BACKGROUND:Neuro-related proteins are promising biomarkers and therapeutic targets for Parkinson's disease (PD), yet their specific roles remain uncertain. METHODS:We conducted Mendelian randomisation by integrating protein quantitative trait loci with genome-wide association study data from 33,647 patients with PD and 449,056 controls for risk, 28,568 patients for age at onset (AAO), and 4093 patients for progression. Subsequent analyses included genetic colocalisation, protein-protein interaction, functional enrichment, tissue and cell-specific expression profiling, and druggability assessment. In an case-control study (30 patients with PD, 14 controls), plasma neuro-related proteins were measured using the Olink platform. FINDINGS:59 neuro-related proteins were associated with PD: 4 (CLEC1B, IL5RA, SNCG, CDH17) associated with risk, 7 with AAO, and 58 with progression. Colocalisation supported shared variants for TDGF1, PVR, and IL5RA with the progression. 47 proteins were evaluated as druggable targets. Pathway analysis highlighted cytokine-receptor interactions, neuroimmune modulation, and axon guidance. BMP-4, DDR1, GDNF, LAT, and MANF were found to be differentially expressed in patients with PD and correlated with the symptom severity. INTERPRETATION:This integrative genetic-proteomic-clinical framework identifies neuro-related proteins significantly associated with PD, offering mechanistic insights and prioritising therapeutic targets. FUNDING:National Natural Science Foundation of China (NO: U24A20694, NO: 82471433), and Scientific Research Foundation of Guangzhou (NO: 202206010005) to QW; and National Natural Science Foundation of China (NO: 82401641) to BD; and Basic and Applied Basic Research of Guangdong (NO: 2025A1515012456) to WLY; and Ministry of Education Academic Research Fund Tier 1 (RG111/24) to JNF; and National Medical Research Council grants to EKT.

Introduction: Blood–brain barrier(BBB) disruption promotes the influx of the fibrinogen(FG); however, it remains unknown whether FG deposit contributes to neurodegeneration in Parkinson’s disease(PD). Objectives: We aimed to examine the pathophysiologic link among FG, mitochondrial dysfunction and α-synuclein(α-syn) abnormality in PD. Methods: First, plasma FG levels were measured in 60 healthy controls and 60 PD patients. Second, to determine whether FG contributes to PD pathogenesis, FG was injected into the substantia nigra pars compacta(SNpc) of healthy and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP)-treated PD mice. Meanwhile, intraperitoneal injections of batroxobin were used to deplete FG in the brain of PD mice. Mitochondrial ultrastructure in mouse models was observed by transmission electron microscopy(TEM), and mitochondrial functions in SH-SY5Y cells were examined by different assay kits and flow cytometry. The mechanisms underlying FG-induced α-syn abnormality and mitochondrial dysfunction were observed by RNA sequencing and validated in various experiments including western blot and immunostaining. Last, the endocytosis of FG in primary neurons were detected by confocal microscopy, and α-syn aggregation after FG co-incubation were evaluated by western blot, ThT-binding assay and TEM. Results: PD patients exhibited elevated levels of FG in peripheral blood compared to HCs, and there was a positive correlation between the plasma FG and PD clinical severity. Excessive FG in the SNpc of MPTP-treated mice promoted poly (ADP-ribose) (PAR) polymerase-1(PARP1) elevation, mediated by the αvβ3 integrin receptor. FG exacerbated α-syn abnormalities and mitochondrial dysfunctions via PARP1 activation. Moreover, FG entered neurons by αvβ3 integrin mediation, potentially enhancing α-syn fibrillation and toxicity. FG facilitated α-syn aggregation subsequently reduced ATP-dependent Clp protease(ClpP) level, impairing neuronal mitochondrial unfolded response and increasing mitochondrial ROS. Pharmacological depletion of FG by batroxobin ameliorated neurodegeneration in MPTP-treated mice. Conclusion: Our study indicate that FG plays an essential pathological role in α-syn abnormality. FG-targeting therapy can be a promising strategy against neurodegeneration in PD.

