Nogo-B mediates endothelial oxidative stress and inflammation to promote coronary atherosclerosis in pressure-overloaded mouse hearts.

AIMS: Endothelial dysfunction plays a pivotal role in atherosclerosis, but the detailed mechanism remains incomplete understood. Nogo-B is an endoplasmic reticulum (ER)-localized protein mediating ER-mitochondrial morphology. We previously showed endothelial Nogo-B as a key regulator of endothelial function in the setting of hypertension. Here, we aim to further assess the role of Nogo-B in coronary atherosclerosis in ApoE-/- mice with pressure overload. METHODS AND RESULTS: We generated double knockout (DKO) mouse models of systemically or endothelium-specifically excising Nogo-A/B gene on an ApoE-/- background. After 7 weeks of transverse aortic constriction (TAC) surgery, compared to ApoE-/- mice DKO mice were resistant to the development of coronary atherosclerotic lesions and plaque rapture. Sustained elevation of Nogo-B and adhesion molecules (VCAM-1/ICAM-1), early markers of atherosclerosis, was identified in heart tissues and endothelial cells (ECs) isolated from TAC ApoE-/- mice, changes that were significantly repressed by Nogo-B deficiency. In cultured human umbilical vein endothelial cells (HUVECs) exposure to inflammatory cytokines (TNF-α, IL-1ß), Nogo-B was upregulated and activated reactive oxide species (ROS)-p38-p65 signaling axis. Mitofusin 2 (Mfn2) is a key protein tethering ER to mitochondria in ECs, and we showed that Nogo-B expression positively correlated with Mfn2 protein level. And Nogo-B deletion in ECs or in ApoE-/- mice reduced Mfn2 protein content and increased ER-mitochondria distance, reduced ER-mitochondrial Ca2+ transport and mitochondrial ROS generation, and prevented VCAM-1/ICAM-1 upregulation and EC dysfunction, eventually restrained atherosclerotic lesions development. CONCLUSION: Our study revealed that Nogo-B is a critical modulator in promoting endothelial dysfunction and consequent pathogenesis of coronary atherosclerosis in pressure overloaded hearts of ApoE-/- mice. Nogo-B may hold the promise to be a common therapeutic target in the setting of hypertension.

Hippo pathway activation mediates chemotherapy-induced anti-cancer effect and cardiomyopathy through causing mitochondrial damage and dysfunction.

Rationale: Chemotherapy is a common clinical strategy for cancer treatment. However, the accompanied cardiomyopathy renders cancer patients under risk of another life-threatening condition. Whereas Hippo pathway is known to play key roles in both cancerogenesis and heart disease, it remains unclear whether Hippo pathway activation mediates chemotherapy-induced cardiomyopathy. Methods and Results: In human breast cancer cells, doxorubicin (DOX) significantly induced upregulation of Hippo kinase Mst1, inhibitory phosphorylation of YAP, mitochondrial damage, reduced cell viability and increased apoptosis. Hippo pathway inactivation by Mst1-siRNA transfection effectively improved cell survival and mitigated mitochondrial damage and cell apoptosis. Another anti-cancer drug YAP inhibitor verteporfin also induced lower cancer cell viability, apoptosis and mitochondrial injury. Chronic treatment with DOX in vivo (4 mg/kg/week for 6 weeks) caused mitochondrial damage and dysfunction, oxidative stress and cardiac fibrosis, while acute DOX treatment (16 mg/kg single bolus) also induced myocardial oxidative stress and mitochondrial abnormalities. Chronic treatment with verteporfin (2 months) resulted in cardiomyopathy phenotypes comparable to that by chronic DOX regimen. In transgenic mice with cardiac overexpression of kinase-dead mutant Mst1 gene, these adverse cardiac effects of DOX were significantly attenuated relative to wild-type littermates. Conclusions: Anti-cancer action of both DOX and verteporfin is associated with Hippo pathway activation. Such action on cardiac Hippo pathway mediates mitochondrial damage and cardiomyopathy.

Physiological Effects of Ferroptosis on Organ Fibrosis.

