Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

COVID-19 pandemic impacts on mental health, burnout, and longevity in the workplace among healthcare workers: A mixed methods study

To explore the mental health impacts of the COVID-19 pandemic on healthcare workers in Massachusetts and identify potential strategies to maintain the healthcare workforce we conducted a sequential exploratory mixed methods study. Fifty-two individuals completed interviews from April 22nd - September 7th, 2021; 209 individuals completed an online survey from February 17th - March 23rd, 2022. Interviews and surveys asked about the mental health impacts of working in healthcare during the COVID-19 pandemic, burnout, longevity in the workplace, and strategies for reducing attrition. Interview and survey participants were predominantly White (56%; 73%, respectively), female (79%; 81%) and worked as physicians (37%; 34%). Interviewees indicated high stress and anxiety levels due to frequent exposure to patient deaths from COVID-19. Among survey respondents, 55% reported worse mental health than before the pandemic, 29% reported a new/worsening mental health condition for themselves or their family, 59% reported feeling burned out at least weekly, and 37% intended to leave healthcare in less than 5 years. To decrease attrition, respondents suggested higher salaries (91%), flexible schedules (90%), and increased support to care for patients (89%). Healthcare workers' experiences with death, feeling unvalued, and overworked resulted in unprecedented rates of burnout and intention to leave healthcare.

Healthcare workers' perspectives on the COVID-19 vaccine and boosters for themselves, their patients, and their communities: a mixed methods study

Aim

To examine experiences and attitudes of a diverse sample of clinical and non-clinical healthcare workers regarding COVID-19 vaccines and boosters for themselves, their patients, and their communities.

Subject and methods

We conducted a sequential exploratory mixed methods study; 52 healthcare workers participated in qualitative interviews between April 22 and September 7, 2021, and 209 healthcare workers completed surveys between February 17 and March 23, 2022. Interviews and survey questions asked about personal attitudes toward COVID-19 vaccination and boosters and experiences discussing vaccination with patients.

Results

Participants were predominantly White (56% and 73%, respectively) and female (79% and 81%, respectively). Factors motivating healthcare workers to take the vaccine were the belief that vaccination would protect themselves, their families, patients, and communities. Healthcare workers were accepting of and had high receipt of the booster, though some had diminished belief in its effectiveness after becoming infected with SARS-CoV-2 after initial vaccination. Race related mistrust, misinformation related to vaccine safety, and concerns about vaccine effects during pregnancy were the most common barriers that providers encountered among their patients and communities.

Conclusions

Healthcare workers' primary motivation to receive COVID-19 vaccines was the desire to protect themselves and others. Healthcare workers' perception was that concerns about safety and misinformation were more important barriers for their patients than themselves. Race-related medical mistrust amplified concerns about vaccine safety and hindered communication efforts.

Healthcare workers' attitudes on mandates, incentives, and strategies to improve COVID-19 vaccine uptake: A mixed methods study

Healthcare workers are a trusted health information source and are uniquely positioned to reduce the burden of the COVID-19 pandemic. The purpose of this sequential exploratory mixed methods study was to understand attitudes of healthcare workers working in Massachusetts during the COVID-19 pandemic regarding strategies to improve COVID-19 vaccine utilization, including vaccine mandates and incentives. Fifty-two individuals completed one-on-one interviews between April 22^nd and September 7th, 2021. The survey was developed based on findings from the interviews; 209 individuals completed the online survey between February 17^th and March 23^rd, 2022. Both the interview and survey asked about attitudes toward COVID-19 vaccine and booster mandates, incentives, and strategies to improve vaccination rates. Most participants were female (79%-interview, 81%-survey), Caucasian (56%, 73%), and worked as physicians (37%, 34%) or nurses (10%, 18%). Overall, nuanced attitudes regarding vaccine and booster mandates were expressed; many supported mandates to protect their patients' health, others emphasized personal autonomy, while some were against mandates if job termination was the consequence of declining vaccines. Similarly, views regarding vaccine incentives differed; some considered incentives helpful, yet many viewed them as coercive. Strategies believed to be most effective to encourage vaccination included improving accessibility to vaccination sites, addressing misinformation, discussing vaccine safety, tailored community outreach via trusted messengers, and one-on-one conversations between patients and healthcare workers. Healthcare workers' experiences with strategies to improve utilization of COVID-19 vaccines and boosters have implications for public health policies. Generally, efforts to improve access and education were viewed more favorably than incentives and mandates.

Experiencing discrimination mediates the relationship between victimization and social withdrawal in patients suffering from a severe mental illness: A cross-sectional study

Psychiatric patients are often victims of crime and discrimination and are often socially withdrawn. This has negative consequences for their health and recovery. We examined whether such discrimination mediates the association between victimization and social withdrawal, and whether these associations differ between men and women. We also determined the prevalence of social withdrawal and the discrimination experienced by patients suffering from a severe mental illness. This study is embedded in the Victimization in Psychiatric Patients study. Information on discrimination, social withdrawal and victimization was obtained using structured self-report questionnaires (N = 949). We reported the 12-month prevalence of these phenomena and used path analysis to estimate the direct path between personal and property victimization and social withdrawal, and the indirect path through the discrimination experienced. The impact of gender was assessed by testing interaction terms. Social withdrawal was reported by 20.6% (95%CI 18.1-23.2) of participants, and being discriminated against in the past 12 months by 75.3% (95%CI: 72.6-78.0%). While crime victimization had no direct effects on social withdrawal, personal crime victimization (B = 0.47; 95%CI 0.25-0.72; p < 0.001) and property crime victimization (B = 0.65; 95%CI 0.42-0.93; p < 0.001) had significant indirect effects on social withdrawal, which were mediated by the discrimination experienced. In men we found a direct negative effect of property crime on social withdrawal (B = -0.68; 95%CI: -1.21to -0.11, p = 0.014). We conclude that personal and property victimization, for both men and women, was associated with higher levels of social withdrawal, and this was fully mediated by the discrimination experienced.

