Reactivation of heat-inactivated Ku proteins by heat shock cognate protein HSC73

Purpose: Mouse double-stranded DNA-dependent protein kinase (DNA-PK) activity is heat sensitive. Recovery of heat-inactivated DNA repair activity is a problem after combination therapy with radiation and heat. We investigated the mechanism of recovery of heat-inactivated DNA-PK activity.

Methods: Hybrid cells containing a fragment of human chromosome 8 in scid cells (RD13B2) were used. DNA-PK activity was measured by an in vitro assay. Immunoprecipitation of the nuclear extract was performed with an anti-Ku80 antibody. Proteins co-precipitated with Ku80 were separated by sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis and detected by Western blotting using anti-heat shock protein (HSP)72 and anti-heat shock cognate protein (HSC)73 antibodies. HSC73 was overexpressed with the pcDNA3.1 vector. Short hairpin (sh)RNA was used to downregulate HSC73 and HSP72.

Results: The activity of heat-inactivated DNA-PK recovered to about 50% of control during an additional incubation at 37?°C after heat treatment at 44?°C for 15?min in the presence of cycloheximide (which inhibits de novo protein synthesis). Maximal recovery was observed within 3?h of incubation at 37?°C after heat treatment. Constitutively expressed HSC73, which folds newly synthesized proteins, reached maximal levels 3?h after heat treatment using a co-immunoprecipitation assay with the Ku80 protein. Inhibiting HSC73, but not HSP72, expression with shRNA decreased the recovery of DNA-PK activity after heat treatment.

Conclusions: These results suggest that de novo protein synthesis is unnecessary for recovery of some heat-inactivated DNA-PK. Rather, it might be reactivated by the molecular chaperone activity of HSC73, but not HSP72.     

Touring Arkansas: A Statewide Project to Instruct Nurses and Patient Educators on Consumer Health Resources

Abstract

This article follows up a pilot project to help educate local nurses and patient educators on freely available consumer health resources. The Outreach Coordinator and Clinical Librarian at an academic medical center created a one-hour in-person and online class with continuing education credit and an online guide. Nurses frequently act as patient educators at the bedside and are therefore an important target for consumer health education. While nurses in an urban setting may have more access to educational opportunities, these opportunities are needed even more in rural settings. Librarians can obtain funding to travel and teach classes at rural community hospitals.     

No Influence of the Fat Mass and Obesity-Associated Gene rs9939609 Single Nucleotide Polymorphism on Blood Lipids in Young Males

The fat mass and obesity-associated gene (FTO) rs9939609 A-allele is linked to obesity and dyslipidemia, yet the independent influence of this polymorphism on blood lipids remains equivocal. We examined the influence of the FTO rs9939609 polymorphism on fasting and postprandial blood lipids in individuals homozygous for the risk A-allele or T-allele with similar anthropometric and demographic characteristics. 12 AA and 12 TT males consumed a standardized meal after fasting overnight. Blood samples were collected at baseline (−1.5 h), before the meal (0 h), and for five hours postprandially to measure lipid, glucose, and insulin concentrations. Time-averaged total area under the curve (TAUC) values (0–5 h) were calculated and compared between genotypes. Fasting triacylglycerol (TG), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, total cholesterol, non-esterified fatty acid (NEFA), glucose, and insulin concentrations were similar between groups (p ≥ 0.293). TAUC for TG was similar in AAs and TTs (95% confidence interval (CI) −0.52 to 0.31 mmol/L/h; p = 0.606). Likewise, TAUC values were similar for NEFA (95% CI −0.04 to 0.03 mmol/L/h; p = 0.734), glucose (95% CI −0.41 to 0.44 mmol/L/h; p = 0.951), and insulin (95% CI −6.87 to 2.83 pmol/L/h; p = 0.395). Blood lipids are not influenced by the FTO rs9939609 polymorphism, suggesting the FTO-dyslipidemia link is mediated by adiposity and weight management is important in preventing FTO-related lipid variations.     

beta2- and beta3-Adrenoceptor polymorphisms relate to subsequent weight gain and blood pressure elevation in obese normotensive individuals.