Introduction Multiple system atrophy (MSA) is a sporadic, fatal, and rapidly progressive neurodegenerative disease of unknown etiology, pathologically characterized by the presence of α-synuclein (α-syn) immunoreactive cytoplasmic inclusions in oligodendrocytes. The deposition of α-synuclein in highly interconnected neuronal networks with different neurochemistry properties in different regions of the cortex, diencephalon, brain stem and spinal cord leads to early onset and extensive autonomic dysfunction in MSA. Mainly affected areas include the hypothalamus, pons, raphe nucleus, locus coeruleus, arcuate nucleus, dorsal vagus nucleus, fuzzy nucleus, the thoracolumbar middle lateral column and Onuf’s nucleus of the spinal cord. Clinical manifestations include orthostatic hypotension, incomplete bladder emptying, erectile dysfunction, and constipation.Discussion In this review, we aim to discuss and summarize the clinicopathological correlation of MSA autonomic dysfunction, and focus on the pathophysiological mechanisms of various autonomic dysfunction, from neural control networks under normal physiological conditions to specific pathological involvement structures in MSA. In addition, we also elaborated on the corresponding clinical manifestations caused by various pathological structures.Conclusions In summary, the autonomic dysfunction of MSA involves the comprehensive control of cardiovascular, urinary, reproductive, and gastrointestinal functions by the autonomic nervous network in the central nervous system (CNS). The currently summarized physiology and pathophysiology of MSA have not been fully clarified. Further and deeper studies are needed to elucidate the relationship between pathogenesis and clinical manifestations of MSA.

Multiple system atrophy (MSA) is a rapidly progressive neurodegenerative disease arising from accumulation of the α-synuclein and aberrant protein clearance in oligodendrocytes. The mechanisms of autophagy involved in the progression of MSA remain poorly understood. It is reported that MSA patients have blood-brain barrier impairments, which may increase the entry of fibrinogen into the brain. However, the roles of fibrinogen and its degradation products (FDPs) on autophagy and α-synuclein accumulation in MSA remain unknown. Here, we established the MSA animal model by intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6- tetrahydropyridine (MPTP) and 3-nitropropionic acid (3-NP), and cellular models by adding fibrillar α-syn into oligodendrocytes to investigate the mechanisms of FDPs on autophagy and accumulation of α-synuclein in oligodendrocytes. We found that FDPs inhibit the entry of α-synuclein into lysosomes for degradation, increasing aggregation of α-synuclein in oligodendrocytes (OLN-93). Our findings indicated that in OLN-93, FDPs inhibited the expressions of Beclin1 and Bif-1, which could promote the fusion of autophagosomes with lysosomes. Furthermore, the expression of α-synuclein was elevated in FDPs-injected mice, accompanied by an increase in the protein level of p62. We detected elevated expression of FDPs in the striatum of MSA mice. Finally, FDPs inhibited the expression of Beclin1 and Bif-1, which led to aberrant autophagic degradation and increased aggregation of α-synuclein and phospho-α-synuclein in MSA mice. Our study illustrates that FDPs can cause aggregation of α-synuclein in MSA by inhibiting Beclin1-mediated autophagy, which may exacerbate disease progression. These results provide a new therapeutic approach for MSA, that targets the inhibitory effect of FDPs on oligodendrocyte autophagy.

Abstract Detection of cytoplasmic DNA is an essential biological mechanism that elicits IFN-dependent and immune-related responses. A better understanding of the mechanisms regulating cytoplasmic DNA sensing in tumor cells could help identify immunotherapeutic strategies to improve cancer treatment. Here we identified abundant cytoplasmic DNA accumulated in lung squamous cell carcinoma (LUSC) cells. DNA-PK, but not cGAS, functioned as a specific cytoplasmic DNA sensor to activate downstream ZAK/AKT/mTOR signaling, thereby enhancing the viability, motility, and chemoresistance of LUSC cells. DNA-PK–mediated cytoplasmic DNA sensing boosted glycolysis in LUSC cells, and blocking glycolysis abolished the tumor-promoting activity of cytoplasmic DNA. Elevated DNA-PK–mediated cytoplasmic DNA sensing was positively correlated with poor prognosis of human patients with LUSC. Targeting signaling activated by cytoplasmic DNA sensing with the ZAK inhibitor iZAK2 alone or in combination with STING agonist or anti-PD-1 antibody suppressed the tumor growth and improved the survival of mouse lung cancer models and human LUSC patient-derived xenografts model. Overall, these findings established DNA-PK–mediated cytoplasmic DNA sensing as a mechanism that supports LUSC malignancy and highlight the potential of targeting this pathway for treating LUSC. Significance: DNA-PK is a cytoplasmic DNA sensor that activates ZAK/AKT/mTOR signaling and boosts glycolysis to enhance malignancy and chemoresistance of lung squamous cell carcinoma.

