Association of circulating fibroblast growth factor 21 levels with all-cause and cardiovascular mortality: The multi-ethnic study of atherosclerosis.

BACKGROUND: Fibroblast growth factor 21 (FGF21) levels are often elevated in cardiovascular disease (CVD). However, no study has assessed its association with cardiovascular and all-cause mortality in a population free of clinically evident CVD. METHODS: A total of 5543 Multi-Ethnic Study of Atherosclerosis (MESA) participants (mean age 62.7 years, 47.5 % male), free of clinically evident CVD at baseline, were studied. From baseline (2000-2002), 1606 deaths (including 387 CVD deaths) were observed over a median follow-up of 17.7 years. Multivariable Cox regression analysis was performed to assess the association of plasma FGF21 levels with mortality. RESULTS: FGF21 levels at baseline were associated with all-cause mortality, even after adjustment for traditional risk factors, including demographic, socioeconomic and cardiovascular risk factors (adjusted hazard ratio 1.08 [95% confidence interval 1.01, 1.16] per 1 SD increase in ln-transformed levels; 1.27 for the highest vs, lowest quartile). Baseline FGF21 levels were significantly associated with both CVD and non-CVD mortality in unadjusted models. However, the association with non-CVD mortality, but not CVD mortality, remained statistically significant after adjusting for covariates. Similar results were obtained in FGF21 quartile analyses and also when using competing risk regression or matched case-control cohort in sensitivity analyses. CONCLUSIONS: In subjects without clinically-evident CVD at baseline, over 17.7 years follow-up there is a modest association of baseline FGF21 levels with all-cause mortality. The finding that this is driven primarily by a significant association with non-CVD mortality over almost two decades merits further investigation.

Strategies to Improve Statin Medication Adherence Among Patients at Risk of Cardiovascular Disease Identified Through Electronic Health Records: A Literature Review.

Statin is a group of lipid/cholesterol-lowering medications that is commonly used for primary and secondary prevention of cardiovascular diseases (CVD). In Australia, this is the first line of pharmacological therapy for CVD risk management. High-risk patients who do not adhere to lipid-modifying medicines have an increased risk of CVD mortality, hospitalization, and revascularization. However, studies show that 67% of patients are non-adherent to statins. As such, improving statin adherence through various strategies is very important. This literature review delves into the studies from the past 10 years to identify the various strategies used and their effectiveness to improve statin adherence. The initial search results on PubMed showed 157 articles and based on the inclusion and exclusion criteria, 7 articles were finally used for this review. The patients in the studies were identified through electronic health records. The findings suggest that education, counselling and motivation through face-to-face interaction, phone calls or text messages, reminder messages and frequent follow-up visits are good strategies to improve statin adherence. Alongside these, simplifying regimens, switching combinations of medicines, or using alternate dosing have also been shown to improve statin adherence. In summary, counselling and face-to-face interaction are effective methods for improving statin adherence. The use of electronic health record (EHR) systems combined with targeted interventions delivered to patients identified to be non-adherent to statin may further improve statin adherence.

ApoA-I Protects Pancreatic ß-Cells From Cholesterol-Induced Mitochondrial Damage and Restores Their Ability to Secrete Insulin.

