Oral Administration of Euglena Gracilis Z Alleviates Constipation and Cardiac Dysfunction in a Mouse Model of Isoproterenol-Induced Heart Failure.

Background: Patients with heart failure (HF) often experience gastrointestinal problems such as constipation, diarrhea, and disturbances to drug absorption. In HF, hypoperfusion and congestion cause structural and functional changes in the gut, which, in turn, lead to impaired cardiac function. Euglena gracilis Z (hereafter "Euglena"), called Midorimushi in Japanese, is a microalga that is used as a food or nutritional supplement. It is unclear whether Euglena is beneficial for bowel habitus and cardiac function in subjects with HF. Methods and Results: We injected C57BL/6 male mice subcutaneously with isoproterenol (ISO) (20 mg/kg/day) for 7 days to examine bowel movement in HF. Euglena was orally administered to mice on an ad libitum-feeding to a normal chow containing 2% dietary mixture. ISO induced a decrease in bowel movement and an increase in fecal retention in the cecum, as well as a decrease in left ventricular (LV) contraction. Euglena accelerated intestinal transit, relieved fecal retention, and prevented the alterations in gut pathology in ISO-treated mice. Euglena also suppressed ISO-induced decreases in LV contraction, although it had no significant effect on LV hypertrophy. Conclusions: The results suggested that oral administration of Euglena alleviated constipation and cardiac dysfunction in a mouse model of ISO-induced HF, and highlight the potential clinical benefit of Euglena in patients with HF in preventing constipation and contractile deterioration.

Axitinib Induces and Aggravates Hypertension Regardless of Prior Treatment With Tyrosine Kinase Inhibitors.

Background: Axitinib is a tyrosine kinase inhibitor (TKI) that inhibits vascular endothelial growth factor receptor signaling and is approved for second-line treatment of advanced renal cell carcinoma (RCC). Although the occurrence of hypertension with axitinib use has been documented, it is unclear whether a first-line TKI regimen can significantly affect the development of hypertension when axitinib is used as second-line therapy. Methods and Results: In this single-center retrospective study, advanced RCC patients treated with axitinib after first-line chemotherapy were divided into 2 groups according to the use of TKIs as part of first-line treatment before the initiation of axitinib. Clinical outcomes were compared between patients who were treated with (TKI(+); n=11) or without (TKI(-); n=11) a TKI. Although 63.6% of all patients had hypertension at baseline, axitinib-induced hypertension developed in 81.8% of patients, and 36.4% of patients experienced Grade 3 hypertension. After initiation of axitinib, both systolic and diastolic blood pressures and the hypertension grade were significantly elevated both in the TKI(+) and TKI(-) groups, and the number of antihypertensive drugs was significantly increased among all patients. Conclusions: This study suggests the need for proper monitoring and management of blood pressure in RCC patients treated with axitinib, regardless of a prior regimen with or without TKIs.

Dysbiosis and compositional alterations with aging in the gut microbiota of patients with heart failure.

Emerging evidence has suggested a potential impact of gut microbiota on the pathophysiology of heart failure (HF). However, it is still unknown whether HF is associated with dysbiosis in gut microbiota. We investigated the composition of gut microbiota in patients with HF to elucidate whether gut microbial dysbiosis is associated with HF. We performed 16S ribosomal RNA gene sequencing of fecal samples obtained from 12 HF patients and 12 age-matched healthy control (HC) subjects, and analyzed the differences in gut microbiota. We further compared the composition of gut microbiota of 12 HF patients younger than 60 years of age with that of 10 HF patients 60 years of age or older. The composition of gut microbial communities of HF patients was distinct from that of HC subjects in both unweighted and weighted UniFrac analyses. Eubacterium rectale and Dorea longicatena were less abundant in the gut microbiota of HF patients than in that of HC subjects. Compared to younger HF patients, older HF patients had diminished proportions of Bacteroidetes and larger quantities of Proteobacteria. The genus Faecalibacterium was depleted, while Lactobacillus was enriched in the gut microbiota of older HF patients. These results suggest that patients with HF harbor significantly altered gut microbiota, which varies further according to age. New concept of heart-gut axis has a great potential for breakthroughs in the development of novel diagnostic and therapeutic approach for HF.

Angiotensin II receptor blockade promotes repair of skeletal muscle through down-regulation of aging-promoting C1q expression.

Disruption of angiotensin II type 1 (AT1) receptor prolonged life span in mice. Since aging-related decline in skeletal muscle function was retarded in Atgr1a(-/-) mice, we examined the role of AT1 receptor in muscle regeneration after injury. Administration of AT1 receptor blocker irbesartan increased the size of regenerating myofibers, decreased fibrosis, and enhanced functional muscle recovery after cryoinjury. We recently reported that complement C1q, secreted by macrophages, activated Wnt/ß-catenin signaling and promoted aging-related decline in regenerative capacity of skeletal muscle. Notably, irbesartan induced M2 polarization of macrophages, but reduced C1q expression in cryoinjured muscles and in cultured macrophage cells. Irbesartan inhibited up-regulation of Axin2, a downstream gene of Wnt/ß-catenin pathway, in cryoinjured muscles. In addition, topical administration of C1q reversed beneficial effects of irbesartan on skeletal muscle regeneration after injury. These results suggest that AT1 receptor blockade improves muscle repair and regeneration through down-regulation of the aging-promoting C1q-Wnt/ß-catenin signaling pathway.