Ferroptosis is a new type of programmed cell death with unique morphological, biochemical, and genetic features. From the initial study of histomorphology to the exploration of subcellular organelles and even molecular mechanisms, a net connecting ferroptosis and fibrosis is being woven and formed. Inflammation may be the bridge between both processes. In this review, we will discuss the ferroptosis theory and process and the physiological functions of ferroptosis, followed by a description of the pathological effects and the underlying mechanisms of ferroptosis in the pathogenesis of tumorigenesis, ischemic damage, degenerative lesions, autoimmune diseases, and necroinflammation. We then focus on the role of ferroptosis in the fibrosis process in the liver, lung, kidney, heart, and other organs. Although the molecular mechanism of ferroptosis has been explored extensively in the past few years, many challenges remain to be resolved to translate this information into antifibrotic practice, which is becoming a promising new direction in the field of fibrotic disease prevention and treatment.

aBVA Procedure by Uniportal Video-Assisted Thoracoscopic Surgery for Right Upper Peripheral Lung Cancer: A Randomized Trial.

OBJECTIVE: This study aims to determine the optimal dividing order of anatomic pulmonary resection under uniportal video-assisted thoracoscopic surgery (uni-VATS) for patients with right upper peripheral lung cancer. METHODS: Patients who met the eligibility criteria were randomly allocated into the aBVA and VAB groups. In the aBVA group, the surgical procedure proceeded from the posterior to the anterior region (from the deeper to the superficial site). In the VAB group, the dissection orders were vein first followed by arterial branches, followed by the bronchus. Clinical data were collected and analyzed. RESULTS: Sixty patients were randomly allocated to the aBVA group (n = 30) and the VAB group (n = 30). The operation time in the aBVA group (230.500 ± 68.360 min) was significantly shorter than that in the VAB group (305.600 ± 107.821 min) (p = 0.01). The blood loss in the aBVA group (104.000 ± 70.935 ml) was significantly lower than that in the VAB group (391.000 ± 625.175 ml) (p = 0.01). Two patients in the VAB group underwent conversion to 2-portal VATS. The number of lymph nodes (13.367 ± 5.436 vs. 10.333 ± 7.279, p = 0.072) and lymph node stations (5.067 ± 1.574 vs. 4.467 ± 2.345, p = 0.567) were comparable between the two groups. The differences in the postoperative drainage tube time (5.033 ± 3.113 vs. 6.467 ± 4.447 days, p = 0.278) and hospital stay (8.233 ± 3.390 vs. 9.433 ± 4.523 days, p = 0.361) were not significantly different between the two groups. CONCLUSION: Compared with the VBA procedure, aBVA is easier for patients with right upper peripheral lung cancer who undergo uni-VATS lobectomy.

Resection of calcified lymph nodes confers clinical benefit in patients with non-small cell lung cancer.

The aim of the present study was to compare the metastatic ratio between calcified lymph node stations (CLNS) and non-CLNS (NCLNS) and to explore the impact of CLNS on surgical outcomes. Consecutive patients with non-small cell lung cancer (NSCLC) scheduled to receive surgical treatment between June and December 2020 were included in the present study. Their clinical and radiological data were prospectively collected and analyzed. A total of 91 patients with NCLNS and 64 patients with CLNS were enrolled in the present study. Out of the 91 patients, 38 (24.516%) patients had 61/343 (17.784%) lymph node stations (LNS) that were metastasized. On a per-patient basis, the differences in the LNS metastatic ratio were not significant between the CLNS with NCLNS groups. However, on a per-nodal station basis, all differences in the LNS metastatic ratio between the groups were significant not only in the all-LNS group (P=0.004), but also in the LNS group which in patients with solely CLNS or NCLNS (P=0.009) and in the patients with CLNS (P=0.010). Pathology, T stage and calcification were independent predictive factors for LNS metastasis (P=0.002, P=0.021 and P=0.044, respectively). More patients with CLNS than patients with NCLNS received thoracotomy or conversion from video-assisted thoracoscopic surgery to thoracotomy (P=0.006). The operating time and blood loss were significantly higher in patients with CLNS than in those without (P<0.001 and P<0.001, respectively). Although CLNS are a risk reduction factor for metastasis and their dissection is time- and blood-consuming in patients with NSCLC, their thorough removal is advisable, since metastases were identified in ~15% of patients and 9% of CLNS.

A preliminary study identifies early postoperative lung volume changes in patients with non-small cell lung cancer following video-assisted thoracic surgery using CT volumetry.