Grandiose and vulnerable narcissism, identity integration and self-control related to criminal behavior

BACKGROUND

Although systematic research on narcissism has been conducted for over 100 years, researchers have only recently started to distinguish between grandiose and vulnerable narcissism in relation to criminal behavior. In addition, there is some evidence suggesting that identity integration and self-control may underlie this association. Therefore, the present study aimed to develop a theory-driven hypothetical model that investigates the complex associations between grandiose and vulnerable narcissism, identity integration, self-control, and criminal behavior using structural equation modeling (SEM).

METHODS

The total sample (N = 222) included 65 (29.3%) individuals convicted of criminal behavior and 157 (70.7%) participants from the community, with a mean age of 37.71 years (SD = 13.25). Criminal behavior was a grouping variable used as a categorical outcome, whereas self-report questionnaires were used to assess grandiose and vulnerable narcissism, self-control, and identity integration.

RESULTS

The overall SEM model yielded good fit indices. Grandiose narcissism negatively predicted criminal behavior above and beyond the influence of identity integration and self-control. In contrast, vulnerable narcissism did not have a direct significant effect on criminal behavior, but it was indirectly and positively associated with criminal behavior via identity integration and self-control. Moreover, grandiose narcissism was positively, whereas vulnerable narcissism was negatively associated with identity integration. However, identity integration did not have a direct significant effect on criminal behavior, but it was indirectly and negatively associated with criminal behavior via self-control. Finally, self-control was, in turn, negatively related to criminal behavior.

CONCLUSIONS

We propose that both subtypes of narcissism should be carefully considered in clinical assessment and current intervention practices.

Acylated Ghrelin and The Regulation of Lipid Metabolism in The Intestine

Acylated ghrelin (AG) is a gastrointestinal (GI) peptide mainly secreted by the stomach that promotes cytosolic lipid droplets (CLD) hypertrophy in adipose tissues and liver. However, the role of AG in the regulation of lipid metabolism in the intestine remains unexplored. This study aimed at determining whether AG influences CLD production and chylomicron (CM) secretion in the intestine. The effects of AG and oleic acid on CLD accumulation and CM secretion were first investigated in cultured Caco-2/15 enterocytes. Intestinal lipid metabolism was also studied in Syrian Golden Hamsters submitted to conventional (CD) or Western (WD) diets for 8 weeks and continuously administered with AG or physiological saline for the ultimate 2 weeks. In cultured Caco-2/15 enterocytes, CLD accumulation influenced CM secretion while AG reduced fatty acid uptake. In WD hamsters, continuous AG treatment amplified chylomicron output while reducing postprandial CLD accumulation in the intestine. The present study supports the intimate relationship between CLD accumulation and CM secretion in the intestine and it underlines the importance of further characterizing the mechanisms through which AG exerts its effects on lipid metabolism in the intestine.

Pain mapping of the anterior knee: injured athletes know best

Background and aims

Research investigating differences in pain location and distribution across conditions is lacking. Mapping a patient’s pain may be a useful way of understanding differences in presentations, however the use of pain mapping during a pain provocation task has not been investigated. The aim of this study was to assess the reliability of patient and clinician rated pain maps during a pain provocation task for the anterior knee.

Methods

Participants were recruited from a larger study of professional Australian rules football players (n=17). Players were invited to participate if they reported a current or past history of patellar tendon pain. No clinical diagnosis was performed for this reliability study. Participants were asked to point on their own knee where they usually experienced pain, which was recorded by a clinician on a piloted photograph of the knee using an iPad. Participants then completed a single leg decline squat (SLDS), after which participants indicated where they experienced pain during the task with their finger, which was recorded by a clinician. Participants then recorded their own self-rated pain map. This process was repeated 10 min later. Pain maps were subjectively classified into categories of pain location and spread by two raters. Pain area was quantified by the number of pixels shaded. Intra- and inter-rater reliability (between participants and clinicians) were analysed for pain area, similarity of location as well as subjective classification.

Results

Test-retest reliability was good for participants (intraclass correlation coefficients [ICC]=0.81) but only fair for clinicians (ICC=0.47) for pain area. There was poor agreement between participants and clinicians for pain area (ICC=0.16) and similarity of location (Jaccard index=0.19). Clinicians had good inter- and intra-rater reliability of classification of pain spread (k=0.75 and 0.67).

Conclusions

Participant completed pain maps were more reliable than clinician pain maps. Clinicians were reliable at classifying pain based on location and type of spread.

Implications

Clinicians should ask patients to complete their own pain maps following a pain provocation test, to elicit the most reliable and consistent understanding of their pain perception.

