The ZEB1 Transcription Factor Is a Novel Repressor of Adiposity in Female Mice

gene located in that region, and as it influences the differentiation of various mesodermal lineages, we hypothesized that ZEB1 might also modulate adiposity. The goal of these studies was to test that hypothesis in mice. mice were heavier than WT controls, which was attributed by Echo MRI to increased fat mass (at three months on an HFD: 0.517±0.081 total fat/lean mass versus 0.313±0.036; at three months on an RCD: 0.175±0.013 versus 0.124±0.012). No differences were observed in food uptake or physical activity, suggesting that the genotypes differ in some aspect of their metabolic activity. ZEB1 expression also increases during adipogenesis in cell culture.These results show for the first time that the ZEB1 transcription factor regulates the accumulation of adipose tissue. Furthermore, they corroborate the genome-wide association studies that mapped an “obesity” gene at chromosome 10p11–12

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

The manner in which calories are restricted impacts mammary tumor cancer prevention

Although treatments for breast cancer have improved and long-term survival after diagnosis is now common, prevention of the disease is the ultimate goal. Weight loss or weight maintenance is one approach that has been recommended to reduce the risk of breast cancer, particularly for peri/postmenopausal women. This approach is supported by decades of data indicating that calorie restriction prevents spontaneous and chemically induced mammary tumor development in rodents. In most cases, calorie restriction was implemented by a consistent daily reduction of calories, i.e. chronic calorie restriction (CCR). There have also been several studies where periods of reduced caloric intake were followed by periods of refeeding, i.e. intermittent calorie restriction (ICR), resulting in the prevention of spontaneous mammary tumorigenesis. In most of the early studies, there were no direct comparisons of CCR to ICR. One study using moderate calorie restriction in a chemically induced breast cancer rat model found a slight increase in mammary tumor incidence compared with ad libitum fed and CCR rats. However, recently, it has been demonstrated in several transgenic mouse models of breast cancer that ICR consistently provided a greater degree of protection than CCR. This review will provide a detailed comparison of ICR and CCR for breast cancer prevention. It will also examine potential mechanisms of action that may include periods of reduced IGF-I and leptin as well as an increase in the adiponectin:leptin ratio. Application of this approach to at-risk women may provide an approach to lower the risk of breast cancer in overweight/obese women

Increased fat accumulation is not the result of increased food consumption or decreased physical activity.

<p>(<b>A</b>) Food intake was measured for 72 hours in 2.5-month-old <i>TCF8+/−</i> and WT mice fed regular chow. n = 10 mice per group. (<b>B</b>) The total distance the mice moved. (<b>C</b>) The estimated velocity at which the mice moved. (<b>D</b>) The duration of each activity or time spent resting. (<b>E</b>) Total duration the mice spent performing any activity. <i>TCF8+/−</i> mice are depicted by black bars and WT controls by gray bars. n =  15–17 mice per group for <b>B–E</b>. No significance differences were found for time spent on any activity, resting, total activity, estimated velocity, or number of times an activity was performed.</p

Female <i>TCF8+/−</i> mice exhibit impaired glucose uptake early in fat acquisition.

<p>Mice were fed a high fat diet (<b>A–C</b>) or regular chow (<b>D, E</b>) until they were 2, 3, or 5 months of age. Blood glucose was measured at the indicated times following injection of glucose at 2 mg/kg (<b>A, B, E</b>), 0.5 mg/kg (<b>C</b>), or 3 mg/kg (<b>D</b>). Area under the curve (AUC) was calculated and graphed as histograms. When Student's <i>t-</i>test was used to analyze the AUC, the <i>TCF8+/−</i> mice were significantly different from WT in their ability to manage blood glucose levels as indicated by the asterisks. ANCOVA was performed for <b>A</b> and <b>B</b> with body fat as a co-variate for the differences in glucose tolerance between genotype to assess whether genotype contributed independently of fat mass. For <b>A</b>: genotype p = 0.006, body fat p = not significant, for <b>B</b>: genotype: p =  not significant, body fat p =  not significant. <i>TCF8 +/−</i> (black line) or WT (gray line), n = 5–8 mice per group.</p

ZEB1 mRNA expression increases concomitantly with weight in WT female mice.

<p>Mice were fed regular chow <i>ad libitum</i> or a diet restricted to 75% of the calories of the <i>ad libitum</i> group (calorie restricted). (<b>A</b>) Body weights (g) were recorded as indicated for mice that were fed <i>ad libitum</i> (gray line) or calorie restricted (black line). n = 3–7 mice/group. (<b>B</b>) Corresponding ZEB1 mRNA expression in parametrial fat was determined by quantitative SYBR real time PCR. ZEB1 mRNA was expressed relative to β-actin mRNA, <i>ad libitum</i> (gray bars), calorie restricted (black bars). n = 3–7 mice/group (<b>C</b>) Western blot confirming that ZEB1 protein expression increases in response to increased body weight in mice fed <i>ad libitum</i>. GAPDH was used as a loading control. Individual lanes are labeled as months of age.</p

Female mice missing one <i>TCF8</i> allele gain weight more readily.

<p>Mice were weaned to (<b>A</b>) a diet high in fat (60%) or (<b>B</b>) regular chow diet, and body weights (g) of female <i>TCF8 +/−</i> (black line) or WT (gray line) mice were recorded weekly as indicated. n = 8–34 mice per group, with the number of mice decreasing due to sacrifices at 2 and 3 months. (<b>A</b>) Significance calculated by Student's <i>t</i>-test between age-matched groups, using the Bonferroni post-test correction set at p<0.005. (<b>B</b>) Significance calculated by Student <i>t</i>-test between age-matched groups. All mice from 12–18 weeks have p<0.05. However, when corrected for Bonferroni's post-test at p = 0.003 only those from 14–16 weeks are significant. Significance is denoted by *. (<b>C</b>) An example of the genotyping that was done to identify <i>TCF8+/−</i> and WT mice. The band at ∼500 bp is from the β-galactosidase gene, which was inserted in one of the <i>TCF8</i> alleles. The band at ∼200 bp represents <i>TCF8</i>. (<b>D</b>) ZEB1 protein levels in parametrial adipose tissue of WT (n = 3) and <i>TCF8+/−</i> (n = 4) female mice at 3 months of age. GAPDH was used as a loading control.</p