Publications by authors named "Zilong Geng"

6 Publications

  • Page 1 of 1

LARP7 ameliorates cellular senescence and aging by allosterically enhancing SIRT1 deacetylase activity.

Cell Rep 2021 Nov;37(8):110038

Key Laboratory of Systems Biomedicine, Shanghai Center for Systems Biomedicine, Department of Pediatric Cardiology, Xin Hua Hospital, School of Medicine, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai 200240, China. Electronic address:

Cellular senescence is associated with pleiotropic physiopathological processes, including aging and age-related diseases. The persistent DNA damage is a major stress leading to senescence, but the underlying molecular link remains elusive. Here, we identify La Ribonucleoprotein 7 (LARP7), a 7SK RNA binding protein, as an aging antagonist. DNA damage-mediated Ataxia Telangiectasia Mutated (ATM) activation triggers the extracellular shuttling and downregulation of LARP7, which dampens SIRT1 deacetylase activity, enhances p53 and NF-κB (p65) transcriptional activity by augmenting their acetylation, and thereby accelerates cellular senescence. Deletion of LARP7 leads to senescent cell accumulation and premature aging in rodent model. Furthermore, we show this ATM-LARP7-SIRT1-p53/p65 senescence axis is active in vascular senescence and atherogenesis, and preventing its activation substantially alleviates senescence and atherogenesis. Together, this study identifies LARP7 as a gatekeeper of senescence, and the altered ATM-LARP7-SIRT1-p53/p65 pathway plays an important role in DNA damage response (DDR)-mediated cellular senescence and atherosclerosis.
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http://dx.doi.org/10.1016/j.celrep.2021.110038DOI Listing
November 2021

LARP7 Suppresses Endothelial-to-Mesenchymal Transition by Coupling With TRIM28.

Circ Res 2021 Oct 10;129(9):843-856. Epub 2021 Sep 10.

Key Laboratory of Systems Biomedicine (Ministry of Education), Shanghai Center for Systems Biomedicine, Shanghai Jiao Tong University, China (X.L., S. Wu, Z.G., L.L., S.Z., B.Z.).

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http://dx.doi.org/10.1161/CIRCRESAHA.121.319590DOI Listing
October 2021

Exosomes from miRNA-378-modified adipose-derived stem cells prevent glucocorticoid-induced osteonecrosis of the femoral head by enhancing angiogenesis and osteogenesis via targeting miR-378 negatively regulated suppressor of fused (Sufu).

Stem Cell Res Ther 2021 06 7;12(1):331. Epub 2021 Jun 7.

Department of Orthopaedics, The Second Affiliated Hospital of Xi'an Jiaotong University, No. 157 Xiwu Road, Xi'an, 710004, Shaanxi Province, People's Republic of China.

Background: Local ischemia and defective osteogenesis are implicated in the progression of glucocorticoid (GC)-induced osteonecrosis of the femoral head (ONFH). Recent studies have revealed that exosomes released from adipose-derived stem cells (ASCs) play important roles in ONFH therapy. The present study aimed to investigate whether exosomes derived from miR-378-overexpressing ASCs (miR-378-ASCs-Exos) could promote angiogenesis and osteogenesis in GC-induced ONFH.

Methods: In vitro, we investigated the osteogenic potential of miR-378-ASCs-Exos on bone marrow stromal cells (BMSCs) by alkaline phosphatase staining and western blotting. The angiogenic effects of miR-378-ASCs-Exos on human umbilical vein endothelial cells (HUVECs) were examined by evaluating their proliferation, migration, and tube-forming analyses. We identified the underlying mechanisms of miR-378 in osteogenic and angiogenic regulation. In addition, an ONFH rat model was established to explore the effects of miR-378-ASCs-Exos through histological and immunohistochemical staining and micro-CT in vivo.

Results: Administration of miR-378-ASCs-Exos improved the osteogenic and angiogenic potentials of BMSCs and HUVECs. miR-378 negatively regulated the suppressor of fused (Sufu) and activated Sonic Hedgehog (Shh) signaling pathway, and recombinant Sufu protein reduced the effects triggered by miR-378-ASCs-Exos. In vivo experiments indicated that miR-378-ASCs-Exos markedly accelerated bone regeneration and angiogenesis, which inhibited the progression of ONFH.

Conclusion: Our study indicated that miR-378-ASCs-Exos enhances osteogenesis and angiogenesis by targeting Sufu to upregulate the Shh signaling pathway, thereby attenuating GC-induced ONFH development.
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http://dx.doi.org/10.1186/s13287-021-02390-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8186190PMC
June 2021

LARP7 Protects Against Heart Failure by Enhancing Mitochondrial Biogenesis.

Circulation 2021 May 5;143(20):2007-2022. Epub 2021 Mar 5.

Key Laboratory of Systems Biomedicine, Shanghai Center for Systems Biomedicine, Department of Pediatric Cardiology, Xin Hua Hospital, School of Medicine, Xin Hua Hospital, Shanghai Jiao Tong University, China (H.J.Y., F.Z., P.Y.Y., S.S.Z., Y.M.L., Z.L.G., Z.X.L., Y.J.X., Y.N.L., K.S., B.Z.).

