Cholesterol-lowering Statin Drugs Research Articles

Phenotypes Associated with HFE p.C282Y Homozygosity, the Main Hereditary Hemochromatosis Genotype, in Four Large Genetic Cohorts

Introduction Hereditary hemochromatosis (HH) is the most common known recessive hereditary disease in people of northern European descent. HH is most commonly caused by the HFE-C282Y homozygosity. Disease penetrance is highly variable (1-20%). We have examined the association between C282Y homozygosity and multiple phenotypes, both case-control and quantitative, across 4 international cohorts (deCODE genetics, UK Biobank, Denmark (Copenhagen Hospital Biobank / Danish Blood Donor Study) and Intermountain Healthcare) in an effort to shed a new light on the pathophysiology of this common hereditary disease. Methods We preformed a phenome wide association study meta-analyses for C282Y homozygosity across the 4 beforementioned cohorts, comprising around 970.000 individuals, of those 5928 were homozygous for the C282Y mutation (746 in deCODE/Iceland MAF 6.71%, 2865 in UK Biobank MAF 7.94%, 1703 in CHB MAF 5.6% and 614 in Intermountain Healthcare MAF 6.19%). The analyses comprised both case-control phenotypes (approximately 7000), cases being defined by ICD-10 codes, and continuous quantitative phenotypes (approximately 5500), both results from blood tests and proteome data from deCODE and UK Biobank. Results C282Y homozygotes had a higher prevalence of the following liver, hematological and rheumatic diseases compared to a control group with no copy of the C282Y variant. Diagnosed fibrosis and cirrhosis of liver (odds ratio 4.30, 95% confidence interval 3.35 to 5.51, p=1.77x10 -30), liver cell carcinoma (9.04, 6.01 to 13.58, p=3.24x10 -26) and fatty liver disease (1.75, 1.45 to 2.11, p=5.42x10 -09) were strikingly more common in C282Y homozygotes. Unsurprisingly C282Y homozygotes also had higher liver parameters. Notably C282Y homozygotes had a higher prevalence of diagnosed polycythemia vera (7.24, 4.93 to 10.62, p=4.37x10 -24) yet no association was found with clonal hematopoiesis (1.09, 0.88 to 1.34, p=4.47x10 -01). Strong association was found between C282Y homozygosity and increased hemoglobin (0.41 standard deviations, 95% confidence interval 0.38 to 0.45, p=6.84x10 -142), MCH (0.98, 0.93 to 1.03, p=<1.00x10 -300) and MCV (0.82, 0.78 to 0.86, p=<1.00x10 -300). Red blood cell count (RBC) was decreased (-0.27, -0.30 to -0.23, p=1.06x10 -50), while reticulocyte count (0.30, 0.26 to 0.34, p=1.42x10 -54) and percentage (0.36, 0.32 to 0.40, p=7.91x10 -79) were increased. Erythropoietin (EPO) measurements were markedly decreased in C282Y homozygotes (-0.31, -0.40 to -0.22, p=1.77x10 -11). Homozygous individuals had an increased risk of being diagnosed with osteoarthritis of hip (1.83, 1.63 to 2.07, p=4.30x10 -23) and were more likely to undergo total hip replacement (2.00, 1.69 to 2.29, p=5.81x10 -18). In contrast to these risk enhancing effects C282Y homozygotes had a lower prevalence of cardiovascular disease (CVD). C282Y homozygotes had decreased risk of coronary artery disease (CAD) (0.79, 0.72 to 0.86, p=4.26x10 -07) and angina pectoris (0.77, 0.69 to 0.86, p=4.28x10 -06) and were less likely to undergo coronary artery bypass graft (0.60, 0.49 to 0.74, p=2.39x10 -06). Pure hypercholesterolemia (0.76, 0.69 to 0.83, p=2.52x10 -09) and disorders of lipoprotein metabolism (0.75, 0.66 to 0.85, p=8.41x10 -06) was less commonly diagnosed. C282Y homozygotes were less likely to take cholesterol lowering statin drugs (0.74, 0.67 to 0.81, p=1.45x10 -09). Unsurprisingly with regard to these results strong association was found with lower cholesterol measurements in C282Y homozygotes, the effects being most pronounced on LDL cholesterol (-0.38, -0.42 to -0.35, p=1.61x10 -99). Total cholesterol was also markedly lowered (-0.35, -0.38 to -0.31, p=1.38x10 -91), as well as non HDL cholesterol (-0.34, -0.37 to -0.30, p=2.36x10 -81). No significant association was found with HDL cholesterol and triglyceride measurements. Conclusions C282Y homozygosity was associated with significantly increased risk of liver disease, liver cell carcinoma and osteoarthritis of hip. Homozygous individuals had increased risk of non-clonal primary polycythemia, association with polycythemia vera likely due to misdiagnosis or early diagnosis exacerbated by significantly increased hemoglobin. C282Y homozygotes had a significant decrease in LDL, non-HDL and total cholesterol measurements and were protected against cardiovascular disease.

