26 research outputs found

    PIH1D3-knockout rats exhibit full ciliopathy features and dysfunctional pre-assembly and loading of dynein arms in motile cilia

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    Background: Recessive mutation of the X-linked gene, PIH1 domain-containing protein 3 (PIH1D3), causes familial ciliopathy. PIH1D3 deficiency is associated with the defects of dynein arms in cilia, but how PIH1D3 specifically affects the structure and function of dynein arms is not understood yet. To gain insights into the underlying mechanisms of the disease, it is crucial to create a reliable animal model. In humans, rats, and mice, one copy of the PIH1D3 gene is located on the X chromosome. Interestingly, mice have an additional, intronless copy of the Pih1d3 gene on chromosome 1. To develop an accurate disease model, it is best to manipulate the X-linked PIH1D3 gene, which contains essential regulatory sequences within the introns for precise gene expression. This study aimed to develop a tailored rat model for PIH1D3-associated ciliopathy with the ultimate goal of uncovering the intricate molecular mechanisms responsible for ciliary defects in the disease.Methods: Novel Pih1d3-knockout (KO) rats were created by using TALEN-mediated non-homologous DNA recombination within fertilized rat eggs and, subsequently, underwent a comprehensive characterization through a battery of behavioral and pathological assays. A series of biochemical and histological analyses were conducted to elucidate the identity of protein partners that interact with PIH1D3, thus shedding light on the intricate molecular mechanisms involved in this context.Results: PIH1D3-KO rats reproduced the cardinal features of ciliopathy including situs inversus, defects in spermatocyte survival and mucociliary clearance, and perinatal hydrocephalus. We revealed the novel function of PIH1D3 in cerebrospinal fluid circulation and elucidated the mechanism by which PIH1D3 deficiency caused communicating hydrocephalus. PIH1D3 interacted with the proteins required for the pre-assembly and uploading of outer (ODA) and inner dynein arms (IDA), regulating the integrity of dynein arm structure and function in cilia.Conclusion: PIH1D3-KO rats faithfully reproduced the cardinal features of ciliopathy associated with PIH1D3 deficiency. PIH1D3 interacted with the proteins responsible for the pre-assembly and uploading of dynein arms in cilia, and its deficiency led to dysfunctional cilia and, thus, to ciliopathy by affecting the pre-assembly and uploading of dynein arms. The resultant rat model is a valuable tool for the mechanistic study of PIH1D3-caused diseases

    Detergent-insoluble PFN1 inoculation expedites disease onset and progression in PFN1 transgenic rats

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    Accumulating evidence suggests a gain of elusive toxicity in pathogenically mutated PFN1. The prominence of PFN1 aggregates as a pivotal pathological hallmark in PFN1 transgenic rats underscores the crucial involvement of protein aggregation in the initiation and progression of neurodegeneration. Detergent-insoluble materials were extracted from the spinal cords of paralyzed rats afflicted with ALS and were intramuscularly administered to asymptomatic recipient rats expressing mutant PFN1, resulting in an accelerated development of PFN1 inclusions and ALS-like phenotypes. This effect diminished when the extracts derived from wildtype PFN1 transgenic rats were employed, as detergent-insoluble PFN1 was detected exclusively in mutant PFN1 transgenic rats. Consequently, the factor influencing the progression of ALS pathology in recipient rats is likely associated with the presence of detergent-insoluble PFN1 within the extracted materials. Noteworthy is the absence of disease course modification upon administering detergent-insoluble extracts to rats that already displayed PFN1 inclusions, suggesting a seeding rather than augmenting role of such extracts in initiating neuropathological changes. Remarkably, pathogenic PFN1 exhibited an enhanced affinity for the molecular chaperone DNAJB6, leading to the sequestration of DNAJB6 within protein inclusions, thereby depleting its availability for cellular functions. These findings shed light on a novel mechanism that underscores the prion-like characteristics of pathogenic PFN1 in driving neurodegeneration in the context of PFN1-related ALS

    Structural insights into Ca2+-activated long-range allosteric channel gating of RyR1

