Publications by authors named "Ruona Shi"

9 Publications

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SNX27-driven membrane localisation of OTULIN antagonises linear ubiquitination and NF-κB signalling activation.

Cell Biosci 2021 Jul 27;11(1):146. Epub 2021 Jul 27.

CAS Key Laboratory of Regenerative Biology, Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Hefei Institute of Stem Cell and Regenerative Medicine, Center for Cell Lineage and Development, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, 510530, China.

Background: Linear ubiquitination is a novel type of ubiquitination that plays important physiological roles in signalling pathways such as tumour necrosis factor (TNF) signalling. However, little is known about the regulatory mechanisms of linear ubiquitination, except the well-described enzymatic regulators E3 ligase linear ubiquitin chain assembly complex (LUBAC) and deubiquitinase OTULIN.

Results: Previously, we identified SNX27, a member of the sorting nexin family protein, as a selective linear ubiquitin chain interactor in mass spectrometry-based ubiquitin interaction screening. Here, we demonstrated that the interaction between the linear ubiquitin chain and SNX27 is mediated by the OTULIN. Furthermore, we found that SNX27 inhibits LUBAC-mediated linear ubiquitin chain formation and TNFα-induced signalling activation. Mechanistic studies showed that, upon TNFα stimulation, OTULIN-SNX27 is localised to membrane-associated TNF receptor complex, where OTULIN deubiquitinates the linear polyubiquitin chain that formed by the LUBAC complex. Significantly, chemical inhibition of SNX27-retromer translocation by cholera toxin inhibits OTULIN membrane localization.

Conclusions: In conclusion, our study demonstrated that SNX27 inhibits TNFα induced NF-κB signalling activation via facilitating OTULIN to localize to TNF receptor complex.
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http://dx.doi.org/10.1186/s13578-021-00659-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8314547PMC
July 2021

SS18 regulates pluripotent-somatic transition through phase separation.

Nat Commun 2021 07 2;12(1):4090. Epub 2021 Jul 2.

Laboratory of Cell Fate Control, School of Life Sciences, Westlake University, Hangzhou, China.

The transition from pluripotent to somatic states marks a critical event in mammalian development, but remains largely unresolved. Here we report the identification of SS18 as a regulator for pluripotent to somatic transition or PST by CRISPR-based whole genome screens. Mechanistically, SS18 forms microscopic condensates in nuclei through a C-terminal intrinsically disordered region (IDR) rich in tyrosine, which, once mutated, no longer form condensates nor rescue SS18 defect in PST. Yet, the IDR alone is not sufficient to rescue the defect even though it can form condensates indistinguishable from the wild type protein. We further show that its N-terminal 70aa is required for PST by interacting with the Brg/Brahma-associated factor (BAF) complex, and remains functional even swapped onto unrelated IDRs or even an artificial 24 tyrosine polypeptide. Finally, we show that SS18 mediates BAF assembly through phase separation to regulate PST. These studies suggest that SS18 plays a role in the pluripotent to somatic interface and undergoes liquid-liquid phase separation through a unique tyrosine-based mechanism.
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http://dx.doi.org/10.1038/s41467-021-24373-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8253816PMC
July 2021

Loss of SPACA1 function causes autosomal recessive globozoospermia by damaging the acrosome-acroplaxome complex.

Hum Reprod 2021 Aug;36(9):2587-2596

Department of Paediatric Endocrinology/Genetics, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.

Study Question: Is the sperm acrosome membrane-associated protein 1 (SPACA1) gene critical to human globozoospermia?

Summary Answer: The biallelic loss-of-function (variant of SPACA1) causes globozoospermia as a result of acrosome-acroplaxome complex damage.

What Is Known Already: SPACA1 expression decreases in patients with globozoospermia. Spaca1 gene-disrupted mice have abnormally shaped sperm heads that resemble those of human globozoospermia.

Study Design, Size, Duration: We recruited a consanguineous family with two brothers affected by infertility as a consequence of globozoospermia. The semen analysis data and ART outcomes were collected. Exome sequencing (ES) was used to identify potential pathogenic variants. Protein-protein interaction (PPI) technologies and proteomic analysis were utilized to explore the pathogenic mechanism.