The present study aimed to investigate the changes in early postoperative lung volume in patients with non-small cell lung cancer (NSCLC) following video-assisted thoracic surgery (VATS) and to analyze the effects of the clinical characteristics on the lung volume of the patients. Therefore, 38 patients with NSCLC, who planned to undergo VATS at the Department of Thoracic Surgery, The Affiliated Hospital of Guizhou Medical University in June 2019, were enrolled into the present study. The clinical and computed tomography (CT) scan data from the patients was prospectively collected within 1 week preoperatively, and at 1, 3 and 6 months following surgery, then subsequently analyzed. A total of 34 patients successfully completed follow-up and were included in the datasets. The results showed that the volume of the right lung was larger compared with that in the left one, at each observational time point. The whole, right and left lung held the same trendline of volume changes, which was sharply decreased during the first postoperative month, increased quickly over the next 3 months, and slowly increased from months 3 to 6. There were 7 patients, whose whole lung volume was increased at 6 months following surgery compared with that preoperatively. In addition, significant differences were observed between males and females in the whole, right and left lung volume. However, the differences on the postoperative net expansion volume of the whole lung were not significant among sex, age, body mass index (BMI), smoking status and surgical side subgroups. The early changes of the postoperative lung volume were not linear, since the lung volume was significantly reduced during the first postoperative month, quickly increased in the next 3 months, and slowly increased from months 3 to 6. Sex, age, BMI, smoking status and surgical sides was not found to affect the postoperative volume and net expansion of the whole lung following VATS lobectomy.

Case Report: Efficacy of Pyrotinib in ERBB2 Amplification Pulmonary Adenoid Cystic Carcinoma.

Primary pulmonary adenoid cystic carcinomas are salivary tumors that are low-grade malignant and prone to recurrence and metastasis. Surgery is currently the main treatment, but there is no standard with regard to postoperative adjuvant therapy. Adenoid cystic carcinoma is more sensitive to radiotherapy and patients benefit less from chemotherapy, but few studies have focused on targeted therapy, and their conclusions are inconsistent. With respect to primary pulmonary adenoid cystic carcinoma, large-scale studies cannot be conducted due to its low incidence, and studies on the targeted therapy of it are very scarce. A few case reports indicate that targeted therapy can be effective however, suggesting that it may be a good option. The current report is the first on the occurrence of human epidermal growth factor receptor 2 amplification in pulmonary adenoid cystic carcinoma. The patient was treated with pyrotinib for 6 months and achieved stable disease.

AMPK upregulates KCa2.3 channels and ameliorates endothelial dysfunction in diet-induced obese mice.

The opening of endothelial small-conductance calcium-activated potassium channels (KCa2.3) is essential for endothelium-dependent hyperpolarization (EDH), which predominantly occurs in small resistance arteries. Adenosine monophosphate-activated protein kinase (AMPK), an important metabolic regulator, has been implicated in regulating endothelial nitric oxide synthase activity. However, it was unclear whether AMPK regulated endothelial KCa2.3-mediated EDH-type vasodilation. Using bioinformatics analysis and myograph system, we investigated the regulation by AMPK of KCa2.3 in human umbilical vein endothelial cells (HUVECs) or mouse second-order mesenteric resistance arteries. In HUVECs, AMPK activation either by activators (AICAR, A769662 and MK-8722) or expression of the constitutively active form of AMPK significantly upregulated KCa2.3 expression. Such effects were abolished by AMPK inhibitor (compound C) or AMPK α1-/α2-siRNA, extracellular-signal-regulated-kinase 5 (ERK5) inhibitor (ERK5-IN-1), and specific siRNA to myocyte-enhancer factor 2 (MEF2) or krüppel-like factor 2/4 (KLF2/4). KCa2.3 expression was significantly reduced in mesenteric resistance arteries in AMPKα2 knockout mice when compared with littermate control mice. Furthermore, in high-fat diet fed mice, 2-week treatment with AICAR restored endothelial KCa2.3 expression in mesenteric resistance arteries with improved endothelial dysfunction. Our results demonstrate that activation of AMPK upregulates KCa2.3 channel expression through the ERK5-MEF2-KLF2/4 signaling pathway in vascular endothelium, which contributes to benefits through KCa2.3-mediated EDH-type vasodilation in mesenteric resistance arteries.

Left upper lung cancer with persistent left superior vena cava and left azygos vein: a case report.