Hepatocyte Rap1a contributes to obesity- and statin-associated hyperglycemia.

SUMMARYExcessive hepatic glucose production contributes to the development of hyperglycemia and is a key feature of type 2 diabetes. Here, we report that activation of hepatocyte Rap1a suppresses gluconeogenic gene expression and glucose production, whereas Rap1a silencing stimulates them. Rap1a activation is suppressed in obese mouse liver, and restoring its activity improves glucose intolerance. As Rap1a′s membrane localization and activation depends on its geranylgeranylation, which is inhibited by statins, we show that statin-treated hepatocytes and the human liver have lower active-Rap1a levels. Similar to Rap1a inhibition, statins stimulate hepatic gluconeogenesis and increase fasting blood glucose in obese mice. Geranylgeraniol treatment, which acts as the precursor for geranylgeranyl isoprenoids, restores Rap1a activity and improves statin-mediated glucose intolerance. Mechanistically, Rap1a activation induces actin polymerization, which suppresses gluconeogenesis by Akt-mediated FoxO1 inhibition. Thus, Rap1a regulates hepatic glucose homeostasis, and blocking its activity, via lowering geranylgeranyl isoprenoids, contributes to statin-induced glucose intolerance.

Regulated degradation of HMG CoA reductase requires conformational changes in sterol-sensing domain

3-Hydroxy-3-methylglutaryl coenzyme A reductase (HMGCR) is the rate-limiting enzyme in cholesterol synthesis and target of cholesterol-lowering statin drugs. Accumulation of sterols in endoplasmic reticulum (ER) membranes accelerates degradation of HMGCR, slowing the synthesis of cholesterol. Degradation of HMGCR is inhibited by its binding to UBIAD1 (UbiA prenyltransferase domain-containing protein-1). This inhibition contributes to statin-induced accumulation of HMGCR, which limits their cholesterol-lowering effects. Here, we report cryo-electron microscopy structures of the HMGCR-UBIAD1 complex, which is maintained by interactions between transmembrane helix (TM) 7 of HMGCR and TMs 2–4 of UBIAD1. Disrupting this interface by mutagenesis prevents complex formation, enhancing HMGCR degradation. TMs 2–6 of HMGCR contain a 170-amino acid sterol sensing domain (SSD), which exists in two conformations—one of which is essential for degradation. Thus, our data supports a model that rearrangement of the TMs in the SSD permits recruitment of proteins that initate HMGCR degradation, a key reaction in the regulatory system that governs cholesterol synthesis.

Altering NAD(P)H cofactor specificity by structure‐guided modification of class II HMG‐CoA reductase

HMG‐CoA reductase (HMGR) is a central enzyme in metabolism and natural product biosynthesis, as it catalyzes the committed and rate‐determining step of the mevalonate pathway, which produces steroids and isoprenoids, the largest and most diverse class of natural products. Here, HMGR converts HMG‐CoA to mevalonate using two equivalents of a redox cofactor, either NADH or NADPH. Class I HMGRs are highly specific for NADPH, including human HMGR, the target of cholesterol‐lowering statin drugs. However, cofactor specificity of microbial class II HMGR varies widely, as some homologs exhibit a strong preference for either NADH or NADPH, while others homologs are less specific. We have recently identified a key structural feature termed the “cofactor helix” that may govern cofactor specificity in class II HMGR, but until now this helix’s role in conferring NAD(P)H preference has not been tested. In this work, we performed structure‐guided enzyme modification with the aim of altering the cofactor preferences of various class II HMGR homologs. Through kinetic and X‐ray crystallographic studies on these enzyme variants, we have found that the cofactor helix plays a critical but not exclusive role in controlling NAD(P)H preference, expanding our understanding of the structural determinants of cofactor specificity in class II HMGR.

