GGA1 interacts with the endosomal Na+/H+ Exchanger NHE6 governing localization to the endosome compartment.

Mutations in the endosomal Na+/H+ exchanger (NHE6) cause Christianson Syndrome (CS), an X-linked neurological disorder. NHE6 functions in regulation of endosome acidification and maturation in neurons. Using yeast two-hybrid screening with the NHE6 carboxyl-terminus as bait, we identify Golgi-associated, Gamma adaptin ear containing, ARF binding protein 1 (GGA1) as an interacting partner for NHE6. We corroborated the NHE6-GGA1 interaction using: co-immunoprecipitation (co-IP); over-expressed constructs in mammalian cells; and co-IP of endogenously-expressed GGA1 and NHE6 from neuroblastoma cells, as well as from mouse brain. We demonstrate that GGA1 interacts with organellar NHEs (NHE6, NHE7 and NHE9), and that there is significantly less interaction with cell-surface localized NHEs (NHE1 and NHE5). By constructing hybrid NHE1/NHE6 exchangers, we demonstrate that the cytoplasmic tail of NHE6 interacts most strongly with GGA1. We demonstrate the co-localization of NHE6 and GGA1 in cultured, primary hippocampal neurons, using super-resolution microscopy. We test the hypothesis that the interaction of NHE6 and GGA1 functions in the localization of NHE6 to the endosome compartment. Using subcellular fractionation experiments, we show that NHE6 is mis-localized in GGA1 knockout cells, wherein we find less NHE6 in endosomes, but more NHE6 transport to lysosomes, and more Golgi retention of NHE6, with increased exocytosis to the surface plasma membrane. Consistent with NHE6 mis-localization, and Golgi retention, we find the intra-luminal pH in Golgi to be alkalinized in GGA1-null cells. Our study demonstrates a new interaction between NHE6 and GGA1 which functions in the localization of this intra-cellular NHE to the endosome compartment.

Effects of a special continuous quality improvement in nursing on the management of adverse care events: a retrospective study.

OBJECTIVE: To explore the application effect of the direct reporting system of adverse nursing events and special continuous nursing quality improvement measures in the management of these adverse events. METHODS: The implementation time of continuous nursing improvement based on the direct reporting system was the demarcation point. We retrospectively collected and analyzed nursing adverse event reports and hospitalization data from Xiangtan Central Hospital before implementation (2015-2018) and after implementation (2019-2022). The active reporting rate of adverse events, the composition of these events and the processing time were compared between the two groups. RESULTS: The rate of active reporting of adverse events before the implementation was lower than that after the implementation (6.7% vs. 8.1%, X2 = 25.561, P < 0.001). After the implementation of the direct reporting system for nursing events and the continuous improvement of nursing quality, the reporting proportion of first-level and second-level events decreased significantly. Moreover, the reporting proportion of third-level events increased significantly. The proportion of falls and medication errors decreased, and the proportion of unplanned extubation, infusion xerostomia and improper operation increased. The processing time of the reported nursing adverse events was significantly reduced (31.87 ± 7.83 vs. 56.87 ± 8.21, t = 18.73, P < 0.001). CONCLUSION: The direct reporting system of adverse nursing events and the continuous improvement measures for nursing quality can effectively improve the active reporting rate of adverse events, change their composition and reduce their processing time, as well as help create a safe psychological environment for both patients and nursing staff.

Early lysosome defects precede neurodegeneration with amyloid-ß and tau aggregation in NHE6-null rat brain.

