ASPM and CITK regulate spindle orientation by affecting the dynamics of astral microtubules.

Correct orientation of cell division is considered an important factor for the achievement of normal brain size, as mutations in genes that affect this process are among the leading causes of microcephaly. Abnormal spindle orientation is associated with reduction of the neuronal progenitor symmetric divisions, premature cell cycle exit, and reduced neurogenesis. This mechanism has been involved in microcephaly resulting from mutation of ASPM, the most frequently affected gene in autosomal recessive human primary microcephaly (MCPH), but it is presently unknown how ASPM regulates spindle orientation. In this report, we show that ASPM may control spindle positioning by interacting with citron kinase (CITK), a protein whose loss is also responsible for severe microcephaly in mammals. We show that the absence of CITK leads to abnormal spindle orientation in mammals and insects. In mouse cortical development, this phenotype correlates with increased production of basal progenitors. ASPM is required to recruit CITK at the spindle, and CITK overexpression rescues ASPM phenotype. ASPM and CITK affect the organization of astral microtubules (MT), and low doses of MT-stabilizing drug revert the spindle orientation phenotype produced by their knockdown. Finally, CITK regulates both astral-MT nucleation and stability. Our results provide a functional link between two established microcephaly proteins

ISSAID/EMQN Best Practice Guidelines for the Genetic Diagnosis of Monogenic Autoinflammatory Diseases in the Next-Generation Sequencing Era

Abstract Background Monogenic autoinflammatory diseases are caused by pathogenic variants in genes that regulate innate immune responses, and are characterized by sterile systemic inflammatory episodes. Since symptoms can overlap within this rapidly expanding disease category, accurate genetic diagnosis is of the utmost importance to initiate early inflammation-targeted treatment and prevent clinically significant or life-threatening complications. Initial recommendations for the genetic diagnosis of autoinflammatory diseases were limited to a gene-by-gene diagnosis strategy based on the Sanger method, and restricted to the 4 prototypic recurrent fevers (MEFV, MVK, TNFRSF1A, and NLRP3 genes). The development of best practices guidelines integrating critical recent discoveries has become essential. Methods The preparatory steps included 2 online surveys and pathogenicity annotation of newly recommended genes. The current guidelines were drafted by European Molecular Genetics Quality Network members, then discussed by a panel of experts of the International Society for Systemic Autoinflammatory Diseases during a consensus meeting. Results In these guidelines, we combine the diagnostic strength of next-generation sequencing and recommendations to 4 more recently identified genes (ADA2, NOD2, PSTPIP1, and TNFAIP3), nonclassical pathogenic genetic alterations, and atypical phenotypes. We present a referral-based decision tree for test scope and method (Sanger versus next-generation sequencing) and recommend on complementary explorations for mosaicism, copy-number variants, and gene dose. A genotype table based on the 5-category variant pathogenicity classification provides the clinical significance of prototypic genotypes per gene and disease. Conclusions These guidelines will orient and assist geneticists and health practitioners in providing up-to-date and appropriate diagnosis to their patients

IL-6 Mediated Degeneration of Forebrain GABAergic Interneurons and Cognitive Impairment in Aged Mice through Activation of Neuronal NADPH Oxidase

BACKGROUND:Multiple studies have shown that plasma levels of the pro-inflammatory cytokine interleukin-6 (IL-6) are elevated in patients with important and prevalent adverse health conditions, including atherosclerosis, diabetes, obesity, obstructive sleep apnea, hypertension, and frailty. Higher plasma levels of IL-6, in turn, increase the risk of many conditions associated with aging including age-related cognitive decline. However, the mechanisms underlying this association between IL-6 and cognitive vulnerability remain unclear. METHODS AND FINDINGS:We investigated the role of IL-6 in brain aging in young (4 mo) and aged (24 mo) wild-type C57BL6 and genetically-matched IL-6(-/-) mice, and determined that IL-6 was necessary and sufficient for increased neuronal expression of the superoxide-producing immune enzyme, NADPH-oxidase, and this was mediated by non-canonical NFkappaB signaling. Furthermore, superoxide production by NADPH-oxidase was directly responsible for age-related loss of parvalbumin (PV)-expressing GABAergic interneurons, neurons essential for normal information processing, encoding, and retrieval in hippocampus and cortex. Targeted deletion of IL-6 or elimination of superoxide by chronic treatment with a superoxide-dismutase mimetic prevented age-related loss of PV-interneurons and reversed age-related cognitive deficits on three standard tests of spatial learning and recall. CONCLUSIONS:Present results indicate that IL-6 mediates age-related loss of critical PV-expressing GABAergic interneurons through increased neuronal NADPH-oxidase-derived superoxide production, and that rescue of these interneurons preserves cognitive performance in aging mice, suggesting that elevated peripheral IL-6 levels may be directly and mechanistically linked to long-lasting cognitive deficits in even normal older individuals. Further, because PV-interneurons are also selectively affected by commonly used anesthetic agents and drugs, our findings imply that IL-6 levels may predict adverse CNS effects in older patients exposed to these compounds through specific derangements in inhibitory interneurons, and that therapies directed at lowering IL-6 may have cognitive benefits clinically