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    Ryanodine receptors (RyRs) are a class of giant ion channels with molecular mass over 2.2 mega-Daltons. These channels mediate calcium signaling in a variety of cells. Since more than 80% of the RyR protein is folded into the cytoplasmic assembly and the remaining residues form the transmembrane domain, it has been hypothesized that the activation and regulation of RyR channels occur through an as yet uncharacterized long-range allosteric mechanism. Here we report the characterization of a Ca2+-activated open-state RyR1 structure by cryo-electron microscopy. The structure has an overall resolution of 4.9 angstrom and a resolution of 4.2 angstrom for the core region. In comparison with the previously determined apo/closed-state structure, we observed long-range allosteric gating of the channel upon Ca2+ activation. In-depth structural analyses elucidated a novel channel-gating mechanism and a novel ion selectivity mechanism of RyR1. Our work not only provides structural insights into the molecular mechanisms of channel gating and regulation of RyRs, but also sheds light on structural basis for channel-gating and ion selectivity mechanisms for the six-transmembrane-helix cation channel family.Strategic Priority Research Program of Chinese Academy of Sciences [XDB08030202]; National Basic Research Program (973 Program); Ministry of Science & Technology of China [2012CB917200, 2014CB910700]; National Natural Science Foundation of China [31270768]; Ministry of Education of China (111 Program China)SCI(E)PubMed中国科技核心期刊(ISTIC)[email protected]; [email protected]

    Research on the Duality of China’s Marine Fishery Carbon Emissions and Its Coordination with Economic Development

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    Through the Tapio model, this paper measures the “decoupling and coupling” relationship between carbon emissions, carbon sinks, and economic growth of marine fisheries in nine coastal provinces of China in 2009–2019, objectively evaluates the economic benefits of carbon emissions and low-carbon development potential, and then discusses the economic development models of marine fisheries in detail. The results showed that the total carbon sink and carbon emission of China’s marine fisheries are increasing. Guangdong is dominated by “double low” economic benefits and low-carbon potential, and “double high” provinces have better resource endowment conditions; China’s marine fishery economic development is still dominated by conventional types. To further promote the sustainable development of China’s marine fisheries, all provinces should define the development orientation of marine fisheries, improve the production methods of marine fisheries according to local conditions, and adjust the industrial structure of marine fisheries in a timely manner, to achieve the low-carbon fishery goal of reducing carbon emissions and growing the economy

    Deep-Reinforcement-Learning-Based Low-Carbon Economic Dispatch for Community-Integrated Energy System under Multiple Uncertainties

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    A community-integrated energy system under a multiple-uncertainty low-carbon economic dispatch model based on the deep reinforcement learning method is developed to promote electricity low carbonization and complementary utilization of community-integrated energy. A demand response model based on users’ willingness is proposed for the uncertainty of users’ demand response behavior; a training scenario set of a reinforcement learning agent is generated with a Latin hypercube sampling method for the uncertainties of power, load, temperature, and electric vehicle trips. Based on the proposed demand response model, low-carbon economic dispatch of the community-integrated energy system under multiple uncertainties is achieved by training the agent to interact with the environment in the training scenario set and reach convergence after 250 training rounds. The simulation results show that the reinforcement learning agent achieves low-carbon economic dispatch under 5%, 10%, and 15% renewable energy/load fluctuation scenarios, temperature fluctuation scenarios, and uncertain scenarios of the number of trips, time periods, and mileage of electric vehicles, with good generalization performance under uncertain scenarios

    Kumatakenin inhibited iron-ferroptosis in epithelial cells from colitis mice by regulating the Eno3-IRP1-axis

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    Inhibition of epithelial ferroptosis in colonic tissues relieved clinical symptoms and improved endoscopic presentations in inflammatory bowel disease (IBD). Kumatakenin, the main ingredient of traditional Chinese medicinal cloves and Alpinia purpurata, is reported to possess therapeutic benefits. However, whether kumatakenin could inhibit ferroptosis and further alleviate colitis remains unclear. Here, we measured the effects of kumatakenin on ferroptosis of colonic epithelial cells from colitis mice. The colitis model was induced in mice by oral intake of 2.5% dextran sulfate sodium in drinking water. RNA sequencing was performed to investigate the mechanism underlying kumatakenin-mediated effects on colitis. The results showed that different doses of kumatakenin significantly alleviated symptoms and suppressed intestinal inflammation in the colitis mouse model. Kumatakenin supplementation decreased cellular iron levels and suppressed ferroptosis in epithelial cells from colitis mice. RNA sequencing, qPCR, and pharmacological inhibition assays showed that kumatakenin reduced cellular iron levels and suppressed ferroptosis in epithelial cells from colitis mice at least partially by upregulating expression of enolase (Eno-3). Furthermore, kumatakenin decreased iron levels in epithelial cells by modulating the Eno3-iron regulatory protein (IRP1) axis. Molecular docking results revealed that kumatakenin could bind Eno3 via hydrogen bonding with the amino acid residues Thr208, Val206, and Pro203. This work will provide a scientific basis for the clinical use of kumatakenin in the treatment of colitis

    Sesquiterpenoids from the Florets of Carthamus tinctorius (Safflower) and Their Anti-Atherosclerotic Activity