Loss-of-function mutations in the X-linked endosomal Na+/H+ exchanger 6 (NHE6) cause Christianson syndrome in males. Christianson syndrome involves endosome dysfunction leading to early cerebellar degeneration, as well as later-onset cortical and subcortical neurodegeneration, potentially including tau deposition as reported in post-mortem studies. In addition, there is reported evidence of modulation of amyloid-ß levels in experimental models wherein NHE6 expression was targeted. We have recently shown that loss of NHE6 causes defects in endosome maturation and trafficking underlying lysosome deficiency in primary mouse neurons in vitro. For in vivo studies, rat models may have an advantage over mouse models for the study of neurodegeneration, as rat brain can demonstrate robust deposition of endogenously-expressed amyloid-ß and tau in certain pathological states. Mouse models generally do not show the accumulation of insoluble, endogenously-expressed (non-transgenic) tau or amyloid-ß. Therefore, to study neurodegeneration in Christianson syndrome and the possibility of amyloid-ß and tau pathology, we generated an NHE6-null rat model of Christianson syndrome using CRISPR-Cas9 genome-editing. Here, we present the sequence of pathogenic events in neurodegenerating NHE6-null male rat brains across the lifespan. NHE6-null rats demonstrated an early and rapid loss of Purkinje cells in the cerebellum, as well as a more protracted neurodegenerative course in the cerebrum. In both the cerebellum and cerebrum, lysosome deficiency is an early pathogenic event, preceding autophagic dysfunction. Microglial and astrocyte activation also occur early. In the hippocampus and cortex, lysosome defects precede loss of pyramidal cells. Importantly, we subsequently observed biochemical and in situ evidence of both amyloid-ß and tau aggregation in the aged NHE6-null hippocampus and cortex (but not in the cerebellum). Tau deposition is widely distributed, including cortical and subcortical distributions. Interestingly, we observed tau deposition in both neurons and glia, as has been reported in Christianson syndrome post-mortem studies previously. In summary, this experimental model is among very few examples of a genetically modified animal that exhibits neurodegeneration with deposition of endogenously-expressed amyloid-ß and tau. This NHE6-null rat will serve as a new robust model for Christianson syndrome. Furthermore, these studies provide evidence for linkages between endolysosome dysfunction and neurodegeneration involving protein aggregations, including amyloid-ß and tau. Therefore these studies may provide insight into mechanisms of more common neurodegenerative disorders, including Alzheimer's disease and related dementias.

Development and validation of a gene model predicting lymph node metastasis and prognosis of oral squamous cell carcinoma based on single-cell and bulk RNA-seq analysis.

BACKGROUND: Lymph node metastasis can independently predict oral squamous cell carcinoma patients' survival. This study would investigate the genetic and cellular differences between oral squamous cell carcinoma with positive and negative lymph node metastases. METHODS: We gathered single-cell RNA sequencing and bulk gene expression data from the Cancer Genome Atlas and Gene Expression Omnibus databases. Sixty lymph node-metastasis-related genes were discovered with refined single-cell RNA sequencing data analysis, and consensus clustering provided three molecular subtypes of oral squamous cell carcinoma. Least absolute shrinkage and selection operator analyses were then utilized to establish a five-gene risk model. CIBERSORT analysis revealed the immune infiltration profile of different risk subgroups. RESULTS: Oral squamous cell carcinoma patients were classified into three subtypes based on the 60 lymph node-metastasis-related key genes identified by single-cell RNA sequencing data. Patients in Subtype 3 showed a tendency for lymph node metastasis and poorer prognosis. Moreover, five biomarkers were selected from the 60 genes to construct a five-gene risk model evaluating the risk of lymph node metastasis. A lower probability of lymph node metastasis and a better prognosis was observed in the low-risk group. The immune infiltration of three different risk groups was explored with CIBERSORT. Besides, further analysis implied different sensitivities of anticancer drugs, including immunotherapy drugs and targeted compounds, in the three risk groups. CONCLUSION: In view of intratumoral heterogeneity, we found 60 genes associated with lymph node metastasis of oral squamous cell carcinoma. Subsequently, we constructed a five-gene signature that could improve the prediction of lymph node metastasis, clinical outcome, and promote individualized treatment strategies for oral squamous cell carcinoma.