BACKGROUND: With the popularization of thoracoscopic surgery, more and more macrovascular malformations have been reported. Understanding some vascular malformations with relatively fixed anatomical site and their range of drainage could avoid severe complications during the surgery. Persistent left superior vena cava (PLSVC) is a common thoracic vascular malformation, and is always combined with other cardiovascular dysplasia. As for the patient with upper left lung cancer in this case, he had PLSVC and left azygos vein, and non-metastatic enlargement of the lymph nodes at the same time, which had influenced the decisions on surgery and treatment. We made a summary of experience regarding this. CASE PRESENTATION: A 46-years-old male patient, his CT found a space-occupying lesion in the superior lobe of the left lung. The chest CT showed that the patient had PLSVC and left azygos vein, and multiple enlarged lymph nodes in the mediastinum. The patient received thoracoscopic upper left lung lobectomy and lymph node dissection. It was discovered that the left azygos vein had a concealed form, which influenced the lymph node dissection. The post-surgery pathology showed that there was squamous cell carcinoma in the upper left lung (pT2bN0M0 p Phase IIA) and no cancer metastasis with the lymph nodes. The patient had a good post-surgery recovery. CONCLUSIONS: PLSVC is not rare, and is always combined with other vascular malformations. If discovering PLSVC before surgery, we suggest completing chest enhanced CT and vascular reconstruction, to find out other cardiovascular malformations that may exist. Left azygos vein is a rare vascular malformation, but it has a relatively fixed anatomical site, and always co-exists with PLSVC, therefore, understanding anatomy of left azygos vein is good for preventing accidental damage. Especially when performing surgery above the left pulmonary artery trunk, attention shall be paid to preventing damage to the left azygos vein. In addition, as for the patient with the diagnosis of lung cancer before surgery, it is not reliable to judge whether there is metastasis or not merely according to the size of the lymph nodes, instead, PET-CT or needle biopsy is recommended.

Surgery in patients with small cell lung cancer: A period propensity score matching analysis of the Seer database, 2010-2015.

Surgery as a therapeutic modality for non-small cell lung cancer is widely accepted in clinical practice. However, the role of surgery for small cell lung cancer (SCLC) remains controversial. Therefore, in the present study a period propensity score matching analysis using the Surveillance, Epidemiology and End Results (SEER) Registry database was performed to investigate the role of surgery on survival in patients with SCLC. Patients with SCLC between January 2010 and December 2015 were identified from the SEER database, and individual data for each case regarding general clinical characteristics, surgery of primary site (SPS), cause-specific death classification and survival time were retrieved. Differences of cause-specific survival (CSS) between subgroups were estimated by the log-rank test. Cox regression analysis was used to evaluate the effects of multiple variables on CSS, and differences between the incidences of cause-specific death were examined using a χ2 test. A total of 1,707 records met the inclusion criteria and were retrieved for analysis. There were significant differences of CSS in the clinicopathological features of N (P=0.01), Stage (P<0.01) and Surgery (P<0.01) when comparing non-surgery with surgery, and in N (P<0.001), Stage (P=0.006) and Surgery (P=0.049) when comparing sublobectomy with lobectomy or bilobectomy (lobe/s). Patients who did not receive surgery (P<0.001) or who received sublobectomy (P=0.03) had an increased risk of mortality when compared with patients who received surgery and lobe/s. The findings of the present study indicate that surgery should be taken into consideration when an initial treatment strategy is made in patients for patients with SCLC at clinical stage I-IIA (T1-2,N0,M0), regardless of whether they are >50 years of age, their sex, histology and grade. The results suggest that certain patients with SCLC with stage IIB (N1) can also benefit from lobe/s, although further investigation is required. In addition, lobe/s is preferable to sublobectomy when surgery is performed. However, the present study was unable to comprehensively analyze the efficacy of pneumonectomy for SCLC.

Galectin-3 deficiency ameliorates fibrosis and remodeling in dilated cardiomyopathy mice with enhanced Mst1 signaling.