BACKGROUND: High cholesterol levels in pancreatic ß-cells cause oxidative stress and decrease insulin secretion. ß-cells can internalize apo (apolipoprotein) A-I, which increases insulin secretion. This study asks whether internalization of apoA-I improves ß-cell insulin secretion by reducing oxidative stress. METHODS: Ins-1E cells were cholesterol-loaded by incubation with cholesterol-methyl-ß-cyclodextrin. Insulin secretion in the presence of 2.8 or 25 mmol/L glucose was quantified by radioimmunoassay. Internalization of fluorescently labeled apoA-I by ß-cells was monitored by flow cytometry. The effects of apoA-I internalization on ß-cell gene expression were evaluated by RNA sequencing. ApoA-I-binding partners on the ß-cell surface were identified by mass spectrometry. Mitochondrial oxidative stress was quantified in ß-cells and isolated islets with MitoSOX and confocal microscopy. RESULTS: An F1-ATPase ß-subunit on the ß-cell surface was identified as the main apoA-I-binding partner. ß-cell internalization of apoA-I was time-, concentration-, temperature-, cholesterol-, and F1-ATPase ß-subunit-dependent. ß-cells with internalized apoA-I (apoA-I+ cells) had higher cholesterol and cell surface F1-ATPase ß-subunit levels than ß-cells without internalized apoA-I (apoA-I- cells). The internalized apoA-I colocalized with mitochondria and was associated with reduced oxidative stress and increased insulin secretion. The IF1 (ATPase inhibitory factor 1) attenuated apoA-I internalization and increased oxidative stress in Ins-1E ß-cells and isolated mouse islets. Differentially expressed genes in apoA-I+ and apoA-I- Ins-1E cells were related to protein synthesis, the unfolded protein response, insulin secretion, and mitochondrial function. CONCLUSIONS: These results establish that ß-cells are functionally heterogeneous, and apoA-I restores insulin secretion in ß-cells with elevated cholesterol levels by improving mitochondrial redox balance.

Effect of insulin insufficiency on ultrastructure and function in skeletal muscle.

BACKGROUND: Decreased insulin availability and high blood glucose levels, the hallmark features of poorly controlled diabetes, drive disease progression and are associated with decreased skeletal muscle mass. We have shown that mice with ß-cell dysfunction and normal insulin sensitivity have decreased skeletal muscle mass. This project asks how insulin deficiency impacts on the structure and function of the remaining skeletal muscle in these animals. METHODS: Skeletal muscle function was determined by measuring exercise capacity and specific muscle strength prior to and after insulin supplementation for 28 days in 12-week-old mice with conditional ß-cell deletion of the ATP binding cassette transporters ABCA1 and ABCG1 (ß-DKO mice). Abca1 and Abcg1 floxed (fl/fl) mice were used as controls. RNAseq was used to quantify changes in transcripts in soleus and extensor digitorum longus muscles. Skeletal muscle and mitochondrial morphology were assessed by transmission electron microscopy. Myofibrillar Ca2+ sensitivity and maximum isometric single muscle fibre force were assessed using MyoRobot biomechatronics technology. RESULTS: RNA transcripts were significantly altered in ß-DKO mice compared with fl/fl controls (32 in extensor digitorum longus and 412 in soleus). Exercise capacity and muscle strength were significantly decreased in ß-DKO mice compared with fl/fl controls (P = 0.012), and a loss of structural integrity was also observed in skeletal muscle from the ß-DKO mice. Supplementation of ß-DKO mice with insulin restored muscle integrity, strength and expression of 13 and 16 of the dysregulated transcripts in and extensor digitorum longus and soleus muscles, respectively. CONCLUSIONS: Insulin insufficiency due to ß-cell dysfunction perturbs the structure and function of skeletal muscle. These adverse effects are rectified by insulin supplementation.

ApoA-I and Diabetes.

ApoA-I-the main apolipoprotein constituent of the HDL (high-density lipoprotein) fraction of human plasma-is of therapeutic interest because it has several cardioprotective functions. Recent reports have established that apoA-I also has antidiabetic properties. In addition to improving glycemic control by increasing insulin sensitivity, apoA-I improves pancreatic ß-cell function by amplifying expression of transcription factors that are essential for ß-cell survival and increasing insulin production and secretion in response to a glucose challenge. These findings indicate that increasing circulating apoA-I levels may be of therapeutic value in patients with diabetes in whom management of glycemic control is suboptimal. This review summarizes current knowledge of the antidiabetic functions of apoA-I and the mechanistic basis of these effects. It also evaluates the therapeutic potential of small, clinically relevant peptides that mimic the antidiabetic functions of full-length apoA-I and describes potential strategies for development of these peptides into innovative options for treatment of diabetes.

Using machine learning to predict cardiovascular risk using self-reported questionnaires: Findings from the 45 and Up Study.