Older Ethnic Minority Women's Perceptions of Stroke Prevention and Walking

OBJECTIVE: To inform development of a tailored behavioral stroke risk reduction intervention for ethnic minority seniors, we sought to explore gender differences in perceptions of stroke prevention and physical activity (walking). METHODS: In collaboration with community-based organizations, we conducted 12 mixed-gender focus groups of African-American, Latino, Chinese, and Korean seniors aged 60 years and older with a history of hypertension (women=89, men=42). Transcripts were coded and recurring topics compared by gender. RESULTS: Women expressed beliefs that differed from men in 4 topic areas: 1) stroke-related interest; 2) barriers to walking; 3) facilitators to walking; and 4) health behavior change attitudes. Compared to men, women were more interested in their role in response to a stroke and poststroke care. Women described walking as an acceptable form of exercise, but cited neighborhood safety and pain as walking barriers. Fear of nursing home placement and weight loss were identified as walking facilitators. Women were more prone than men to express active/control attitudes towards health behavior change. CONCLUSIONS: Older ethnic minority women, a high risk population for stroke, may be more receptive to behavioral interventions that address the gender-specific themes identified by this study

Let’s walk! Age reattribution and physical activity among older Hispanic/Latino adults: results from the ¡Caminemos! Randomized trial

Abstract Background Many older Hispanics/Latinos are physically inactive and suffer the harmful health consequences associated with prolonged periods of inactivity. Negative age attributions that equate getting older with “slowing down” reinforce this inactive behavior. We implemented a community-based exercise intervention among insufficiently active older Hispanics/Latinos with a randomized trial of an attribution-retraining program, ¡Caminemos! (Let’s Walk!), and measured the effect of the program on walking behavior. Methods Five hundred and seventy-two older Hispanics/Latinos (≥60 years) were enrolled in an exercise program that randomly assigned participants to the exercise class and one of two conditions: (a) treatment (attribution retraining to dispel the notion that physical activity inevitably ceases with age) or (b) control (generic health education). Data were collected at baseline and follow-up (1, 12, and 24 months). Physical activity was determined through pedometer data and the Yale Physical Activity Survey. We also measured the intervention effects on age-expectations, self-efficacy expectations, and outcome expectations for physical activity. Mixed-effects regression models were used to determine intervention effects on prospective measures of physical activity and intrapersonal expectations. Results The sample had a mean age of 73 years (SD = 6.8) and was 77% female, and 76% of the sample reported income <$20,000. At baseline, control and treatment groups walked about 3000 steps/day. By 24 months, participants in both arms of the intervention maintained greater than 10,000 mean steps/day, but the difference between the groups was not statistically significant. In analyses adjusted for age, sex, education, income, health status, and acculturation, participants in both trial arms increased their mean numbers of steps at 12 and 24 months, with the treatment group showing a greater number of mean steps compared to the controls at 12 months. Conclusions In this group of physically inactive older Hispanics/Latinos, attribution retraining in combination with an exercise class was superior to the exercise class alone with regard to increasing walking behavior. This success was sustained at 12 months (the pre-defined primary study outcome) but not at 24 months. For older Hispanics/Latinos, enrollment in an attribution-retraining exercise program can improve an inactive lifestyle. Trial registration clinicaltrials.gov identifier: NCT00183014

Physical Activity, Physical Performance, and Biological Markers of Health among Sedentary Older Latinos.

Background. Physical activity is associated with better physical health, possibly by changing biological markers of health such as waist circumference and inflammation, but these relationships are unclear and even less understood among older Latinos-a group with high rates of sedentary lifestyle. Methods. Participants were 120 sedentary older Latino adults from senior centers. Community-partnered research methods were used to recruit participants. Inflammatory (C-reactive protein) and metabolic markers of health (waist circumference, HDL-cholesterol, triglycerides, insulin, and glucose), physical activity (Yale physical activity survey), and physical performance (short physical performance NIA battery) were measured at baseline and 6-month followup. Results. Eighty percent of the sample was female. In final adjusted cross-sectional models, better physical activity indices were associated with faster gait speed (P &lt; 0.05). In adjusted longitudinal analyses, change in self-reported physical activity level correlated inversely with change in CRP (β = -0.05; P = 0.03) and change in waist circumference (β = -0.16; P = 0.02). Biological markers of health did not mediate the relationship between physical activity and physical performance. Conclusion. In this community-partnered study, higher physical activity was associated with better physical performance in cross-sectional analyses. In longitudinal analysis, increased physical activity was associated with improvements in some metabolic and inflammatory markers of health