Hygiene auditing in mass catering: a 4-year study in a university canteen

OBJECTIVES

The outcomes of hygiene audits carried out two times per year were used to determine the correct execution of the procedures foreseen by the Hazard Analysis and Critical Control Points (HACCP) plan over 4 years (2013-2016) in a university canteen producing about 1200 meals a day.

STUDY DESIGN

Critical analysis of hygiene audits.

METHODS

Hygiene audits were carried out on the basis of a checklist divided into seven main items and subitems that covered all the production areas of the canteen. For each audit subitem, total percentage of inadequacy was calculated as the total number of negative answers (N) divided by the total number of answers (n = 8) collected in the period 2013-2016.

RESULTS

The results showed a discontinuous trend among years. In more detail, the highest percentage of inadequacy was seen for food maintaining temperatures, thus highlighting management issues mainly related to time taken for food preparation. A relatively high level of inadequacy was also recorded for staff clothing and hygiene.

CONCLUSIONS

The critical analysis of data emerged from the audits was useful to obtain an overview of improvements and emerging criticalities.

The role of spitefulness in personality disorders: Toward a better comprehension of the cluster B

Introduction

Cluster B personality disorders (i.e., Antisocial, Borderline, Histrionic, and Narcissistic Personality Disorders), is characterized by a dramatic pattern of relating to others, with symptoms characterized by a difficulty regulating emotional states and behavior (APA, 2000). The desire to cause pain often characterized these disorders (i.e. borderline) involving vindictively harming another with serious and often negative interpersonal consequences. Nevertheless, there is a paucity of research about the nature of relationships between spitefulness and personality disorders.

Objective

This study aims to investigate the association between spitefulness and personality disorders in an offenders samples (N = 305).

Aims

To investigate the associations among spitefulness and personality disorders. We hypothesized that spitefulness would be differently associated with emotional and impulsive personality disorders (cluster B: antisocial, borderline, histrionic and narcissistic).

Results

As expected, spitefulness and some personality, disorders were positively associated. Specifically, ASPD and Borderline are strongly associated with high levels of spitefulness.

Conclusions

Such results confirm the theorization that the assessment of spitefulness improve the accuracy of diagnosing of these personality disorders.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Not just ‘callous-unemotional’: Psychopathic traits are associated with emotion dysregulation dimensions

Introduction

Historically, psychopathic individuals have mainly been described as characterized by pervasive callous-unemotional traits, with dramatic implications for clinical and forensic practices – such as the tendency to deem psychopathic individuals as untreatable. However, recent evidence with community samples have highlighted that psychopathic traits may be in fact related to emotion dysregulation rather than being the mere reflection of an underlying ‘unemotionality’. Yet, it is no clear if this association extends to populations with more severe forms of psychopathy (i.e., offenders).

Objectives

We wanted to replicate previous evidence of an association between emotion dysregulation and psychopathic traits in a sample of incarcerated offenders.

Aims

To investigate the associations among emotion dysregulation dimensions and psychopathic traits, exploring similarities and differences between the Interpersonal-Affective and the Antisocial-Lifestyle facets of psychopathy.

Methods

A sample of male offenders incarcerated in Italian jails completed the Self-Report Psychopathy Scale (SRP-4; Paulhus, Neumann, & Hare, 2015) and the Difficulties in Emotion Regulation Scale (DERS; Gratz & Roemer, 2004).

Results

In line with the expectations, emotion dysregulation dimensions did predict higher levels of psychopathic traits. Structural Equation Modelling revealed that selected dimensions of emotion dysregulation were associated with different facets of psychopathy.

Conclusions

Based on our findings, we argue that psychopathic traits may be associated to a certain extent with emotion dysregulation, and thus a focus on improving emotion regulation skills may hold the promise to dampen the therapeutic pessimism when dealing with psychopathic offenders.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

[Epidemiology of CKD in Italy and prevention strategies]

Although chronic kidney disease (CKD) is a major health problem worldwide; it is not adequately considered in the strategies for the prevention of non-communicable diseases. To plan properly preventive strategies in our country, we need to know what is the prevalence of CKD, the risk factors, the level of awareness for the diagnosis, the referral to specialists nephrologists and the prognosis of patients followed in primary care. The prevalence of CKD, adjusted for age and gender, is 6.3% and the major independent risk factors are represented by old age, arterial hypertension, obesity, diabetes, cardiovascular disease and smoking . The awareness of the diagnosis in our country in 2003 is underestimated and nephrology referral for individuals with glomerular filtration (GF) under 60 ml / min was only 10%. The prognosis of patients, followed exclusively in primary care, worsens progressively for values of GF under 45 ml / min, both as need for substitutive treatment and mortality, compared with patients of stage I and II. To improve the management of CKD, it would be useful to set up an electronic database on our national territory by a network among laboratories, primary care, and nephrologists. An example of this organization is Great Britain that evidences encouraging results in the treatment and prevention of this debilitating disease.