Background: Heart failure (HF) is among the leading causes of morbidity and mortality, and its prevalence continues to rise. LARP7 (La ribonucleoprotein domain family member 7) is a master regulator that governs the DNA damage response and RNAPII (RNA polymerase II) pausing pathway, but its role in HF pathogenesis is incompletely understood.

Methods: We assessed LARP7 expression in human HF and in nonhuman primate and mouse HF models. To study the function of LARP7 in heart, we generated global and cardiac-specific knockout mice. We acutely abolished LARP7 in mature cardiomyocytes by Cas9-mediated somatic knockout. We overexpressed LARP7 in cardiomyocytes using adeno-associated virus serotype 9 and ATM (ataxia telangiectasia mutated protein) inhibitor. The therapeutic potential of LARP7-regulated pathways in HF was tested in a mouse myocardial infarction model.

Results: LARP7 was profoundly downregulated in failing human hearts and in nonhuman primate and murine hearts after myocardial infarction. Low LARP7 levels in failing hearts were linked to elevated reactive oxygen species, which activated the ATM-mediated DNA damage response pathway and promoted LARP7 ubiquitination and degradation. Constitutive knockout in mouse resulted in impaired mitochondrial biogenesis, myocardial hypoplasia, and midgestational lethality. Cardiac-specific inactivation resulted in defective mitochondrial biogenesis, impaired oxidative phosphorylation, elevated oxidative stress, and HF by 4 months of age. These abnormalities were accompanied by reduced SIRT1 (silent mating type information regulation 2 homolog 1) stability and deacetylase activity that impaired SIRT1-mediated transcription of genes for oxidative phosphorylation and energy metabolism and dampened cardiac function. Restoring LARP7 expression after myocardial infarction by either adeno-associated virus-mediated LARP7 expression or small molecule ATM inhibitor substantially improved the function of injured heart.

Conclusions: LARP7 is essential for mitochondrial biogenesis, energy production, and cardiac function by modulating SIRT1 homeostasis and activity. Reduction of LARP7 in diseased hearts owing to activation of the ATM pathway contributes to HF pathogenesis and restoring LARP7 in the injured heart confers myocardial protection. These results identify the ATM-LARP7-SIRT1 pathway as a target for therapeutic intervention in HF.
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http://dx.doi.org/10.1161/CIRCULATIONAHA.120.050812DOI Listing
May 2021

Mitochondrial Pyruvate Carriers Prevent Cadmium Toxicity by Sustaining the TCA Cycle and Glutathione Synthesis.

Plant Physiol 2019 05 15;180(1):198-211. Epub 2019 Feb 15.

Key Laboratory of Plant Development and Environmental Adaption Biology, Ministry of Education, School of Life Science, Shandong University, Qingdao 266237, China

Cadmium (Cd) is a major heavy metal pollutant, and Cd toxicity is a serious cause of abiotic stress in the environment. Plants protect themselves against Cd stress through a variety of pathways. In a recent study, we found that mitochondrial pyruvate carriers (MPCs) are involved in Cd tolerance in Arabidopsis (). Following the identification of MPCs in yeast () in 2012, most studies have focused on the function of MPCs in animals, as a possible approach to reduce the risk of cancer developing. The results of this study show that AtMPC protein complexes are required for Cd tolerance and prevention of Cd accumulation in Arabidopsis. AtMPC complexes are composed of two elements, AtMPC1 and AtMPC2 (AtNRGA1 or AtMPC3). When the formation of AtMPCs was interrupted by the loss of , glutamate could supplement the synthesis of acetyl-coenzyme A and sustain the TCA cycle. With the up-regulation of glutathione synthesis following exposure to Cd stress, the supplementary pathway could not efficiently drive the tricarboxylic acid cycle without AtMPC. The ATP content decreased concomitantly with the deletion of tricarboxylic acid activity, which led to Cd accumulation in Arabidopsis. More importantly, ScMPCs were also required for Cd tolerance in yeast. Our results suggest that the mechanism of Cd tolerance may be similar in other species.
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http://dx.doi.org/10.1104/pp.18.01610DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6501077PMC
May 2019

Programming Bacteria With Light-Sensors and Applications in Synthetic Biology.

Front Microbiol 2018 8;9:2692. Epub 2018 Nov 8.

State Key Laboratory of Microbial Technology, Shandong University, Jinan, China.

Photo-receptors are widely present in both prokaryotic and eukaryotic cells, which serves as the foundation of tuning cell behaviors with light. While practices in eukaryotic cells have been relatively established, trials in bacterial cells have only been emerging in the past few years. A number of light sensors have been engineered in bacteria cells and most of them fall into the categories of two-component and one-component systems. Such a sensor toolbox has enabled practices in controlling synthetic circuits at the level of transcription and protein activity which is a major topic in synthetic biology, according to the central dogma. Additionally, engineered light sensors and practices of tuning synthetic circuits have served as a foundation for achieving light based real-time feedback control. Here, we review programming bacteria cells with light, introducing engineered light sensors in bacteria and their applications, including tuning synthetic circuits and achieving feedback controls over microbial cell culture.
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http://dx.doi.org/10.3389/fmicb.2018.02692DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6236058PMC
November 2018
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