The effect and mechanism of inulin on atherosclerosis is mediated by the characteristic intestinal flora and metabolites.

BACKGROUND: Inflammation and hyperlipidemia can cause atherosclerosis. Prebiotic inulin has been proven to effectively reduce inflammation and blood lipid levels. Utilizing a mouse model induced by a high-fat diet, this study aimed to explore whether the characteristic intestinal flora and its metabolites mediate the effects of inulin intervention on atherosclerosis and to clarify the specific mechanism. METHODS: Thirty apolipoprotein E-deficient (ApoE-/-) mice were randomly divided into three groups. They were fed with a normal diet, a high-fat diet or an inulin+high-fat diet for 16 weeks. The total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) in the three groups were compared. The gross aorta and aortic sinus of mice were stained with oil red O, and the area of atherosclerotic plaque was observed and compared. The diversity and structure of the mouse fecal flora were detected by sequencing the V3-V4 region of the 16S rRNA gene, and the levels of metabolites in mouse feces were assessed by gas chromatography-mass spectrometry. The plasma lipopolysaccharide (LPS) levels and aortic inflammatory factors were measured by multi-index flow cytometry (CBA). RESULTS: ApoE-/- mice fed with the high-fat diet exhibited an increase of approximately 46% in the area of atherosclerotic lesions, and the levels of TC, TG and LDL-C were significantly increased ( P < 0.05) compared with levels in the normal diet group. After inulin was added to the high-fat group, the area of atherosclerotic lesions, the level of serum LPS and aortic inflammation were reduced, and the levels of TC, TG and LDL-C were decreased ( P  < 0.05). Based on 16S rRNA gene detection, we found that the composition of the intestinal microbiota, such as Prevotella, and metabolites, such as L-arginine, changed significantly due to hyperlipidemia, and the dietary inulin intervention partially reversed the relevant changes. CONCLUSION: Inulin can inhibit the formation of atherosclerotic plaques, which may be related to the changes in lipid metabolism, the composition of the intestinal microbial community and its metabolites, and the inhibition of the expression of related inflammatory factors. Our study identified the relationships among the characteristic intestinal microbiota, metabolites and atherosclerosis, aiming to provide a new direction for future research to delay or treat atherosclerosis by changing the composition and function of the host intestinal microbiota and metabolites.

Trying to Survive A Serious Heart Condition in Time of COVID-19.

The world has suffered over the past year under COVID-19. Unfortunately, people still are getting sick from other, also severe, diseases. Although the COVID-19 infection is present, patients need treatment for other life-threatening conditions. We present the case of a 36-year-old patient with severe infective endocarditis with a large abscess of the aortic root, who also is COVID-19 positive. Definitive diagnostics and treatment were avoided due to COVID-19 infection. In the end, emergent surgery was indicated due to acute cardiac decompensation and the development of heart failure symptoms, and the patient recovered uneventfully after surgery.

Primary Aortoduodenal Fistula: A Case Report and Current Literature Review.

Primary aortoduodenal fistula is a rare, life-threatening pathology that is difficult to diagnose and manage. We present the case of a 64-year-old male with a primary aortoduodenal fistula. Our patient initially underwent an endovascular aneurysm repair at an outside institution before being transferred to our tertiary care center, where he ultimately had definitive management with an extra-anatomic bypass, aortic ligation, duodenal resection with primary anastomosis, and gastrojejunostomy tube placement. His surgical cultures grew Candida albicans, and he was discharged with a 6-week course of intravenous antibiotics with subsequent antibiotic suppression for 1 year. He died 14 months postoperatively from tongue squamous cell carcinoma. We also review the current literature regarding epidemiology, pathology, diagnostics, management, and case reports from 2015 to present. Overall, timely diagnosis and treatment is imperative for reducing mortality from primary aortoduodenal fistula, and although formal consensus is lacking regarding most clinical aspects, an increasing number of case reports has helped describe options for management.

Mycobacterium bovis Bacille-Calmette-Guérin Infection Aggravates Atherosclerosis.