Dilated cardiomyopathy (DCM) is a major cause of heart failure without effective therapy. Fibrogenesis plays a key role in the development of DCM, but little is known of the expression of the profibrotic factor galectin-3 (Gal-3) and its role in DCM pathophysiology. In a mouse DCM model with transgenic (TG) overexpression of mammalian sterile 20-like kinase 1 (Mst1), we studied Gal-3 expression and effects of the Gal-3 inhibitor modified citrus pectin (MCP) or Gal-3 gene knockout (KO). Gal-3 deletion in TG mice (TG/KO) was achieved by crossbreeding Mst1-TG mice with Gal-3 KO mice. The DCM phenotype was assessed by echocardiography and micromanometry. Cardiac expression of Gal-3 and fibrosis were determined. The cardiac transcriptome was profiled by RNA sequencing. Mst1-TG mice at 3-8 mo of age exhibited upregulated expression of Gal-3 by ~40-fold. TG mice had dilatation of cardiac chambers, suppressed left ventricular (LV) ejection fraction, poor LV contractility and relaxation, a threefold increase in LV collagen content, and upregulated fibrotic genes. Four-month treatment with MCP showed no beneficial effects. Gal-3 deletion in Mst1-TG mice attenuated chamber dilatation, organ congestion, and fibrogenesis. RNA sequencing identified profound disturbances by Mst1 overexpression in the cardiac transcriptome, which largely remained in TG/KO hearts. Gal-3 deletion in Mst1-TG mice, however, partially reversed the dysregulated transcriptional signaling involving extracellular matrix remodeling and collagen formation. We conclude that cardiac Mst1 activation leads to marked Gal-3 upregulation and transcriptome disturbances in the heart. Gal-3 deficiency attenuated cardiac remodeling and fibrotic signaling. NEW & NOTEWORTHY We found in a transgenic mouse dilated cardiomyopathy (DCM) model a pronounced upregulation of galectin-3 in cardiomyocytes. Galectin-3 gene deletion reduced cardiac fibrosis and fibrotic gene profiles and ameliorated cardiac remodeling and dysfunction. These benefits of galectin-3 deletion were in contrast to the lack of effect of treatment with the galectin-3 inhibitor modified citrus pectin. Our study suggests that suppression of galectin-3 mRNA expression could be used to treat DCM with high cardiac galectin-3 content.

Serelaxin attenuates renal inflammation and fibrosis in a mouse model of dilated cardiomyopathy.

NEW FINDINGS: What is the central question of this study? The aim was to determine the renoprotective effects of serelaxin in the setting of chronic heart failure. What are the main findings and its importance? Our data indicate that serelaxin can reduce renal fibrosis and inflammation in experimental heart failure. Currently, there are no effective treatments to rescue renal function in heart failure patients, and our data suggest that serelaxin might have the potential to reduce renal fibrosis and inflammation in heart failure. ABSTRACT: Serelaxin has been demonstrated to attenuate renal fibrosis and inflammation in cardiorenal disease. In the present study, we tested the hypothesis that serelaxin can prevent the decline in renal function in dilated cardiomyopathy (DCM) by targeting renal fibrosis and inflammation. Male transgenic mice with DCM (n = 16) and their wild-type littermates (WT; n = 20) were administered either vehicle or serelaxin (500 µg kg-1  day-1 ; subcutaneous minipumps; 8 weeks). Cardiac function was assessed via echocardiography before and during the eighth week of serelaxin treatment. Renal function and inflammation as well as cardiac and renal fibrosis were assessed at the end of the study. Serelaxin had minimal effect on cardiac function (P ≥ 0.99). Tubulointerstitial and glomerular fibrosis were ∼3-fold greater in vehicle-treated DCM mice compared with vehicle-treated WT mice (P ≤ 0.001). Renal mRNA expression of Tnfα and Il1α were ∼4- and ∼3-fold greater, respectively, in vehicle-treated DCM mice compared with vehicle-treated WT mice (P ≤ 0.05). Tubulointerstitial and glomerular fibrosis were 46 and 45% less, respectively, in serelaxin-treated DCM mice than in vehicle-treated DCM mice (P ≤ 0.01). Renal cortical mRNA expression of Tnfα and Il1α were 56 and 58% less, respectively, in the former group compared with the latter (P ≤ 0.05). The urinary albumin:creatinine ratio was ∼3-fold greater in vehicle-treated DCM mice compared with vehicle-treated WT mice (P = 0.02). The urinary albumin:creatinine ratio was not significantly different between vehicle-treated DCM mice and serelaxin-treated DCM mice (P = 0.38). These data suggest that serelaxin can attenuate renal fibrosis and inflammation and has the potential to exert renoprotective effects in DCM.

A comparison between laryngeal mask airway and endotracheal intubation for anaesthesia in adult patients undergoing NUSS procedure.

