Jun Ding

Traumatic brain injury (TBI) is a leading cause of death among young adults worldwide. However, the role of G protein‐coupled receptor 124 (GPR124), a key regulator of the nervous system, in TBI remains unexplored. We employed a controlled cortical impact (CCI) model combined with single‐cell RNA sequencing to analyze the localization of GPR124 expression following TBI. Additionally, we used mice with endothelial cell (EC)‐specific conditional knockout (CKO) of GPR124 to perform behavioral experiments. A stretch injury (SI) model was also established to investigate the effects of GPR124 on ECs. Neurological recovery after TBI was significantly impaired in mice with the EC‐specific CKO of GPR124. Furthermore, GPR124 knockdown reduced EC function after SI. Notably, tight junction integrity was disrupted both in vivo and in vitro after GPR124 knockdown. Mass spectrometry and immunoprecipitation analyses confirmed that GPR124 interacts with fibroblast growth factor binding protein‐1, thereby activating the Wnt/β‐catenin pathway. Our study demonstrates that GPR124 regulates microvascular endothelial function and maintains blood–brain barrier integrity by activating the Wnt/β‐catenin pathway. This mechanism plays a crucial role in improving TBI prognosis and may represent a potential new therapeutic target.

JOURNAL/nrgr/04.03/01300535-202405000-00039/inline-graphic1/v/2023-09-28T063346Z/r/image-tiff Endorepellin plays a key role in the regulation of angiogenesis, but its effects on angiogenesis after traumatic brain injury are unclear. This study explored the effects of endorepellin on angiogenesis and neurobehavioral outcomes after traumatic brain injury in mice. Mice were randomly divided into four groups: sham, controlled cortical impact only, adeno-associated virus (AAV)-green fluorescent protein, and AAV-shEndorepellin-green fluorescent protein groups. In the controlled cortical impact model, the transduction of AAV-shEndorepellin-green fluorescent protein downregulated endorepellin while increasing the number of CD31⁺/Ki-67⁺ proliferating endothelial cells and the functional microvessel density in mouse brain. These changes resulted in improved neurological function compared with controlled cortical impact mice. Western blotting revealed increased expression of vascular endothelial growth factor and angiopoietin-1 in mice treated with AAV-shEndorepellin-green fluorescent protein. Synchrotron radiation angiography showed that endorepellin downregulation promoted angiogenesis and increased cortical neovascularization, which may further improve neurobehavioral outcomes. Furthermore, an in vitro study showed that downregulation of endorepellin increased tube formation by human umbilical vein endothelial cells compared with a control. Mechanistic analysis found that endorepellin downregulation may mediate angiogenesis by activating vascular endothelial growth factor- and angiopoietin-1-related signaling pathways.