Statins in patients with chronic kidney disease: new evidence

Dyslipidemia represents a common metabolic alteration in chronic kidney disease (CKD). Alterations can be different depending on the stage of the disease and the extent of proteinuria. Despite the high cardiovascular risk in patients with renal impairment, only a small percentage of patients receive adequate cholesterol-lowering therapy. The use of statins, inhibitors of the endogenous synthesis of cholesterol in patients with CKD, represents an efficient therapeutic instrument for reducing cardiovascular risk, at least in the early stage of the disease. Such evidence is currently lacking in dialysis, that is a setting where cardiovascular mortality is not consistently due to classical atherosclerosis. In addition to their efficacy, statins are proved as safe drugs with a high tolerability profile in CKD. In the case of intolerant patients, a new therapeutic perspective is represented by ezetimibe, inhibitor of intestinal absorption of cholesterol, whose effectiveness and tolerability allow its use throughout all stages of the renal disease.

Characterisation of Lactobacillus helveticus strains producing antihypertensive peptides by RAPD and inverse-PCR of IS elements

Lactobacillus helveticus is used for the manufacture of cheeses and milk-based products. Although it is not considered a probiotic microorganism, some strains demonstrated beneficial effects through the production of antihypertensive peptides from the hydrolysis of casein during milk fermentation. Strain-specificity of bioactive peptide production by L. helveticus makes the availability of reliable typing methods essential for both legal and good manufacturing processes. Accordingly, RAPD and inverse-PCR of five insertion sequence elements were comparatively evaluated for the molecular characterisation of four L. helveticus dairy cultures producing antihypertensive peptides and fourteen reference strains. Calculation of discriminatory indices and cluster analysis of the DNA fingerprints confirmed the suitability of both approaches for acceptable strain differentiation. Although RAPD was more discriminating, for a few test strains a neat discrimination was only achieved through multiplex inverse-PCR, thus suggesting the suitability of a combined analytical approach for a finer strain discrimination.

The estrogen receptor alpha:insulin receptor substrate 1 complex in breast cancer: structure-function relationships

BACKGROUND

Insulin receptor substrate 1 (IRS-1) is a signaling molecule that exerts a key role in mediating cross talk between estrogen receptor alpha (ERalpha) and insulin-like growth factor 1 (IGF-1) in breast cancer cells. Previously, we demonstrated that a fraction of IRS-1 binds ERalpha, translocates to the nucleus, and modulates ERalpha-dependent transcription at estrogen response elements (ERE). Here, we studied structure-function relationships of the ERalpha:IRS-1 complex under IGF-1 and/or estradiol (E2) stimulation.

MATERIALS AND METHODS

ERalpha and IRS-1 deletion mutants were used to analyze structural and functional ERalpha/IRS-1 interactions. IRS-1 binding to ERE and IRS-1 role in ERalpha-dependent ERE transcription was examined by chromatin immunoprecipitation and gene reporter analysis, respectively. The requirement for IRS-1 in ERalpha function was tested with RNAi technology.

RESULTS

Nuclear translocation of IRS-1 was induced by E2, IGF-1, and a combination of both stimuli. ERalpha/IRS-1 binding was direct and involved the activation function-1 (AF-1)/DNA binding domain (DBD) region of ERalpha and two discrete regions of IRS-1 (the N-terminal pleckstrin homology domain and a region within the C-terminus). IRS-1 knock down abrogated IGF-1-dependent transcriptional activity of unliganded ERalpha, but induced the activity of liganded ERalpha.

CONCLUSIONS

ERalpha/IRS-1 interactions are direct and involve the ERalpha AF-1/DBD domain and IRS-1 domains mapping within N- and C-terminus. IRS-1 may act as a repressor of liganded ERalpha and coactivator of unliganded ERalpha.

Asymmetrical regulation of scavenger receptor class B type I by apical and basolateral stimuli using Caco-2 cells

Cholesterol uptake and the mechanisms that regulate cholesterol translocation from the intestinal lumen into enterocytes remain for the most part unclear. Since scavenger receptor class B type I (SR-BI) has been suggested to play a role in cholesterol absorption, we investigated cellular SR-BI modulation by various potential effectors administered in both apical and basolateral sides of Caco-2 cells. With differentiation, Caco-2 cells increased SR-BI protein expression. Western blot analysis showed the ability of cholesterol and oxysterols in both cell compartments to reduce SR-BI protein expression. Among the n-3, n-6, and n-9 fatty acid families, only eicosapentaenoic acid was able to lower SR-BI protein expression on both sides, whereas apical alpha-linolenic acid decreased SR-BI abundance and basolateral arachidonic acid (AA) raised it. Epidermal growth factor and growth hormone, either in the apical or basolateral medium, diminished SR-BI cellular content, while insulin displayed the same effect only on the basolateral side. In the presence of proinflammatory agents (LPS, TNF-alpha, IFN-gamma), Caco-2 cells exhibited differential behavior. SR-BI was downregulated by lipopolysaccharide on both sides. Finally, WY-14643 fibrate diminished SR-BI protein expression when it was added to the apical medium. Biotinylation studies in response to selected stimuli revealed that regulatory modifications in SR-BI protein expression occurred for the most part at the apical cell surface irrespective of the effector location. Our data indicate that various effectors supplied to the apical and basolateral compartments may impact on SR-BI at the apical membrane, thus suggesting potential regulation of intestinal cholesterol absorption and distribution in various intracellular pools.