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    (1) Background: The florets of Carthamus tinctorius L. are traditionally used as a blood-activating drug and can be used for the treatment of atherosclerosis, but no compounds with anti-atherosclerotic activity have been reported. (2) Methods: This study investigated the chemical compounds from the florets of C. tinctorius. Comprehensive spectroscopic techniques revealed their structures, and ECD calculations established their absolute configurations. Nile Red staining, Oil Red O staining, and cholesterol assessment were performed on these compounds and their aglycones for the inhibitory activity against the formation of foam cells induced by oxidized low-density lipoprotein (ox-LDL) in RAW264.7 macrophages. In addition, RAW264.7 macrophages were tested for their anti-inflammatory activity by measuring the inhibition of NO production caused by LPS. (3) Results: Five new sesquiterpenoids (1–5) isolated from the florets of C. tinctorius were identified as (–)-(1R,4S,9S,11R)-caryophyll-8(13)-en-14-ol-5-one (1), (+)-(1R,4R,9S,11R)-caryophyll-8(13)-en-14-ol-5-one (2), (–)-(3Z,1R,5S,8S,9S,11R)-5,8-epoxycaryophyll-3-en-14-O-β-D-glucopyranoside (3), (+)-(1S,7R,10S)-guai-4-en-3-one-11-O-β-D-fucopyranoside (4), and (–)-(2R,5R,10R)-vetispir-6-en-8-one-11-O-β-D-fucopyranoside (5). All compounds except for compound 3 reduced the lipid content in ox-LDL-treated RAW264.7 cells. Compounds 3 and 4 and their aglycones were found to reduce the level of total cholesterol (TC) and free cholesterol (FC) in ox-LDL-treated RAW264.7 cells. However, no compounds showed anti-inflammatory activity. (4) Conclusion: Sesquiterpenoids from C. tinctorius help to decrease the content of lipids, TC and FC in RAW264.7 cells, but they cannot inhibit NO production, which implies that their anti-atherogenic effects do not involve the inhibition of inflammation

    Synchronously Strengthen and Toughen Polypropylene Using Tartaric Acid-Modified Nano-CaCO3

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    In order to overcome the challenge of synchronously strengthening and toughening polypropylene (PP) with a low-cost and environmental technology, CaCO3 (CC) nanoparticles are modified by tartaric acid (TA), a kind of food-grade complexing agent, and used as nanofillers for the first time. The evaluation of mechanical performance showed that, with 20 wt.% TA-modified CC (TAMCC), the impact toughness and tensile strength of TAMCC/PP were 120% and 14% more than those of neat PP, respectively. Even with 50 wt.% TAMCC, the impact toughness and tensile strength of TAMCC/PP were still superior to those of neat PP, which is attributable to the improved compatibility and dispersion of TAMCC in a PP matrix, and the better fluidity of TAMCC/PP nanocomposite. The strengthening and toughening mechanism of TAMCC for PP involves interfacial debonding between nanofillers and PP, and the decreased crystallinity of PP, but without the formation of β-PP. This article presents a new applicable method to modify CC inorganic fillers with a green modifier and promote their dispersion in PP. The obtained PP nanocomposite simultaneously achieved enhanced mechanical strength and impact toughness even with high content of nanofillers, highlighting bright perspective in high-performance, economical, and eco-friendly polymer-inorganic nanocomposites

    Relationship between Soybean Protein Isolate and Textural Properties of Texturized Vegetable Protein

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    To identify the ideal soybean protein isolate for texturized vegetable protein processing, the effect of different soybean protein isolates on texturized vegetable protein composition was studied. Three different types of soybean protein isolates were selected and analyzed for functional properties (water holding capacity (WHC), emulsifying properties, foaming properties), amino acid content, and protein secondary structure. Then, using the same formulation, the soybean protein isolates were extruded to produce texturized vegetable protein, and its textural properties, degree of texturization, microstructure, free sulfhydryl (free SH), and disulfide (S-S) content were determined. Lastly, a correlation analysis was performed to examine the connection between soybean protein isolates and texturized vegetable proteins. After correlation analysis, the soybean protein isolate functional properties that affect the textural properties of the texturized vegetable protein were as follows: the emulsifying property affected the hardness, adhesiveness, springiness, gumminess, and chewiness of the texturized vegetable proteins; and the foaming property affected the gumminess, chewiness, and the degree of texturization of the texturized vegetable proteins. In addition, 16 amino acids including threonine (Thr), methionine (Met), and arginine (Arg) affect texturized vegetable proteins, mainly with respect to adhesiveness, springiness, and free SH. The effects of secondary structure (α-helix, random coil) on texturized vegetable proteins were degree of texturization, resilience, and cohesion, respectively. Therefore, choosing the soybean protein isolate with better emulsifying and foaming properties provides a more suitable approach for processing texturized vegetable protein
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