Tuberculosis has been associated with increased risk of atherosclerotic cardiovascular disease. To examine whether mycobacterial infection exacerbates atherosclerosis development in experimental conditions, we infected low-density lipoprotein receptor knockout (Ldlr-/-) mice with Mycobacterium bovis Bacille-Calmette-Guérin (BCG), an attenuated strain of the Mycobacterium tuberculosis complex. Twelve-week old male Ldlr-/- mice were infected with BCG (0.3-3.0x106 colony-forming units) via the intranasal route. Mice were subsequently fed a western-type diet containing 21% fat and 0.2% cholesterol for up to 16 weeks. Age-matched uninfected Ldlr-/- mice fed with an identical diet served as controls. Atherosclerotic lesions in aorta were examined using Oil Red O staining. Changes induced by BCG infection on the immunophenotyping profile of circulating T lymphocytes and monocytes were assessed using flow cytometry. BCG infection increased atherosclerotic lesions in en face aorta after 8 weeks (plaque ratio; 0.021±0.01 vs. 0.013±0.01; p = 0.011) and 16 weeks (plaque ratio, 0.15±0.13 vs. 0.06±0.02; p = 0.003). No significant differences in plasma cholesterol or triglyceride levels were observed between infected and uninfected mice. Compared to uninfected mice, BCG infection increased systemic CD4/CD8 T cell ratio and the proportion of Ly6Clow non-classical monocytes at weeks 8 and 16. Aortic plaque ratios correlated with CD4/CD8 T cell ratios (Spearman's rho = 0.498; p = 0.001) and the proportion of Ly6Clow non-classical monocytes (Spearman's rho = 0.629; p < 0.001) at week 16. In conclusion, BCG infection expanded the proportion of CD4+ T cell and Ly6Clow monocytes, and aggravated atherosclerosis formation in the aortas of hyperlipidemic Ldlr-/- mice. Our results indicate that mycobacterial infection is capable of enhancing atherosclerosis development.

Sudden death with massive hemoptysis from aortobronchial fistula.

Aortobronchial fistula is an uncommon clinical entity, with unpredictable clinical course and significant mortality. Here, we describe a case of fistulous tract between a descending aortic graft and a branch of the left upper lobar bronchus leading to massive hemoptysis causing death for hemorrhagic shock in a 72-year-old man.

Genital Chlamydia infection in hyperlipidemic mouse models exacerbates atherosclerosis.

BACKGROUND AND AIMS: Atherosclerosis is a chronic inflammatory disease, and recent studies have shown that infection at remote sites can contribute to the progression of atherosclerosis in hyperlipidemic mouse models. In this report, we tested the hypothesis that genital Chlamydia infection could accelerate the onset and progression of atherosclerosis. METHODS: Apolipoprotein E (Apoe-/-) and LDL receptor knockout (Ldlr-/-) mice on a high-fat diet were infected intra-vaginally with Chlamydia muridarum. Atherosclerotic lesions on the aortic sinuses and in the descending aorta were assessed at 8-weeks post-infection. Systemic, macrophage, and vascular site inflammatory responses were assessed and quantified. RESULTS: Compared to the uninfected groups, infected Apoe-/- and Ldlr-/- mice developed significantly more atherosclerotic lesions in the aortic sinus and in the descending aorta. Increased lesions were associated with higher circulating levels of serum amyloid A-1, IL-1ß, TNF-α, and increased VCAM-1 expression in the aortic sinus, suggesting an association with inflammatory responses observed during C. muridarum infection. Genital infection courses were similar in Apoe-/-, Ldlr-/-, and wild type mice. Further, Apoe-/- mice developed severe uterine pathology with increased dilatations. Apoe-deficiency also augmented cytokine/chemokine response in C. muridarum infected macrophages, suggesting that the difference in macrophage response could have contributed to the genital pathology in Apoe-/- mice. CONCLUSIONS: Overall, these studies demonstrate that genital Chlamydia infection exacerbates atherosclerotic lesions in hyperlipidemic mouse and suggest a novel role for Apoe in full recovery of uterine anatomy after chlamydial infection.

Glomerulonephritis triggered by chronical aortic graft infection in a male with Loeys-Dietz syndrome: A case report.