Participants/materials, Setting, Methods: Two globozoospermic brothers and their consanguineous parents were recruited to identify the potential pathogenic variant through ES. A homozygous nonsense variant in the SPACA1 gene in both brothers inherited from the heterozygous parents was identified. Twenty normal fertile males were recruited as controls. Sperm ultrastructure was observed with transmission electron microscopy. Western blotting was performed to measure SPACA1 expression level in the sperm from the patients. Mass spectrometry (MS) analyses were used to identify differentially expressed proteins and to investigate proteins that interact with SPACA1. Co-immunoprecipitation (co-IP), yeast two-hybrid (Y2H) and immunofluorescence colocalization assays were used to confirm the PPI.

Main Results And The Role Of Chance: A nonsense variant (NM_030960.2: c.53G>A; p. Trp18*) in the SPACA1 gene was identified as the pathogenic variant in a family with globozoospermia. Patient IV:1 and Patient IV:2 had a phenotype very similar to that of Spaca1 gene-disrupted mice. The nonsense variant in SPACA1 led to premature transcriptional termination in the signal peptide, which was confirmed by western blotting. MS-based proteomics analysis showed that eight interactors of SPACA1 were differentially expressed in the patients' sperm, including actin-like Protein 7A (ACTL7A), an important component of the acrosome-acroplaxome complex. The PPI of SPACA1 and ACTL7A was confirmed via co-IP and Y2H assays. Immunofluorescence showed that SPACA1 and ACTL7A colocalized in mature sperm, revealing that these proteins were coexpressed spatially.

Limitations, Reasons For Caution: Given the rarity of globozoospermia, only two patients from one family harbouring the SPACA1 variant were found. Future studies should evaluate SPACA1 variants in larger cohorts to corroborate this finding.

Wider Implications Of The Findings: This study revealed that the SPACA1 gene was critical for globozoospermia, which expanded the spectrum of causative genes for globozoospermia. This study also provided evidence for ICSI clinical outcomes for patients with SPACA1-deficient globozoospermia, which may guide clinical treatment strategies. Furthermore, this study explored the pathogenesis of globozoospermia caused by SPACA1 deficiency.

Study Funding/competing Interest(s): This work was funded by the Precision Medical Research of National Key Research and Development Program (2018YFC1002400), National Natural Science Foundation of China (81873724), and Natural Science Foundation of Shanghai (20ZR1472700). The authors have no conflicts of interest to disclose.

Trial Registration Number: N/A.
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http://dx.doi.org/10.1093/humrep/deab144DOI Listing
August 2021

SETDB1-Mediated Cell Fate Transition between 2C-Like and Pluripotent States.

Cell Rep 2020 01;30(1):25-36.e6

CAS Key Laboratory of Regenerative Biology, Joint School of Life Sciences, Guangzhou Institutes of Biomedicine and Health, Guangzhou Medical University, Chinese Academy of Sciences, Guangzhou, China; Guangdong Provincial Key Laboratory of Stem Cell and Regenerative Medicine, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510530, China; University of Chinese Academy of Sciences, Beijing 100049, China; Guangzhou Regenerative Medicine and Health GuangDong Laboratory (GRMH-GDL), Guangzhou 510005, China. Electronic address:

Known as a histone H3K9 methyltransferase, SETDB1 is essential for embryonic development and pluripotent inner cell mass (ICM) establishment. However, its function in pluripotency regulation remains elusive. In this study, we find that under the "ground state" of pluripotency with two inhibitors (2i) of the MEK and GSK3 pathways, Setdb1-knockout fails to induce trophectoderm (TE) differentiation as in serum/LIF (SL), indicating that TE fate restriction is not the direct target of SETDB1. In both conditions, Setdb1-knockout activates a group of genes targeted by SETDB1-mediated H3K9 methylation, including Dux. Notably, Dux is indispensable for the reactivation of 2C-like state genes upon Setdb1 deficiency, delineating the mechanistic role of SETDB1 in totipotency restriction. Furthermore, Setdb1-null ESCs maintain pluripotent marker (e.g., Nanog) expression in the 2i condition. This "ground state" Setdb1-null population undergoes rapid cell death by activating Ripk3 and, subsequently, RIPK1/RIPK3-dependent necroptosis. These results reveal the essential role of Setdb1 between totipotency and pluripotency transition.
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http://dx.doi.org/10.1016/j.celrep.2019.12.010DOI Listing
January 2020

Physicochemical Characterization and Functional Analysis of the Polysaccharide from the Edible Microalga Nostoc sphaeroides.

Molecules 2018 Feb 24;23(2). Epub 2018 Feb 24.