BACKGROUND: This study evaluates and compares the feasibility and safety of application of laryngeal mask airway (LMA) and endotracheal intubation (ETT) for anaesthesia in adult patients undergoing thoracoscopic surgery. METHODS: Sixty adult patients with pectus excavatum (PE) undergoing video-assisted thoracoscopic surgery for the NUSS procedure (VATS-NUSS) between September 2016 and March 2017 were selected and randomly separated into two groups with different methods of airway management. In one group, LMA was applied for general anaesthesia, and in the other group, ETT was used. The clinical parameters before, during and after the surgery in patients from both groups were collected from multiple data resources in a hospital. SPSS software was used for the analysis. RESULTS: Of all the selected patients, the physiological parameters showed similarity between the LMA and ETT groups, indicating consistency in the clinical characteristics of the study sample. Additionally, no significant differences were discovered between the two groups in terms of the anaesthesia and surgical time, peak PetCO2 during operation, anaesthetic satisfaction score, and amount of blood loss as well as inpatient time for recovery. However, with a similar level of anaesthesia effects and suitable parameters for mechanical ventilation, patients in the LMA group showed much more stability in the physiological indicators for inflammation and haemodynamics, including white blood cell count (ΔWBC) and percentage of neutrophil granulocytes (ΔNEU%) in the blood as well as heart rate (ΔHR) and mean arterial pressure (ΔMAP). Moreover, the LMA patients had a significantly shorter time for recovery of consciousness and food/water intake. Finally, compared to the ETT group, patients in the LMA group also had a significantly lower incidence of side effects induced by the anaesthesia procedure after surgery, such as gastrointestinal reactions, throat discomfort and hoarseness. CONCLUSIONS: Compared with ETT, the application of LMA for general anaesthesia may demonstrate promising advantages in airway management for the VATS-NUSS procedure.

Compensatory hyperhidrosis after different surgeries at the same sympathetic levels: a meta-analysis.

BACKGROUND: Different techniques of video-assisted thoracoscopic sympathetic surgery have become the radical treatments for palmar and axillary hyperhidrosis (AH). However, there is no consensus over which technique can make a minimal incidence of compensatory hyperhidrosis (CH). This study was designed to compare the incidence of CH after different techniques at the same sympathetic levels in the treatment of upper limb and facial hyperhidrosis (FH). METHODS: The databases of PubMed, Web of Science, ScienceDirect, Ovid Medline, Embase, and Cochrane Library were searched to identify studies comparing different surgical techniques at the same sympathetic levels for upper limb and FH. The data was analyzed by Revman 5.3 software. RESULTS: A total of ten studies involving 896 patients were included, of whom 149 underwent sympathectomy, 435 underwent sympathicotomy, and 312 under endoscopic sympathetic clip (ESC). Meta-analysis showed that the difference of incidence of CH and patients' satisfaction was not significant between sympathectomy and sympathicotomy (P=0.05, 0.19, respectively). But, the incidence of CH is significant lower after ESC than after sympathicotomy (OR: 1.58, 95% CI: 1.04-2.38, P=0.03). However, the incidence of moderate/severe CH between these two groups is not significant different (OR: 1.49, 95% CI: 0.93-2.39, P=0.10). CONCLUSIONS: If only CH and the same sympathetic levels concerned, sympathectomy and sympathicotomy is equal for upper limb hyperhidrosis and FH. And, ESC should be recommended for a lower incidence of CH, comparing with sympathicotomy.

Diabetes Reduces Severity of Aortic Aneurysms Depending on the Presence of Cell Division Autoantigen 1 (CDA1).

Diabetes is a negative risk factor for aortic aneurysm, but the underlying explanation for this phenomenon is unknown. We have previously demonstrated that cell division autoantigen 1 (CDA1), which enhances transforming growth factor-ß signaling, is upregulated in diabetes. We hypothesized that CDA1 plays a key role in conferring the protective effect of diabetes against aortic aneurysms. Male wild-type, CDA1 knockout (KO), apolipoprotein E (ApoE) KO, and CDA1/ApoE double-KO (dKO) mice were rendered diabetic. Whereas aneurysms were not observed in diabetic ApoE KO and wild-type mice, 40% of diabetic dKO mice developed aortic aneurysms. These aneurysms were associated with attenuated aortic transforming growth factor-ß signaling, reduced expression of various collagens, and increased aortic macrophage infiltration and matrix metalloproteinase 12 expression. In the well-characterized model of angiotensin II-induced aneurysm formation, concomitant diabetes reduced fatal aortic rupture and attenuated suprarenal aortic expansion, changes not seen in dKO mice. Furthermore, aortic CDA1 expression was downregulated ∼70% within biopsies from human abdominal aortic aneurysms. The identification that diabetes is associated with upregulation of vascular CDA1 and that CDA1 deletion in diabetic mice promotes aneurysm formation provides evidence that CDA1 plays a role in diabetes to reduce susceptibility to aneurysm formation.

