacology documents. This review reported the progress of research on the active ingredients, efficacy, and underlying mechanism of anti-MIRI in TCM and TCM formulas, provided scientific support to the clinical use of TCM in the treatment of MIRI, and revealed the corresponding clinical significance and development prospects of TCM in treating MIRI.

Overview of the preparation method, structure and function, and application of natural peptides and polypeptides.

Natural polypeptides, a kind of molecular polymer with obvious biological activity, are widely existing in nature. They participate in various physiological activities of living organisms and play an important role in promoting human health. They are also widely applied in medicine, food, and cosmetic industries. By searching literature from Pubmed, Google Scholar, Web of Science, Springer Link and Elsevier, this work presents an overview of the preparation methods, the relationship between structure and function, and the application of natural polypeptides. The preparation methods mainly include solvent extraction, enzymatic decomposition, microbiological fermentation, chemical synthesis, genetic engineering recombination, and using cell free system. Natural polypeptide's physiological function mainly includes antioxidative, antibacterial, antihypertensive. This review could provide scientific basis for the research and development of natural polypeptide.

Progress in the treatment of diabetic peripheral neuropathy.

Diabetic peripheral neuropathy (DPN) is one of the most common chronic complications of diabetes. Symptoms of DPN mainly include spontaneous intractable pain that is diffuse and continuous and can last from several weeks to several months. DPN is associated with a high mortality rate and poor prognosis. Its pathogenesis is not fully understood, and clinical treatment is focused on relieving its clinical symptoms, as well as improving blood sugar control and cardiovascular risk factors. DPN and its clinically effective treatments need to be studied. This study discusses the treatment methods and pathogenesis of DPN, summarizes the related research progress, and attempts to provide a reference for DPN research.

Innate Immune Nod1/RIP2 Signaling Is Essential for Cardiac Hypertrophy but Requires Mitochondrial Antiviral Signaling Protein for Signal Transductions and Energy Balance.

BACKGROUND: Cardiac hypertrophy is a key biological response to injurious stresses such as pressure overload and, when excessive, can lead to heart failure. Innate immune activation by danger signals, through intracellular pattern recognition receptors such as nucleotide-binding oligomerization domain 1 (Nod1) and its adaptor receptor-interacting protein 2 (RIP2), might play a major role in cardiac remodeling and progression to heart failure. We hypothesize that Nod1/RIP2 are major contributors to cardiac hypertrophy, but may not be sufficient to fully express the phenotype alone. METHODS: To elucidate the contribution of Nod1/RIP2 signaling to cardiac hypertrophy, we randomized Nod1-/-, RIP2-/-, or wild-type mice to transverse aortic constriction or sham operations. Cardiac hypertrophy, fibrosis, and cardiac function were examined in these mice. RESULTS: Nod1 and RIP2 proteins were upregulated in the heart after transverse aortic constriction, and this was paralleled by increased expression of mitochondrial proteins, including mitochondrial antiviral signaling protein (MAVS). Nod1-/- and RIP2-/- mice subjected to transverse aortic constriction exhibited better survival, improved cardiac function, and decreased cardiac hypertrophy. Downstream signal transduction pathways that regulate inflammation and fibrosis, including NF (nuclear factor) κB and MAPK (mitogen-activated protein kinase)-GATA4/p300, were reduced in both Nod1-/- and RIP2-/- mice after transverse aortic constriction compared with wild-type mice. Coimmunoprecipitation of extracted cardiac proteins and confocal immunofluorescence microscopy showed that Nod1/RIP2 interaction was robust and that this complex also included MAVS as an essential component. Suppression of MAVS expression attenuated the complex formation, NF κB signaling, and myocyte hypertrophy. Interrogation of mitochondrial function compared in the presence or ablation of MAVS revealed that MAVS serves to suppress mitochondrial energy output and mediate fission/fusion related dynamic changes. The latter is possibly linked to mitophagy during cardiomyocytes stress, which may provide an intriguing link between innate immune activation and mitochondrial energy balance under stress or injury conditions. CONCLUSIONS: We have identified that innate immune Nod1/RIP2 signaling is a major contributor to cardiac remodeling after stress. This process is critically joined by and regulated through the mitochondrial danger signal adapter MAVS. This novel complex coordinates remodeling, inflammatory response, and mitochondrial energy metabolism in stressed cardiomyocytes. Thus, Nod1/RIP2/MAVS signaling complex may represent an attractive new therapeutic approach toward heart failure.

DL-3-n-butylphthalide protects endothelial cells against advanced glycation end product-induced injury by attenuating oxidative stress and inflammation responses.