Impact of Visceral Fat Area on Intraoperative Complexity and Surgical Approach Decision for Robot-Assisted Partial Nephrectomy: A Comparative Analysis with BMI.

BACKGROUND Optimizing surgical approaches for robot-assisted partial nephrectomy (RAPN) is vital for better patient outcomes. This retrospective study aimed to examine how visceral fat area (VFA) and body mass index (BMI) correlate with intraoperative complexities, thereby guiding the selection of surgical techniques for RAPN. MATERIAL AND METHODS The study analyzed the medical records of 213 Chinese patients diagnosed with a range of benign and malignant renal neoplasms and treated with RAPN in 2020. Visceral fat area was quantified using computed tomography (CT) scans taken at the umbilical level. Various perioperative indicators, such as demographic details, clinicopathological parameters, operation time, estimated blood loss (EBL), warm ischemic time (WIT), and intraoperative complications, were assessed. RESULTS For the retroperitoneal approach, patients with either visceral obesity or general obesity had longer operation times (P<0.001 and P=0.004) and had a tendency for higher EBL (P=0.003 and P=0.001) compared to non-obese patients. In the transperitoneal approach, those with visceral obesity had significantly longer operation times (P=0.008) than their non-viscerally obese counterparts; however, general obesity showed no impact on operation time (P=0.251). Estimated blood loss was higher for patients with visceral obesity (P=0.004), but no significant difference was noted among those with general obesity (P=0.980). CONCLUSIONS VFA appears to offer predictive advantages over BMI in assessing intraoperative complexities for transperitoneal RAPN. When used in conjunction with BMI, it could serve as a valuable tool in selecting the most appropriate surgical approach for RAPN.

Loss of Christianson Syndrome Na+/H+ Exchanger 6 (NHE6) Causes Abnormal Endosome Maturation and Trafficking Underlying Lysosome Dysfunction in Neurons.

Loss-of-function mutations in endosomal Na+/H+ exchanger 6 (NHE6) cause the X-linked neurologic disorder Christianson syndrome. Patients exhibit symptoms associated with both neurodevelopmental and neurodegenerative abnormalities. While loss of NHE6 has been shown to overacidify the endosome lumen, and is associated with endolysosome neuropathology, NHE6-mediated mechanisms in endosome trafficking and lysosome function have been understudied. Here, we show that NHE6-null mouse neurons demonstrate worsening lysosome function with time in culture, likely as a result of defective endosome trafficking. NHE6-null neurons exhibit overall reduced lysosomal proteolysis despite overacidification of the endosome and lysosome lumen. Akin to Nhx1 mutants in Saccharomyces cerevisiae, we observe decreased endosome-lysosome fusion in NHE6-null neurons. Also, we find premature activation of pH-dependent cathepsin D (CatD) in endosomes. While active CatD is increased in endosomes, CatD activation and CatD protein levels are reduced in the lysosome. Protein levels of another mannose 6-phosphate receptor (M6PR)-dependent enzyme, ß-N-acetylglucosaminidase, were also decreased in lysosomes of NHE6-null neurons. M6PRs accumulate in late endosomes, suggesting defective M6PR recycling and retromer function in NHE6-null neurons. Finally, coincident with decreased endosome-lysosome fusion, using total internal reflection fluorescence, we also find a prominent increase in fusion between endosomal multivesicular bodies and the plasma membrane, indicating enhanced exosome secretion from NHE6-null neurons. In summary, in addition to overacidification of endosomes and lysosomes, loss of NHE6 leads to defects in endosome maturation and trafficking, including enhanced exosome release, contributing to lysosome deficiency and potentially leading to neurodegenerative disease.SIGNIFICANCE STATEMENT Loss-of-function mutations in the endosomal Na+/H+ exchanger 6 (NHE6) cause Christianson syndrome, an X-linked neurologic disorder. Loss of NHE6 has been shown to overacidify endosomes; however, endosome trafficking mechanisms have been understudied, and the mechanisms leading to neurodegeneration are largely unknown. In NHE6-null mouse neurons in vitro, we find worsening lysosome function with days in culture. Notably, pH-dependent lysosome enzymes, such as cathepsin D, have reduced activity in lysosomes yet increased, precocious activity in endosomes in NHE6-null neurons. Further, endosomes show reduced fusion to lysosomes, and increased fusion to the plasma membrane with increased exosome release. This study identifies new mechanisms involving defective endosome maturation and trafficking that impair lysosome function in Christianson syndrome, likely contributing to neurodegeneration.

