Publications by authors named "Ren-Ping Xiong"

Article Synopsis
  • Motor learning (ML) is crucial for growth and rehabilitation, involving various learning stages and memory processes across different brain areas, yet its underlying neural mechanisms remain poorly understood.
  • A new neuronal projection from the dorsal hippocampus (dHPC) to the zona incerta (ZI) has been identified, originating from specific subregions: the dorsal dentate gyrus (DG) and CA1.
  • Chemogenetic and optogenetic manipulations show that the dorsal CA1 projection to the ZI is essential for acquiring and consolidating ML behaviors, while the dorsal DG to ZI pathway is important for retrieving and retaining those behaviors.
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Praziquantel (PZQ) is a pyrazino-isoquinoline compound with broad spectrum of activity against parasitic trematodes and cestodes, and a key veterinary drug in the parasitic disease control field. However, PZQ residues caused by non-conforming or excessive use in food-producing animals may pose a serious threat to human health. Herein, a simple, sensitive and reproducible LC-MS/MS method was developed for the simultaneous determination of praziquantel and - and -4-hydroxypraziquantel in black goat tissues to guide the reasonable use of PZQ.

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Traumatic brain injury (TBI) survivors suffer from long-term disability and neuropsychiatric sequelae due to irreparable brain tissue destruction. However, there are still few efficient therapies to promote neurorestoration in damaged brain tissue. This study aimed to investigate whether the pro-oncogenic gene ski can promote neurorestoration after TBI.

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NLRP3 inflammasome plays a crucial role in the innate immune system. Our group previously reported that the microglial adenosine 2A receptor (AR) regulates canonical neuroinflammation, which is affected by the glutamate concentration. However, the regulatory effect of AR on NLRP3 inflammasome and the effects of glutamate concentration remain unknown.

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Tau hyperphosphorylation is a characteristic alteration present in a range of neurological conditions, such as traumatic brain injury (TBI) and neurodegenerative diseases. Treatments targeting high-mobility group box protein 1 (HMGB1) induce neuroprotective effects in these neuropathologic conditions. However, little is known about the interactions between hyperphosphorylated tau and HMGB1 in neuroinflammation.

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Objectives: The present study clarified the role and signalling pathway of Ski in regulating proliferation and apoptosis in fibroblasts under high-glucose (HG) conditions.

Materials And Methods: The proliferation and apoptosis of rat primary fibroblasts were assessed using EdU incorporation and TUNEL assays. The protein and phosphorylation levels of the corresponding factors were measured using immunofluorescence staining and Western blotting.

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TGF-β1 promotes cell proliferation in only some tumors and exerts bidirectional regulatory effects on the proliferation of fibroblasts. This study intends to explore whether the mechanism is related to increased expression of Ski. Cell proliferation of the fibrosarcoma cell line L929 was assessed with an ELISA BrdU kit.

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Pathogens such as bacterial lipopolysaccharide (LPS) play an important role in promoting the production of the inflammatory cytokines interleukin-1 beta (IL-1β) and tumour necrosis factor-α (TNF-α) in response to infection or damage in microglia. However, whether different signalling pathways regulate these two inflammatory factors remains unclear. The protein kinase C (PKC) family is involved in the regulation of inflammation, and our previous research showed that the activation of the PKC pathway played a key role in the LPS-induced transformation of the adenosine A receptor (AR) from anti-inflammatory activity to pro-inflammatory activity under high glutamate concentrations.

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Increasing evidence has suggested that bidirectional regulation of cell proliferation is one important effect of TGF-β1 in wound healing. Increased c-Ski expression plays a role in promoting fibroblast proliferation at low TGF-β1 concentrations, but the mechanism by which low TGF-β1 concentrations regulate c-Ski levels remains unclear. In this study, the proliferation of rat primary fibroblasts was assessed with an ELISA BrdU kit.