Center for Bioresources & Drug Discovery and School of Biosciences & Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou 510006, China.

colonies have been used as food and medicine for centuries, and their main supporting matrix is polysaccharides, which help cells resist various environmental stresses including oxidative stress. Here we isolated a polysaccharide, nostoglycan, from cultured colonies and determined its physicochemical properties, which revealed a characteristic infrared absorption spectrum typical of polysaccharides and an amorphous morphology with rough surfaces. We also show that nostoglycan has strong moisture absorption and retention capacities and a high relative viscosity. Using models, we then demonstrate that nostoglycan is capable of improving overall survival rate of the animals under increased oxidative stress caused by paraquat. Nostoglycan also reduces reactive oxygen species level, inhibits protein carbonyl formation and lipid peroxidation, and increases activities of superoxide dismutase and catalase in paraquat-exposed nematodes. As oxidative stress may drive tumor progression, we further demonstrate that nostoglycan can suppress the proliferation of several types of tumor cells and induce apoptosis of human lung adenocarcinoma A549 cells via caspase-3 activation. Together, our results yield important information on the physicochemical characteristics and demonstrate the antioxidant and anti-proliferative functions of nostoglycan, and thus provide an insight into its potential in food and health industries.
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http://dx.doi.org/10.3390/molecules23020508DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6017307PMC
February 2018

Food-Derived Antioxidant Polysaccharides and Their Pharmacological Potential in Neurodegenerative Diseases.

Nutrients 2017 Jul 19;9(7). Epub 2017 Jul 19.

Center for Bioresources & Drug Discovery and School of Biosciences & Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou 510006, China.

Oxidative stress is known to impair architecture and function of cells, which may lead to various chronic diseases, and therefore therapeutic and nutritional interventions to reduce oxidative damages represent a viable strategy in the amelioration of oxidative stress-related disorders, including neurodegenerative diseases. Over the past decade, a variety of natural polysaccharides from functional and medicinal foods have attracted great interest due to their antioxidant functions such as scavenging free radicals and reducing oxidative damages. Interestingly, these antioxidant polysaccharides are also found to attenuate neuronal damages and alleviate cognitive and motor decline in a range of neurodegenerative models. It has recently been established that the neuroprotective mechanisms of polysaccharides are related to oxidative stress-related pathways, including mitochondrial function, antioxidant defense system and pathogenic protein aggregation. Here, we first summarize the current status of antioxidant function of food-derived polysaccharides and then attempt to appraise their anti-neurodegeneration activities.
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http://dx.doi.org/10.3390/nu9070778DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5537892PMC
July 2017

Tanshinone IIA Inhibits Glutamate-Induced Oxidative Toxicity through Prevention of Mitochondrial Dysfunction and Suppression of MAPK Activation in SH-SY5Y Human Neuroblastoma Cells.

Oxid Med Cell Longev 2017 11;2017:4517486. Epub 2017 Jun 11.

Center for Bioresources & Drug Discovery and School of Biosciences & Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou 510006, China.

Glutamate excitotoxicity is associated with many neurological diseases, including cerebral ischemia and neurodegenerative diseases. Tanshinone IIA, a diterpenoid naphthoquinone from , has been shown to suppress presynaptic glutamate release, but its protective mechanism against glutamate-induced neurotoxicity is lacking. Using SH-SY5Y human neuroblastoma cells, we show here that excessive glutamate exposure decreases cell viability and proliferation and increases LDH release. Pretreatment with tanshinone IIA, however, prevents the decrease in cell viability and proliferation and the increase in LDH release induced by glutamate. Tanshinone IIA also attenuates glutamate-induced oxidative stress by reducing reactive oxygen species level and malondialdehyde and protein carbonyl contents and by enhancing activities and protein levels of superoxide dismutase and catalase. We then show that tanshinone IIA prevents glutamate-induced mitochondrial dysfunction by increasing mitochondrial membrane potential and ATP content and by reducing mitochondrial protein carbonyl content. Moreover, tanshinone IIA can inhibit glutamate-induced apoptosis through regulation of apoptosis-related protein expression and MAPK activation, including elevation of Bcl-2 protein level, decrease in Bax and cleaved caspase-3 levels, and suppression of JNK and p38 MAPK activation. Collectively, our findings demonstrate that tanshinone IIA protects SH-SY5Y cells against glutamate toxicity by reducing oxidative stress and regulating apoptosis and MAPK pathways.
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http://dx.doi.org/10.1155/2017/4517486DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5485345PMC
May 2018

Polysaccharide Suppresses 6-Hydroxydopamine-Induced Neurotoxicity in .