Activated mesangial cells acquire the function of antigen presentation.

Mesangial cells (MCs), as resident cells of the kidneys, play an important role in maintaining glomerular function. MCs are located between the capillary loops of the glomeruli and mainly support the capillary plexus, constrict blood vessels, extracellular matrix components, produce cytokines, and perform phagocytosis and clearance of macromolecular substances. When the glomerular environment changes, MCs are often affected, which can lead to functional transformation. The immune response is involved in the occurrence and development of various kidney diseases, in these diseases, antigen-presenting cells (APCs) play an important role. APCs can present antigens to T lymphocytes, causing them to become activated and proliferate. Studies have shown that MCs have phagocytic function and express APC markers on the cell surface. Additionally, MCs are stimulated by or produce various inflammatory factors to participate in the renal inflammatory response. Therefore, MCs have potential antigen presentation function and participate in the pathological changes of various kidney diseases as APCs upon activation. In this paper, by reviewing MC phagocytic function, activated MC expression of APC surface markers, and MC participation in the inflammatory response and local renal immune response, we confirm that activated MCs can act as APCs in renal disease.

GPT2 mutations in autosomal recessive developmental disability: extending the clinical phenotype and population prevalence estimates.

The glutamate pyruvate transaminase 2 (GPT2) gene produces a nuclear-encoded mitochondrial enzyme that catalyzes the reversible transfer of an amino group from glutamate to pyruvate, generating alanine and alpha-ketoglutarate. Recessive mutations in GPT2 have been recently identified in a new syndrome involving intellectual and developmental disability (IDD), postnatal microcephaly, and spastic paraplegia. We have identified additional families with recessive GPT2 mutations and expanded the phenotype to include small stature. GPT2 loss-of-function mutations were identified in four families, nine patients total, including: a homozygous mutation in one child [c.775T>C (p.C259R)]; compound heterozygous mutations in two siblings [c.812A>C (p.N271T)/c.1432_1433delGT (p.V478Rfs*73)]; a novel homozygous, putative splicing mutation [c.1035C>T (p.G345=)]; and finally, a recurrent mutation, previously identified in a distinct family [c.1210C>T (p.R404*)]. All patients were diagnosed with IDD. A majority of patients had remarkably small stature throughout development, many < 1st percentile for height and weight. Given the potential biological function of GPT2 in cellular growth, this phenotype is strongly suggestive of a newly identified clinical susceptibility. Further, homozygous GPT2 mutations manifested in at least 2 of 176 families with IDD (approximately 1.1%) in a Pakistani cohort, thereby representing a relatively common cause of recessive IDD in this population, with recurrence of the p.R404* mutation in this population. Based on variants in the ExAC database, we estimated that approximately 1 in 248 individuals are carriers of moderately or severely deleterious variants in GPT2.

Mutations in mitochondrial enzyme GPT2 cause metabolic dysfunction and neurological disease with developmental and progressive features.