BACKGROUND: Machine learning has been shown to outperform traditional statistical methods for risk prediction model development. We aimed to develop machine learning-based risk prediction models for cardiovascular mortality and hospitalisation for ischemic heart disease (IHD) using self-reported questionnaire data. METHODS: The 45 and Up Study was a retrospective population-based study in New South Wales, Australia (2005-2009). Self-reported healthcare survey data on 187,268 participants without a history of cardiovascular disease was linked to hospitalisation and mortality data. We compared different machine learning algorithms, including traditional classification methods (support vector machine (SVM), neural network, random forest and logistic regression) and survival methods (fast survival SVM, Cox regression and random survival forest). RESULTS: A total of 3687 participants experienced cardiovascular mortality and 12,841 participants had IHD-related hospitalisation over a median follow-up of 10.4 years and 11.6 years respectively. The best model for cardiovascular mortality was a Cox survival regression with L1 penalty at a re-sampled case/non-case ratio of 0.3 achieved by under-sampling of the non-cases. This model had the Uno's and Harrel's concordance indexes of 0.898 and 0.900 respectively. The best model for IHD hospitalisation was a Cox survival regression with L1 penalty at a re-sampled case/non-case ratio of 1.0 with Uno's and Harrel's concordance indexes of 0.711 and 0.718 respectively. CONCLUSION: Machine learning-based risk prediction models developed using self-reported questionnaire data had good prediction performance. These models may have the potential to be used in initial screening tests to identify high-risk individuals before undergoing costly investigation.

The association of circulating fibroblast growth factor 21 levels with incident heart failure: The Multi-Ethnic Study of Atherosclerosis.

BACKGROUND: Fibroblast growth factor 21 (FGF21) levels are often elevated in heart failure (HF), although this has not been assessed using a longitudinal study design. Therefore, we investigated the association between baseline plasma FGF21 levels and incident HF in the Multi-Ethnic Study of Atherosclerosis (MESA). METHODS: A total of 5408 participants, free of clinically apparent cardiovascular disease, were included in the analysis, of which 342 developed HF over a median follow-up period of 16.7 years. Multivariable Cox regression analysis was performed and the additive value of FGF21 in the performance of risk prediction over other well-established cardiovascular biomarkers was assessed. RESULTS: The mean age of the participants was 62.6 years with 47.6 % male. Regression spline analysis demonstrated a significant association of FGF21 levels with incident HF among participants with FGF21 levels ≥239.0 pg/mL (hazard ratio = 1.84 [95 % confidence interval 1.21, 2.80] per SD increase in ln-transformed levels) after adjustment for traditional cardiovascular risk factors and biomarkers, but not in participants with FGF21 levels <239.0 pg/mL (p for heterogeneity = 0.004). Among participants with FGF21 levels ≥239.0 pg/mL, FGF21 levels were associated with HF with preserved ejection fraction (HR [95 % CI] = 2.57 [1.51, 4.37]), but not HF with reduced ejection fraction. CONCLUSIONS: The present study suggests baseline FGF21 levels could predict the development of incident HF with preserved ejection fraction, among participants with elevated FGF21 levels at baseline. This study may suggest a pathophysiological role of FGF21 resistance in HF with preserved ejection fraction.

Impact of Impaired Cholesterol Homeostasis on Neutrophils in Atherosclerosis.

Atherosclerosis is complex chronic disease characterized by intimal cholesterol accumulation and vascular inflammation. There is a well-established relationship of hypercholesterolemia and inflammation with atherosclerosis. However, the link between inflammation and cholesterol is not completely understood. Myeloid cells, in particular, monocytes, macrophages, and neutrophils play essential roles in the pathogenesis of atherosclerotic cardiovascular disease. It is well known that macrophages accumulate cholesterol, forming foam cells, which drive atherosclerosis-associated inflammation. However, the interaction between cholesterol and neutrophils remains poorly defined-an important gap in the literature given that neutrophils represent up to 70% of total circulating leukocytes in humans. Elevated levels of biomarkers of neutrophil activation (myeloperoxidase and neutrophil extracellular traps) and higher absolute neutrophil counts are both associated with increased rates of cardiovascular events. Neutrophils contain the necessary machinery to uptake, synthesize, efflux and esterify cholesterol; yet, the functional consequence of dysregulated cholesterol homeostasis on neutrophil activity remains poorly defined. Preclinical animal data suggest a direct link between cholesterol metabolism and hematopoiesis, although current evidence in humans has been unable to corroborate such findings. This review will explore the impact of impaired cholesterol homeostasis neutrophils and draw focus on the discordant data from animal models and atherosclerotic disease in humans.