BACKGROUND:Non-small cell lung cancer (NSCLC) is one of the predominant malignancies globally. Percutaneous thermal ablation (PTA) has gained widespread use among NSCLC patients, with the potential to elicit immune responses but limited therapeutic efficacies for advanced-stage disease. T-helper type 9 (Th9) cells are a subset of CD4+ effector T cells with robust and persistent anti-tumor effects. This study proposes to develop PTA-Th9 cell integrated therapy as a potential strategy for NSCLC treatment.METHODS:The therapeutic efficacies were measured in mice models with subcutaneously transplanted, recurrence, or lung metastatic tumors. The tumor microenvironments (TMEs) were evaluated by flow cytometry. The cytokine levels were assessed by ELISA. The signaling molecules were determined by quantitative PCR and Western blotting. The translational potential was tested in the humanized NSCLC patient-derived xenograft (PDX) model.RESULTS:We find that PTA combined with adoptive Th9 cell transfer therapy substantially suppresses tumor growth, recurrence, and lung metastasis, ultimately extending the survival of mice with NSCLC grafts, outperforming both PTA and Th9 cell transfer monotherapy. Analysis of TMEs indicates that combinatorial therapy significantly augments tumor-infiltrating Th9 cells, boosts anti-tumor effects of CD8+ T cells, and remodels tumor immunosuppressive microenvironments. Moreover, combinatorial therapy significantly strengthens the regional and circulation immune response of CD8+ T cells in mice with tumor lung metastasis and induces peripheral CD8+ T effector memory cells in mice with tumor recurrence. Mechanically, PTA reinforces the anti-tumor ability of Th9 cells primarily through upregulating interleukin (IL)-1β and subsequently activating the downstream STAT1/IRF1 pathway, which could be effectively blocked by intercepting IL-1β signaling. Finally, the enhanced therapeutic effect of combinatorial therapy is validated in humanized NSCLC PDX models.CONCLUSIONS:Collectively, this study demonstrates that combinatorial therapy displays robust and durable anti-tumor efficacy and excellent translational potential, offering excellent prospects for translation and emerging as a promising approach for NSCLC treatment.

IntroductionMesenchymal stromal cell (MSC)-based cell therapy is a promising approach for various inflammatory disorders based on their immunosuppressive capacity. Osteopontin (OPN) regulates several cellular functions including tissue repair, bone metabolism and immune reaction. However, the biological function of OPN in regulating the immunosuppressive capacity of MSCs remains elusive.ObjectivesThis study aims to highlight the underlying mechanism of the proinflammatory cytokines affect the therapeutic ability of MSCs through OPN.MethodsMSCs in response to the proinflammatory cytokines were collected to determine the expression profile of OPN. In vitro T-cell proliferation assays and gene editing were performed to check the role and mechanisms of OPN in regulating the immunosuppressive capacity of MSCs. Inflammatory disease mouse models were established to evaluate the effect of OPN on improving MSC-based immunotherapy.ResultsWe observed that OPN, including its two isoforms iOPN and sOPN, was downregulated in MSCs upon proinflammatory cytokine stimulation. Interestingly, iOPN, but not sOPN, greatly enhanced the immunosuppressive activity of MSCs on T-cell proliferation and thus alleviated the inflammatory pathologies of hepatitis and colitis. Mechanistically, iOPN interacted with STAT1 and mediated its deubiquitination, thereby inducing the master immunosuppressive mediator inducible nitric oxide synthase (iNOS) in MSCs. In addition, iOPN expression was directly downregulated by activated STAT1, which formed a negative feedback loop to restrain MSC immunosuppressive capacity.ConclusionOur findings demonstrated that iOPN expression modulation in MSCs is a novel strategy to improve MSC-based immunotherapy.