Leptin expression in breast nipple aspirate fluid (NAF) and serum is influenced by body mass index (BMI) but not by the presence of breast cancer

While obesity is a known risk factor for postmenopausal breast cancer, the molecular mechanisms involved are unclear. Systemic levels of leptin, the product of the ob (obesity) gene, are increased in obese individuals (body mass index, BMI, over 25) and are higher in women than men. Leptin has been found to stimulate the growth of breast cancer cells in vitro. Our goal was to determine whether leptin was 1) present in nipple aspirate fluid (NAF), and 2) whether NAF leptin levels were associated with a) levels in serum, b) obesity, and c) breast cancer. We collected and evaluated NAF specimens from 83 subjects and serum specimens from 49 subjects. NAF leptin was detectable in 16/41 (39 %) of premenopausal and 21/42 (50 %) postmenopausal subjects. NAF leptin was significantly lower (p = 0.042) in premenopausal than postmenopausal women with a BMI < 25, but not in those with a higher BMI. NAF leptin was significantly associated with BMI in premenopausal (p = 0.011) but not in postmenopausal women. Serum leptin was associated with BMI in both premenopausal and postmenopausal women (p = 0.0001 for both). NAF and serum leptin were associated in premenopausal (p = 0.02) but not postmenopausal women. Neither NAF nor serum leptin was associated with premenopausal or postmenopausal breast cancer. Our findings include that 1) leptin is present in the breast and detectable in a subset of NAF samples, 2) NAF leptin in premenopausal but not postmenopausal women parallels serum leptin levels, and 3) neither NAF nor serum levels of leptin were associated with premenopausal or postmenopausal breast cancer.

Expression of the insulin-like growth factor-I receptor in primary breast cancer and lymph node metastases: correlations with estrogen receptors alpha and beta

Numerous laboratory studies and some epidemiological data have suggested the involvement of the insulin-like growth factor-I receptor (IGF-IR) in breast cancer development and progression. However, data on IGF-IR expression in human tissues, including breast cancer sections, are limited and often inconsistent. We therefore examined by immunohistochemistry the expression of IGF-IR in primary tumors and breast cancer metastases to lymph nodes, and correlated IGF-IR positivity with estrogen receptor (ER) status and selected clinicopathological features. We found that 1) IGF-IR was expressed in primary tumors as well as in lymph node metastases, but the expression in primary tumors was more frequent (56 % vs. 44.4 %); 2) IGF-IR expression in primary tumors was associated with negative node status (p < 0.033); 3) in node-negative primary tumors, IGF-IR positively correlated with ERbeta (p < 0.008; r = 0.538), but not with ERalpha, tumor size or grade; 4) both IGF-IR-positive and IGF-IR-negative primary tumors were found to produce IGF-IR-positive as well as IGF-IR-negative metastases; 5) in metastases, IGF-IR expression did not associate with ERalpha, ERbeta or any of the studied pathobiological markers. The results suggest that IGF-IR could become a viable pharmaceutical target in breast cancer therapy, but such therapy should be based on IGF-IR assessment in primary tumor and metastasis in each potential patient.

Modulation of intestinal and liver fatty acid-binding proteins in Caco-2 cells by lipids, hormones and cytokines

Intestinal and liver fatty acid binding proteins (I- and L-FABP) are thought to play a role in enterocyte fatty acid (FA) trafficking. Their modulation by cell differentiation and various potential effectors was investigated in the human Caco-2 cell line. With the acquisition of enterocytic features, Caco-2 cells seeded on plastic progressively increased L-FABP quantities, whereas I-FABP was not detectable even very late in the maturation process. On permeable filters that improved differentiation markers (sucrase, alkaline phosphatase, transepithelial resistance), Caco-2 cells furthered their L-FABP content and expressed I-FABP. Western blot analysis showed a significant increase in I- and L-FABP expression following an 8-hour incubation period with butyric acid, oleic acid, and phosphatidylcholine. However, in all cases, I-FABP levels were higher than L-FABP concentrations regardless of the lipid substrates added. Similarly, hydrocortisone and insulin enhanced the cellular content of I- and L-FABP whereas leptin triggered I-FABP expression only after an 8-hour incubation. Finally, tumor necrosis factor-alpha was more effective in increasing the cytosolic amount of I-FABP levels. In conclusion, our data demonstrate that I-FABP expression is limited to fully differentiated Caco-2 cells and can be more easily regulated than L-FABP by lipids, hormones, and cytokines.

Immunolocalization, ontogeny, and regulation of microsomal triglyceride transfer protein in human fetal intestine

To examine the multiple stages of lipoprotein packaging during development, we studied localization, ontogeny, and regulation of microsomal transfer protein (MTP), a crucial protein for lipid transport. With the use of immunofluorescence, MTP was identified in villus and crypt epithelial cells in different regions of human fetal intestine, including colon. Staining was detected as early as the 13th wk of gestation in all gut segments and was almost entirely confined to the columnar epithelial cells of the jejunum and colon. Unlike immunofluorescence, which provides qualitative but not quantitative information on MTP signal, enzymatic assays revealed a decreasing gradient from proximal small intestine to distal, as confirmed by immunoblot. Activity of MTP in small intestinal explants cultured for different incubation periods (0, 4, 8, and 24 h) peaked at 4 h but remained insensitive to different concentrations of oleic acid. Also, a trend toward increasing MTP activity was observed at 20-22 wk of gestation. Finally, in strong contrast to jejunal efficiency, colonic explants displayed impaired lipid production, apolipoprotein biogenesis, and lipoprotein assembly, in association with poor expression of MTP. These findings provide the first evidence that human fetal gut is able to express MTP and emphasize the distinct regional distribution, regulation by oleic acid, and ontogeny of MTP.