Type 2 diabetes influences intraepithelial corneal nerve parameters and corneal stromal-epithelial nerve penetration sites.

INTRODUCTION: The quantification of intraepithelial corneal basal nerve parameters by in vivo confocal microscopy represents a promising modality to identify the earliest manifestations of diabetic peripheral neuropathy. However, its diagnostic accuracy is hampered by its dependence on neuron length, with minimal consideration for other parameters, including the origin of these nerves, the corneal stromal-epithelial nerve penetration sites. This study sought to utilize high-resolution images of murine corneal nerves to analyze comprehensively the morphological changes associated with type 2 diabetes progression. MATERIALS AND METHODS: ßIII-Tubulin immunostained corneas from prediabetic and type 2 diabetic mice and their respective controls were imaged by scanning confocal microscopy and analyzed automatically for nerve parameters. Additionally, the number and distribution of penetration sites was manually ascertained and the average length of the axons exiting them was computed. RESULTS: The earliest detectable changes included a significant increase in nerve density (6.06 ± 0.41% vs 8.98 ± 1.99%, P = 0.03) and branching (2867.8 ± 271.3/mm2 vs 4912.1 ± 1475.3/mm2 , P = 0.03), and in the number of penetration sites (258.80 ± 20.87 vs 422.60 ± 63.76, P = 0.0002) at 8 weeks of age. At 16 weeks, corneal innervation decreased, most notably in the periphery. The number of penetration sites remained significantly elevated relative to controls throughout the monitoring period. Similarly, prediabetic mice exhibited an increased number of penetration sites (242.2 ± 13.55 vs 305.6 ± 30.96, P = 0.003) without significant changes to the nerves. CONCLUSIONS: Our data suggest that diabetic peripheral neuropathy may be preceded by a phase of neuron growth rather than regression, and that the peripheral cornea is more sensitive than the center for detecting changes in innervation.

Targeting negative energy balance with calorie restriction and mitochondrial uncoupling in db/db mice.

OBJECTIVE: Calorie restriction is a first-line treatment for overweight individuals with metabolic impairments. However, few patients can adhere to long-term calorie restriction. An alternative approach to calorie restriction that also causes negative energy balance is mitochondrial uncoupling, which decreases the amount of energy that can be extracted from food. Herein we compare the metabolic effects of calorie restriction with the mitochondrial uncoupler BAM15 in the db/db mouse model of severe hyperglycemia, obesity, hypertriglyceridemia, and fatty liver. METHODS: Male db/db mice were treated with ∼50% calorie restriction, BAM15 at two doses of 0.1% and 0.2% (w/w) admixed in diet, or 0.2% BAM15 with time-restricted feeding from 5 weeks of age. Mice were metabolically phenotyped over 4 weeks with assessment of key readouts including body weight, glucose tolerance, and liver steatosis. At termination, liver tissues were analysed by metabolomics and qPCR. RESULTS: Calorie restriction and high-dose 0.2% BAM15 decreased body weight to a similar extent, but mice treated with BAM15 had far better improvement in glucose control. High-dose BAM15 treatment completely normalized fasting glucose and glucose tolerance to levels similar to lean db/+ control mice. Low-dose 0.1% BAM15 did not affect body mass but partially improved glucose tolerance to a similar degree as 50% calorie restriction. Both calorie restriction and high-dose BAM15 significantly improved hyperglucagonemia and liver and serum triglyceride levels. Combining high-dose BAM15 with time-restricted feeding to match the time that calorie restricted mice were fed resulted in the best metabolic phenotype most similar to lean db/+ controls. BAM15-mediated improvements in glucose control were associated with decreased glucagon levels and decreased expression of enzymes involved in hepatic gluconeogenesis. CONCLUSIONS: BAM15 and calorie restriction treatments improved most metabolic disease phenotypes in db/db mice. However, mice fed BAM15 had superior effects on glucose control compared to the calorie restricted group that consumed half as much food. Submaximal dosing with BAM15 demonstrated that its beneficial effects on glucose control are independent of weight loss. These data highlight the potential for mitochondrial uncoupler pharmacotherapies in the treatment of metabolic disease.