Introduction: Peripheral cytokine levels may affect specific brain volumes. Few studies have examined this possible relationship. Objective: In a case–control study, we used magnetic resonance imaging (MRI) voxel-based morphological analysis techniques to examine the relationship between gray matter volume changes and cognitive, motor and emotional dysfunction as well as between gray matter volume changes and peripheral blood cytokine levels. Method: A total of 134 subjects, comprising 66 PD patients and 68 healthy controls, were recruited. Peripheral venous blood was collected to measure the concentrations of 12 cytokines, including IL-1β, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, IL-17, IFN-α, IFN-γ, and TNF-α. All the subjects also underwent MRI, where 3D-T1-weighted MR images were used for the analysis. In addition, the Montreal Cognitive Assessment (MoCA), Mini-Mental Status Examination (MMSE), Unified Parkinson's disease Rating Scale (UPDRS), Hamilton Anxiety Scale (HAMA), and Hamilton Depression Scale (HAMD) scores were assessed in PD patients. Statistical parameter mapping 12 software was used for the statistical analysis of the images. Result: Compared with control patients, PD patients presented decreased gray matter volume (GMV) in the bilateral frontal lobe, temporal lobe, parietal lobe, occipital lobe, insula, and right cerebellar lobule VIII. Regional GMV in the temporal lobe, parietal lobe, and cerebellum was correlated with MoCA, MMSE, UPDRS, HAMA, and HAMD scores in PDs. In addition, the regional GMV in PDs was correlated with the concentrations of cytokines, including IL-4, IL-6, IFN-γ, and TNF-α. The IL-6 concentration was negatively correlated with the UPDRS-IV score. Conclusion: PD patients exhibit gray matter atrophy in a wide range of brain regions, which are symmetrically distributed and mainly concentrated in the frontal and temporal lobes, and these changes may be linked to motor disorders and neuropsychiatric manifestations. Cytokine concentrations in peripheral blood are correlated with regional gray matter volume in PDs, and the IL-6 level affects gray matter volume in the left precentral gyrus and the manifestation of motor complications.

Increasing evidence has shown that gut dysbacteriosis may play a crucial role in neuroinflammation in Parkinson's disease (PD). However, the specific mechanisms that link gut microbiota to PD remain unexplored. Given the critical roles of blood-brain barrier (BBB) dysfunction and mitochondrial dysfunction in the development of PD, we aimed to evaluate the interactions among the gut microbiota, BBB, and mitochondrial resistance to oxidation and inflammation in PD. We investigated the effects of fecal microbiota transplantation (FMT) on the physiopathology of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice. The aim was to explore the role of fecal microbiota from PD patients and healthy human controls in neuroinflammation, BBB components, and mitochondrial antioxidative capacity via the AMPK/SOD2 pathway. Compared to control mice, MPTP-treated mice exhibited elevated levels of Desulfovibrio, whereas mice given FMT from PD patients exhibited enriched levels of Akkermansia and mice given FMT from healthy humans showed no significant alterations in gut microbiota. Strikingly, FMT from PD patients to MPTP-treated mice significantly aggravated motor impairments, dopaminergic neurodegeneration, nigrostriatal glial activation and colonic inflammation, and inhibited the AMPK/SOD2 signaling pathway. However, FMT from healthy human controls greatly improved the aforementioned MPTP-caused effects. Surprisingly, the MPTP-treated mice displayed a significant loss in nigrostriatal pericytes, which was restored by FMT from healthy human controls. Our findings demonstrate that FMT from healthy human controls can correct gut dysbacteriosis and ameliorate neurodegeneration in the MPTP-induced PD mouse model by suppressing microgliosis and astrogliosis, ameliorating mitochondrial impairments via the AMPK/SOD2 pathway, and restoring the loss of nigrostriatal pericytes and BBB integrity. These findings raise the possibility that the alteration in the human gut microbiota may be a risk factor for PD and provide evidence for potential application of FMT in PD preclinical treatment.

Retinal thickness is related to Parkinson’s disease (PD), but its association with the severity of PD is still unclear. We conducted a Mendelian randomized (MR) study to explore the association between retinal thickness and PD. For the two-sample MR analysis, the summary statistics obtained from genome-wide association studies on the thickness of Retinal nerve fiber layer (RNFL) and ganglion cell inner plexiform layer (GCIPL) were employed as exposure, while the summary statistics associated with PD were used as the outcome. The primary approach utilized was inverse variance weighted. To correct for multiple testing, the false discovery rate (FDR) was employed. For sensitivity analysis, an array of robust MR methods was utilized. We found genetically predicted significant association between reduced RNFL thickness and a reduced risk of constipation in PD (odds ratio [OR] = 0.854, 95% confidence interval [CI] (0.782, 0.933), P < 0.001, FDR-corrected P = 0.018). Genetically predicted reduced RNFL thickness was associated with a reduced Unified Parkinson’s Disease Rating Scale total score ( β = −0.042, 95% CI (−0.079, 0.005), P = 0.025), and reduced GCIPL thickness was associated with a lower risk of constipation (OR = 0.901, 95% CI (0.821, 0.988), P = 0.027) but a higher risk of depression (OR = 1.103, 95% CI (1.016, 1.198), P = 0.020), insomnia (OR = 1.090, 95% CI (1.013, 1.172), P = 0.021), and rapid eye movement sleep behaviour disorder (RBD) (OR = 1.198, 95% CI (1.061, 1.352), P = 0.003). In conclusion, we identify an association between retinal thickness and non-motor symptoms (constipation, depression, insomnia and RBD) in PD, highlighting the potential of retinal thickness as a biomarker for PD nonmotor symptoms.

