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Motor learning (ML), which plays a fundamental role in growth and physical rehabilitation, involves different stages of learning and memory processes through different brain regions. However, the neural mechanisms that underlie ML are not sufficiently understood. Here, a previously unreported neuronal projection from the dorsal hippocampus (dHPC) to the zona incerta (ZI) involved in the regulation of ML behaviors is identified. Using recombinant adeno‐associated virus, the projections to the ZI are surprisingly identified as originating from the dorsal dentate gyrus (DG) and CA1 subregions of the dHPC. Furthermore, projection‐specific chemogenetic and optogenetic manipulation reveals that the projections from the dorsal CA1 to the ZI play key roles in the acquisition and consolidation of ML behaviors, whereas the projections from the dorsal DG to the ZI mediate the retrieval/retention of ML behaviors. The results reveal new projections from the dorsal DG and dorsal CA1 to the ZI involved in the regulation of ML and provide insight into the stages over which this regulation occurs. [ABSTRACT FROM AUTHOR]

Aims: Adenosine 2A receptor (A2AR) is widely expressed in the brain and plays important roles in neuroinflammation, and the nucleotide‐binding oligomerization domain, leucine‐rich repeat, and pyrin domain‐containing protein 3 (NLRP3) inflammasome is a crucial component of the innate immune system while the regulation of A2AR on it in the central nervous system (CNS) has not been clarified. Methods: The effects of microglial A2AR on NLRP3 inflammasome assembly and activation were investigated in wild‐type, A2AR‐ or NLRP3‐knockout primary microglia with pharmacological treatment. Microglial A2AR or NLRP3 conditional knockout mice were used to interrogate the effects of this regulation on neuroinflammation posttraumatic brain injury (TBI). Results: We found that A2AR directly interacted with NLRP3 and facilitated NLRP3 inflammasome assembly and activation in primary microglia while having no effects on mRNA levels of inflammasome components. Inhibition of the interaction via A2AR agonist or knockout attenuated inflammasome assembly and activation in vitro. In the TBI model, microglial A2AR and NLRP3 were co‐expressed at high levels in microglia next to the peri‐injured cortex, and abrogating of this interaction by microglial NLRP3 or A2AR conditional knockout attenuated the neurological deficits and neuropathology post‐TBI via reducing the NLRP3 inflammasome activation. Conclusion: Our results demonstrated that inhibition of the interaction between A2AR and NLRP3 in microglia could mitigate the NLRP3 inflammasome assembly and activation and ameliorate the neuroinflammation post‐TBI. It provides new insights into the effects of A2AR on neuroinflammation regulation post‐TBI and offers a potential target for the treatment of NLRP3 inflammasome‐related CNS diseases. [ABSTRACT FROM AUTHOR]

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. Immunoprecipitation was used to determine the interactions between Ski and FoxO1 or Ski and HDAC1. The Ski protein was overexpressed via recombinant adenovirus transfection, and FoxO1 and HDAC1 were knocked down using targeted small‐interfering RNA. Results: The present study found that HG inhibited fibroblast proliferation, increased apoptosis and reduced Ski levels in rat primary fibroblasts. Conversely, increasing Ski protein levels alleviated HG‐induced proliferation inhibition and apoptosis promotion. Increasing Ski protein levels also increased Ski binding to FoxO1 to decrease FoxO1 acetylation, and interfering with FoxO1 caused loss of the regulatory effect of Ski in fibroblasts under HG. Increasing Ski protein levels decreased FoxO1 acetylation via HDAC1‐mediated deacetylation. Conclusions: Therefore, these findings confirmed for the first time that Ski regulated fibroblast proliferation and apoptosis under HG conditions via the FoxO1 pathway. [ABSTRACT FROM AUTHOR]

Spatial recognition memory impairment is an important complication after traumatic brain injury (TBI). We previously found that spatial recognition memory impairment can be alleviated in adenosine A2A receptor knockout (A2AR KO) mice after TBI, but the mechanism remains unclear. In the current study, we used manganese‐enhanced magnetic resonance imaging and the Y‐maze test to determine whether the electrical activity of neurons in the retrosplenial cortex (RSC) was reduced and spatial recognition memory was impaired in wild‐type (WT) mice after moderate TBI. Furthermore, spatial recognition memory was damaged by optogenetically inhibiting the electrical activity of RSC neurons in WT mice. Additionally, the electrical activity of RSC neurons was significantly increased and spatial recognition memory impairment was reduced in A2AR KO mice after moderate TBI. Specific inhibition of A2AR in the ipsilateral RSC alleviated the impairment in spatial recognition memory in WT mice. In addition, A2AR KO improved autophagic flux in the ipsilateral RSC after injury. In primary cultured neurons, activation of A2AR reduced lysosomal‐associated membrane protein 1 and cathepsin D (CTSD) levels, increased phosphorylated protein kinase A and phosphorylated extracellular signal‐regulated kinase 2 levels, reduced transcription factor EB (TFEB) nuclear localization and impaired autophagic flux. These results suggest that the impairment of spatial recognition memory after TBI may be associated with impaired autophagic flux in the RSC and that A2AR activation may reduce lysosomal biogenesis through the PKA/ERK2/TFEB pathway to impair autophagic flux. [ABSTRACT FROM AUTHOR]