Impact of Reperfusion on Temporal Immune Cell Dynamics After Myocardial Infarction.

Excessive inflammation and impaired healing of cardiac tissue following a myocardial infarction (MI) can drive the development of heart failure. Cardiac repair begins immediately after the onset of MI and continues for months. The repair process can be divided into the following 3 overlapping phases, each having distinct functions and sequelae: the inflammatory phase, the proliferative phase, and the maturation phase. Macrophages, neutrophils, and lymphocytes are present in the myocardium throughout the repair process and govern the duration and function of each of these phases. However, changes in the functions of these cell types across each phase are poorly characterized. Numerous immunomodulatory therapies that specifically target inflammation have been developed for promoting cardiac repair and preventing heart failure after MI. However, these treatments have been largely unsuccessful in large-scale clinical randomized controlled trials. A potential explanation for this failure is the lack of a thorough understanding of the time-dependent evolution of the functions of immune cells after a major cardiovascular event. Failure to account for this temporal plasticity in cell function may reduce the efficacy of immunomodulatory approaches that target cardiac repair. This review is concerned with how the functions of different immune cells change with time following an MI. Improved understanding of the temporal changes in immune cell function is important for the future development of effective and targeted treatments for preventing heart failure after MI.

Association of omega 3 polyunsaturated fatty acids with incident chronic kidney disease: pooled analysis of 19 cohorts.

OBJECTIVE: To assess the prospective associations of circulating levels of omega 3 polyunsaturated fatty acid (n-3 PUFA) biomarkers (including plant derived α linolenic acid and seafood derived eicosapentaenoic acid, docosapentaenoic acid, and docosahexaenoic acid) with incident chronic kidney disease (CKD). DESIGN: Pooled analysis. DATA SOURCES: A consortium of 19 studies from 12 countries identified up to May 2020. STUDY SELECTION: Prospective studies with measured n-3 PUFA biomarker data and incident CKD based on estimated glomerular filtration rate. DATA EXTRACTION AND SYNTHESIS: Each participating cohort conducted de novo analysis with prespecified and consistent exposures, outcomes, covariates, and models. The results were pooled across cohorts using inverse variance weighted meta-analysis. MAIN OUTCOME MEASURES: Primary outcome of incident CKD was defined as new onset estimated glomerular filtration rate <60 mL/min/1.73 m2. In a sensitivity analysis, incident CKD was defined as new onset estimated glomerular filtration rate <60 mL/min/1.73 m2 and <75% of baseline rate. RESULTS: 25 570 participants were included in the primary outcome analysis and 4944 (19.3%) developed incident CKD during follow-up (weighted median 11.3 years). In multivariable adjusted models, higher levels of total seafood n-3 PUFAs were associated with a lower incident CKD risk (relative risk per interquintile range 0.92, 95% confidence interval 0.86 to 0.98; P=0.009, I2=9.9%). In categorical analyses, participants with total seafood n-3 PUFA level in the highest fifth had 13% lower risk of incident CKD compared with those in the lowest fifth (0.87, 0.80 to 0.96; P=0.005, I2=0.0%). Plant derived α linolenic acid levels were not associated with incident CKD (1.00, 0.94 to 1.06; P=0.94, I2=5.8%). Similar results were obtained in the sensitivity analysis. The association appeared consistent across subgroups by age (≥60 v <60 years), estimated glomerular filtration rate (60-89 v ≥90 mL/min/1.73 m2), hypertension, diabetes, and coronary heart disease at baseline. CONCLUSIONS: Higher seafood derived n-3 PUFA levels were associated with lower risk of incident CKD, although this association was not found for plant derived n-3 PUFAs. These results support a favourable role for seafood derived n-3 PUFAs in preventing CKD.

Relationship of fibroblast growth factor 21 with the prevalence and progression of vascular and valvular calcification: Multi-ethnic study of atherosclerosis.