Multiple system atrophy (MSA) is a sporadic, fatal, and rapidly progressive neurodegenerative disease of unknown etiology that is clinically characterized by autonomic failure, parkinsonism, cerebellar ataxia, and pyramidal signs in any combination. Early onset and extensive autonomic dysfunction, including cardiovascular dysfunction characterized by orthostatic hypotension (OH) and supine hypertension, urinary dysfunction characterized by overactive bladder and incomplete bladder emptying, sexual dysfunction characterized by sexual desire deficiency and erectile dysfunction, and gastrointestinal dysfunction characterized by delayed gastric emptying and constipation, are the main features of MSA. Autonomic dysfunction greatly reduces quality of life and increases mortality. Therefore, early diagnosis and intervention are urgently needed to benefit MSA patients. In this review, we aim to discuss the systematic treatment of autonomic dysfunction in MSA, and focus on the current methods, starting from non-pharmacological methods, such as patient education, psychotherapy, diet change, surgery, and neuromodulation, to various drug treatments targeting autonomic nerve and its projection fibers. In addition, we also draw attention to the interactions among various treatments, and introduce novel methods proposed in recent years, such as gene therapy, stem cell therapy, and neural prosthesis implantation. Furthermore, we elaborate on the specific targets and mechanisms of action of various drugs. We would like to call for large-scale research to determine the efficacy of these methods in the future. Finally, we point out that studies on the pathogenesis of MSA and pathophysiological mechanisms of various autonomic dysfunction would also contribute to the development of new promising treatments and concepts.

Rab7 GTPase regulates mitochondrial morphology and function. Missense mutation(s) of Rab7 underlies the pathogenesis of Charcot Marie Tooth 2B (CMT2B) peripheral neuropathy. Herein, we investigate how mitochondrial morphology and function are impacted by the CMT2B associated Rab7 V162M mutation. In contrast to recent studies of using heterologous overexpression systems, our results demonstrate significant mitochondrial fragmentation in both human CMT2B patient fibroblasts and CMT2B embryonic fibroblasts (MEFs). Primary cultured E18 dorsal root ganglion (DRG) sensory neurons also show mitochondrial fragmentation and altered axonal mitochondrial movement. In addition, we demonstrate that inhibitors to either the mitochondrial fission protein Drp1 or to the nucleotide binding to Rab7 normalize the mitochondrial deficits in both MEFs and E18 cultured DRG neurons. Our study reveals, for the first time, that expression of CMT2B Rab7 mutation at the physiological level enhances Drp1 activity to promote mitochondrial fission, potentially underlying selective vulnerability of peripheral sensory neurons in CMT2B pathogenesis.

Progranulin (GRN) mutations are a major cause of frontotemporal dementia (FTD); the spectrum of clinical phenotypes of FTD is much more extensive than previously reported.The frequency and locations of GRN mutations in Chinese patients with FTD remain uncertain.We performed cDNA sequencing in one sporadic male patient who initially presented FTD symptoms.Brain magnetic resonance imaging (MRI) and positron emission computed tomography/computed tomography (PET/CT) were applied to further confirm the diagnosis of FTD from this patient.Cellular apoptosis and survival test were performed to identify the function of GRN.We identified one novel missense GRN mutation (c.1498G>A, p.V500I) in this patient, who initially presented typical behavioral-variant frontotemporal dementia (bvFTD) features but then presented progressive supranuclear palsy (PSP) clinical characteristics 5 years after onset.Besides, WT GRN protein showed an adequate trophic stimulus to preserve the survival of SH-SY5Y cells in the medium free of serum, while GRN mutation (c.1498G>A, p.V500I) may impair the ability of supporting cell survival.This study owns significant implications for genetic counseling and clinical heterogeneity.We illustrate the fact that FTD presenting features of bvFTD and PSP in one patient could be considered as a specific phenotype in patients with GRN mutations.GRN p.V500I led to the neuronal degeneration in vitro; this finding provides a significant evidence that this mutation may be a new causative mutation in patients with FTD.