RATIONALE: Glomerulonephritis triggered by a chronically infected graft is increasingly identified because of widely used implanted device. Removal of the aortic graft and sustained antibiotic therapy is the usual approach to maximize the chance of renal recovery, but as this case shows graft removal is not always possible. PATIENT CONCERNS: A 35-year-old man with intractable and recurrent fever had acute renal failure in sustained antibiotic therapy. DIAGNOSES: Renal biopsy suggested crescentic glomerulonephritis. fluorodeoxyglucose/positron emission tomography-computed tomography showed increased metabolic activity at the site of aortic graft, reminding that chronic infection of an implanted graft can lead to severe glomerulonephritis. TGFBR2 c.1133G>T mutation was observed in mutation analysis, which was reported to be associated with Loeys-Dietz syndrome. INTERVENTIONS: Although infection was properly controlled with appropriate antimicrobial treatment, his renal dysfunction did not improve. A short-term inclusion of low-dose corticosteroid significantly benefit without introducing harm. OUTCOMES: He partly recovered from renal injury. LESSONS: In patients with glomerulonephritis triggered by a long-duration infection, low-dose corticosteroid therapy may be considered when renal dysfunction secondary to nephritis does not improve after appropriate antimicrobial treatment.

Late ascending aortic prosthesis infection by Porphyromonas pogonae: An unexpected infectious complication.

Late complications in ascending aortic surgeries are uncommon and may occur by infectious processes, usually caused by gram positive bacteria. We report a case of aortic prosthesis infection by Porphyromonas pogonae, an anaerobic gram-negative coccobacillus that can grow under microaerobic conditions, three years after ascending aortic reconstruction surgery.

A Proinflammatory Gut Microbiota Increases Systemic Inflammation and Accelerates Atherosclerosis.

RATIONALE: Several studies have suggested a role for the gut microbiota in inflammation and atherogenesis. A causal relation relationship between gut microbiota, inflammation, and atherosclerosis has not been explored previously. OBJECTIVE: Here, we investigated whether a proinflammatory microbiota from Caspase1-/- ( Casp1-/-) mice accelerates atherogenesis in Ldlr-/- mice. METHOD AND RESULTS: We treated female Ldlr-/- mice with antibiotics and subsequently transplanted them with fecal microbiota from Casp1-/- mice based on a cohousing approach. Autologous transplantation of fecal microbiota of Ldlr-/- mice served as control. Mice were cohoused for 8 or 13 weeks and fed chow or high-fat cholesterol-rich diet. Fecal samples were collected, and factors related to inflammation, metabolism, intestinal health, and atherosclerotic phenotypes were measured. Unweighted Unifrac distances of 16S rDNA (ribosomal DNA) sequences confirmed the introduction of the Casp1-/- and Ldlr-/- microbiota into Ldlr-/- mice (referred to as Ldlr-/-( Casp1-/-) or Ldlr-/-( Ldlr-/-) mice). Analysis of atherosclerotic lesion size in the aortic root demonstrated a significant 29% increase in plaque size in 13-week high-fat cholesterol-fed Ldlr-/-( Casp1-/-) mice compared with Ldlr-/-( Ldlr-/-) mice. We found increased numbers of circulating monocytes and neutrophils and elevated proinflammatory cytokine levels in plasma in high-fat cholesterol-fed Ldlr-/-( Casp1-/-) compared with Ldlr-/-( Ldlr-/-) mice. Neutrophil accumulation in the aortic root of Ldlr-/-( Casp1-/-) mice was enhanced compared with Ldlr-/-( Ldlr-/-) mice. 16S-rDNA-encoding sequence analysis in feces identified a significant reduction in the short-chain fatty acid-producing taxonomies Akkermansia, Christensenellaceae, Clostridium, and Odoribacter in Ldlr-/-( Casp1-/-) mice. Consistent with these findings, cumulative concentrations of the anti-inflammatory short-chain fatty acids propionate, acetate and butyrate in the cecum were significantly reduced in 13-week high-fat cholesterol-fed Ldlr-/-( Casp1-/-) compared with Ldlr-/-( Ldlr-/-) mice. CONCLUSIONS: Introduction of the proinflammatory Casp1-/- microbiota into Ldlr-/- mice enhances systemic inflammation and accelerates atherogenesis.

