Stress Resistance Screen in a Human Primary Cell Line Identifies Small Molecules That Affect Aging Pathways and Extend Caenorhabditis elegans' Lifespan.

Increased resistance to environmental stress at the cellular level is correlated with the longevity of long-lived mutants and wild-animal species. Moreover, in experimental organisms, screens for increased stress resistance have yielded mutants that are long-lived. To find entry points for small molecules that might extend healthy longevity in humans, we screened ∼100,000 small molecules in a human primary-fibroblast cell line and identified a set that increased oxidative-stress resistance. Some of the hits fell into structurally related chemical groups, suggesting that they may act on common targets. Two small molecules increased C. elegans' stress resistance, and at least 9 extended their lifespan by ∼10-50%. We further evaluated a chalcone that produced relatively large effects on lifespan and were able to implicate the activity of two, stress-response regulators, NRF2/skn-1 and SESN/sesn-1, in its mechanism of action. Our findings suggest that screening for increased stress resistance in human cells can enrich for compounds with promising pro-longevity effects. Further characterization of these compounds may reveal new ways to extend healthy human lifespan

PERK eIF2α kinase regulates neonatal growth by controlling the expression of circulating insulin-like growth factor-I derived from the liver

Humans afflicted with the Wolcott-Rallison syndrome and mice deficient for PERK (pancreatic endoplasmic reticulum eIF2α kinase) show severe postnatal growth retardation. In mice, growth retardation in Perk−/− mutants is manifested within the first few days of neonatal development. Growth parameters of Perk−/− mice, including comparison of body weight to length and organ weights, are consistent with proportional dwarfism. Tibia growth plates exhibited a reduction in proliferative and hypertrophic chondrocytes underlying the longitudinal growth retardation. Neonatal Perk−/− deficient mice show a 75% reduction in liver IGF-I mRNA and serum IGF-I within the first week, whereas the expression of IGF-I mRNA in most other tissues is normal. Injections of IGF-I partially reversed the growth retardation of the Perk−/− mice, whereas GH had no effect. Transgenic rescue of PERK activity in the insulin- secreting β-cells of the Perk−/− mice reversed the juvenile but not the neonatal growth retardation. We provide evidence that circulating IGF-I is derived from neonatal liver but is independent of GH at this stage. We propose that PERK is required to regulate the expression of IGF-I in the liver during the neonatal period, when IGF-I expression is GH-independent, and that the lack of this regulation results in severe neonatal growth retardation

DDX58 deficiency leads to triple negative breast cancer chemotherapy resistance by inhibiting Type I IFN-mediated signalling apoptosis

IntroductionTriple-negative breast cancer (TNBC) is characterized by its aggressive nature and absence of specific therapeutic targets, necessitating the reliance on chemotherapy as the primary treatment modality. However, the drug resistance poses a significant challenge in the management of TNBC. In this study, we investigated the role of DDX58 (DExD/H-box helicase 58), also known as RIG-I, in TNBC chemoresistance.MethodsThe relationship between DDX58 expression and breast cancer prognosis was investigated by online clinical databases and confirmed by immunohistochemistry analysis. DDX58 was knockout by CRISPR-Cas9 system (DDX58-KO), knockdown by DDX58-siRNA (DDX58-KD), and stably over expressed (DDX58-OE) by lentivirus. Western blotting, immunofluorescence and qPCR were used for related molecules detection. Apoptosis was analyzed through flow cytometry (Annexin V/7AAD apoptosis assay) and Caspase 3/7 activity assay.ResultsPatients with lower expression of DDX58 led to lower rate of pathological complete response (pCR) and worse prognosis by online databases and hospital clinical data. DDX58-KD cells showed multiple chemo-drugs resistance (paclitaxel, doxorubicin, 5-fluorouracil) in TNBC cell lines. Similarly, DDX58-KO cells also showed multiple chemo-drugs resistance in a dosage-dependent manner. In the CDX model, tumours in the DDX58-KO group had a 25% reduction in the tumour growth inhibition rate (IR) compared to wild-type (WT) group after doxorubicin (Dox) treatment. The depletion of DDX58 inhibited proliferation and promoted the migration and invasion in MDA-MB-231 cells. The findings of our research indicated that DDX58-KO cells exhibit a reduction in Dox-induced apoptosis both in vivo and in vitro. Mechanistically, Dox treatment leads to a significant increase in the expression of double-stranded RNAs (dsRNAs) and activates the DDX58-Type I interferon (IFN) signaling pathway, ultimately promoting apoptosis in TNBC cells.DiscussionIn the process of TNBC chemotherapy, the deficiency of DDX58 can inhibit Dox-induced apoptosis, revealing a new pathway of chemotherapy resistance, and providing a possibility for developing personalized treatment strategies based on DDX58 expression levels