Mutations that cause neurological phenotypes are highly informative with regard to mechanisms governing human brain function and disease. We report autosomal recessive mutations in the enzyme glutamate pyruvate transaminase 2 (GPT2) in large kindreds initially ascertained for intellectual and developmental disability (IDD). GPT2 [also known as alanine transaminase 2 (ALT2)] is one of two related transaminases that catalyze the reversible addition of an amino group from glutamate to pyruvate, yielding alanine and α-ketoglutarate. In addition to IDD, all affected individuals show postnatal microcephaly and ∼80% of those followed over time show progressive motor symptoms, a spastic paraplegia. Homozygous nonsense p.Arg404* and missense p.Pro272Leu mutations are shown biochemically to be loss of function. The GPT2 gene demonstrates increasing expression in brain in the early postnatal period, and GPT2 protein localizes to mitochondria. Akin to the human phenotype, Gpt2-null mice exhibit reduced brain growth. Through metabolomics and direct isotope tracing experiments, we find a number of metabolic abnormalities associated with loss of Gpt2. These include defects in amino acid metabolism such as low alanine levels and elevated essential amino acids. Also, we find defects in anaplerosis, the metabolic process involved in replenishing TCA cycle intermediates. Finally, mutant brains demonstrate misregulated metabolites in pathways implicated in neuroprotective mechanisms previously associated with neurodegenerative disorders. Overall, our data reveal an important role for the GPT2 enzyme in mitochondrial metabolism with relevance to developmental as well as potentially to neurodegenerative mechanisms.

Neuron-Derived ADAM10 Production Stimulates Peripheral Nerve Injury-Induced Neuropathic Pain by Cleavage of E-Cadherin in Satellite Glial Cells.

BACKGROUND: Increasing evidence suggests the potential involvement of metalloproteinase family proteins in the pathogenesis of neuropathic pain, although the underlying mechanisms remain elusive. METHODS: Using the spinal nerve ligation model, we investigated whether ADAM10 proteins participate in pain regulation. By implementing invitro methods, we produced a purified culture of satellite glial cells to study the underlying mechanisms of ADAM10 in regulating neuropathic pain. RESULTS: Results showed that the ADAM10 protein was expressed in calcitonin gene-related peptide (CGRP)-containing neurons of the dorsal root ganglia, and expression was upregulated following spinal nerve ligation surgery invivo. Intrathecal administration of GI254023X, an ADAM10 selective inhibitor, to the rats one to three days after spinal nerve ligation surgery attenuated the spinal nerve ligation-induced mechanical allodynia and thermal hyperalgesia. Intrathecal injection of ADAM10 recombinant protein simulated pain behavior in normal rats to a similar extent as those treated by spinal nerve ligation surgery. These results raised a question about the relative contribution of ADAM10 in pain regulation. Further results showed that ADAM10 might act by cleaving E-cadherin, which is mainly expressed in satellite glial cells. GI254023X reversed spinal nerve ligation-induced downregulation of E-cadherin and activation of cyclooxygenase 2 after spinal nerve ligation. ß-catenin, which creates a complex with E-cadherin in the membranes of satellite glial cells, was also downregulated by spinal nerve ligation surgery in satellite glial cells. Finally, knockdown expression of ß-catenin by lentiviral infection in purified satellite glial cells increased expression of inducible nitric oxide synthase and cyclooxygenase 2. CONCLUSION: Our findings indicate that neuron-derived ADAM10 production stimulates peripheral nerve injury-induced neuropathic pain by cleaving E-cadherin in satellite glial cells.

Oncogenic role of neurotensin and neurotensin receptors in various cancers.

Neurotensin (NTS) has long been recognized as a neurotransmitter or neuromodulator in the central nervous system and as an endocrine agent in the periphery via actions mediated through neurotensin receptors (NTSRs). Many studies support a role for NTS in the endocrine, autocrine and paracrine growth stimulation of cancer, with oncogenic actions described for NTS in different types of cancers and cancer cell lines at each step of cancer progression, ranging from tumour growth and survival to metastatic spread. The mechanisms underlying the effects of the NTS/NTSR system in cell proliferation, migration and invasion, as well as the anti-apoptotic effects of this system, have been elucidated in different types of cancers, and include mitogen-activated protein kinases, phosphatidylinositol 3-kinase and RhoGTPases. The present mini review summarizes recent findings relating to the oncogenic function of the NTS/NTSR system.

