The Alzheimer's disease risk factor INPP5D restricts neuroprotective microglial responses in amyloid beta-mediated pathology.

INTRODUCTION: Mutations in INPP5D, which encodes for the SH2-domain-containing inositol phosphatase SHIP-1, have recently been linked to an increased risk of developing late-onset Alzheimer's disease. While INPP5D expression is almost exclusively restricted to microglia in the brain, little is known regarding how SHIP-1 affects neurobiology or neurodegenerative disease pathogenesis. METHODS: We generated and investigated 5xFAD Inpp5dfl/fl Cx3cr1Ert2Cre mice to ascertain the function of microglial SHIP-1 signaling in response to amyloid beta (Aß)-mediated pathology. RESULTS: SHIP-1 deletion in microglia led to substantially enhanced recruitment of microglia to Aß plaques, altered microglial gene expression, and marked improvements in neuronal health. Further, SHIP-1 loss enhanced microglial plaque containment and Aß engulfment when compared to microglia from Cre-negative 5xFAD Inpp5dfl/fl littermate controls. DISCUSSION: These results define SHIP-1 as a pivotal regulator of microglial responses during Aß-driven neurological disease and suggest that targeting SHIP-1 may offer a promising strategy to treat Alzheimer's disease. HIGHLIGHTS: Inpp5d deficiency in microglia increases plaque-associated microglia numbers. Loss of Inpp5d induces activation and phagocytosis transcriptional pathways. Plaque encapsulation and engulfment by microglia are enhanced with Inpp5d deletion. Genetic ablation of Inpp5d protects against plaque-induced neuronal dystrophy.

Investigating neuroepigenetic alterations in chronic low back pain with positron emission tomography.

ABSTRACT: Epigenetics has gained considerable interest as potential mediators of molecular alterations that could underlie the prolonged sensitization of nociceptors, neurons, and glia in response to various environmental stimuli. Histone acetylation and deacetylation, key processes in modulating chromatin, influence gene expression; elevated histone acetylation enhances transcriptional activity, whereas decreased acetylation leads to DNA condensation and gene repression. Altered levels of histone deacetylase (HDAC) have been detected in various animal pain models, and HDAC inhibitors have demonstrated analgesic effects in these models, indicating HDACs' involvement in chronic pain pathways. However, animal studies have predominantly examined epigenetic modulation within the spinal cord after pain induction, which may not fully reflect the complexity of chronic pain in humans. Moreover, methodological limitations have previously impeded an in-depth study of epigenetic changes in the human brain. In this study, we employed [11C]Martinostat, an HDAC-selective radiotracer, positron emission tomography to assess HDAC availability in the brains of 23 patients with chronic low back pain (cLBP) and 11 age-matched and sex-matched controls. Our data revealed a significant reduction of [11C]Martinostat binding in several brain regions associated with pain processing in patients with cLBP relative to controls, highlighting the promising potential of targeting HDAC modulation as a therapeutic strategy for cLBP.

Health and lifestyle behaviors in colorectal cancer survivors with and without Lynch syndrome.

Lynch syndrome (LS), a hereditary cancer syndrome, accounts for approximately 3% of colorectal cancers (CRC). Positive health behaviors and surveillance are preventive strategies, but research on whether recommended behavioral guidelines are followed by individuals with LS is limited. Additional health education and promotion could be beneficial to the improved survivorship of CRC survivors. Explore health and lifestyle behaviors in CRC survivors with and without LS. We conducted a case-control study of CRC survivors with and without LS using a mailed questionnaire. Recruitment was conducted via patient registries at The University of Texas MD Anderson Cancer Center (cases n = 33; controls n = 75) and through social media (cases n = 42). CRC survivors with and without LS in our study had substantially lower smoking prevalence (5.5% and 2.7%) compared to national prevalence (18.0%). However, they had higher levels of alcohol consumption (36.8% and 10.3% for male and female LS survivors, respectively, and 35.8% and 22.0% for male and female sporadic survivors, respectively) compared to national prevalence of 13.88% for males and 6.02% for females. Both groups of CRC survivors participate in negative health behaviors that impact survivorship. More research is needed to examine the relationship between personal engagement in preventive behaviors and patient-provider relationships to improve health behaviors and explore strategies for intervention. Additionally, better health education and lifestyle change recommendations would promote and reinforce positive health outcomes in the CRC population and especially in LS survivors.