BackgroundNeuroinflammation and mitochondrial impairment play important roles in the neuropathogenesis of Parkinson’s disease (PD). The activation of NLRP3 inflammasome and the accumulation of α-synuclein (α-Syn) are strictly correlated to neuroinflammation. Therefore, the regulation of NLRP3 inflammasome activation and α-Syn aggregation might have therapeutic potential. It has been indicated that Dl-3-n-butylphthalide (NBP) produces neuroprotection against some neurological diseases such as ischemic stroke. We here intended to explore whether NBP suppressed NLRP3 inflammasome activation and reduced α-Syn aggregation, thus protecting dopaminergic neurons against neuroinflammation.MethodsIn our study, we established a MPTP-induced mouse model and 6-OHDA-induced SH-SY5Y cell model to examine the neuroprotective actions of NBP. We then performed behavioral tests to examine motor dysfunction in MPTP-exposed mice after NBP treatment. Western blotting, immunofluorescence staining, flow cytometry and RT-qPCR were conducted to investigate the expression of NLRP3 inflammasomes, neuroinflammatory cytokines, PARP1, p-α-Syn, and markers of microgliosis and astrogliosis.ResultsThe results showed that NBP exerts a neuroprotective effect on experimental PD models. In vivo, NBP ameliorated behavioral impairments and reduced dopaminergic neuron loss in MPTP-induced mice. In vitro, treatment of SH-SY5Y cells with 6-OHDA (100uM,24 h) significantly decreased cell viability, increased intracellular ROS production, and induced apoptosis, while pretreatment with 5uM NBP could alleviated 6-OHDA-induced cytotoxicity, ROS production and cell apoptosis to some extent. Importantly, both in vivo and in vitro, NBP suppressed the activation of the NLRP3 inflammasome and the aggregation of α-Syn, thus inhibited neuroinflammation ameliorated mitochondrial impairments.ConclusionsIn summary, NBP rescued dopaminergic neurons by reducing NLRP3 inflammasome activation and ameliorating mitochondrial impairments and increases in p-α-Syn levels. This current study may provide novel neuroprotective mechanisms of NBP as a potential therapeutic agent.

A missense point mutation in nerve growth factor (NGFR100W) is associated with hereditary sensory autonomic neuropathy V (HSAN V), originally discovered in a Swedish family. These patients develop severe loss of perception to deep pain but with apparently normal cognitive functions. To better understand the disease mechanism, we have generated the first NGFR100W knockin mouse model of HSAN V. Mice homozygous for the NGFR100W mutation (NGFfln/fln) showed significant structural deficits in intra-epidermal nerve fibers (IENFs) at birth. These mice had a total loss of pain perception at ∼2 months of age and they often failed to survive to full adulthood. Heterozygous mice (NGF+/fln) developed a progressive degeneration of small sensory fibers both behaviorally and functionally: they showed a progressive loss of IENFs starting at the age of 9 months accompanied with progressive loss of perception to painful stimuli such as noxious temperature. Quantitative analysis of lumbar 4/5 dorsal root ganglia (DRG) revealed a significant reduction in small size neurons positive for calcitonin gene-related peptide, while analysis of sciatic nerve fibers revealed the mutant NGF+/fln mice had no reduction in myelinated nerve fibers. Significantly, the amount of NGF secreted from fibroblasts were reduced in heterozygous and homozygous mice compared to their wild-type littermates. Interestingly, NGF+/fln showed no apparent structural alteration in the brain: neither the anterior cingulate cortex nor the medial septum including NGF-dependent basal forebrain cholinergic neurons. Accordingly, these animals did not develop appreciable deficits in tests for central nervous system function. Our study provides novel insights into the selective impact of NGFR100W mutation on the development and function of the peripheral sensory system.