Interferon-microRNA signalling drives liver precancerous lesion formation and hepatocarcinogenesis.

OBJECTIVE: Precancerous lesion, a well-established histopathologically premalignant tissue with the highest risk for tumourigenesis, develops preferentially from activation of DNA damage checkpoint and persistent inflammation. However, little is known about the mechanisms by which precancerous lesions are initiated and their physiological significance. DESIGN: Laser capture microdissection was used to acquire matched normal liver, precancerous lesion and tumour tissues. miR-484(-/-), Ifnar1(-/-) and Tgfbr2(△hep) mice were employed to determine the critical role of the interferon (IFN)-microRNA pathway in precancerous lesion formation and tumourigenesis. RNA immunoprecipitation (RIP), pull-down and chromatin immunoprecipitation (ChIP) assays were applied to explore the underlying mechanisms. RESULTS: miR-484 is highly expressed in over 88% liver samples clinically. DEN-induced precancerous lesions and hepatocellular carcinoma were dramatically impaired in miR-484(-/-) mice. Mechanistically, ectopic expression of miR-484 initiates tumourigenesis and cell malignant transformation through synergistic activation of the transforming growth factor-ß/Gli and nuclear factor-κB/type I IFN pathways. Specific acetylation of H3K27 is indispensable for basal IFN-induced continuous transcription of miR-484 and cell transformation. Convincingly, formation of precancerous lesions were significantly attenuated in both Tgfbr2(△hep) and Ifnar1(-/-) mice. CONCLUSIONS: These findings demonstrate a new protumourigenic axis involving type I IFN-microRNA signalling, providing a potential therapeutic strategy to manipulate or reverse liver precancerous lesions and tumourigenesis.

Enhanced RAGE Expression in the Dorsal Root Ganglion May Contribute to Neuropathic Pain Induced by Spinal Nerve Ligation in Rats.

OBJECTIVE: There is some evidence implicating receptor for advanced glycation end products (RAGE) signaling in the pathogenesis of neuropathic pain (NP). The objective was to investigate whether RAGE signaling in the dorsal root ganglion (DRG) might contribute to NP following peripheral nerve injury. DESIGN: Experimental study before and after spinal nerve ligation (SNL) surgery. SETTING: Caged in a controlled environment. SUBJECTS: Male Sprague-Dawley rats. METHODS: A SNL rat model of NP was used. Mechanical hyperalgesia was measured by the paw withdrawal threshold (PWT) to mechanical stimuli (1.4-15 g). Protein expressions of RAGE (immunofluorescence and western blotting), glial fibrillary acidic protein (GFAP; satellite glial cell [SGC] activation marker), IL-1ß (ELISA), TNF-α (ELISA), and NF-κB (western blotting) in the DRG were determined. RAGE signaling was inhibited by intrathecal injection of anti-RAGE antibody. RESULTS: After 7 days, SNL surgery reduced the PWT and upregulated the protein expression of RAGE, GFAP, NF-κB, TNF-α, and IL-1ß. Intrathecal injection of RAGE-neutralizing antibody attenuated the SNL-induced mechanical hyperalgesia, activation of SGCs, and upregulation of NF-κB, TNF-α, and IL-1ß in the DRG. CONCLUSION: RAGE signaling may contribute to the pain hypersensitivity observed in the rat SNL model of NP. Although the precise mechanism remains to be established, NF-κB, TNF-α, and IL-1ß likely play a role, together with the activation of SGCs.

MicroRNAs and cell cycle of malignant glioma.