Endothelial dysfunction, regarded as a key step in the pathophysiological course of diabetic vascular complications, is initiated and deteriorated by advanced glycation end products (AGEs). DL-3-n-butylphthalide (DL-NBP) has been proven to have protective effects on neurons and vascular endothelial cells against ischemic and anoxic damage. The aim of the present study was to investigate whether NBP is able to attenuate AGE-induced endothelial dysfunction in vitro, and also elucidate the possible underlying mechanism. An injury model of human umbilical vein endothelial cells (HUVECs) induced by AGEs (200 µg/ml) was established. The results demonstrated that pretreatment with NBP (1-100 µM) significantly increased HUVEC viability and inhibited the apoptosis induced by AGEs. In addition, AGEs stimulated the expression levels of the receptor for AGEs protein and the downstream protein nuclear factor-κB in HUVECs, which were inhibited by pretreatment with NBP. Furthermore, it significantly reduced reactive oxygen species generation and the level of the inflammatory cytokines, intercellular cell adhesion molecule-1 and monocyte chemotactic protein-1, in HUVECs mediated by AGEs. The current findings indicated that NBP attenuated AGE-induced endothelial dysfunction by ameliorating inflammation and oxidative stress responses.

Protection of the Transplant Kidney from Preservation Injury by Inhibition of Matrix Metalloproteinases.

BACKGROUND: Matrix metalloproteinases (MMPs), particularly MMP-2 and MMP-9, play an important role in ischemic injury to the heart, yet it is not known if these MMPs are involved in the injury that occurs to the transplant kidney. We therefore studied the pharmacologic protection of transplant kidneys during machine cold perfusion. METHODS: Human kidney perfusates were analyzed for the presence of injury markers such as cytochrome c oxidase, lactate dehydrogenase, and neutrophil-gelatinase associated lipocalin (NGAL), and MMP-2 and MMP-9 were measured. The effects of MMP inhibitors MMP-2 siRNA and doxycycline were studied in an animal model of donation after circulatory determination of death (DCDD). RESULTS: Markers of injury were present in all analyzed perfusates, with higher levels seen in perfusates from human kidneys donated after controlled DCDD compared to brain death and in perfusate from kidneys with delayed graft function. When rat kidneys were perfused at 4°C for 22 hours with the addition of MMP inhibitors, this resulted in markedly reduced levels of MMP-2, MMP-9 and analyzed injury markers. CONCLUSIONS: Based on our study, MMPs are involved in preservation injury and the supplementation of preservation solution with MMP inhibitors is a potential novel strategy in protecting the transplant kidney from preservation injury.

Subthreshold nitric oxide synthase inhibition improves synergistic effects of subthreshold MMP-2/MLCK-mediated cardiomyocyte protection from hypoxic injury.

Injury of myocardium during ischaemia/reperfusion (I/R) is a complex and multifactorial process involving uncontrolled protein phosphorylation, nitration/nitrosylation by increased production of nitric oxide and accelerated contractile protein degradation by matrix metalloproteinase-2 (MMP-2). It has been shown that simultaneous inhibition of MMP-2 with doxycycline (Doxy) and myosin light chain kinase (MLCK) with ML-7 at subthreshold concentrations protects the heart from contractile dysfunction triggered by I/R in a synergistic manner. In this study, we showed that additional co-administration of nitric oxide synthase (NOS) inhibitor (1400W or L-NAME) in subthreshold concentrations improves this synergistic protection in the model of hypoxia-reoxygenation (H-R)-induced contractile dysfunction of cardiomyocytes. Isolated cardiomyocytes were subjected to 3 min. of hypoxia and 20 min. of reoxygenation in the presence or absence of the inhibitor cocktails. Contractility of cardiomyocytes was expressed as myocyte peak shortening. Inhibition of MMP-2 by Doxy (25-100 µM), MLCK by ML-7 (0.5-5 µM) and NOS by L-NAME (25-100 µM) or 1400W (25-100 µM) protected myocyte contractility after H-R in a concentration-dependent manner. Inhibition of these activities resulted in full recovery of cardiomyocyte contractility after H-R at the level of highest single-drug concentration. The combination of subthreshold concentrations of NOS, MMP-2 and MLCK inhibitors fully protected cardiomyocyte contractility and MLC1 from degradation by MMP-2. The observed protection with addition of L-NAME or 1400W was better than previously reported combination of ML-7 and Doxy. The results of this study suggest that addition of NOS inhibitor to the mixture of inhibitors is better strategy for protecting cardiomyocyte contractility.

Inhibition of MMP-2 expression with siRNA increases baseline cardiomyocyte contractility and protects against simulated ischemic reperfusion injury.