Aim: Oxidative stress and inflammation play critical roles in the neuropathogenesis of PD. We aimed to evaluate oxidative stress and inflammation status by measuring serum superoxide dismutase (SOD) with lipoprotein cholesterol and high-sensitivity C-reactive protein (hsCRP) respectively in PD patients, and explore their correlation with the disease severity. Methods: We performed a cross-sectional study that included 204 PD patients and 204 age-matched healthy controls (HCs). Plasma levels of SOD, hsCRP, total cholesterol, high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were measured. A series of neuropsychological assessments were performed to rate the severity of PD. Results: The plasma levels of SOD (135.7 ± 20.14 vs. 147.2 ± 24.34, P < 0.0001), total cholesterol, HDL-C and LDL-C in PD were significantly lower than those in HCs; the hsCRP level was remarkably increased in PD compared to HC (2.766 ± 3.242 vs. 1.637 ± 1.597, P < 0.0001). The plasma SOD was negatively correlated with the hsCRP, while positively correlated with total cholesterol, HDL-C, and LDL-C in PD patients. The plasma SOD were negatively correlated with H&Y, total UPDRS, UPDRS (I), UPDRS (II), and UPDRS (III) scores, but positively correlated with MoCA and MMSE scores. Besides, hsCRP was negatively correlated with MoCA; while total cholesterol, HDL-C and LDL-C were positively correlated with the MoCA, respectively. Conclusion: Our findings suggest that lower SOD along with cholesterol, HDL-C and LDL-C, and higher hsCRP levels might be important markers to assess the PD severity. A better understanding of SOD and hsCRP may yield insights into the pathogenesis of PD.

Background In Alzheimer’s Disease (AD), about one-third of the risk genes identified by GWAS encode proteins that function predominantly in the endocytic pathways. Among them, the Ras and Rab Interactor 3(RIN3) is a guanine nucleotide exchange factor (GEF) for the Rab5 small GTPase family and has been implicated to be a risk factor for both late onset AD (LOAD) and sporadic early onset AD (sEOAD). However, how RIN3 is linked to AD pathogenesis is currently undefined. Methods Quantitative PCR and immunoblotting were used to measure the RIN3 expression level in mouse brain tissues and cultured basal forebrain cholinergic neuron (BFCNs). Immunostaining was used to define subcellular localization of RIN3 and to visualize endosomal changes in cultured primary BFCNs and PC12 cells. Recombinant flag-tagged RIN3 protein was purified from HEK293T cells and was used to define RIN3-interactomes by mass spectrometry. RIN3-interacting partners were validated by co-immunoprecipitation, immunofluorescence and yeast two hybrid assays. Live imaging of primary neurons was used to examine axonal transport of amyloid precursor protein (APP) and β-secretase 1 (BACE1). Immunoblotting was used to detect protein expression, processing of APP and phosphorylated forms of Tau. Results We have shown that RIN3 mRNA level was significantly increased in the hippocampus and cortex of APP/PS1 mouse brain. Basal forebrain cholinergic neurons (BFCNs) cultured from E18 APP/PS1 mouse embryos also showed increased RIN3 expression accompanied by early endosome enlargement. In addition, via its proline rich domain, RIN3 recruited BIN1(bridging integrator 1) and CD2AP (CD2 associated protein), two other AD risk factors, to early endosomes. Interestingly, overexpression of RIN3 or CD2AP promoted APP cleavage to increase its carboxyl terminal fragments (CTFs) in PC12 cells. Upregulation of RIN3 or the neuronal isoform of BIN1 increased phosphorylated Tau level. Therefore, upregulation of RIN3 expression promoted accumulation of APP CTFs and increased phosphorylated Tau. These effects by RIN3 was rescued by the expression of a dominant negative Rab5 (Rab5 S34N ) construct. Our study has thus pointed to that RIN3 acts through Rab5 to impact endosomal trafficking and signaling. Conclusion RIN3 is significantly upregulated and correlated with endosomal dysfunction in APP/PS1 mouse. Through interacting with BIN1 and CD2AP, increased RIN3 expression alters axonal trafficking and procession of APP. Together with our previous studies, our current work has thus provided important insights into the role of RIN3 in regulating endosomal signaling and trafficking.