Directly compressible formulation of immediate release rosuvastatin calcium tablets stabilized with tribasic calcium phosphate

Reliable and stable tablet formulations for rosuvastatin calcium (RSC) in four strengths: 5 mg, 10 mg, 20 mg, and 40 mg have been developed. Rosuvastatin is a cholesterol-lowering statin drug and is known to be unstable during storage. The possibility of its stabilization with inorganic salts of multivalent metals has already been reported in the literature. In the present study, a special grade of tribasic calcium phosphate excipient was used to chemically stabilize RSC in a directly compressible immediate release tablet formulation. The developed tablets exhibited good mechanical properties (breaking force ranging from 177 N to 250 N depending on tablet strength), rapid disintegration (less than three minutes) and fast dissolution rate (85% of the drug substance dissolved within 15 minutes) as well as satisfactory chemical stability during storage under stress conditions (50 °C/80% RH), even compared to the reference commercial product.

Outcomes of Screening for Prostate Cancer Among Men Who Use Statins

Prostate-specific antigen (PSA) screening for prostate cancer has resulted in a slight reduction in prostate cancer mortality but also a concomitant overdiagnosis of low-risk tumors. Prostate-specific antigen levels are affected by use of cholesterol-lowering statin drugs, but the association of statin use with PSA screening performance is unknown. To investigate whether statin use was associated with outcomes of a randomized PSA-based prostate cancer screening intervention. This post hoc subgroup analysis of a cohort from a population-based randomized clinical trial used data from the population-based Finnish Randomized Study of Prostate Cancer Screening, which randomized men to PSA screening or routine care from March 1, 1996, to December 31, 1999, with follow-up continuing until December 31, 2015. The population included all men aged 55 to 67 years at baseline and residing in the Tampere or Helsinki districts of Finland. Information on statin purchases from 1996 to 2009 was obtained from a national prescription registry. Eligible men were identified from the population registry of Finland. Prevalent prostate cancer cases at baseline were excluded. Data were analyzed from January 1, 2019 to March 31, 2021. Three invitations for PSA screening at 4-year intervals from 1996 to 2007 vs routine care. Risk for prostate cancer overall, high-risk disease, and prostate cancer mortality in the screening group vs the control group as an intention-to-treat analysis. The analysis was stratified by statin use. The study comprised 78 606 men (median age, 59 years [range, 55-67 years]) with statin purchase data available. Although PSA screening was associated with increased prostate cancer incidence among statin nonusers (screening vs control, 11.2 vs 8.6 per 1000 person-years); rate ratio [RR], 1.31; 95% CI, 1.24-1.38), no similar increase in incidence was observed among statin users (6.9 vs 5.9 per 1000 person-years; RR, 1.02; 95% CI, 0.95-1.10; P < .001 for interaction). Incidence of low-risk (Gleason score 6) and localized tumors was lower among statin users, whereas detection of tumors with a Gleason score of 8 to 10 was similar. Screening was associated with a lower incidence of metastatic tumors regardless of statin use. In this post hoc subgroup analysis of a cohort from a population-based randomized clinical trial, PSA screening among statin users was associated with a decreased incidence of advanced prostate cancer that was similar among statin nonusers, but with less increase in detection of low-grade localized tumors in statin users than in nonusers. These findings suggest that statin use does not materially compromise benefits of PSA-based screening.

Abstract 162: Cholesterol metabolism gene expression and prostate cancer-specific outcomes in radiotherapy-treated patients

