AAV mediated carboxyl terminus of Hsp70 interacting protein overexpression mitigates the cognitive and pathological phenotypes of APP/PS1 mice.

JOURNAL/nrgr/04.03/01300535-202501000-00033/figure1/v/2024-05-14T021156Z/r/image-tiff The E3 ubiquitin ligase, carboxyl terminus of heat shock protein 70 (Hsp70) interacting protein (CHIP), also functions as a co-chaperone and plays a crucial role in the protein quality control system. In this study, we aimed to investigate the neuroprotective effect of overexpressed CHIP on Alzheimer's disease. We used an adeno-associated virus vector that can cross the blood-brain barrier to mediate CHIP overexpression in APP/PS1 mouse brain. CHIP overexpression significantly ameliorated the performance of APP/PS1 mice in the Morris water maze and nest building tests, reduced amyloid-ß plaques, and decreased the expression of both amyloid-ß and phosphorylated tau. CHIP also alleviated the concentration of microglia and astrocytes around plaques. In APP/PS1 mice of a younger age, CHIP overexpression promoted an increase in ADAM10 expression and inhibited ß-site APP cleaving enzyme 1, insulin degrading enzyme, and neprilysin expression. Levels of HSP70 and HSP40, which have functional relevance to CHIP, were also increased. Single nuclei transcriptome sequencing in the hippocampus of CHIP overexpressed mice showed that the lysosomal pathway and oligodendrocyte-related biological processes were up-regulated, which may also reflect a potential mechanism for the neuroprotective effect of CHIP. Our research shows that CHIP effectively reduces the behavior and pathological manifestations of APP/PS1 mice. Indeed, overexpression of CHIP could be a beneficial approach for the treatment of Alzheimer's disease.

Identifying potential causal effects of Parkinson's disease: A polygenic risk score-based phenome-wide association and mendelian randomization study in UK Biobank.

There is considerable uncertainty regarding the associations between various risk factors and Parkinson's Disease (PD). This study systematically screened and validated a wide range of potential PD risk factors from 502,364 participants in the UK Biobank. Baseline data for 1851 factors across 11 categories were analyzed through a phenome-wide association study (PheWAS). Polygenic risk scores (PRS) for PD were used to diagnose Parkinson's Disease and identify factors associated with PD diagnosis through PheWAS. Two-sample Mendelian randomization (MR) analysis was employed to assess causal relationships. PheWAS results revealed 267 risk factors significantly associated with PD-PRS among the 1851 factors, and of these, 27 factors showed causal evidence from MR analysis. Compelling evidence suggests that fluid intelligence score, age at first sexual intercourse, cereal intake, dried fruit intake, and average total household income before tax have emerged as newly identified risk factors for PD. Conversely, maternal smoking around birth, playing computer games, salt added to food, and time spent watching television have been identified as novel protective factors against PD. The integration of phenotypic and genomic data may help to identify risk factors and prevention targets for PD.

5-ALA-PDT induced ferroptosis in keloid fibroblasts via ROS, accompanied by downregulation of xCT, GPX4.

Keloids display many cancerous properties, including uncontrolled and invasive growth, high rates of recurrence as well as similar bioenergetics. 5-aminolevulinic acid-based photodynamic therapy (5-ALA-PDT) is an effective treatment that performs cytotoxic effects by producing reactive oxygen species (ROS), which is linked to lipid peroxidation and ferroptosis. Herein, we explored underlying mechanisms of 5-ALA-PDT against keloids. We identified that 5-ALA-PDT led to elevated levels of ROS and lipid peroxidation in keloid fibroblasts, accompanied by downregulation of xCT and GPX4, which are associated with anti-oxidation effects and ferroptosis inhibition. These results may indicate that 5-ALA-PDT treatment increases ROS while inhibiting xCT and GPX4, thus promoting lipid peroxidation to induce ferroptosis in keloid fibroblasts.

Dysregulation of peripheral monocytes and pro-inflammation of alpha-synuclein in Parkinson's disease.