Aortic Root Pseudoaneurysm Caused by Mycobacterium Chimaera.

Nontuberculous mycobacteria cause severe pulmonary, vascular graft, and bloodstream infections after cardiac surgery. Patient prognosis remains poor because of delays in diagnosis and treatment. Complicated aortic root infections caused by nontuberculous mycobacteria have been mostly fatal. We describe a case of a 50-year-old man who developed an invasive Mycobacterium chimaera infection with an aortic root pseudoaneurysm after a Bentall-de Bono procedure for a Stanford type A aortic dissection.

Impact of Gut Microbiota and Diet on the Development of Atherosclerosis in Apoe-/- Mice.

Objective- To investigate the effect of gut microbiota and diet on atherogenesis. Approach and Results- Here, we investigated the interaction between the gut microbiota and diet on atherosclerosis by feeding germ-free or conventionally raised Apoe-/- mice chow or Western diet alone or supplemented with choline (which is metabolized by the gut microbiota and host enzymes to trimethylamine N-oxide) for 12 weeks. We observed smaller aortic lesions and lower plasma cholesterol levels in conventionally raised mice compared with germ-free mice on a chow diet; these differences were not observed in mice on a Western diet. Choline supplementation increased plasma trimethylamine N-oxide levels in conventionally raised mice but not in germ-free mice. However, this treatment did not affect the size of aortic lesions or plasma cholesterol levels. Gut microbiota composition was analyzed by sequencing of 16S rRNA genes. As expected, the global community structure and relative abundance of many taxa differed between mice fed chow or a Western diet. Choline supplementation had minor effects on the community structure although the relative abundance of some taxa belonging to Clostridiales was altered. Conclusions- In conclusion, the impact of the gut microbiota on atherosclerosis is dietary dependent and is associated with plasma cholesterol levels. Furthermore, the microbiota was required for trimethylamine N-oxide production from dietary choline, but this process could not be linked to increased atherosclerosis in this model.

Berberine treatment increases Akkermansia in the gut and improves high-fat diet-induced atherosclerosis in Apoe-/- mice.

BACKGROUND AND AIMS: Gut microbiota plays a major role in metabolic disorders. Berberine is used to treat obesity, diabetes and atherosclerosis. The mechanism underlying the role of berberine in modulating metabolic disorders is not fully clear because berberine has poor oral bioavailability. Thus, we evaluated whether the antiatherosclerotic effect of berberine is related to alterations in gut microbial structure and if so, whether specific bacterial taxa contribute to the beneficial effects of berberine. METHODS: Apoe-/- mice were fed either a normal-chow diet or a high-fat diet (HFD). Berberine was administered to mice in drinking water (0.5 g/L) for 14 weeks. Gut microbiota profiles were established by high throughput sequencing of the V3-V4 region of the bacterial 16S ribosomal RNA gene. The effects of berberine on metabolic endotoxemia, tissue inflammation and gut barrier integrity were also investigated. RESULTS: Berberine treatment significantly reduced atherosclerosis in HFD-fed mice. Akkermansia spp. abundance was markedly increased in HFD-fed mice treated with berberine. Moreover, berberine decreased HFD-induced metabolic endotoxemia and lowered arterial and intestinal expression of proinflammatory cytokines and chemokines. Berberine treatment increased intestinal expression of tight junction proteins and the thickness of the colonic mucus layer, which are related to restoration of gut barrier integrity in HFD-fed mice. CONCLUSIONS: Modulation of gut microbiota, specifically an increase in the abundance of Akkermansia, may contribute to the antiatherosclerotic and metabolic protective effects of berberine, which is poorly absorbed orally. Our findings therefore support the therapeutic value of gut microbiota manipulation in treating atherosclerosis.

Regulation of calcification in human aortic smooth muscle cells infected with high-glucose-treated Porphyromonas gingivalis.

