Project description:Gut microbiota transplantation drives the adoptive transfer of colonic genotype-phenotype characteristics between mice lacking catestatin and their wild type counterparts
Project description:Sterile inflammation, also known as “inflammaging”, is a hallmark of tissue ageing. Cellular senescence contributes to tissue aging in part through secretion of proinflammatory factors known as senescence-associated secretory phenotype (SASP). Thioredoxin reductase 1 (TXNRD1) genetic variability is associated with aging and age-associated phenotypes such as late-life survival, activity of daily living, and physical performance at old age. TXNRD1’s role in regulating tissue ageing has been attributed to its enzymatic role in reducing reactive oxygen species. Here we show that TXNRD1 drives SASP and inflammaging through the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) innate immune response pathway independent of its enzymatic activity
Project description:Sterile inflammation, also known as “inflammaging”, is a hallmark of tissue ageing. Cellular senescence contributes to tissue aging in part through secretion of proinflammatory factors known as senescence-associated secretory phenotype (SASP). Thioredoxin reductase 1 (TXNRD1) genetic variability is associated with aging and age-associated phenotypes such as late-life survival, activity of daily living, and physical performance at old age. TXNRD1’s role in regulating tissue ageing has been attributed to its enzymatic role in reducing reactive oxygen species. Here we show that TXNRD1 drives SASP and inflammaging through the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) innate immune response pathway independent of its enzymatic activity
Project description:Maintaining proteostasis is key to resisting stress and to promoting healthy aging. Proteostasis is necessary to preserve stem cell function, but little is known about the mechanisms that regulate proteostasis during stress in stem cells, and whether disruptions in proteostasis contribute stem cell aging is largely unexplored. We determined that ex vivo cultured mouse and human hematopoietic stem cells (HSCs) rapidly increase protein synthesis. This challenge to HSC proteostasis was associated with nuclear accumulation of Hsf1, and deletion of Hsf1 impaired HSC maintenance ex vivo. Strikingly, supplementing cultures with small molecules that enhance Hsf1 activation partially suppressed protein synthesis, rebalanced proteostasis, and supported retention of HSC serial reconstituting activity. Although Hsf1 was dispensable for young adult HSCs in vivo, Hsf1 deficiency increased protein synthesis and impaired the reconstituting activity of middle-aged HSCs. Hsf1 thus promotes proteostasis and the regenerative activity of HSCs in response to culture stress and aging.
Project description:Maintaining proteostasis is key to resisting stress and to promoting healthy aging. Proteostasis is necessary to preserve stem cell function, but little is known about the mechanisms that regulate proteostasis during stress in stem cells, and whether disruptions in proteostasis contribute stem cell aging is largely unexplored. We determined that ex vivo cultured mouse and human hematopoietic stem cells (HSCs) rapidly increase protein synthesis. This challenge to HSC proteostasis was associated with nuclear accumulation of Hsf1, and deletion of Hsf1 impaired HSC maintenance ex vivo. Strikingly, supplementing cultures with small molecules that enhance Hsf1 activation partially suppressed protein synthesis, rebalanced proteostasis, and supported retention of HSC serial reconstituting activity. Although Hsf1 was dispensable for young adult HSCs in vivo, Hsf1 deficiency increased protein synthesis and impaired the reconstituting activity of middle-aged HSCs. Hsf1 thus promotes proteostasis and the regenerative activity of HSCs in response to culture stress and aging.
Project description:Sterile inflammation, also known as inflammaging, is a hallmark of tissue ageing. Cellular senescence contributes to tissue aging in part through secretion of proinflammatory factors known as senescence-associated secretory phenotype (SASP). Thioredoxin reductase 1 (TXNRD1) genetic variability is associated with aging and age-associated phenotypes such as late-life survival, activity of daily living, and physical performance at old age. TXNRD1 role in regulating tissue ageing has been attributed to its enzymatic role in regulating cellular redox. Here we show that TXNRD1 drives SASP and inflammaging through the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) innate immune response pathway independently of its enzymatic activity. TXNRD1 localizes to cytoplasmic chromatin fragment and interacts with cGAS in a senescence status dependent manner. TXNRD1 enhances the enzymatic activity of cGAS. TXNRD1 and its interaction with cGAS is necessary for the SASP. TXNRD1 is required for both the tumor-promoting and immune-surveillance functions of senescent cells, which are mediated by SASP in vivo in mouse models. Treatment of aged mice with an TXNRD1 inhibitor that disrupts its interaction with cGAS, but not an inhibitor of its enzymatic activity, downregulated inflammaging in several tissues. In summary, our results report TXNRD1 promotes inflammaging via the innate immune response. They indicate that TXNRD1 and cGAS interaction is a relevant target for selectively suppressing inflammaging.