BACKGROUND AND OBJECTIVES: Mounting evidence indicates the involvement of the innate immune system in Parkinson's disease (PD). Nevertheless, the implications of peripheral monocytes have not been fully elucidated. Although alpha-synuclein (α-synuclein) has been described as a pathological hallmark of PD, the proinflammatory effect of α-synuclein on monocytes is understudied. This study aimed to comprehensively characterize peripheral monocytes in PD patients and to investigate the proinflammatory magnitude of fibrillar α-synuclein. METHODS: Using flow cytometry, we explored the distribution of monocytic subpopulations. We also investigated the actions of peripheral monocytes in response to lipopolysaccharides (LPS) and to fibrillar α-synuclein stimuli by measuring inflammatory molecule levels in post-culture supernatants. RESULTS: Classical monocytes were enriched, in parallel with lower proportions of intermediate and nonclassical monocytes in patients with PD than in controls. Lower levels of TNF-α and IL-6 were spontaneously produced by unstimulated monocytes in patients with PD. LPS and fibrillar α-synuclein stimuli induced high levels of TNF-α, IL-1ß, IL-6, and sCD163 in the PD and control groups. Strikingly, the fold induction of TNF-α and IL-6 was lower in patients with PD than that in normal controls under the same stimulation. CONCLUSION: Our results revealed a strong dysregulation of peripheral monocytes in PD patients, including subpopulation shifts and impaired response to specific stimuli, and the proinflammatory effect of α-synuclein on monocytes. Further studies are needed to clarify the specific mechanisms by which these immunological abnormalities are present in PD to open the possibility of immunoregulatory therapy.

CHIP ameliorates cerebral ischemia-reperfusion injury by attenuating necroptosis and inflammation.

Blood reperfusion of ischemic cerebral tissue may cause cerebral ischemia-reperfusion (CIR) injury. Necroptosis and inflammation have been demonstrated to be involved in the disease-related process of CIR injury. The E3 ubiquitin ligase carboxyl terminus of Hsp70-interacting protein (CHIP) can modulate multiple cellular signaling processes, including necroptosis and inflammation. Numerous studies have demonstrated the neuroprotective effects of CHIP on multiple central nervous system (CNS) diseases. However, the effects of CHIP on CIR injury have not been fully explored. We hypothesize that CHIP can exert neuroprotective effects by attenuating necroptosis and inflammation during CIR injury. In the present study, adult wild-type (WT) C57BL/6 mice and CHIP knock-in (KI) mice with a C57BL/6 background and CHIP overexpression in neural tissue underwent middle cerebral artery occlusion (MCAO) surgery to simulate CIR onset. Our data indicated that CHIP expression in the peri-infarct tissue was markedly increased after MCAO surgery. Compared with WT mice, CHIP KI mice significantly improved neurological deficit scores, decreased cerebral infarct volume, and attenuated brain edema and neuronal damage. Meanwhile, CHIP overexpression attenuated necroptosis and inflammation induced by MCAO surgery. These findings indicated that overexpression of CHIP might exert neuroprotective effects by attenuating necroptosis and inflammation during CIR injury, and increasing CHIP levels may be a potential strategy in cerebrovascular disease therapy.

CHIP protects against MPP+/MPTP-induced damage by regulating Drp1 in two models of Parkinson's disease.

Mitochondrial dysfunction has been implicated in the pathogenesis of Parkinson's disease (PD). Carboxyl terminus of Hsp70-interacting protein (CHIP) is a key regulator of mitochondrial dynamics, and mutations in CHIP or deficits in its expression have been associated with various neurological diseases. This study explores the protective role of CHIP in cells and murine PD models. In SH-SY5Y cell line, overexpression of CHIP improved the cell viability and increased the ATP levels upon treatment with 1-methyl-4-phenylpyridinium (MPP+). To achieve CHIP overexpression in animal models, we intravenously injected mice with AAV/BBB, a new serotype of adeno-associated virus that features an enhanced capacity to cross the blood-brain barrier. We also generated gene knock-in mice that overexpressed CHIP in neural tissue. Our results demonstrated that CHIP overexpression in mice suppressed 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced damage, including movement impairments, motor coordination, and spontaneous locomotor activity, as well as loss of dopaminergic neurons. In vitro and in vivo experiments showed that overexpression of CHIP inhibited the pathological increase in Drp1 observed in the PD models, suggesting that CHIP regulates Drp1 degradation to attenuate MPP+/MPTP-induced injury. We conclude that CHIP plays a protective role in MPP+/MPTP-induced PD models. Our experiments further revealed that CHIP maintains the integrity of mitochondria.