Abstract Introduction Dysregulated lipid metabolism is a hallmark of prostate cancer. Furthermore, use of the cholesterol lowering statin drugs has been linked to a reduced risk of lethal prostate cancer. To understand the molecular pathways implicated in this relationship, we examined the association between differential expression of genes involved in intratumoral cholesterol metabolism in prostate tumor biopsies and prostate cancer-specific outcomes. Methods Tumor biopsy gene expression data from 242 men diagnosed with localized/locally advanced prostate cancer and treated with radiotherapy and androgen deprivation therapy was analyzed. A total of 71 genes involved in cholesterol transport, biosynthesis and regulation were selected from the Reactome pathway database, with additional genes involved in cholesterol metabolism extracted from literature. For each gene, expression levels were dichotomized by median expression level. Cox proportional hazards regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for associations of gene expression with biochemical recurrence and metastasis. Models were adjusted for age at diagnosis and Gleason score. Multiple-testing correction was performed using the Bonferroni correction method. Results During a median follow-up of 10.4 years, 72 (30%) patients experienced biochemical recurrence and 32 (13%) developed metastatic disease. Differential expression of several genes was found to be associated with risk of biochemical recurrence and metastasis, though none remained statistically significant following Bonferroni correction. However, several genes showed similar patterns of association with risk of biochemical recurrence and of metastasis, an association which remained similar following adjustment for age and Gleason score. Low (below median) expression of FDFT1, a gene encoding squalene synthase, a key enzyme in cholesterol biosynthesis, was associated with an increased risk of biochemical recurrence (HR 1.87; 95% CI, 1.15-3.01) and metastasis (HR 3.52; 95% CI, 1.52-8.16). High (above median) expression of SLCO1B3, a gene encoding an organic anion transporting polypeptide transporting a variety of small molecules including statins, was associated with higher risk of biochemical recurrence (HR 2.14; 95% CI, 1.31-3.49) and metastasis (HR 2.70; 95% CI, 1.25-5.90). Conclusion These hypothesis-generating results point to a potential role for altered intratumoral cholesterol metabolism in prostate cancer-specific outcomes. Our findings highlighting differential expression of FDFT1 and SLCO1B3, genes involved in cholesterol biosynthesis and anion transport, respectively, in association with risk of biochemical recurrence and metastasis may provide clues as to the mechanistic pathways of most importance. Validation in other prostate cancer gene expression datasets is required. Citation Format: Sarah J. Winter, Sophia Halliday, Konrad H. Stopsack, Sarah O. Osman, Alan R. Hounsell, Gillian Prue, Suneil Jain, Emma H. Allott. Cholesterol metabolism gene expression and prostate cancer-specific outcomes in radiotherapy-treated patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 162.

Regulation of serotonin transport by geranylgeranyl transferase and Ca 2+ /calmodulin‐dependent protein kinase II

The serotonin transporter (SERT) transports extracellular serotonin (5HT) into neuron terminals and serves as the primary mechanism by which 5HT is regulated in the brain. Recently, it has been shown that SERT activity is increased after treatment with cholesterol-lowering statin drugs in a manner independent of cholesterol but dependent on the cholesterol biosynthetic intermediate geranylgeranyl pyrophosphate (GGPP). GGPP and its corresponding enzyme geranylgeranyl transferase (GGT) lipidate proteins for targeting to the plasma membrane. Although statins are known to increase constitutive activity of the canonical targets of GGPP including Rac1, CDC42, and RhoA, the mechanism by which GGPP regulates SERT activity is unknown. To investigate the role of GGPP on neuronal SERT function, serotonin neurons were modeled in serotonergic RN46A-B14 cells with stably overexpressed SERT. Simvastatin or a GGT inhibitor that specifically blocks geranylgeranylation by GGPP were applied to cells for 24hr and 5HT transport was assayed by measuring 5HT uptake in cells after incubation with exogenous 5HT. Simvastatin and GGT inhibition increased 5HT uptake by 58% and 82% (Mean (SEM): Veh=2.09 (0.30), Sim=4.99 (0.53), GGT=11.84 (2.63), p<0.05), respectively, in a manner blocked by fluoxetine. Pharmacological inhibition of CDC42 or knockdown of the mRNA for RhoA did not block statin-increased 5HT uptake. Protein kinases p38 mitogen-activated protein kinase (P38MAPK) and Ca2+/calmodulin-dependent protein kinase II (CaMKII) were also investigated based on their regulation downstream of GGPP. While phosphorylation of P38MAPK was significantly increased by 37% after 24hr simvastatin treatment (Mean (SEM): Veh=100 (6.7), Sim=159 (19.0), p<0.02), inhibition of P38MAPK did not block statin-increased uptake. However, inhibition of CaMKII with CaMKII inhibitor Tat-CN21 dose-dependently blocked statin-increased 5HT uptake (Mean (SEM): Veh=100 (0), Sim=263 (25.8), Tat-CN21=119.48 (12.2), p<0.001). Ongoing studies of the inhibition of GGT on 5HT uptake are being conducted using a panel of CaMKII inhibitors including Tat-CN21, myristoylated autocamtide-2-related inhibitory peptide, and small molecule inhibitors with corresponding control agents. Our results indicate that SERT is regulated through the isoprenylation pathway in a GGPP, GGT and CaMKII-dependent manner.