Iron-ascorbate alters the efficiency of Caco-2 cells to assemble and secrete lipoproteins

Although oxidative stress has been implicated in development of gut pathologies, its role in intestinal fat transport has not been investigated. We assessed the effect of Fe(2+)-ascorbate-mediated lipid peroxidation on lipid synthesis, apolipoprotein biogenesis, and lipoprotein assembly and secretion. Incubation of postconfluent Caco-2 cells with iron(II)-ascorbate (0.2 mM/2 mM) in the apical compartment significantly promoted malondialdehyde formation without affecting sucrase activity, transepithelial resistance, DNA and protein content, and cell viability. However, addition of the oxygen radical-generating system reduced 1) [(14)C]oleic acid incorporation into cellular triglycerides (15%, P < 0.0002) and phospholipids (16%, P < 0.0005); 2) de novo synthesis of cellular apolipoprotein A-I (apo A-I) (18%, P < 0.05), apo A-IV (38%, P < 0.05), and apo B-48 (45%, P < 0.003) after [(35)S]methionine addition; and 3) production of chylomicrons (50%), VLDL (40%), LDL (37%), and HDL (30%) (all P < 0.0001). In contrast, increased total cellular cholesterol formation (96%, P < 0.0001), assayed by [(14)C]acetate incorporation, was noted, attributable to marked elevation (70%, P < 0.04) in activity of DL-3-hydroxy-3-methyl-glutaryl-CoA reductase, the rate-limiting enzyme in cholesterol synthesis. The ratio of Acyl-CoA to cholesterol acyltransferase, the esterifying cholesterol enzyme, remained unchanged. Fe(2+)-ascorbate-mediated lipid peroxidation modifies intracellular fat absorption and may decrease enterocyte efficiency in assembling and transporting lipids during gut inflammation.

Caco-2 cells and human fetal colon: a comparative analysis of their lipid transport

Caco-2 cells and human colonic explants were compared for their ability to esterify lipid classes, synthesize apolipoproteins and assemble lipoproteins. Highly differentiated cells and colonic explants were incubated with [(14)C]oleic acid or [(35)S]methionine for 48 h. Caco-2 cells demonstrated a higher ability to incorporate [(14)C]oleic acid into cellular phospholipids (13-fold, P<0.005), triglycerides (28-fold, P<0.005) and cholesteryl ester (2-fold, P<0. 01). However, their medium/cell lipid ratio was 11 times lower, indicating a limited capacity to export newly synthesized lipids. De novo synthesis of apo B-48 and apo B-100 was markedly increased (7%0 and 240%, respectively), whereas the biogenesis of apo A-I was decreased (60%) in Caco-2 cells. The calculated apo B-48/apo B-100 ratio was substantially diminished (107%), suggesting less efficient mRNA editing in Caco-2 cells. When lipoprotein distribution was examined, it displayed a prevalence of VLDL and LDL, accompanied along with a lower proportion of chylomicron and HDL. In addition, differences in lipoprotein composition were evidenced between colonic explants and Caco-2 cells. Therefore, our findings stress the variance in the magnitude of lipid, apolipoprotein and lipoprotein synthesis and secretion between the two intestinal models. This may be due to various factors, including the origin of Caco-2 cell line, i.e., colon carcinoma.

Impact of essential fatty acid deficiency on hepatic sterol metabolism in rats

The major aim of the current investigation was to define whether essential fatty acid (EFA) deficiency modifies the intrahepatic metabolism and biliary output of sterols in rats. EFA-deficient diet caused an impoverishment in linoleic, arachidonic, and docosahexaenoic acids, and a marked enrichment in the eicosatrienoic acid of the plasma, liver, and hepatic microsomes. During a short term of biliary drainage, a significant decline of the pool size of biliary sterols was noted in EFA-deficient rats compared with control rats. To assess the biosynthesis of biliary components, the common bile duct was cannulated and the pool size depleted (24 hours). Subsequently, a 6-hour bile collection disclosed a significant decrease (nmoles/min/g liver) in bile acids (4.8 +/- 0.3 vs. 8.4 +/- 0.7, P < .005), cholesterol (0.26 +/- 0.01 vs. 0.34 +/- 0.02, P < .05), and phospholipids (1.49 +/- 0.11 vs. 2.82 +/- 0.32, P < .005) in EFA-deficient rats compared with controls (n = 6/group). When cholesterogenesis was measured by the incorporation of [14C]acetate and 3H20 into cholesterol, using liver slices, it was also found to be significantly (P < .001) reduced in EFA-deficient rats. The activity of hepatic 3-hydroxy-3-methylglutaryl coenzyme A reductase, the rate-limiting enzyme in cholesterol biosynthesis, was consistently lower (80 percent, P < .001) in EFA-deficient rats. In parallel experiments, the direct measurement of microsomal acyl-CoA:cholesterol acyl-transferase (ACAT) showed a decrease averaging 52 percent (P < .001). This is in striking contrast to the elevated activity (157 percent, P < .005) of cholesterol 7 alpha-hydroxylase, the rate-limiting enzyme in bile acid biosynthesis. Current experiments also suggest that the enzyme regulation involving phosphorylation and dephosphorylation is modified by EFA deficiency. Among the structural alterations observed in the morphology of hepatocytes in EFA-deficient rats, the lumen of bile canaliculi was reduced in size. These results underline the importance of EFA in the major mechanisms involved in the maintenance of hepatocyte sterol balance.