Background: The transplantation of bone marrow mesenchymal stem cells (BMSCs) is a promising therapeutic strategy for wound healing. However, the poor migration capacity and low survival rate of transplanted BMSCs in wounds weaken their potential application. Objective: To identify the optimal protocol for BMSCs preconditioned with H2O2 and improve the therapeutic efficacy using H2O2-preconditioned BMSCs in wound healing. Methods: Mouse BMSCs were exposed to various concentrations of H2O2, and the key cellular functional properties were assessed to determine the optimal precondition with H2O2. The H2O2-preconditioned BMSCs were transplanted into mice with full-thickness excisional wounds to evaluate their healing capacity and tissue engraftment. Results: Treatment BMSCs with 50 μM H2O2 for 12 h could significantly enhance their proliferation, migration, and survival by maximizing the upregulation of cyclin D1, SDF-1, and its receptors CXCR4/7 expressions, and activating the PI3K/Akt/mTOR pathway, but inhibiting the expression of p16 and GSK-3β. Meanwhile, oxidative stress-induced BMSC apoptosis was also significantly attenuated by the same protocol pretreatment with a decreased ratio of Bax/Bcl-2 and cleaved caspase-9/3 expression. Moreover, after the identification of the optimal protocol of H2O2 precondition in vitro, the migration and tissue engraftment of transfused BMSCs with H2O2 preconditioning were dramatically increased into the wound site as compared to the un-preconditioned BMSCs. The increased microvessel density and the speedy closure of the wounds were observed after the transfusion of H2O2-preconditioned BMSCs. Conclusions: The findings suggested that 50 μM H2O2 pretreated for 12 h is the optimal precondition for the transplantation of BMSCs, which gives a considerable insight that this protocol may be served as a promising candidate for improving the therapeutic potential of BMSCs for wound healing. [ABSTRACT FROM AUTHOR]

Traumatic brain injury (TBI) can induce cognitive dysfunction due to the regional accumulation of hyperphosphorylated tau protein (p-tau). However, the factors that cause p-tau to concentrate in specific brain regions remain unclear. Here, we show that AQP4 polarization in the perivascular astrocytic end feet was impaired after TBI, which was most prominent in the ipsilateral brain tissue surrounding the directly impacted region and the contralateral hippocampal CA1 area and was accompanied by increased local p-tau, changes in dendritic spine density and morphology, and upregulation of the adenosine A 2A receptor (A 2A R). The critical role of the A 2A R signaling in these pathological changes was confirmed by alleviation of the impairment of AQP4 polarity and accumulation of p-tau in the contralateral CA1 area in A 2A R knockout mice. Given that p-tau can be released to the extracellular space and that the astroglial water transport via AQP4 is involved in tau clearance from the brain interstitium, our results suggest that regional disruption of AQP4 polarity following TBI may reduce the clearance of the toxic interstitial solutes such as p-tau and lead to changes in dendritic spine density and morphology. This may explain why TBI patients are more vulnerable to cognitive dysfunction.

Objective: To study the role of Smad3 in transforming growth factor-beta1 (TGF-beta1)-induced bi-directional effects on skin fibroblast proliferation., Methods: The Smad3 small interfering (siRNA) plasmid was constructed using a pSUPER vector. The efficiency of cell transfection was detected by fluorescence microscopy, and the inhibitory effect of the plasmid was assessed by real-time quantitative RT-PCR and immunohistochemistry. The effect of the plasmid on the fibroblast proliferation and Smad3 binding activity was analyzed by BRDU ELISA and EMSA, respectively., Results: The transfection efficiency of the plasmid into the cells was 41.2%. The Smad3 siRNA plasmid produced efficient and specific inhibition of the expression of Smad3, and promoted the cell proliferation in a dose-dependent manner and abrogated the bi-directional effect of TGF-beta1 on the cell proliferation and Smad3 binding activity., Conclusion: The siRNA targeting Smad3 gene can inhibit the protein expression and RNA transcription of Smad3, and TGF-beta1 exerts bi-directional regulation on fibroblast proliferation by modulating Smad3 activity.