Role of high-density lipoprotein cholesterol in health and diseases

Primary function of high-density lipoprotein cholesterol is to reverse transport the cholesterol from extrahepatic cell to liver for its metabolism and excretion. Studies have demonstrated the anti-inflammatory, anti-atherogenic, anti-oxidant, and anti-diabetic property of the high-density lipoprotein cholesterol. Although the exact mechanism still remains unelucidated, high-density lipoprotein cholesterol is a complex of lipids and proteins carrying many associated cargo molecules such as enzymes, signaling molecules, miRNA, which imparts overall functionality of high-density lipoprotein cholesterol for its beneficial health effects. However, the protein and lipids components get transform by the enzymes associated with high-density lipoprotein cholesterol, hyperglycemia, oxidative stressor, and free radicals, leading to qualitative and quantitative alterations in high-density lipoprotein cholesterol (HDLc) and diminishes its beneficial effects. In this review, we have discussed the different property of high-density lipoprotein cholesterol, its function and factors influencing HDLc property in light of anti-inflammatory activity in rheumatoid arthritis and the role of cholesterol-lowering statin drug in enhancing the beneficial effect of high-density lipoprotein cholesterol in different cell types.

Effect of rosuvastatin on the concentration of each fatty acid in the fraction of free fatty acids and total lipids in human plasma: The role of cholesterol homeostasis

Each fatty acid (FA) or class of FAs has a different behavior in the pathologies of atherosclerosis. The aim of this study was to investigate changes in the concentration of each fatty acid in the fraction of free fatty acids (FFAs) and total lipids in human plasma after short-term therapy with rosuvastatin as a cholesterol-lowering statin drug. Six hypercholesterolemic men on a habitual diet were studied in a randomized, double-blind, and crossover process. They received 20 mg rosuvastatin or placebo in random order, each for 4 weeks and after 2 weeks of washout period, they received another medication (placebo or rosuvastatin) for another period of 4 weeks. Rosuvastatin treatment significantly decreased the absolute concentrations of saturated and monounsaturated FAs in the total FAs as well as in FFAs. Long chain polyunsaturated fatty acids with 20 and 22 carbon atoms in the molecule had no significant change in the fraction of FFAs. Rosuvastatin is directly involved in cholesterol biosynthesis and indirectly through cholesterol homeostasis in the biosynthesis of other plasma lipids.In conclusion, our findings show that rosuvastatin treatment leads to significant changes in the concentration of each fatty acid, except for long-chain polyunsaturated fatty acids in FFAs. Our observations indicate that cholesterol homeostasis through its regulatory mechanisms appears to be the main cause of changes in the concentration of each plasma fatty acid during rosuvastatin treatment. These changes can be a source of beneficial consequences, in addition to lowering low-density lipoprotein cholesterol in cardiovascular diseases.

Is drug consumption correlated with benign paroxysmal positional vertigo (BPPV) recurrence?

Benign paroxysmal positional vertigo (BPPV) is the most common cause of peripheral vertigo and its recurrence is fairly common. Several studies correlated the pathophysiological role of different comorbidities-such as diabetes, osteoporosis, vascular, psychiatric and autoimmune diseases-in the development and recurrence of BPPV. The aim of this study is to analyse the pharmacological history of patients with idiopathic BPPV in relation to the risk of developing recurrence. Data regarding 715 patients aged 12 to 87years (62.7 ± 14) with non-traumatic BPPV were retrospectively evaluated. These refer to the Vestibular Service, day clinic, and were collected over a 4-year period, between 2014 and 2018. Recurrence of BPPV was observed in 220/715 patients (30.76%). A statistically significant correlation (p < 0.006) between recurrence and drug consumption was observed for SNC agents (p = 0.0001), vitamin D (p = 0.0005), PPI (p = 0.0007), thyroid hormones (p = 0.0011), and antihypertensives in single use (p = 0.0031). On the contrary, cholesterol-lowering statin drugs, hypoglycaemic agents, antiplatelet medication, estroprogestins and combination of two or more antihypertensives did not show significant correlation. Specific classes of drugs are significantly associated with recurrence: antihypertensive therapy with a singular agent, central nervous system agents, PPIs, vitamin D and thyroid hormones. On the other hand, the lack of correlation between some drugs and recurrence could be linked to the effectiveness of therapy in controlling hypertension, dyslipidaemia and diabetes. Pharmacological history is an essential tool to identify patients at risk of BPPV recurrence.

Acute Statin Administration Reduces Levels of Steroid Hormone Precursors.