Direct and Indirect Gene Regulation by a Life-Extending FOXO Protein in C. elegans: Roles for GATA Factors and Lipid Gene Regulators

In long-lived C. elegans insulin/IGF-1 pathway mutants, the life-extending FOXO transcription factor DAF-16 is present throughout the animal, but we find that its activity in a single tissue can delay the aging of other tissues and extend the animal's life span. To better understand the topography of DAF-16 action among the tissues, we analyzed a collection of DAF-16-regulated genes. DAF-16 regulated most of these genes in a cell-autonomous fashion, often using tissue-specific GATA factors to direct their expression to specific tissues. DAF-16 could also act cell nonautonomously to influence gene expression. DAF-16 affected gene expression in other cells, at least in part, via the lipid-gene regulator MDT-15. DAF-16, and probably MDT-15, could act cell nonautonomously in the endoderm to ameliorate the paralysis caused by expressing Alzheimer's Aβ protein in muscles. These findings suggest that MDT-15-dependent intercellular signals, possibly lipid signals, can help to coordinate tissue physiology, enhance proteostasis, and extend life in response to DAF-16/FOXO activity

Direct and Indirect Gene Regulation by a Life-Extending FOXO Protein in C. elegans: Roles for GATA Factors and Lipid Gene Regulators

In long-lived C. elegans insulin/IGF-1 pathway mutants, the life-extending FOXO transcription factor DAF-16 is present throughout the animal, but we find that its activity in a single tissue can delay the aging of other tissues and extend the animal's life span. To better understand the topography of DAF-16 action among the tissues, we analyzed a collection of DAF-16-regulated genes. DAF-16 regulated most of these genes in a cell-autonomous fashion, often using tissue-specific GATA factors to direct their expression to specific tissues. DAF-16 could also act cell nonautonomously to influence gene expression. DAF-16 affected gene expression in other cells, at least in part, via the lipid-gene regulator MDT-15. DAF-16, and probably MDT-15, could act cell nonautonomously in the endoderm to ameliorate the paralysis caused by expressing Alzheimer's A beta protein in muscles. These findings suggest that MDT-15-dependent intercellular signals, possibly lipid signals, can help to coordinate tissue physiology, enhance proteostasis, and extend life in response to DAF-16/FOXO activity.X117565sciescopu

Distinct Activities of the Germline and Somatic Reproductive Tissues in the Regulation of Caenorhabditis elegans' Longevity

The two parts of the Caenorhabditis elegans reproductive system, the germ cells and the somatic reproductive tissues, each influence the life span of the animal. Removing the germ cells increases longevity, and this life span extension requires the somatic gonad. Here we show that the somatic gonad and the germ cells make distinct contributions to life span determination. The life span increase produced by loss of the germ cells requires the DAF-16/FOXO transcription factor. In response to germ-cell removal, DAF-16 accumulates in nuclei. We find that the somatic gonad is not required for DAF-16 nuclear accumulation or for the increased stress resistance that is produced by germ-cell removal. The somatic gonad is required, however, for expression of specific DAF-16 target genes. DAF-16 is known to be activated by reduced insulin/IGF-1 signaling in C. elegans. In certain insulin/IGF-1-pathway mutants, the somatic gonad is not required for germ-cell removal to extend life span. Our genetic experiments suggest that these mutations reduce insulin/IGF-1 signaling below a critical threshold level. At these low levels of insulin/IGF-1 signaling, factors normally provided by the somatic gonad are no longer needed for germ-cell removal to increase the expression of DAF-16 target genes

Application of microfluidic chips in the simulation of the urinary system microenvironment

The urinary system, comprising the kidneys, ureters, bladder, and urethra, has a unique mechanical and fluid microenvironment, which is essential to the urinary system growth and development. Microfluidic models, based on micromachining and tissue engineering technology, can integrate pathophysiological characteristics, maintain cell-cell and cell-extracellular matrix interactions, and accurately simulate the vital characteristics of human tissue microenvironments. Additionally, these models facilitate improved visualization and integration and meet the requirements of the laminar flow environment of the urinary system. However, several challenges continue to impede the development of a tissue microenvironment with controllable conditions closely resemble physiological conditions. In this review, we describe the biochemical and physical microenvironment of the urinary system and explore the feasibility of microfluidic technology in simulating the urinary microenvironment and pathophysiological characteristics in vitro. Moreover, we summarize the current research progress on adapting microfluidic chips for constructing the urinary microenvironment. Finally, we discuss the current challenges and suggest directions for future development and application of microfluidic technology in constructing the urinary microenvironment in vitro