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Excitatory amino acid transporters (EAATs) on cerebral vascular endothelial cells play an important role in maintaining glutamate homeostasis in the brain. The dysfunction of endothelial EAATs is an important reason for the dramatically elevated brain glutamate levels after brain injury, such as traumatic brain injury (TBI). The adenosine A receptor (AR) plays an important role in regulating the brain glutamate level after brain injury; however, researchers have not clearly determined whether this role was related to its ability to regulate endothelial EAATs.

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Glucocorticoids are commonly used for the treatment of pancreatitis and complicated acute lung injury and help to reduce the mortality rates of both. The effect of gene variants in heat shock protein 90 (Hsp90), a key chaperone molecule of the glucocorticoid receptor (GR), on the therapeutic effect of glucocorticoids is unclear. Our study aims to investigate the different susceptibility to glucocorticoid treatment in BALB/c and C57BL/6 mice carrying different Hsp90 genotypes in an animal model of pancreatitis-induced lung injury.

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A series of neurological and psychiatric symptoms occur after traumatic brain injury (TBI), with cognitive dysfunction being one of the most prominent sequela. Given that tau hyperphosphorylation is an important cause of cognitive impairment in patients of Alzheimer's disease, our present study detected the presence of hyperphosphorylated tau (p-tau), mainly at Ser404, in multiple brain regions, including the ipsilateral parietal cortex, contralateral hippocampus and prefrontal cortex, immediately after the injury in a mouse TBI model; these changes lasted for at least 4w. All of these brain regions play important roles in working memory.

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We previously demonstrated that cellular Sloan-Kettering Institute (c-Ski) played a dual role, both promoting wound healing and alleviating scar formation. However, its mechanism and therapeutic effects are not clear, especially compared with widely used treatments, such as basic fibroblast growth factor (bFGF) administration. However, Ski treatment led to an even shorter healing time and a more significant reduction in scar area than bFGF treatment.

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Background/aims: Although it has been reported that somatostatin (SOM) upregulated the level of 90-kD heat shock protein (Hsp90), which participates in the inflammatory regulation by its client proteins, such as glucocorticoid receptor (GR), it remains unclear if it has a protective role against acute lung injury (ALI).

Methods: ALI model was established by the injection of oleic acid (OA) into the tail vein of mice. Lung injury was assessed by histological analysis, lung water content and arterial blood gases.

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Objective: Inflammatory injury plays a critical role in intracerebral hemorrhage (ICH)-induced secondary brain injury. However, the upstream events that initiate inflammatory responses following ICH remain elusive. Our previous studies suggested that Toll-like receptor 4 (TLR4) may be the upstream signal that triggers inflammatory injury in ICH.

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Recent reports have shown that preconditioning with the TLR3 ligand polyinosinic-polycytidylic acid (poly(I:C)) protects against cerebral ischemia/reperfusion (I/R) injury. However, it is unclear whether poly(I:C) treatment after cerebral I/R injury is also effective. We used mouse/rat middle cerebral artery occlusion and cell oxygen-glucose deprivation models to evaluate the therapeutic effects and mechanisms of poly(I:C) treatment.

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Traumatic brain injury (TBI), particularly explosive blast-induced TBI (bTBI), has become the most prevalent injury among military personnel. The disruption of cognitive function is one of the most serious consequences of bTBI because its long-lasting effects prevent survivors fulfilling their active duty and resuming normal civilian life. However, the mechanisms are poorly understood and there is no treatment available.

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Renal interstitial fibrosis (RIF) is the common pathological process of chronic kidney diseases leading inevitably to renal function deterioration. RIF and its preceding epithelial-mesenchymal transition (EMT) are commonly triggered by an early occurring renal inflammation. However, an effective approach to prevent EMT and RIF is still lacking and of urgent need.

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Objective: To explore the effect of dexamethasone (DEX) on monocyte adhesion function and its underlying mechanism.

Methods: The effects of DEX and fasudil on adhesion of cultured U937 monocytes to human umbilical vein endothelial cells (HUVEC) following stimulation with phorbol myristate acetate (PMA) were studied; Changes in the Rho-associated coiled-coil protein kinase 1 (ROCK1) protein content and activity were evaluated.