Gene delivery of medium chain acyl-coenzyme A dehydrogenase induces physiological cardiac hypertrophy and protects against pathological remodelling.

We previously showed that medium chain acyl-coenzyme A dehydrogenase (MCAD, key regulator of fatty acid oxidation) is positively modulated in the heart by the cardioprotective kinase, phosphoinositide 3-kinase (PI3K(p110α)). Disturbances in cardiac metabolism are a feature of heart failure (HF) patients and targeting metabolic defects is considered a potential therapeutic approach. The specific role of MCAD in the adult heart is unknown. To examine the role of MCAD in the heart and to assess the therapeutic potential of increasing MCAD in the failing heart, we developed a gene therapy tool using recombinant adeno-associated viral vectors (rAAV) encoding MCAD. We hypothesised that increasing MCAD expression may recapitulate the cardioprotective properties of PI3K(p110α). rAAV6:MCAD or rAAV6:control was delivered to healthy adult mice and to mice with pre-existing pathological hypertrophy and cardiac dysfunction due to transverse aortic constriction (TAC). In healthy mice, rAAV6:MCAD induced physiological hypertrophy (increase in heart size, normal systolic function and increased capillary density). In response to TAC (~15 weeks), heart weight/tibia length increased by ~60% in control mice and ~45% in rAAV6:MCAD mice compared with sham. This was associated with an increase in cardiomyocyte cross-sectional area in both TAC groups which was similar. However, hypertrophy in TAC rAAV6:MCAD mice was associated with less fibrosis, a trend for increased capillary density and a more favourable molecular profile compared with TAC rAAV6:control mice. In summary, MCAD induced physiological cardiac hypertrophy in healthy adult mice and attenuated features of pathological remodelling in a cardiac disease model.

Endogenous Annexin-A1 Regulates Haematopoietic Stem Cell Mobilisation and Inflammatory Response Post Myocardial Infarction in Mice In Vivo.

Endogenous anti-inflammatory annexin-A1 (ANX-A1) plays an important role in preserving left ventricular (LV) viability and function after ischaemic insults in vitro, but its long-term cardioprotective actions in vivo are largely unknown. We tested the hypothesis that ANX-A1-deficiency exaggerates inflammation, haematopoietic stem progenitor cell (HSPC) activity and LV remodelling in response to myocardial ischaemia in vivo. Adult ANX - A1 -/- mice subjected to coronary artery occlusion exhibited increased infarct size and LV macrophage content after 24-48 h reperfusion compared with wildtype (WT) counterparts. In addition, ANX - A1 -/- mice exhibited greater expansion of HSPCs and altered pattern of HSPC mobilisation 8 days post-myocardial infarction, with increased circulating neutrophils and platelets, consistent with increased cardiac inflammation as a result of increased myeloid invading injured myocardium in response to MI. Furthermore, ANX - A1 -/- mice exhibited significantly increased expression of LV pro-inflammatory and pro-fibrotic genes and collagen deposition after MI compared to WT counterparts. ANX-A1-deficiency increased cardiac necrosis, inflammation, hypertrophy and fibrosis following MI, accompanied by exaggerated HSPC activity and impaired macrophage phenotype. These findings suggest that endogenous ANX-A1 regulates mobilisation and differentiation of HSPCs. Limiting excessive monocyte/neutrophil production may limit LV damage in vivo. Our findings support further development of novel ANX-A1-based therapies to improve cardiac outcomes after MI.

N-Acetylcysteine Attenuates the Development of Renal Fibrosis in Transgenic Mice with Dilated Cardiomyopathy.