Cholesterol-lowering statin drugs are used by approximately 25% of US adults 45 years of age and older and frequency of use is even higher among the elderly. Cholesterol provides the substrate for steroid hormone synthesis and its intracellular concentrations are tightly regulated. Our aim was to evaluate whether statin use acutely changes the circulating levels of cortisol, other glucocorticoid precursor molecules and their metabolites. Fourteen subjects not taking statins were administered a single oral dose (2 mg) of pitavastatin. Blood samples collected at baseline and 24 h post-treatment were analyzed for plasma cholesterol and steroid hormone profile. A parallel study in mice entailed the administration of atorvastatin (10 mg/kg) via orogastric delivery for three consecutive days. Cholesterol and corticosterone levels were quantified at baseline and at 1-day and 1-week post-treatment. Several precursor molecules in the steroidogenic pathway (corticosterone, cortisone, and 11-deoxycortisol) were significantly decreased 24 h after administration of a single dose of pitavastatin in human study subjects. Their circulating cholesterol concentrations were unchanged. In mice, there were no significant differences in serum cholesterol or corticosterone at 1-day or 1-week post-treatment compared to both pre-treatment baseline levels and control group levels. We conclude that acute dysregulation of the production of certain glucocorticoid precursor molecules was observed after a single treatment with a lipophilic statin drug. This may be of clinical relevance for individuals with underlying or subclinical adrenal insufficiency.

Anti-cancer effect of doxorubicin is mediated by downregulation of HMG-Co A reductase via inhibition of EGFR/Src pathway

Doxorubicin is a widely used DNA damage-inducing anti-cancer drug. However, its use is limited by its dose-dependent side effects, such as cardiac toxicity. Cholesterol-lowering statin drugs increase the efficacy of some anti-cancer drugs. Cholesterol is important for cell growth and a critical component of lipid rafts, which are plasma membrane microdomains important for cell signaling. 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase (HMG-CR) is a critical enzyme in cholesterol synthesis. Here, we show that doxorubicin downregulated HMG-CR protein levels and thus reduced levels of cholesterol and lipid rafts. Cholesterol addition attenuated doxorubicin-induced cell death, and cholesterol depletion enhanced it. Reduction of HMG-CR activity by simvastatin, a statin that acts as an HMG-CR inhibitor, or by siRNA-mediated HMG-CR knockdown enhanced doxorubicin cytotoxicity. Doxorubicin-induced HMG-CR downregulation was associated with inactivation of the EGFR-Src pathway. Furthermore, a high-cholesterol-diet attenuated the anti-cancer activity of doxorubicin in a tumor xenograft mouse model. In a multivulva model of Caenorhabditis elegans expressing an active-EGFR mutant, doxorubicin decreased hyperplasia more efficiently in the absence than in the presence of cholesterol. These data indicate that EGFR/Src/HMG-CR is a new pathway mediating doxorubicin-induced cell death and that cholesterol control could be combined with doxorubicin treatment to enhance efficacy and thus reduce side effects.

Degradation kinetic study of cholesterol lowering statin drug using sono-hybrid techniques initiated by metal-free polymeric catalyst

Abstract The present study addressed the degradation kinetics of cholesterol lowering statin drug using metal-free polymeric catalyst g-C3N4 synthesized through sonochemical method followed by thermal condensation. The photocatalytic experiments were performed to assess the catalytic activity of the synthesized g-C3N4 catalyst. The results revealed that the g-C3N4 possesses high oxidation properties and able to degrade ∼93% of lovastatin within a short span of time 10 min under sono-hybrid technique with a rate constant of 15.1 × 10–2 min–1. On the other hand, the maximum synergy index was attained when the ultrasound was applied with g-C3N4 nanoparticles. A significant enhancement of 2.25 folds higher degradation efficiency was achieved as compared to the sonolysis process alone. This enhancement is due to the addition of catalyst which facilitates more nucleation sites for cavitation bubbles and promoted cavitation phenomenon in the system. The study of adsorption and oxidation processes revealed that the degradation of lovastatin was primarily by oxidation reaction. When the experiments were performed at low pH, a significant degradation was observed – which is due to the formation of hydronium ions (H3O+). This H3O+ produces alternative and reactive species such as •OH, •O, HO 2 • in the presence of free electrons in the reaction solution. The maximum synergy was seen for (US+g-C3N4) process followed by (US+g-C3N4+H2O2+UVC) and (US+UVC). The experimental results of stability and reusability of the catalyst also confirmed that the catalyst could be easily regenerated and reused for several times without losing any catalytic activity – which might be useful for reducing the total operating cost for a wastewater treatment plant.

Combining Multiple Treatment Comparisons with Personalized Patient Preferences: A Randomized Trial of an Interactive Platform for Statin Treatment Selection.