BACKGROUND: Elevated circulating levels of fibroblast growth factor 21 (FGF21) are associated with cardiovascular disease (CVD). Therefore, we investigated the relationship of plasma FGF21 with calcification at different vascular and valvular sites. METHODS: A total of 5786 participants, free of clinically apparent CVD at baseline and with valid data on plasma FGF21 and calcification (Agatston score, volume and density) at coronary arteries, thoracic arteries, mitral and aortic valves, and aortic valve ring, were included in the analysis. Vascular calcification was measured at 2-3 follow-up visits. RESULTS: At baseline, higher FGF21 levels were associated with prevalent descending thoracic aortic calcification (DTAC) (prevalence ratio = 1.06 [95% CI 1.01-1.11] per SD increase in log-transformed unit, P = 0.016). Among participants without prevalent calcification, higher FGF21 levels were associated with incident DTAC (relative risk [RR] = 1.13 [95% CI 1.04-1.22], P = 0.002). Among all participants, higher FGF21 levels were also associated with the progression of DTAC score and volume (RR = 1.07 [95% CI 1.03-1.12] and 1.08 [95% CI 1.03-1.12] respectively, both P < 0.01). No significant association of FGF21 was found for prevalence (prevalence ratio = 0.89-1.05), incidence (RR = 0.97-1.16) and progression of calcification (RR = 0.94-1.14) at the other sites. CONCLUSION: Higher FGF21 levels were associated with the presence, incidence and progression of DTAC. However, the magnitude of this association was similar to those of the non-significant associations of FGF21 levels with calcifications at other sites. Further research is needed to assess the potential of FGF21 as a biomarker for vascular calcification.

The pleiotropic effects of high-density lipoproteins and apolipoprotein A-I.

The high density lipoprotein (HDL) fraction of human plasma consists of multiple subpopulations of spherical particles that are structurally uniform, but heterogeneous in terms of size, composition and function. Numerous epidemiological studies have established that an elevated high density lipoprotein cholesterol (HDL-C) level is associated with decreased cardiovascular risk. However, with several recent randomised clinical trials of HDL-C raising agents failing to reduce cardiovascular events, contemporary research is transitioning towards clinical development of the cardioprotective functions of HDLs and the identification of functions that can be exploited for treatment of other diseases. This review describes the origins of HDLs and the causes of their compositional and functional heterogeneity. It then summarises current knowledge of how cardioprotective and other functions of HDLs are regulated. The final section of the review summarises recent advances in the clinical development of HDL-targeted therapies.

Fibroblast growth factor 21 in heart failure.

Fibroblast growth factor 21 (FGF21) is a peptide hormone involved in energy homeostasis that protects against the development of obesity and diabetes in animal models. Its level is elevated in atherosclerotic cardiovascular diseases (CVD) in humans. However, little is known about the role of FGF21 in heart failure (HF). HF is a major global health problem with a prevalence that is predicted to rise, especially in ageing populations. Despite improved therapies, mortality due to HF remains high, and given its insidious onset, prediction of its development is challenging for physicians. The emergence of cardiac biomarkers to improve prediction, diagnosis, and prognosis of HF has received much attention over the past decade. Recent studies have suggested FGF21 is a promising biomarker candidate for HF. Preclinical research has shown that FGF21 is involved in the pathophysiology of HF through the prevention of oxidative stress, cardiac hypertrophy, and inflammation in cardiomyocytes. However, in the available clinical literature, FGF21 levels appear to be paradoxically raised in HF, potentially implying a FGF21 resistant state as occurs in obesity. Several potential confounding variables complicate the verdict on whether FGF21 is of clinical value as a biomarker. Further research is thus needed to evaluate whether FGF21 has a causal role in HF, and whether circulating FGF21 can be used as a biomarker to improve the prediction, diagnosis, and prognosis of HF. This review draws from preclinical and clinical studies to explore the role of FGF21 in HF.

Atorvastatin improves cisplatin sensitivity through modulation of cholesteryl ester homeostasis in breast cancer cells.