Background: Microglia-mediated neuroinflammatory response following traumatic brain injury (TBI) is considered as a vital secondary injury factor, which drives trauma-induced neurodegeneration and is lack of efficient treatment. ACT001, a sesquiterpene lactone derivative, is reportedly involved in alleviation of inflammatory response. However, little is known regarding its function in regulating innate immune response of central nervous system (CNS) after TBI. This study aimed to investigate the role and underlying mechanism of ACT001 in TBI. Methods: Controlled cortical impact (CCI) models were used to establish model of TBI. Cresyl violet staining, evans blue extravasation, neurobehavioral function assessments, immunofluorescence and transmission electron microscopy were used to evaluate therapeutic effects of ACT001 in vivo. Microglial depletion was induced by administering mice with colony stimulating factor 1 receptor (CSF1R) inhibitor, PLX5622. Cell-cell interaction models were established as co-culture system to simulate TBI conditions in vitro. Cytotoxic effect of ACT001 on cell viability was assessed by cell counting kit-8 and activation of microglia cells were induced by Lipopolysaccharides (LPS). Pro-inflammatory cytokines expression was determined by Real-time PCR and nitric oxide production. Apoptotic cells were detected by TUNEL and flow cytometry assays. Tube formation was performed to evaluate cellular angiogenic ability. ELISA and western blot experiments were used to determine proteins expression. Pull-down assay was used to analyze proteins that bound ACT001. Results: ACT001 relieved the extent of blood-brain barrier integrity damage and alleviated motor function deficits after TBI via reducing trauma-induced activation of microglia cells. Delayed depletion of microglia with PLX5622 hindered therapeutic effect of ACT001. Furthermore, ACT001 alleviated LPS-induced activation in mouse and rat primary microglia cells. Besides, ACT001 was effective in suppressing LPS-induced pro-inflammatory cytokines production in BV2 cells, resulting in reduction of neuronal apoptosis in HT22 cells and improvement of tube formation in bEnd.3 cells. Mechanism by which ACT001 functioned was related to AKT/NFκB/NLRP3 pathway. ACT001 restrained NFκB nuclear translocation in microglia cells through inhibiting AKT phosphorylation, resulting in decrease of NLRP3 inflammasome activation, and finally down-regulated microglial neuroinflammatory response. Conclusions: Our study indicated that ACT001 played critical role in microglia-mediated neuroinflammatory response and might be a novel potential chemotherapeutic drug for TBI.

The lysyl oxidase (LOX) family is closely related to the progression of glioma. To ensure the clinical significance of LOX family in glioma, The Cancer Genome Atlas (TCGA) database was mined and the analysis indicated that higher LOXL1 expression was correlated with more malignant glioma progression. The functions of LOXL1 in promoting glioma cell survival and inhibiting apoptosis were studied by gain- and loss-of-function experiments in cells and animals. LOXL1 was found to exhibit antiapoptotic activity by interacting with multiple antiapoptosis modulators, especially BAG family molecular chaperone regulator 2 (BAG2). LOXL1-D515 interacted with BAG2-K186 through a hydrogen bond, and its lysyl oxidase activity prevented BAG2 degradation by competing with K186 ubiquitylation. Then, we discovered that LOXL1 expression was specifically upregulated through the VEGFR-Src-CEBPA axis. Clinically, the patients with higher LOXL1 levels in their blood had much more abundant BAG2 protein levels in glioma tissues. Conclusively, LOXL1 functions as an important mediator that increases the antiapoptotic capacity of tumor cells, and approaches targeting LOXL1 represent a potential strategy for treating glioma. In addition, blood LOXL1 levels can be used as a biomarker to monitor glioma progression.

Aloin is a small-molecule drug well known for its protective actions in various models of damage. Traumatic brain injury (TBI)-induced cerebral edema from secondary damage caused by disruption of the blood–brain barrier (BBB) often leads to an adverse prognosis. Since the role of aloin in maintaining the integrity of the BBB after TBI remains unclear, we explored the protective effects of aloin on the BBB using in vivo and in vitro TBI models. Adult male C57BL/6 mice underwent controlled cortical impact injury, and mouse brain capillary endothelial bEnd.3 cells underwent biaxial stretch injury, then both received aloin treatment. In the animal experiments, we found 20 mg/kg aloin to be the optimum concentration to decrease cerebral edema, decrease disruption of the BBB, and improve neurobehavioral performance after cortical impact injury. In the cellular studies, the optimum concentration of 40 μg/mL aloin reduced apoptosis and reversed the loss of tight junctions by reducing the reactive oxygen species levels and changes in mitochondrial membrane potential after stretch injury. The mechanisms may be that aloin downregulates the phosphorylation of p38 mitogen-activated protein kinase, the activation of p65 nuclear factor-kappa B, and the ratios of B cell lymphoma (Bcl)-2-associated X protein/Bcl-2 and cleaved caspase-3/caspase-3. We conclude that aloin exhibits these protective effects on the BBB after TBI through its anti-oxidative stress and anti-apoptotic properties in mouse brain capillary endothelial cells. Aloin may thus be a promising therapeutic drug for TBI.