Matrix metalloproteinases (MMPs) significantly contribute to ischemia reperfusion (I/R) injury, namely, by the degradation of contractile proteins. However, due to the experimental models adopted and lack of isoform specificity of MMP inhibitors, the cellular source and identity of the MMP(s) involved in I/R injury remain to be elucidated. Using isolated adult rat cardiomyocytes, subjected to chemically induced I/R-like injury, we show that specific inhibition of MMP-2 expression and activity using MMP-2 siRNA significantly protected cardiomyocyte contractility from I/R-like injury. This was also associated with increased expression of myosin light chains 1 and 2 (MLC1/2) in comparison to scramble siRNA transfection. Moreover, the positive effect of MMP-2 siRNA transfection on cardiomyocyte contractility and MLC1/2 expression levels was also observed under control conditions, suggesting an important additional role for MMP-2 in physiological sarcomeric protein turnover. This study clearly demonstrates that intracellular expression of MMP-2 plays a significant role in sarcomeric protein turnover, such as MLC1 and MLC2, under aerobic (physiological) conditions. In addition, this study identifies intracellular/autocrine, cardiomyocyte-produced MMP-2, rather than paracrine/extracellular, as responsible for the degradation of MLC1/2 and consequent contractile dysfunction in cardiomyocytes subjected to I/R injury.

Inhibition of MMP-2 expression affects metabolic enzyme expression levels: proteomic analysis of rat cardiomyocytes.

In this study we examined the effect of inhibition of MMP-2 expression, using siRNA, on the cardiomyocyte proteome. Isolated cardiomyocytes were transfected with MMP-2 siRNA and incubated for 24h. Control cardiomyocytes from the same heart were transfected with scrambled siRNA following the same protocol. Comparison of control cardiomyocyte proteomes with proteomes from MMP-2 suppressed cardiomyocytes revealed 13 protein spots of interest (9 protein spots increased; 4 decreased). Seven protein spots were identified as mitochondrial enzymes involved in energy production and represent: ATP synthase beta subunit, dihydrolipoyllysine-residue succinyltransferase component of 2-oxoglutarate dehydrogenase complex, cytochrome c oxidase subunit 5A, electron transfer flavoprotein subunit beta, NADH dehydrogenase (ubiquinone) 1 alpha subcomplex subunit 5 and a fragment of mitochondrial precursor of long-chain specific acyl-CoA dehydrogenase. Furthermore, precursor of heat shock protein 60 and Cu-Zn superoxide dismutase were identified. Two protein spots corresponding to MLC1 were also detected. In addition, ATP synthase activity was measured and was increased by approximately 30%. Together, these results indicate that MMP-2 inhibition represents a novel cardioprotective therapy by promoting alterations in the levels of mitochondrial enzymes for improved energy metabolism and by preventing degradation of contractile proteins needed for normal excitation-contraction coupling. BIOLOGICAL SIGNIFICANCE: During ischemia and reperfusion of cardiomyocytes, abnormality in excitation-contraction coupling and decreased energy metabolism often lead to myocardial infarction, but the cellular mechanisms are not fully elucidated. We show for the first time that intracellular inhibition of MMP-2 in cardiomyocytes increases contractility of aerobically perfused myocytes, which was accompanied by increased expression of contractile proteins (e.g., MLC-1). We also showed that MMP-2 inhibition produced a cardiomyocyte proteome that is consistent with improved mitochondrial energy metabolism (e.g., increased expression and activity of mitochondrial beta ATP synthase). Thus, MMP-2 appears to be involved in homeostatic regulation of protein turnover. Our results are significant since they point to targeting MMP-2 activity as a novel therapeutic option to limit myocardial damage by decreasing proteolytic degradation of mitochondrial metabolic enzymes and myocardial contractile proteins during ischemia. In addition, the development of novel pharmacological agents that selectively targets cardiac MMP-2 represents a novel approach to treat and prevent other heart diseases.

Synergistic protection of MLC 1 against cardiac ischemia/reperfusion-induced degradation: a novel therapeutic concept for the future.

Cardiovascular diseases are a major burden to society and a leading cause of morbidity and mortality in the developed world. Despite clinical and scientific advances in understanding the molecular mechanisms and treatment of heart injury, novel therapeutic strategies are needed to prevent morbidity and mortality due to cardiac events. Growing evidence reported over the last decade has focused on the intracellular targets for proteolytic degradation by MMP-2. Of particular interest is the establishment of MMP-2-dependent degradation of cardiac contractile proteins in response to increased oxidative stress conditions, such as ischemia/reperfusion. The authors' laboratory has identified a promising preventive therapeutic target using the classical pharmacological concept of synergy to target MMP-2 activity and its proteolytic action on a cardiac contractile protein. This manuscript provides an overview of the body of evidence that supports the importance of cardiac contractile protein degradation in ischemia/reperfusion injury and the use of synergy to protect against it.

Effect of the myosin light chain kinase inhibitor ML-7 on the proteome of hearts subjected to ischemia-reperfusion injury.