The control of malignant glioma cell cycle by microRNAs (miRNAs) is well established. The deregulation of miRNAs in glioma may contribute to tumor proliferation by directly targeting the critical cell-cycle regulators. Tumor suppressive miRNAs inhibit cell cycle through repressing the expression of positive cell-cycle regulators. However, oncogenic miRNAs promote the cell-cycle progression by targeting cell-cycle negative regulators. Recent studies have identified that transcription factors had involved in the expression of miRNAs. Transcription factors and miRNAs are implicated in regulatory network of glioma cell cycle, the deregulation of these transcription factors might be a cause of the deregulation of miRNAs. Abnormal versions of miRNAs have been implicated in the cell cycle of glioma. Based on those, miRNAs are excellent biomarker candidates and potential targets for therapeutic intervention in glioma.

Neurotensin promotes the progression of malignant glioma through NTSR1 and impacts the prognosis of glioma patients.

BACKGROUND: The poor prognosis and minimally successful treatments of malignant glioma indicate a challenge to identify new therapeutic targets which impact glioma progression. Neurotensin (NTS) and its high affinity receptor (NTSR1) overexpression induces neoplastic growth and predicts the poor prognosis in various malignancies. Whether NTS can promote the glioma progression and its prognostic significance for glioma patients remains unclear. METHODS: NTS precursor (ProNTS), NTS and NTSR1 expression levels in glioma were detected by immunobloting Elisa and immunohistochemistry assay. The prognostic analysis was conducted from internet by R2 microarray platform. Glioma cell proliferation was evaluated by CCK8 and BrdU incorporation assay. Wound healing model and Matrigel transwell assay were utilized to test cellular migration and invasion. The orthotopic glioma implantations were established to analyze the role of NTS and NTSR1 in glioma progression in vivo. RESULTS: Positive correlations were shown between the expression levels of NTS and NTSR1 with the pathological grade of gliomas. The high expression levels of NTS and NTSR1 indicate a worse prognosis in glioma patients. The proliferation and invasiveness of glioma cells could be enhanced by NTS stimulation and impaired by the inhibition of NTSR1. NTS stimulated Erk1/2 phosphorylation in glioma cells, which could be reversed by SR48692 or NTSR1-siRNA. In vivo experiments showed that SR48692 significantly prolonged the survival length of glioma-bearing mice and inhibited glioma cell invasiveness. CONCLUSION: NTS promotes the proliferation and invasion of glioma via the activation of NTSR1. High expression levels of NTS and NTSR1 predict a poor prognosis in glioma patients.

N-methyl-D-aspartic acid receptor 1 (NMDAR1) aggravates secondary inflammatory damage induced by hemin-NLRP3 pathway after intracerebral hemorrhage.

OBJECTIVE: Inflammation plays a critical role in secondary brain damage after intracerebral hemorrhage (ICH). However, the mechanisms of inflammatory injury following ICH are still unclear, particularly the involvement of NLRP3 inflammasome, which are crucial to sterile inflammatory responses. In this study, we aim to test the hypothesis that NLRP3 signaling pathway takes a vital position in ICH-induced secondary inflammatory damage and detect the role of N-methyl-D-aspartic acid receptor 1 (NMDAR1) in this progress. METHODS: ICH was induced in mice by microinjection of hemin into the striatum. The protein levels of NMDAR1, NMDAR1 phosphorylation, NLRP3 and IL-1b were measured by Western blot. The binding of NMDAR1 to NLRP3 was detected by immunoprecipitation. RESULTS: The expression of NMDAR1, NMDAR1 phosphorylation, NLRP3 and IL-1b were rapidly increased after ICH. Hemin treatment enhanced NMDAR1 expression and NMDAR1 phosphorylation, as well in cultured microglial cells treated by hemin. Hemin up regulated NLRP3 and IL-1b level, which was reversed by MK801 (NMDAR antagonist) in vitro. Hemin also promoted the binding of NMDAR1 to NLRP3. CONCLUSION: Our findings suggest that NMDAR1 plays a pivotal role in hemin-induced NLRP3-mediated inflammatory damage through synergistic activation.