NOTCH2NLC Intermediate-Length Repeat Expansions Are Associated with Parkinson Disease.

NOTCH2NLC GGC repeat expansions were recently identified in neuronal intranuclear inclusion disease (NIID); however, it remains unclear whether they occur in other neurodegenerative disorders. This study aimed to investigate the role of intermediate-length NOTCH2NLC GGC repeat expansions in Parkinson disease (PD). We screened for GGC repeat expansions in a cohort of 1,011 PD patients and identified 11 patients with intermediate-length repeat expansions ranging from 41 to 52 repeats, with no repeat expansions in 1,134 controls. Skin biopsy revealed phospho-alpha-synuclein deposition, confirming the PD diagnosis in 2 patients harboring intermediate-length repeat expansions instead of NIID or essential tremor. Fibroblasts from PD patients harboring intermediate-length repeat expansions revealed NOTCH2NLC upregulation and autophagic dysfunction. Our results suggest that intermediate-length repeat expansions in NOTCH2NLC are potentially associated with PD. ANN NEUROL 2021;89:182-187.

Identification of a novel PAFAH1B1 missense mutation as a cause of mild lissencephaly with basal ganglia calcification.

PURPOSE: To investigate the genetic and clinical features of a Chinese family exhibiting an autosomal dominant inheritance pattern of lissencephaly. METHODS: Clinical examinations and cranial imaging studies were performed for all members of the family (two unaffected members and three surviving members from a total of four affected members). In addition, whole-exome sequencing analysis was performed for DNA from an affected patient to scan for candidate mutations, followed by Sanger sequencing to verify these candidate mutations in the entire family. A total of 200 ethnicity-matched healthy controls without neuropsychiatric disorder were also included and analyzed. RESULTS: We identified a novel missense mutation, c.412G > A, p.(E138K), that cosegregated with the disease in exon 6 of the platelet activating factor acetylhydrolase 1b regulatory subunit 1 (PAFAH1B1) gene in the affected members; this mutation was not found in the 200 controls. Multiple sequence alignments showed that codon 138, where the mutation (c.G412A) occurred, was located within a phylogenetically conserved region. Brain magnetic resonance imaging revealed calcification within the bilateral globus pallidus in all three affected members. CONCLUSIONS: We identified a novel missense mutation, c.412G > A, p.(E138K),in the PAFAH1B1 gene of a Chinese family with lissencephaly. In addition, our findings suggest that basal ganglia calcification is a novel clinical feature of PAFAH1B1-related lissencephaly.

Anisomycin prevents OGD-induced necroptosis by regulating the E3 ligase CHIP.

Necroptosis is an essential pathophysiological process in cerebral ischemia-related diseases. Therefore, targeting necroptosis may prevent cell death and provide a much-needed therapy. Ansiomycin is an inhibitor of protein synthesis which can also activate c-Jun N-terminal kinases. The present study demonstrated that anisomycin attenuated necroptosis by upregulating CHIP (carboxyl terminus of Hsc70-interacting protein) leading to the reduced levels of receptor-interacting protein kinase 1 (RIPK1) and receptor-interacting protein kinase 3 (RIPK3) proteins in two in vitro models of cerebral ischemia. Further exploration in this research revealed that losing neither the co-chaperone nor the ubiquitin E3 ligase function of CHIP could abolish its ability to reduce necroptosis. Collectively, this study identifies a novel means of preventing necroptosis in two in vitro models of cerebral ischemia injury through activating the expression of CHIP, and it may provide a potential target for the further study of the disease.