In the development of ischemia/reperfusion (I/R) injury, the role of the myosin light chain (MLC) phosphorylation has been given increased consideration. ML-7, a MLC kinase inhibitor, has been shown to protect cardiac function from I/R, however the exact mechanism remains unclear. Isolated rat hearts were perfused under aerobic conditions (controls) or subjected to I/R in the presence or absence of ML-7. Continuous administration of ML-7 (5 µM) from 10 min before onset of ischemia to the first 10 min of reperfusion resulted in significant recovery of heart contractility. Analysis of gels from two-dimensional electrophoresis revealed eight proteins with decreased levels in I/R hearts. Six proteins are involved in energy metabolism:ATP synthase beta subunit, cytochrome b-c1 complex subunit 1, 24-kDa mitochondrial NADH dehydrogenase, NADH dehydrogenase [ubiquinone] iron-sulfur protein 8, cytochrome c oxidase subunit, and succinyl-CoA ligase subunit. The other two proteins with decreased levels in I/R hearts are: peroxiredoxin-2 and tubulin. Administration of ML-7 increased level of succinyl-CoA ligase, key enzyme involved in the citric acid cycle. The increased level of succinyl-CoA ligase in I/R hearts perfused with ML-7 suggests that the cardioprotective effect of ML-7, at least partially, also may involve increase of energy production.

Proteomic analysis of right and left cardiac ventricles under aerobic conditions and after ischemia/reperfusion.

Ischemia/reperfusion (I/R) injury is a major consequence of a cardiovascular intervention. The study of changes of the left and right ventricle proteomes from hearts subjected to I/R may be a key to revealing the pathological mechanisms underlying I/R-induced heart contractile dysfunction. Isolated rat hearts were perfused under aerobic conditions or subjected to 25 min global ischemia and 30 min reperfusion. At the end of perfusion, right and left ventricular homogenates were analyzed by 2DE. Contractile function and coronary flow were significantly reduced by I/R. 2DE followed by mass spectrometry identified ten protein spots whose levels were significantly different between aerobic left and right ventricles, eight protein spots whose levels were different between aerobic and I/R left ventricle, ten protein spots whose levels were different between aerobic and I/R right ventricle ten protein spots whose levels were different between the I/R groups. Among these protein spots were ATP synthase beta subunit, myosin light chain 2, myosin heavy chain fragments, peroxiredoxin-2, and heat shock proteins, previously associated with cardiovascular disease. These results reveal differences between proteomes of left and right ventricle both under aerobic conditions and in response to I/R that contribute to a better understanding of I/R injury.

Crohn disease of small bowel: multidetector row CT with CT enteroclysis, dynamic contrast enhancement, CT angiography, and 3D imaging.

BACKGROUND: CT could be used to evaluate abnormalities in the bowel wall, mesentery, adjacent structures, vasculature, and even the activity of Crohn disease (CD). To our knowledge, few direct comparisons of CD characterization using multidetector row CT with dynamic contrast enhancement, 3D imaging, CT angiography (CTA), and CT-enteroclysis (CT-E) on the same cohort of patients. The purpose of this study was to evaluate the diagnostic value of CD using multidetector helical CT with CT-E, dynamic contrast enhancement, 3D imaging, and CTA. METHODS: Twenty-eight patients known or suspected CD underwent CT-E, dynamic contract enhancement, CTA, and 3D imaging. The multidetector CT series images were performed on eight-slice CT scanner. All the examinations were performed when water was used as an oral contrast starting 25 s after 140 mL of intravenous contrast agent was administered, followed by portal venous phase (60 s), and a 60-70 s delay, then sending 1.25-mm slices to the 3D workstation, CT angiograms and 3D images were reconstructed. All the images were reviewed to detect abnormalities of CD. The abnormalities of the bowel wall, mucosal and submucosal ulceration, prominent perienteric vasculature, sinus tracts or fistulae, abscess were evaluated. RESULTS: Crohn disease was diagnosed in 28 patients by CT images, and 54 inflammatory segments were revealed. In active inflammatory cases, the diseased bowel wall thickened and the enhancement of diseased bowel wall increased significantly in 34 inflammatory segments of 22 cases, the enhancement of diseased bowel wall increased significantly but without the wall thickened in three patients. Prominent vasculature was found in CTA and 3D images in 21 patients with active diseases. In 16 patients, the sharp interface between bowel and mesentery was lost and the attenuation of fat increased. Sinus tracts or fistulae were observed in eight patients, four of 28 patients demonstrated abscesses, all were active inflammatory patients. In three chronic inflammatory patients, normal bowel, bowel lumen stricture, and the normal enhancement of the wall were displayed. CONCLUSION: The abnormalities of CD and its complications can be identified by multidetector CT with CT-E, dynamic enhancement, CTA, and 3D imaging, and they are important methods in diagnosing CD. Complications of CD can be shown better when CT-E is performed.