BACKGROUND: Acquired treatment resistance is a significant problem in breast cancer management, and alterations in lipid metabolism have been proposed to contribute to the development of drug resistance as well as other aspects of tumor progression. The present study aimed to identify the role of cholesterol metabolism in MCF-7 and MDA-MB-231 breast cancer cell response to cisplatin (CDDP) treatment in the acute setting and in a model of CDDP resistance. METHODS: MCF-7 (luminal A), MDA-MB-231 (triple-negative) and CDDP-resistant MDA-MB-231 (MDACR) cell lines were grown in the presence or absence of CDDP in combination with atorvastatin (ATV), lipid depletion or low-density lipoprotein loading and were analyzed by a variety of biochemical and radiometric techniques. RESULTS: Co-administration of CDDP and ATV strongly reduced cell proliferation and viability to a greater extent than CDDP alone, especially in MDA-MB-231 cells. These findings were associated with reduced cholesteryl ester synthesis and storage in MDA-MB-231 cells. In MDACR cells, acetyl-CoA acetyltransferase 1 (ACAT-1) was upregulated compared to naïve MDA-MB-231 cells and ATV treatment restored CDDP sensitivity, suggesting that aberrant ACAT-1 expression and associated changes in cholesterol metabolism contribute to CDDP resistance in MDA-MB-231 cells. CONCLUSION: These findings indicate that the elevated susceptibility of MDA-MB-231 cells to co-administration of CDDP and ATV, is associated with an increased reliance on cholesteryl ester availability. Our data from these cell culture-based studies identifies altered cholesterol homeostasis as an adaptive response to CDDP treatment that contributes to aggressiveness and chemotherapy resistance.

Translating atherosclerosis research from bench to bedside: navigating the barriers for effective preclinical drug discovery.

Cardiovascular disease (CVD) remains the leading cause of death worldwide. An ongoing challenge remains the development of novel pharmacotherapies to treat CVD, particularly atherosclerosis. Effective mechanism-informed development and translation of new drugs requires a deep understanding of the known and currently unknown biological mechanisms underpinning atherosclerosis, accompanied by optimization of traditional drug discovery approaches. Current animal models do not precisely recapitulate the pathobiology underpinning human CVD. Accordingly, a fundamental limitation in early-stage drug discovery has been the lack of consensus regarding an appropriate experimental in vivo model that can mimic human atherosclerosis. However, when coupled with a clear understanding of the specific advantages and limitations of the model employed, preclinical animal models remain a crucial component for evaluating pharmacological interventions. Within this perspective, we will provide an overview of the mechanisms and modalities of atherosclerotic drugs, including those in the preclinical and early clinical development stage. Additionally, we highlight recent preclinical models that have improved our understanding of atherosclerosis and associated clinical consequences and propose model adaptations to facilitate the development of new and effective treatments.

Haploinsufficiency of CYP8B1 associates with increased insulin sensitivity in humans.

BACKGROUNDCytochrome P450 family 8 subfamily B member 1 (CYP8B1) generates 12α-hydroxylated bile acids (BAs) that are associated with insulin resistance in humans.METHODSTo determine whether reduced CYP8B1 activity improves insulin sensitivity, we sequenced CYP8B1 in individuals without diabetes and identified carriers of complete loss-of-function (CLOF) mutations utilizing functional assays.RESULTSMutation carriers had lower plasma 12α-hydroxylated/non-12α-hydroxylated BA and cholic acid (CA)/chenodeoxycholic acid (CDCA) ratios compared with age-, sex-, and BMI-matched controls. During insulin clamps, hepatic glucose production was suppressed to a similar magnitude by insulin, but glucose infusion rates to maintain euglycemia were higher in mutation carriers, indicating increased peripheral insulin sensitivity. Consistently, a polymorphic CLOF CYP8B1 mutation associated with lower fasting insulin in the AMP-T2D-GENES study. Exposure of primary human muscle cells to mutation-carrier CA/CDCA ratios demonstrated increased FOXO1 activity, and upregulation of both insulin signaling and glucose uptake, which were mediated by increased CDCA. Inhibition of FOXO1 attenuated the CDCA-mediated increase in muscle insulin signaling and glucose uptake. We found that reduced CYP8B1 activity associates with increased insulin sensitivity in humans.CONCLUSIONOur findings suggest that increased circulatory CDCA due to reduced CYP8B1 activity increases skeletal muscle insulin sensitivity, contributing to increased whole-body insulin sensitization.FUNDINGBiomedical Research Council/National Medical Research Council of Singapore.