There are limited data on vascular, inflammatory, metabolic risk factors of dementia in Parkinson’s disease (PD) with type 2 diabetes mellitus (DM) (PD-DM). In a study of 928 subjects comprising of 215 PD with DM (including 31 PD-DM with dementia, PD-DMD), 341 PD without DM (including 31 PD with dementia, PDD) and 372 DM without PD (including 35 DM with dementia, DMD) patients, we investigated if vascular, inflammatory, metabolic, and magnetic resonance imaging (MRI) markers were associated with dementia in PD-DM. Lower fasting blood glucose (FBG<5mmol/L, OR=4.380; 95%CI: 1.748-10.975; p=0.002), higher homocysteine (HCY>15μmol/L, OR=3.131; 95%CI: 1.243-7.888; p=0.015) and hyperlipidemia (OR=3.075; 95%CI: 1.142-8.277; p=0.026), increased age (OR=1.043; 95%CI: 1.003-1.084; p=0.034) were the most significant risk factors in PDD patients. Lower low-density lipoprotein cholesterol (LDL-C<2mmol/L, OR=4.499; 95%CI: 1.568-12.909; p=0.005) and higher fibrinogen (>4g/L, OR=4.066; 95%CI: 1.467-11.274; p=0.007) were the most significant risk factors in PD-DMD patients. The area under the curve (AUC) for fibrinogen and LDL-C was 0.717 (P=0.001), with a sensitivity of 80.0% for the prediction of PD-DMD. In summary, we identified several factors including LDL-C and fibrinogen as significant risk factors for PD-DMD and these may have prognostic and treatment implications.

Nerve growth factor (NGF) is a powerful trophic factor that provides essential support for the survival and differentiation of sympathetic and sensory neurons during development. However, NGF also activates nociceptors contributing significantly to inflammatory pain and neuropathic pain after tissue injury. As such anti-NGF based therapies represent a promising strategy for pain management. Because of dose-dependent serious side effects such as back pain, injection site hyperalgesia, clinical trials of using NGF to treat various disorders such as diabetic neuropathies, chemotherapy-induced and human immunodeficiency virus-associated peripheral neuropathies were all discontinued. Thus far, worldwide clinical applications of NGF in treating patients are very limited except in China. Hereditary sensory autonomic neuropathy type V (HSAN V) is an extremely rare disease. Genetic analyses have revealed that HSAN V is associated with autosomal recessive mutations in NGF. One of the mutations occurred at the 100th position of mature NGF resulting in a change of residue from arginine to tryptophan (R100W). Although those HSAN V patients associated with the NGFR100W mutation suffer from severe loss of deep pain, bone fractures and joint destruction, interestingly patients with the NGFR100W mutation do not show apparent cognitive deficits, suggesting important trophic support function is preserved. We believe that NGFR100W provides an ideal tool to uncouple the two important functions of NGF: trophic versus nociceptive. Studies from investigators including ourselves have indeed confirmed in animal testing that the NGFR100W no longer induced pain. More importantly, the trophic function seemed to be largely preserved in NGF harboring the R100W mutation. On the mechanistic level, we found that the NGFR100W mutation was capable of binding to and signaling through the tyrosine receptor kinase A receptor. But its ability to bind to and activate the 75 kDa neurotrophic factor was significantly diminished. The significance of these findings is at least two folds: 1) the NGFR100W mutation can be used as an alternative to the wildtype NGF to treat human conditions without eliciting pain; and 2) the 75 kDa neurotrophic factor may serve as a novel target for pain management. We will discuss all the details in this mini-review.

Our previous studies have indicated that depression and declined cognition have been involved in some neurodegenerative diseases including Stroke, Parkinson's diseases and Vascular Parkinsonism. Post-stroke depression (PSD) is the most common psychiatric disorder following a stroke and has high morbidity and mortality. Studies on PSD are increasingly common, but the specific mechanisms remain unknown. Current research mainly includes clinical and animal aspects. Questionnaires and peripheral blood examination are two of the most common methods used to study clinical PSD. The results of questionnaires are influenced by multiple factors such as disease history, education background, occupation, economic status, family relationships and social support. There are certain limitations to blood sample testing; for example, it is influenced by cerebrovascular diseases and some other disruptions of the internal environment. It is difficult for either method to fully clarify the pathophysiological mechanism of PSD. Animal models provide alternative methods to further understand the pathophysiological mechanisms of PSD, such as the involvement of neuronal circuits and cytokines. More than ten animal models of PSD have been developed, and new models are constantly being introduced. Therefore, it is important to choose the appropriate model for any given study. In this paper, we will discuss the characteristics of the different models of PSD and comment on the advantages and disadvantages of each model, drawing from research on model innovation. Finally, we briefly describe the current assessment methods for the core symptoms of PSD models, point out the shortcomings, and present the improved sucrose preference test as a rational evaluation of anhedonia.