Experimental Study on the Skyhook Control of a Magnetorheological Torsional Vibration Damper.

This study proposes a dual-coil magnetorheological torsional vibration damper (MRTVD) and verifies the effectiveness of semi-active damping control to suppress the shaft system's torsional vibration via experimental research. Firstly, the mechanical model of the designed MRTVD and its coupling mechanical model with the rotating shaft system are established. Secondly, the torsional response of the shaft system is obtained via resonance experiments, and the influence of the current on the torsional characteristics of the magnetorheological torsional damper is analyzed. Finally, the MRTVD is controlled using the skyhook control approach. The experimental results demonstrate that when the main shaft passes through the critical speed range at various accelerations, the amplitude of the shaft's torsional vibration decreases by more than 15%, and the amplitude of the shaft's torsional angular acceleration decreases by more than 22%. These conclusions validate the inhibitory effect of MRTVD on the main shaft's torsional vibrations under skyhook control.

Design and Control of Upper Limb Rehabilitation Training Robot Based on a Magnetorheological Joint Damper.

In recent years, rehabilitation robots have been developed and used in rehabilitation training for patients with hemiplegia. In this paper, a rehabilitation training robot with variable damping is designed to train patients with hemiplegia to recover upper limb function. Firstly, a magnetorheological joint damper (MR joint damper) is designed for the rehabilitation training robot, and its structural design and dynamic model are tested theoretically and experimentally. Secondly, the rehabilitation robot is simplified into a spring-damping system, and the rehabilitation training controller for human movement is designed. The rehabilitation robot dynamically adjusts the excitation current according to the feedback speed and human-machine interaction torque, so that the rehabilitation robot always outputs a stable torque. The magnetorheological joint damper acts as a clutch to transmit torque safely and stably to the robot joint. Finally, the upper limb rehabilitation device is tested. The expected torque is set to 20 N, and the average value of the output expected torque during operation is 20.02 N, and the standard deviation is 0.635 N. The output torque has good stability. A fast (0.5 s) response can be achieved in response to a sudden motor speed change, and the average expected output torque is 20.38 N and the standard deviation is 0.645 N, which can still maintain the stability of the output torque.

Is cranioplasty the optimal treatment for contralateral subdural effusion after decompressive craniectomy?: a case report.

Introduction and importance: Contralateral subdural effusion (CSDE) is a rare complication secondary to decompressive craniectomy (DC), which can lead to encephalocele and neurologic deterioration. The authors report a case that confirm the existence of unidirectional membrane valve, and cranioplasty is an effective treatment for CSDE. Case presentation: The authors reported a case of 43-year-old female was diagnosed with ruptured intracranial aneurysm and treated with interventional embolization. She underwent DC because of postoperative cerebral infarction subsequently. Her conscious state deteriorated accompanied by encephalocele in postoperative 2 week. A craniocerebral computed tomography (CT) confirmed the diagnosis of CSDE with cerebral hernia. A compression bandaging of the skull defect was applicated, whereas, her conscious state progressive deteriorated. She was transferred to the author's hospital where she underwent burr-hole drainage and clinical symptom has been improved. However, a relapse of CSDE was observed after the removal of drainage tube. Continuous lumbar drainage was employed, and which was ineffective for CSDE in this case. Finally, she underwent cranioplasty, with the help of drainage of subdural effusion, CSDE was completely resolved. Clinical discussion: CSDE is occasionally observed in patients after DC. Intracranial pressure (ICP) gradient and unidirectional membrane valve are the possible mechanisms of CSDE. At present, there is no optimal therapy for CSDE. For symptomatic CSDE patients, one or more treatment measures should be applicated. Conclusion: Cranioplasty is one of the curative and optimal method to treat symptomatic CSDE patients, early cranioplasty combined with burr-hole drainage should be performed for conservative treatment failed and intractable cases.