Patients and clinicians are often required to make tradeoffs between the relative benefits and harms of multiple treatment options. Combining network meta-analysis results with user preferences can be useful when choosing among several treatment alternatives. Using cholesterol-lowering statin drugs as a case study, we aimed to determine whether an interactive web-based platform that combines network meta-analysis findings with patient preferences had an effect on the decision-making process in a general population sample. This was a pilot parallel randomized controlled trial. We used Amazon's Mechanical Turk to recruit adults residing in the United States. A total of 349 participants were randomly allocated to view either the interactive tool (intervention) or a series of bar charts (control). The primary endpoint was decisional conflict, and secondary endpoints included decision self-efficacy, preparation for decision making, and the overall ranking of statins. A total of 258 participants completed the trial and were included in the analysis. On the primary outcome, participants randomized to the interactive tool had significantly lower levels of decisional conflict than those in the control group (difference, -8.53; 95% confidence interval [CI], -12.96 to -4.11 on a 100-point scale; P = 0.001). They also appeared to have higher levels of preparation for decision making (difference, 4.19; 95% CI, -0.24 to 8.63 on a 100-point scale; P = 0.031). No difference was found for decision self-efficacy, although groups were statistically significantly different in how they ranked different statins. The findings of our proof-of-concept evaluation suggest that an interactive web-based tool combining published clinical evidence with individual preferences can reduce decisional conflict and better prepare individuals for decision making.

‘An investigation into the occurrence and removal of pharmaceuticals in Colombian wastewater’

In this work, the presence of 20 pharmaceuticals in wastewater from Colombia is investigated. Several widely consumed compounds have been detected in wastewater samples from different origins and geographical areas in Colombia. The studied pharmaceuticals included antibiotics, analgesics and anti-inflammatories, cholesterol lowering statin drugs, lipid regulators, and anti-depressants. The investigated samples were urban wastewater collected during one whole week before (influent) and after treatment (effluent) in the wastewater treatment plants (WWTPs) of Bogotá and Medellin. Raw wastewater from the Hospital of Tumaco and from the city of Florencia were also collected. Analyses performed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) revealed that most of the target analytes were present in all the wastewater samples. The highest concentrations (up to 50 μg/L) corresponded to acetaminophen, but several antibiotics, such as azithromycin, ciprofloxacin and norfloxacin, and antihypertensive drugs, such as losartan and valsartan, were commonly present in influent wastewater (IWW) at levels above 1 μg/L. Moreover, the treatment applied in WWTPs seemed to not efficiently remove the compounds under study, because most pharmaceuticals were also present in effluent wastewater (EWW) at concentrations close to those of the IWW. Special emphasis was made in this work on the quality of data reported, performing a detailed study of quality control (QC) samples. The analytical approach used –direct injection of 5-fold diluted samples without any additional treatment – is simpler and faster than the commonly applied solid phase extraction (SPE). The use of 12 isotope-labelled internal standards ensured the satisfactory correction of matrix effects for the corresponding analytes. For the remaining 8 compounds, no drastic matrix effects were observed, and only four compounds (cloxacillin, doxycycline, losartan, tetracycline) presented QC recoveries near or slightly below 60%, revealing ionization suppression, particularly in the IWW. Data on the occurrence of pharmaceuticals reported in this paper are the basis for current studies that aim to develop efficient systems for the degradation/removal of these compounds from the aquatic environment.

The UPRmt Protects Caenorhabditis elegans from Mitochondrial Dysfunction by Upregulating Specific Enzymes of the Mevalonate Pathway.

The mevalonate pathway is the primary target of the cholesterol-lowering drugs statins, some of the most widely prescribed medicines of all time. The pathway's enzymes not only catalyze the synthesis of cholesterol but also of diverse metabolites such as mitochondrial electron carriers and isoprenyls. Recently, it has been shown that one type of mitochondrial stress response, the UPRmt, can protect yeast, Caenorhabditis elegans, and cultured human cells from the deleterious effects of mevalonate pathway inhibition by statins. The mechanistic basis for this protection, however, remains unknown. Using C. elegans, we found that the UPRmt does not directly affect the levels of the statin target HMG-CoA reductase, the rate-controlling enzyme of the mevalonate pathway in mammals. Instead, in C. elegans the UPRmt upregulates the first dedicated enzyme of the pathway, HMG-CoA synthase (HMGS-1). A targeted RNA interference (RNAi) screen identified two UPRmt transcription factors, ATFS-1 and DVE-1, as regulators of HMGS-1 A comprehensive analysis of the pathway's enzymes found that, in addition to HMGS-1, the UPRmt upregulates enzymes involved with the biosynthesis of electron carriers and geranylgeranylation intermediates. Geranylgeranylation, in turn, is requisite for the full execution of the UPRmt 3response. Thus, the UPRmt acts in at least three coordinated, compensatory arms to upregulate specific branches of the mevalonate pathway, thereby alleviating mitochondrial stress. We propose that statin-mediated inhibition of the mevalonate pathway blocks this compensatory system of the UPRmt and consequentially impedes mitochondrial homeostasis. This effect is likely one of the principal bases for the adverse side effects of statins.