Intraluminal and intracellular phases of fat absorption are impaired in essential fatty acid deficiency

The structure and function of enterocyte membranes are particularly sensitive to the degree of fatty acid saturation. The objective of the present study was to assess intestinal fat transport in essential fatty acid (EFA)-deficient animal models. Both the digestive and absorptive phases leading to the formation and the secretion of triglyceride (TG)-rich lipoproteins were investigated. After an intraduodenal fat infusion, the percentage increase of plasma TG over fasting values was examined over a period of 4 h in two groups of control and EFA-deficient rats. Lower values at 1 and 2 h (P less than 0.05) were observed in EFA-deficient rats, suggesting fat malabsorption. Likewise, postprandial chylomicronemia was diminished. In a separate group of rats, EFA deficiency was associated with reduced TG and chylomicron-TG transport into lymph. Although pancreatic lipase activity did not change (47.1 vs. 46.2 mumol free fatty acids.mg protein-1.h-1), bile flow was decreased over the 8-h period of collection. Concomitantly, a significant decline (nmol.min-1.g liver-1, P less than 0.05) was discernible in the biliary secretory rate of bile salts (14.09 +/- 2.13 vs. 35.09 +/- 3.73), phospholipids (7.01 +/- 0.61 vs. 11.79 +/- 1.65) and cholesterol (0.19 +/- 0.01 vs. 0.83 +/- 0.06). In vitro studies, utilizing everted sacs incubated with mixed micelles, revealed that EFA-deficient jejunal segments of rats incorporated and esterified less [14C]oleic acid (21 and 32%, respectively). Moreover, the synthesis and secretion of TG-rich lipoproteins were found markedly reduced in mouse jejunal explant cultures. We conclude that EFA deficiency modifies both the intraluminal and intracellular phases of fat absorption.

The ontogeny and site of intestinal lipid and lipoprotein synthesis

The developmental aspects of characteristic intestinal lipoprotein synthesis, chlomicrons (CM), very low density lipoproteins (VLDL) and high density lipoproteins (HDL), are unknown. Our objective was to determine the ontogeny of intestinal lipid and lipoprotein synthesis in both the jejunum and the ileum. Explants of the jejunum and the ileum from fetal (F) (18-19 days of gestation), suckling (S) (5 days old) and weaning (W) (23 days old) rats were cultured in the presence of [14C]-oleic acid to examine lipid synthesis. The results indicate the following. (1) The incorporation of oleic acid is higher for the fetal explants. However, the efficiency of esterification of free fatty acids (FFA) into triglycerides (TG) in the jejunum increases with age (33% F, 37% S, 48% W) (P less than 0.05, by ANOVA). (2) The same profile is found at the ideal site for the incorporation of oleic acid. However, the capacity for the synthesis of TG is more intense at the suckling period (34% F, 54% S, 42% W) (P less than 0.05, by ANOVA). (3) The relative content of TG in CM changes with age: F, 90-93%; S, 80-84%; W, 33-40%. (4) A low percentage of TG content is found in CM at the weaning period while high levels are detectable in VLDL (40-42%). (5) A most significant difference is noted between the jejunum and the ileum in TG synthesis at the suckling period. The ileum synthesizes 53% more TG than the jejunum (P less than 0.025). (6) HDL particles contain substantial amounts of FFA. Nevertheless, they were also found to be able to transport TG mainly in the suckling rat. Thus, this study demonstrates that with growth the rat is able to synthesize CM, VLDL and HDL. Our findings indicate changes in the synthesis of intestinal lipids and lipoproteins, depending on both the development and the site, which suggests an ontogeny. These modifications can be attributed to dietary and hormonal influences present during the period of development.

The effect of a new calcium channel blocker (TA-3090) on lipoprotein profile and intestinal lipid handling in rodents

Recent interest has focused on findings that drugs used to lower blood pressure may adversely modify plasma lipids and lipoprotein metabolism. This observation may explain why pharmacologic control of hypertension has failed to reduce the incidence of morbidity and mortality from coronary artery disease. The present study aims to evaluate the effect of TA-3090, a new calcium channel blocker, on fasting plasma lipids and lipoproteins, as well as on processes of intestinal fat absorption. Rats were treated by gavage with TA-3090 (10 mg/kg twice daily) for 4 days and compared with controls (n = 6 per group). Plasma cholesterol was increased in the treated group to (mean +/- SE) 74 +/- 2 vs 60 +/- 4 mg/dl (P less than 0.01), due mainly to an increased high density lipoprotein-cholesterol level (50 +/- 2 vs 37 +/- 3 mg/dl, P less than 0.005). Notably plasma triglycerides (TG) and low density lipoprotein-cholesterol were not significantly affected. Another group of TA-3090-treated animals was given an intraduodenal fat meal, and the rise in plasma TG and chylomicrons followed over 4 hr. Postprandial hypertriglyceridemia and chylomicronemia were significantly lower at 2 hr (P less than 0.05) and 3 hr (P less than 0.01) compared with controls. In a separate group of animals, the addition of TA-3090 to a 2% intralipid infusion intraduodenally was associated with significantly reduced TG and chylomicron-TG transport into lymph (P less than 0.05). Furthermore, experiments in rats pretreated with TA-3090 intraperitoneally and then given 2% intralipid intraduodenally were shown to have a significant decrease in mean flow rate (27%), TG transport (31%) and chylomicron-TG output (37%), when compared with controls. In vitro studies using jejunal organ culture to examine the effect of TA-3090 on intracellular lipid synthesis and secretion revealed that the addition of the drug to the medium resulted in significantly decreased TG synthesis and secretion. These data suggest that TA-3090 could be effective in increasing HDL-cholesterol and reducing postprandial chylomicronemia. Our findings support a role for TA-3090 directly on enterocyte absorption and/or intracellular lipid transport, and thus indicate the importance of intracellular calcium on these processes.