Statin Prescription Patterns and Associations with Subclinical Inflammation.

Background and Objectives: Statins have been extensively utilised in atherosclerotic cardiovascular disease (ASCVD) prevention and can inhibit inflammation. However, the association between statin therapy, subclinical inflammation and associated health outcomes is poorly understood in the primary care setting. Materials and Methods: Primary care electronic health record (EHR) data from the electronic Practice-Based Research Network (ePBRN) from 2012−2019 was used to assess statin usage and adherence in South-Western Sydney (SWS), Australia. Independent determinants of elevated C-reactive protein (CRP) were determined. The relationship between baseline CRP levels and hospitalisation rates at 12 months was investigated. Results: The prevalence of lipid-lowering medications was 14.0% in all adults and 44.6% in the elderly (≥65 years). The prevalence increased from 2012 to 2019 despite a drop in statin use between 2013−2015. A total of 55% of individuals had good adherence (>80%). Hydrophilic statin use and higher intensity statin therapy were associated with elevated CRP levels. However, elevated CRP levels were not associated with all-cause or ASCVD hospitalisations after adjusting for confounders. Conclusions: The prevalence and adherence patterns associated with lipid-lowering medications highlighted the elevated ASCVD-related burden in the SWS population, especially when compared with the Australian general population. Patients in SWS may benefit from enhanced screening protocols, targeted health literacy and promotion campaigns, and timely incorporation of evidence into ASCVD clinical guidelines. This study, which used EHR data, did not support the use of CRP as an independent marker of future short-term hospitalisations.

Inhibition of Vascular Inflammation by Apolipoprotein A-IV.

Background: Apolipoprotein (apo) A-IV, the third most abundant apolipoprotein in human high density lipoproteins (HDLs), inhibits intestinal and systemic inflammation. This study asks if apoA-IV also inhibits acute vascular inflammation. Methods: Inflammation was induced in New Zealand White rabbits by placing a non-occlusive silastic collar around the common carotid artery. A single 1 mg/kg intravenous infusion of lipid-free apoA-IV or saline (control) was administered to the animals 24 h before collar insertion. The animals were euthanised 24 h post-collar insertion. Human coronary artery cells (HCAECs) were pre-incubated with reconstituted HDLs containing apoA-IV complexed with phosphatidylcholine, (A-IV)rHDLs, then activated by incubation with tumour necrosis factor (TNF)-α. Cell surface vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) in the TNF-α-activated HCAECs was quantified by flow cytometry. VCAM-1, ICAM-1 and 3ß-hydroxysteroid-Δ24 reductase (DHCR24) mRNA levels were quantified by real time PCR. Results: Apolipoprotein ApoA-IV treatment significantly decreased collar-induced endothelial expression of VCAM-1, ICAM-1 and neutrophil infiltration into the arterial intima by 67.6 ± 9.9% (p < 0.01), 75.4 ± 6.9% (p < 0.01) and 74.4 ± 8.5% (p < 0.05), respectively. It also increased endothelial expression of DHCR24 by 2.6-fold (p < 0.05). Pre-incubation of HCAECs with (A-IV)rHDLs prior to stimulation with TNF-α inhibited VCAM-1 and ICAM-1 protein levels by 62.2 ± 12.1% and 33.7 ± 5.7%, respectively. VCAM-1 and ICAM-1 mRNA levels were decreased by 55.8 ± 7.2% and 49.6 ± 7.9%, respectively, while DHCR24 mRNA expression increased by threefold. Transfection of HCAECs with DHCR24 siRNA attenuated the anti-inflammatory effects of (A-IV)rHDLs. Pre-incubation of TNF-α-activated HCAECs with (A-IV)rHDLs also inhibited nuclear translocation of the p65 subunit of nuclear factor-κB (NF-κB), and decreased IκBα phosphorylation. Conclusion: These results indicate that apoA-IV inhibits vascular inflammation in vitro and in vivo by inhibiting NF-κB activation in a DHCR24-dependent manner.