Project description:Homoharringtonine could be a novel therapeutic agent for the treatment and the prevention of aging and age-related diseases (ARDs). Cellular senescence contributes to aging and ARDs. Removal and modulation of senescent cells (SCs) improve physical functions and extend healthspan in animal models. Thus, the development of therapeutics that target SCs (i.e., senotherapeutics) has been proposed as a promising strategy for the treatment and the prevention of aging itself and ARDs. We used drug repositioning to discover new senotherapeutics from 2,150 clinically applied compounds and found that homoharringtonine (HHT) has a senolytic activity in human dermal fibroblasts (HDFs) in vitro and in vivo models. HHT improved physical status and rescued aging phenotypes in progeroid mice and aged mice. In addition, HHT administration ameliorates bleomycin-induced lung fibrosis in mice.
Project description:The classic piebald mutation in the endothelin receptor type B (Ednrb) gene was found on rolling Nagoya genetic background (PROD-s/s) mice with white coat spotting. To examine whether genetic background influenced the phenotype in the piebald mutant mice, we generated a congenic strain (B6.PROD-s/s), produced by repeated backcrosses to the C57BL/6J (B6) strain. Although B6.PROD-s/s mice showed white coat spotting, 7% of B6.PROD-s/s mice died between 2 and 5 weeks after birth due to megacolon. The PROD-s/s, s/s and Japanese fancy mouse 1 (JF1) strains, which also have piebald mutations on different genetic backgrounds with B6, showed only pigmentation defects without megacolon. In expression analyses, rectums of B6.PROD-s/s with megacolon mice showed ~5% of the level of Ednrb gene expression versus B6 mice. In histological analyses, aganglionosis was detected in the rectum of megacolon animals. The aganglionic rectum was thought to lead to severe constipation and intestinal blockage, resulting in megacolon. We also observed an abnormal intestinal flora, including a marked increase in Bacteroidaceae and Erysipelotrichaceae and a marked decrease in Lactobacillus and Clostridiales, likely inducing endotoxin production and a failure of the mucosal barrier system, leading ultimately to death. These results indicate that the genetic background plays a key role in the development of enteric ganglion neurons, controlled by the Ednrb gene, and that B6 has modifier gene (s) regarding aganglionosis.
Project description:Exposure to plant toxins or microbiota that are able to digest common food ingredients to toxic structures might be responsible for biliary atresia (BA). An isoflavonoid, biliatresone is known to effectively alter the extrahepatic bile duct (EHBD) development in BALB/c mice. Biliatresone causes a reduction of Glutathione (GSH) levels, SOX17 downregulation and is effectively countered with N-Acetyl-L-cysteine treatment in vitro. Therefore, reversing GSH-loss appears to be a promising treatment target for a translational approach. Since BALB/c mice have been described as sensitive in various models, we evaluated the toxic effect of biliatresone in robust C57BL/6J mice and confirmed its toxicity. Comparison between BALB/c and C57BL/6J mice revealed similarity in the toxic model. Affected neonates exhibited clinical symptoms of BA, such as jaundice, ascites, clay-colored stools, yellow urine and impaired weight gain. The gallbladders of jaundiced neonates were hydropic and EHBD were twisted and enlarged. Serum and histological analysis proved cholestasis. No anomalies were seen in the liver and EHBD of control animals. With our study we join a chain of evidence confirming that biliatresone is an effective agent for cross-lineage targeted alteration of the EHBD system.