High blood pressure (BP) is a major determinant of cardiovascular events in obesity. The beta2- and beta3-adrenoceptor polymorphisms are associated with obesity and hypertension. In the present study, we examine the relationships of beta2- and beta3-adrenoceptor polymorphisms with further weight gain-induced BP elevation in obese subjects. Changes in BP, body weight, total body fat-mass, waist-to-hip ratio, plasma norepinephrine (NE) and leptin levels, and beta2(Arg16Gly)- and beta3(Trp64Arg)-adrenoceptor polymorphisms were measured periodically over a 5-year period in 55 entry obese (body mass index [BMI]> or =25.0 kg/m(2)) normotensive (BP<140/90 mmHg) men. BP elevation and weight gain were defined as > or =10% increases from entry levels over 5 years in mean BP or BMI. Obese subjects with weight gain, BP elevation or weight gain-induced BP elevation had higher frequencies of the Gly16 allele of Arg16GIy and Arg64 allele of Trp64Arg. Subjects carrying the Gly16 or Arg64 alleles had significantly greater total fat-mass and waist-to-hip ratio at entry and over a 5-year period compared to the subjects who did not carry these polymorphisms. Subjects carrying the Gly16 allele had similar levels of plasma NE, higher levels of plasma leptin and a lower slope of the regression lines between plasma leptin and NE levels. Those carrying the Arg64 allele had higher plasma NE levels at entry and over a 5-year period compared to the subjects without the Arg64 allele, but plasma leptin levels and slopes were similar. The findings demonstrate that the Arg64 allele of the beta3-adrenoceptor polymorphisms relates to weight gain-induced BP elevation accompanying high plasma NE (heightened sympathetic activity) in obese men. The Gly16 allele of the beta2-adrenoceptor polymorphisms links to weight gain-induced BP elevation associated with leptin resistance. beta2- and beta3-adrenoceptor polymorphisms could predict the future BP elevation and further weight gain-induced BP elevation in originally obese subjects.     

Velopharyngeal function during vocalization in infants.

OBJECTIVE: To determine the age at which infants achieve velopharyngeal closure during vocalization. DESIGN: Longitudinal with repeated measures. SETTING: Laboratory. PARTICIPANTS: Six healthy infants were studied monthly from ages 2 to 6 months while they interacted with a parent and an investigator. MAIN OUTCOME MEASURES: The presence or absence of velopharyngeal closure, as determined by sensing ram pressure at the anterior nares. RESULTS: The velopharynx was open for windups, whimpers, and laughs, and it was closed for cries, screams, and raspberries, regardless of age. The frequency with which the velopharynx closed during syllable utterances increased significantly with age. CONCLUSIONS: Velopharyngeal closure for speech-like utterance increases with age, but is not complete and is still undergoing development at 6 months of age. Velopharyngeal closure during infancy may be influenced by pressure demands of the utterance; however, support for this speculation is stronger for other types of utterances than it is for speech-like utterances. The method used in this study holds promise for evaluating infants with suspected velopharyngeal impairment.     

Americans' Awareness, Knowledge, and Behaviors Regarding Fats: 2006-2007

In recent years, epidemiologic and clinical studies, public and regulatory policy activity, and media coverage have focused on issues related to trans fats. To help increase awareness and understanding of trans fats and other fats, the American Heart Association (AHA) launched the “Face the Fats” national consumer education campaign in April 2007. The AHA commissioned a quantitative tracking survey between 2006 and 2007 to measure changes in consumer awareness, knowledge, and behaviors related fats and oils and their perceived impact on heart disease. The survey was conducted by Cogent Research. Data were collected during March 2006 and May 2007. At both time points, the survey included a representative sample of the American population age 18 to 65 years (n=1,000). The sampling plan for the survey was designed based on the 2000 and 2003 US Census. The margin of error was ±3.10 percentage points. Awareness of trans fats increased during the 1-year study period. In 2007, 92% of respondents were aware of trans fats, an increase from 84% in 2006 (P<0.05). The 2007 level was similar to the awareness of saturated fats (93%). Perceptions that certain fats and oils heighten the risk of heart disease increased for trans fats (73% in 2007 vs 63% in 2006; P<0.05), saturated fats (77% in 2007 vs 73% in 2006; P<0.05), and partially hydrogenated oils (56% in 2007 vs 49% in 2006; P<0.05). Knowledge about food sources of different fats remained low. On an unaided basis, 21% could name three food sources of trans fats in 2007, up from 17% in 2006 (P<0.05). Knowledge of food sources of saturated fat remained unchanged at 30% in 2007. Significantly more respondents in 2007 reported behavioral changes related to trans fat information, such as buying food products because they show “zero trans fat” on labels or packages (37% in 2007 vs. 32% in 2006; P<0.05). Between 2006 and 2007, consumer awareness about trans fats increased and attained awareness levels similar to saturated fats. The increased awareness is associated with improved self-reported behaviors in grocery shopping. Nonetheless, overall knowledge, especially regarding food sources of saturated and trans fats, remains relatively low, underscoring the need for heightened consumer education activities. The positive change in consumer awareness about trans fats is likely attributable to the wide range of messages available to them, including the AHA “Face the Fats” national consumer education campaign.