Oxid Med Cell Longev 2016 3;2016:4856761. Epub 2016 Nov 3.

Center for Bioresources & Drug Discovery and School of Biosciences & Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou 510006, China; Guangdong Province Key Laboratory for Biotechnology Drug Candidates, Guangdong Pharmaceutical University, Guangzhou 510006, China.

is a medicinal plant traditionally used in China for a variety of conditions, including inflammatory and neural diseases. polysaccharides are shown to reduce the adverse effect of levodopa which is used to treat Parkinson's disease (PD). However, the neuroprotective effect of polysaccharides in PD is lacking. Using models, we investigated the protective effect of astragalan, an acidic polysaccharide isolated from , against the neurotoxicity of 6-hydroxydopamine (6-OHDA), a neurotoxin that can induce parkinsonism. We show that 6-OHDA is able to degenerate dopaminergic neurons and lead to the deficiency of food-sensing behavior and a shorter lifespan in . Interestingly, these degenerative symptoms can be attenuated by astragalan treatment. Astragalan is also shown to alleviate oxidative stress through reducing reactive oxygen species level and malondialdehyde content and increasing superoxide dismutase and glutathione peroxidase activities and reduce the expression of proapoptotic gene in 6-OHDA-intoxicated nematodes. Further studies reveal that astragalan is capable of elevating the decreased acetylcholinesterase activity induced by 6-OHDA. Together, our results demonstrate that the protective effect of astragalan against 6-OHDA neurotoxicity is likely due to the alleviation of oxidative stress and regulation of apoptosis pathway and cholinergic system and thus provide an important insight into the therapeutic potential of polysaccharide in neurodegeneration.
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http://dx.doi.org/10.1155/2016/4856761DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5112302PMC
March 2017

Antioxidant and neuroprotective effects of Dictyophora indusiata polysaccharide in Caenorhabditis elegans.

J Ethnopharmacol 2016 Nov 17;192:413-422. Epub 2016 Sep 17.

School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, China; Center for Bioresources & Drug Discovery and School of Biosciences & Biopharmaceutics, Guangdong Pharmaceutical University, Guangzhou 510006, China; Guangdong Province Key Laboratory for Biotechnology Drug Candidates, Guangdong Pharmaceutical University, Guangzhou 510006, China. Electronic address:

Ethnopharmacological Relevance: Dictyophora indusiata is a medicinal mushroom traditionally used in China for a variety of conditions, including inflammatory and neural diseases. D. indusiata polysaccharides (DiPS) are shown to have in vitro antioxidant activity but in vivo evidence is lacking. This study aimes to explore the antioxidant capacity and related neuroptotective activities of DiPS using wild-type and neurodegenerative Caenorhabditis elegans models.

Materials And Methods: The antioxidant capacities of DiPS were first determined using paraquat survival and Pgst-4::GFP expression assays in wild-type and transgenic C. elegans models, respectively, and then further investigated by determining reactive oxygen species (ROS) level, malondialdehyde (MDA) content and superoxide dismutase (SOD) activity as well as functional parameters of mitochondria. The activation of stress response transcription factors and neuroptotective activities were examined using nuclear localization and chemosensory behavioral assays in transgenic nematodes, respectively.

Results: DiPS was shown not only to increase survival rate and reduce stress level under paraquat-induced oxidative conditions but also to decrease ROS and MDA levels and increase SOD activity in C. elegans models. Moreover, DiPS was also able to restore the functional parameters of mitochondria, including membrane potential and ATP content, in paraquat-stressed nematodes. In addition, nuclear translocation assays demonstrate that the stress response transcription factor DAF-16/FOXO was involved in the antioxidant activity of the polysaccharide. Further experiments reveal that DiPS was capable of reducing ROS levels and alleviating chemosensory behavior dysfunction in transgenic nematode models of neurodegenerative diseases mediated by polyglutamine and amyloid-β protein.

Conclusions: These findings demonstrate the antioxidant and neuroprotective activities of the D. indusiata polysaccharide DiPS in wild-type and neurodegenerative C. elegans models, and thus provide an important pharmacological basis for the therapeutic potential of D. indusiata in neurodegeneration.
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http://dx.doi.org/10.1016/j.jep.2016.09.031DOI Listing
November 2016
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