Effect of clentiazem on lipid profile, lipoprotein composition and aortic fatty streaks in cholesterol-fed rabbits

Numerous experimental studies have reported that common antihypertensive drugs such as diuretics, beta-blockers, and methyldopa have adverse effects on plasma lipids and lipoproteins. The present study was designed to define the effect of clentiazem (10 mg/kg/day) an antihypertensive drug, on hyperlipidemia in rabbits on a cholesterol-rich diet (1%) for 12 weeks. Compared with controls, clentiazem treated rabbits had lower plasma concentrations of triglycerides (55%), total cholesterol (24%), free cholesterol (27%), esterified cholesterol (23%) and phospholipids (24%). The decrease in cholesterol was accounted for by a reduction of VLDL-cholesterol (13%), IDL-cholesterol (24%) and primarily LDL-cholesterol (45%). Neither HDL-cholesterol nor chemical composition of VLDL, IDL, LDL and HDL was altered. When the aortic atherosclerotic involvement was evaluated by computerized planimetry, a 24% reduction of lesions was noted in clentiazem treated animals (P less than 0.05). Similarly, cholesterol content extracted from aortic wall was decreased. Our data therefore demonstrated that clentiazem is a potential antiatherosclerotic agent capable of decreasing plasma lipids and atherogenic lipoproteins as well as aortic fatty streaks.

Combined (n-3 and n-6) essential fatty deficiency is a potent modulator of plasma lipids, lipoprotein composition, and lipolytic enzymes

Essential fatty acids (EFA) are important structural and functional components of cell membranes. Their deficiency has been associated with several clinical and biochemical abnormalities. In the present study, the lipid profile as well as the concentration, composition, and metabolism of lipoproteins were examined in rats rendered EFA-deficient over a period of 12 weeks. Changes in plasma fatty acids mainly induced an increase of palmitoleic (16:1 n-7) and eicosatrienoic (20:3 n-9) acids, while linoleic (18:2 n-6), arachidonic (20:4 n-6), linolenic (18:3 n-3), and docosahexaenoic (22:6 n-3) acids were decreased. The results show increased concentrations of free fatty acids (FFA) (P less than 0.001), triglycerides (P less than 0.001), total cholesterol (P less than 0.02), free cholesterol (P less than 0.005), and phospholipids (P less than 0.05) when compared to pair-fed controls. Similar levels of cholesteryl esters were found in the two groups, and lecithin: cholesterol acyltransferase activity (nmol/100 microliters plasma per h) (8.98 +/- 1.44 vs 8.72 +/- 0.50) did not differ. On the other hand, postheparin extrahepatic lipoprotein lipase (LPL) activity was significantly (P less than 0.002) decreased (5.96 +/- 0.29 vs 7.29 +/- 0.68 mumol FFA/ml per h) and could account for the hypertriglyceridemia as well for the relative triglyceride enrichment of very low density lipoprotein, intermediate density lipoprotein, and low density lipoprotein particles. This enzymatic depletion of LPL was mainly due to the adipose tissue, since a higher level (P less than 0.001) of hepatic lipase (325.8 +/- 16.0 vs 130.8 +/- 9.5 nmol FFA/mg protein per h) was found in liver acetone powder extracts.(ABSTRACT TRUNCATED AT 250 WORDS)

The adaptation of the small intestine after resection in response to free fatty acids

The effects of long-chain triglycerides and a mixture of free fatty acid on the adaptive response to small bowel resection were examined. Rats with a 50% small bowel resection were divided into four groups. Two received 10% of their calories intragastrically either as corn oil or as free fatty acid and the remaining calories intravenously while the two control groups were given all their calories either intravenously or orally. The results of DNA and protein determination show that free fatty acids were more effective than long-chain triglyceride in promoting adaptation (p less than 0.01) in both small intestine and in the colon. Furthermore the intragastric infusion of free fatty acids was as effective as the orally fed group. Of the plasma hormones measured (gastrin, gastric inhibitory polypeptide, enteroglucagon, and insulin) gastric inhibitory polypeptide was significantly higher (p less than 0.05) in the orally fed group and insulin levels in the free fatty acid group (p less than 0.05) than in other groups. There was no significant difference obtained in enteroglucagon and gastrin levels for the four groups. This study shows that a small amount of free fatty acids (10% of the total calories) given by continuous gastric infusion is effective in promoting intestinal adaptation after resection.