Results: DEX and fasudil significantly inhibited U937 cell adhesion rates under PMA stimulation and inhibited ROCK1 activity.

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Objective: Radiation is an important cause of delayed wound healing, and there still exist many questions regarding the patterns and mechanisms of wound healing. This study investigated the characteristics of wound healing after varying doses of local radiation and explored possible causes of the delay in healing caused by radiation.

Methods: A full-thickness dorsal longitudinal skin tissue, 2 cm in diameter, was excised after local irradiation on one side of the back of swine, and the other side was wounded as a control.

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We recently demonstrated that Ski is a novel wound healing-related factor that promotes fibroblast proliferation and inhibits collagen secretion. Here, we show that increasing local Ski expression by gene transfer not only significantly accelerated wound healing by relieving inflammation, accelerating re-epithelialization and increasing formation of granulation tissue, but also reduced scar formation by decreasing collagen production in rat dermal wounds. Similarly, ski gene transfer accelerated wound healing, reduced the protuberant height and volume of scars and increased collagen maturity in a hypertrophic scar model in the rabbit ear.

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During brain injury, extracellular adenosine and glutamate levels increase rapidly and dramatically. We hypothesized that local glutamate levels in the brain dictates the adenosine-adenosine A(2A) receptor (A(2A)R) effects on neuroinflammation and brain damage outcome. Here, we showed that, in the presence of low concentrations of glutamate, the A(2A)R agonist 3-[4-[2-[[6-amino-9-[(2R,3R,4S,5S)-5-(ethylcarbamoyl)-3,4-dihydroxy-oxolan-2-yl]purin-2-yl]amino]ethyl]phenyl]propanoic acid (CGS21680) inhibited lipopolysaccharide (LPS)-induced nitric oxide synthase (NOS) activity of cultured microglial cells, an effect that was dependent on the protein kinase A (PKA) pathway.

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Heat shock protein 90 (Hsp90), encoded by hsp84 and hsp86 in mice, has been confirmed to modulate glucocorticoid receptor (GR) function; however, the contribution of Hsp90 in glucocorticoid (GC) sensibility/resistance has received less attention. Previously, we found that genetic variations of Hsp84 are related to differences in the in vivo GC-GR responses between BALB/c and C57BL/6 mice suffering from traumatic injury. To evaluate the modulation of Hsp84 polymorphisms on the GC response, we used a cellular heat-stress injury (HSI) model combined with a transgene-plasmid infection approach and assessed HSI-induced cellular damage and GR nuclear translocation, with or without dexamethasone pretreatment.

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Heat shock protein 90 (Hsp90), encoded by the murine hsp84 and hsp86 genes in mice, is a pivotal regulator of glucocorticoid receptor (GR) function in the hypothalamus-pituitary-adrenal axis and affords stress protection. To explore the underlying molecular mechanisms of strain susceptibility to traumatic stress, we investigated the alteration by Hsp90 of the function of the glucocorticoid-glucocorticoid receptor (GC-GR) pathway in attenuating stress responses in C57BL/6 and BALB/c mice using the whole-body blast injury (WBBI) model. We found that C57BL/6 mice had a lower WBBI-induced mortality, higher nuclear GR level, and higher glucocorticoid-response element (GRE) binding activity than BALB/c mice.

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Objective: To study the association between decreased ligand binding activity of glucocoid receptor (GR) and heat shock protein 90 (Hsp90), the molecular chaperone of GR, after acute lung injury (ALI) in mice.

Methods: In mouse models of oleic acid-induced ALI, the levels of GR, Hsp90 and Hsp70 were dynamically observed using Western blotting, and the binding capacity and binding affinity of GR assessed with radioligand binding assay.

Results: After ALI, pulmonary edema was significantly aggravated in the mice with significantly increased lung body index and lung water ratio.

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