Porphyromonas (P.) gingivalis infection leading to the periodontitis has been associated with the development of systemic diseases, including cardiovascular diseases and diabetes. However, the effect of a high concentration of glucose (HG) on the invasion efficiency of P. gingivalis and the consequent modulation of pathogenesis in vascular cells, especially in the vascular smooth muscle cells (VSMCs), remains unclear. Hence, the aim of this study was to investigate whether treating P. gingivalis with HG could change its invasion capability and result in VSMC calcification and the underlying mechanism. Human aortic SMCs (HASMCs) and P. gingivalis strain CCUG25226 were used in this study. We found that HGPg infection of HASMCs could initiate the HASMC calcification by stimulating the autocrine regulation of bone morphogenetic protein (BMP) 4 in HASMCs. The upregulation of BMP4 expression in HASMCs was mediated by toll-like receptor 4 and ERK1/2-p38 signaling after P. gingivalis infection. Moreover, the autocrine action of BMP4 in HGPg infection-initiated HASMC calcification upregulated BMP4-specific downstream smad1/5/8-runx2 signaling to increase the expressions of bone-related matrix proteins, that is, osteopontin, osteocalcin, and alkaline phosphatase. This study elucidates the detailed mechanism of HGPg infection-initiated calcification of HASMCs and indicates a possible therapeutic role of BMP4 in P. gingivalis infection-associated vascular calcification.

Aortobronchial and aortoenteric fistula.

Pathologic communication between the thoracic aorta and esophagus or tracheobronchial tree is a rare vascular condition and most commonly develops after open or endovascular aortic repair complicated by infection. Patients with aortoesophageal or tracheobronchial fistula often present with systemic infection and are at risk for major hemorrhage. Medical management is uniformly fatal. Expeditious definitive management requires operative repair by open repair or a combination of endovascular and open procedures. Appropriate antibiotic regimens are important for preventing graft reinfection.

First Robinsoniella peoriensis aortic cross homograft mycotic pseudoaneurysm: A case report and review of the literature.

Mycotic aortic aneurysm is a rare and challenging complication of aortic homografts caused by an infection and is associated with high morbidity and mortality. We report the first case of an aortic cross homograft mycotic pseudoaneurysm caused by Robinsoniella peoriensis in a 70-year-old man. Our patient underwent surgery for a recurrence of aortic cross mycotic pseudoaneurysm at the level of the aortic homograft he had had 7 years before. A clot-removal of the pseudoaneurysm was surgically carried out and the homograft was completely removed. Anaerobic culture from tissue samples yielded pure growth of a spore-forming Gram-positive rod, identified later as Robinsoniella peoriensis by 16S rRNA gene sequencing. The patient was then discharged with oral clindamycin according to the in vitro susceptibility testing. Identification of R. peoriensis might be challenging in clinical laboratories with no access to molecular methods.

[Aorto-bifermoral grafs infection due to Candida parapsilosis. An unusual pathogen]. / Infección de injerto aortobifemoral por Candida parapsilosis. Un germen inhabitual.

BACKGROUND: Aorto-enteric fistula is a rare and potentially lethal entity. Its presentation may be as an enteric-paraprosthetic fistula, due to injury in the gut caused by direct contact with the vascular prosthesis. OBJECTIVE: We report a case of enteric-paraprosthetic fistulae with the unusual finding of Candida parapsilosis as the only isolated pathogen. CLINICAL CASE: A 65-year-old male, smoker, with aortobifemoral revascularisation with dacron due to aortoiliac occlusive disease, and re-intervention for thrombosis of left arm at 6 months. Hospitalisation at 22 months was required due to a toxic syndrome, which was diagnosed as enteric-paraprosthetic fistulae after complementary studies. The graft was removed and an extra-anatomic revascularisation was performed. Microbiology specimens taken from the duodenal segment in contact with the prosthesis showed the prosthetic segment and peri-prosthetic fluid were positive to C. parapsilosis. DISCUSSION: The finding of C. parapsilosis in all cultures taken during surgery, along with negative blood cultures and no other known sources of infection, is of interest. It is an unusual pathogen with low virulence and limited as regards other Candida species. Our patient had no clinical data common to cases of infection with C. parapsilosis, and the mechanism of graft infection is unknown. CONCLUSION: Graft infection by C. parapsilosis may be anecdotal. However, its consequences can also be severe. Microbiological tests can be useful to adjust antimicrobial therapy in the post-operative period, but their usefulness for determining the aetiology is doubtful, as it may be just an incidental finding.