Striatal spatial heterogeneity, clustering, and white matter association of GFAP+ astrocytes in a mouse model of Huntington's disease.

Introduction: Huntington's disease (HD) is a neurodegenerative disease that primarily affects the striatum, a brain region that controls movement and some forms of cognition. Neuronal dysfunction and loss in HD is accompanied by increased astrocyte density and astrocyte pathology. Astrocytes are a heterogeneous population classified into multiple subtypes depending on the expression of different gene markers. Studying whether mutant Huntingtin (HTT) alters specific subtypes of astrocytes is necessary to understand their relative contribution to HD. Methods: Here, we studied whether astrocytes expressing two different markers; glial fibrillary acidic protein (GFAP), associated with astrocyte activation, and S100 calcium-binding protein B (S100B), a marker of matured astrocytes and inflammation, were differentially altered in HD. Results: First, we found three distinct populations in the striatum of WT and symptomatic zQ175 mice: GFAP+, S100B+, and dual GFAP+S100B+. The number of GFAP+ and S100B+ astrocytes throughout the striatum was increased in HD mice compared to WT, coinciding with an increase in HTT aggregation. Overlap between GFAP and S100B staining was expected, but dual GFAP+S100B+ astrocytes only accounted for less than 10% of all tested astrocytes and the number of GFAP+S100B+ astrocytes did not differ between WT and HD, suggesting that GFAP+ astrocytes and S100B+ astrocytes are distinct types of astrocytes. Interestingly, a spatial characterization of these astrocyte subtypes in HD mice showed that while S100B+ were homogeneously distributed throughout the striatum, GFAP+ preferentially accumulated in "patches" in the dorsomedial (dm) striatum, a region associated with goal-directed behaviors. In addition, GFAP+ astrocytes in the dm striatum of zQ175 mice showed increased clustering and association with white matter fascicles and were preferentially located in areas with low HTT aggregate load. Discussion: In summary, we showed that GFAP+ and S100B+ astrocyte subtypes are distinctly affected in HD and exist in distinct spatial arrangements that may offer new insights to the function of these specific astrocytes subtypes and their potential implications in HD pathology.

Tumor suppressor p53 regulates heat shock factor 1 protein degradation in Huntington's disease.

p53 and HSF1 are two major transcription factors involved in cell proliferation and apoptosis, whose dysregulation contributes to cancer and neurodegeneration. Contrary to most cancers, p53 is increased in Huntington's disease (HD) and other neurodegenerative diseases, while HSF1 is decreased. p53 and HSF1 reciprocal regulation has been shown in different contexts, but their connection in neurodegeneration remains understudied. Using cellular and animal models of HD, we show that mutant HTT stabilized p53 by abrogating the interaction between p53 and E3 ligase MDM2. Stabilized p53 promotes protein kinase CK2 alpha prime and E3 ligase FBXW7 transcription, both of which are responsible for HSF1 degradation. Consequently, p53 deletion in striatal neurons of zQ175 HD mice restores HSF1 abundance and decrease HTT aggregation and striatal pathology. Our work shows the mechanism connecting p53 stabilization with HSF1 degradation and pathophysiology in HD and sheds light on the broader molecular differences and commonalities between cancer and neurodegeneration.

Multimodal perioperative pain protocol for gynecologic laparotomy is associated with reduced hospital length of stay.

OBJECTIVES: The primary objective was to evaluate the impact of a multimodal perioperative pain regimen on length of hospital stay for patients undergoing laparotomy with a gynecologic oncologist. METHODS: We compared 52 patients who underwent laparotomy with a gynecologic oncologist at a single institution between 2017 and 2018, after implementation of a multimodal perioperative pain regimen, to a historic cohort of 94 patients (2016-2017). The multimodal pain regimen included pre- and post-operative administration of oral acetaminophen, gabapentin, and celecoxib, in addition to standard narcotics and optional epidural analgesia. Demographic, surgical, and post-operative data were collected. RESULTS: On multivariable analysis, bowel resection, stage, surgery length, age, and cohort group were retained as significant independent predictors of length of stay. Patients undergoing laparotomy prior to the pain protocol had a length of stay 1.26 times longer than patients during the post-implementation period (p < 0.01). For complex surgical patients, this translated into a reduction in length of hospital stay of 1.73 days. There was a significant reduction in pain scale score on post-operative day zero from 5 to 3 (p = 0.02) and a non-significant overall reduction of post-operative morphine equivalents, with similar adverse outcomes. CONCLUSION: Implementation of a multimodal perioperative pain regimen in patients undergoing gynecologic oncology laparotomy was associated with a significant reduction of length of hospital stay and improved patient-perceived pain, even in the absence of a complete Enhanced Recovery After Surgery (ERAS) protocol.