Traumatic brain injury (TBI) is a major cause of disability and mortality worldwide, in part resulting from secondary apoptosis of neurons in peri-contusion areas. Serpina3k, a serine protease inhibitor, has been shown to inhibit apoptosis in injury models. In this study, we investigated the anti-apoptotic function of serpina3k in vivo using a mouse model of TBI, as well as the underlying neuroprotective mechanism in vitro using the SH-SY5Y human neuroblastoma cell line. TBI was induced in adult male C57BL/6 mice using controlled cortical impact. Serpina3k protein was intravenously administered at a concentration of 0.5 mg/kg twice daily for up to 14 days. SH-SY5Y cells were subjected to biaxial stretch injury and then treated with different concentrations of serpina3k. We found that endogenous serpina3k protein levels were elevated in peri-contusion areas of the mouse brain following TBI. Serpina3k-treated mice had fewer apoptotic neurons, lower levels of oxidative stress, and showed greater recovery of neurological deficits relative to vehicle-treated mice. Meanwhile, in the SH-SY5Y cell injury model, serpina3k at an optimal concentration (150 nM) inhibited the generation of intracellular reactive oxygen species, abrogated changes of the mitochondrial membrane potential, and reduced the phospho-extracellular regulated protein kinases (p-ERK)/ERK, phospho-P38 (p-P38)/P38, B cell lymphoma (Bcl)-2-associated X protein/Bcl-2, and cleaved caspase-3/caspase-3 ratios, thereby reducing the apoptosis rate. These results demonstrate that serpina3k exerts a neuroprotective function following TBI and thus has therapeutic potential.

BACKGROUND:The phosphatase actin regulator-1 (PHACTR-1) gene on chromosome 6 encodes an actin and protein phosphatase 1 (PP1) binding protein, Phactr-1, which is highly expressed in brain tissues. Phactr-1 expression is involved in physiological and ...

BACKGROUND:This study aimed to evaluate the effects of electro-acupuncture (EA) on neuroplasticity associated with the expressions of neurotrophic factors (NTFs) and their receptors in rats subjected to spinal cord transection (SCT). MATERIAL AND MET...

Sesamin is a well-known antioxidant extracted from sesame seeds that exhibits various curative effects. The present study investigated whether sesamin would protect neuroblastoma SH-SY5Y cells against mechanical stretch injury-induced increases in reactive oxygen species (ROS) and apoptosis. Additionally, the mechanisms underlying these actives were investigated. Following exposure to mechanical stretch injury, cells were incubated for further investigations. Lactate dehydrogenase and Cell Counting Kit-8 assays were used to assess cell viability, and a terminal deoxynucleotidyl transferase dUTP nick end labeling assay and flow cytometric analysis were performed to evaluate changes in mitochondrial membrane potential (ΔΨm). Furthermore, intracellular levels of ROS production were measured by 20, 70-dichlorofluorescein diacetate staining, the mRNA levels of matrix metallopeptidase 9 (MMP-9) were evaluated using real-time polymerase chain reaction analysis, and the determinations had also been made on related proteins by Western blot analysis. Exposure to mechanical stretch injury significantly decreased cell viability but this decrease was attenuated by pretreatment with sesamin (50 μM). Sesamin also significantly inhibited mechanical stretch injury-induced increases in intracellular ROS production, attenuated declines in ΔΨm, diminished the expressions of pro-apoptotic proteins, and decreased cell apoptosis. Stretch injury increased Bax and cleaved caspase 3 levels, enhanced the gene expression of MMP-9, increased the phosphorylation levels of Akt, p38, and JNK and decreased Bcl-2 levels in the cells. However, pretreatment with sesamin reduced the mechanical stretch injury-induced overexpression of MMP-9. Sesamin protected SH-SY5Y cells against stretch injury by attenuating increases in ROS levels and suppressing apoptosis. Accordingly, sesamin seems to be a potentially therapeutic agent in the treatment of traumatic brain injury.