Mechanisms underlying the renal pathology in cardiorenal syndrome (CRS) type 2 remain elusive. We hypothesised that renal glutathione deficiency is central to the development of CRS type 2. Glutathione precursor, N-acetylcysteine (NAC;40 mg/kg/day; 8 weeks) or saline were administered to transgenic mice with dilated cardiomyopathy (DCM) and wild-type (WT) controls. Cardiac structure, function and glutathione levels were assessed at the end of this protocol. Renal fibrosis, glutathione content, expression of inflammatory and fibrotic markers, and function were also evaluated. In both genotypes, NAC had minimal effect on cardiac glutathione, structure and function (P ≥ 0.20). In NAC treated DCM mice, loss of glomerular filtration rate (GFR), tubulointerstitial and glomerular fibrosis and renal oxidised glutathione levels were attenuated by 38%, 99%, 70% and 52% respectively, compared to saline treated DCM mice (P ≤ 0.01). Renal expression of PAI-1 was greater in saline treated DCM mice than in WT mice (P < 0.05). Renal PAI-1 expression was less in NAC treated DCM mice than in vehicle treated DCM mice (P = 0.03). Renal IL-10 expression was greater in the former cohort compared to the latter (P < 0.01). These data indicate that normalisation of renal oxidized glutathione levels attenuates PAI-1 expression and renal inflammation preventing loss of GFR in experimental DCM.

Phosphoinositide 3-kinase (p110α) gene delivery limits diabetes-induced cardiac NADPH oxidase and cardiomyopathy in a mouse model with established diastolic dysfunction.

Phosphoinositide 3-kinase [PI3K (p110α)] is able to negatively regulate the diabetes-induced increase in NADPH oxidase in the heart. Patients affected by diabetes exhibit significant cardiovascular morbidity and mortality, at least in part due to a cardiomyopathy characterized by oxidative stress and left ventricular (LV) dysfunction. Thus, PI3K (p110α) may represent a novel approach to protect the heart from diabetes-induced cardiac oxidative stress and dysfunction. In the present study, we investigated the therapeutic potential of a delayed intervention with cardiac-targeted PI3K gene therapy, administered to mice with established diabetes-induced LV diastolic dysfunction. Diabetes was induced in 6-week-old male mice by streptozotocin (STZ). After 8 weeks of untreated diabetes, LV diastolic dysfunction was confirmed by a reduction in echocardiography-derived transmitral E/A ratio. Diabetic and non-diabetic mice were randomly allocated to receive either recombinant adeno-associated viral vector-6 carrying a constitutively-active PI3K construct (recombinant adeno-associated-virus 6-constitutively active PI3K (p110α) (caPI3K) (rAAV6-caPI3K), single i.v. injection, 2 × 1011 vector genomes) or null vector, and were followed for a further 6 or 8 weeks. At study endpoint, diabetes-induced LV dysfunction was significantly attenuated by a single administration of rAAV6-caPI3K, administered 8 weeks after the induction of diabetes. Diabetes-induced impairments in each of LV NADPH oxidase, endoplasmic reticulum (ER) stress, apoptosis, cardiac fibrosis and cardiomyocyte hypertrophy, in addition to LV systolic dysfunction, were attenuated by delayed intervention with rAAV6-caPI3K. Hence, our demonstration that cardiac-targeted PI3K (p110α) gene therapy limits diabetes-induced up-regulation of NADPH oxidase and cardiac remodelling suggests new insights into promising approaches for the treatment of diabetic cardiomyopathy, at a clinically relevant time point (after diastolic dysfunction is manifested).

Small-molecule-biased formyl peptide receptor agonist compound 17b protects against myocardial ischaemia-reperfusion injury in mice.

Effective treatment for managing myocardial infarction (MI) remains an urgent, unmet clinical need. Formyl peptide receptors (FPR) regulate inflammation, a major contributing mechanism to cardiac injury following MI. Here we demonstrate that FPR1/FPR2-biased agonism may represent a novel therapeutic strategy for the treatment of MI. The small-molecule FPR1/FPR2 agonist, Compound 17b (Cmpd17b), exhibits a distinct signalling fingerprint to the conventional FPR1/FPR2 agonist, Compound-43 (Cmpd43). In Chinese hamster ovary (CHO) cells stably transfected with human FPR1 or FPR2, Compd17b is biased away from potentially detrimental FPR1/2-mediated calcium mobilization, but retains the pro-survival signalling, ERK1/2 and Akt phosphorylation, relative to Compd43. The pathological importance of the biased agonism of Cmpd17b is demonstrable as superior cardioprotection in both in vitro (cardiomyocytes and cardiofibroblasts) and MI injury in mice in vivo. These findings reveal new insights for development of small molecule FPR agonists with an improved cardioprotective profile for treating MI.