Simvastatin inhibits the apoptosis of hippocampal cells in a mouse model of Alzheimer's disease.

Alzheimer's disease is associated with cognitive impairments that affect memory and executive functions. Simvastatin is a cholesterol-lowering statin drug that is used to control levels of cholesterol in the blood, particularly in cases of hypercholesterolemia, and may be used in the treatment of aneurysmal subarachnoid hemorrhage. Previous results have indicated that the apoptosis of hippocampal cells may serve a critical role in the progression of Alzheimer's disease. In the present study, it was determined whether Simvastatin inhibited the apoptosis of hippocampal cells in vitro and in vivo. The therapeutic effects of Simvastatin were evaluated in 24-month-old triple-transgenic Alzheimer's disease (3×Tg-AD) mice, and the efficacy of Simvastatin in attenuating memory and cognitive impairment was investigated. Levels of apoptosis-related gene expression in the hippocampus and hippocampal cells of experimental mice were also detected. In addition, neuron excitability was assessed in the functionally relevant brain regions in the hippocampus. The data indicated that Simvastatin significantly suppressed the apoptosis of hippocampal cells in 3×Tg-AD model mice compared with controls (P<0.01). Furthermore, treatment with Simvastatin improved the dementia status of 3×Tg-AD mice, as determined by a learning task in which mice exhibited significantly reduced attention impairment, impulsivity and compulsivity (P<0.01). In addition, results demonstrated that Simvastatin significantly inhibited hippocampal damage and significantly improved neuronal loss in hippocampal structures classically associated with attentional performance when compared with untreated mice (P<0.01). Thus, Simvastatin prevented cognitive impairment by decreasing hippocampal cell apoptosis and improving learning-memory ability. Simvastatin treatment also increased the expression of anti-apoptotic genes and decreased the expression pro-apoptotic genes (P<0.01), which may have been associated with improved motor attention and cognitive competence in 3×Tg-AD mice. Collectively, these preclinical data indicated that Simvastatin was efficient in attenuating memory lapse and hippocampal cell apoptosis in a 3×Tg-AD mouse model. Thus, Simvastatin may be useful in improving the clinical outcome of patients with Alzheimer's disease.

Annals for Educators - 15 August 2017

Annals for Educators - 15 August 2017

Abstract CT133: Atorvastatin and prostate cancer - a phase 2 clinical trial

Abstract Background: Use of cholesterol-lowering statin drugs has been linked to lowered risk of advanced prostate cancer (PCa) and improved PCa-specific survival. However, statins’ efficacy against specifically against PCa has not been tested in a prospective randomized clinical trial. Materials and methods: A total of 160 men with PCa and scheduled for radical prostatectomy were randomly allocated 1:1 to receive either 80 mg atorvastatin or placebo from recruitment to surgery. The study inclusion criteria included 1) histologically confirmed adenocarcinoma of the prostate, 2) radical prostatectomy selected as the first-line treatment and 3) signing of informed consent. Exclusion criteria were 1) previous oncological treatments 2) previous usage statins, finasteride or dutasteride within a year of inclusion, 3) clinically significant liver or kidney insufficiency, 4) previous adverse effects from cholesterol-lowering drugs and 5) use of drugs that might interact with statins Serum PSA was measured at recruitment and at the time of surgery. After prostatectomy, intraprostatic inflammation was quantified according to international consensus criteria. PSA change, calculated by subtracting PSA value at recruitment from PSA before prostatectomy, was compared between the trial arms using Man-Whitney U test. Extent and amount of intraprostatic inflammation were compared using linear regression and ANOVA. Separate comparisons were made for inflammation in glandular, periglandular and stromal compartments as well as for combined inflammation score. All analyses were performed for all cases combined, and separately for low-grade (prostatectomy Gleason score 3+4 or lower) and high-grade (Gleason score 4+3 or higher) cases. Results: In total 160 men were recruited and randomized. Of these 158 completed the follow-up. Median time from recruitment to surgery was four weeks. Compliance to assigned treatment was excellent, 96%. Four men in the atorvastatin arm, none in the placebo arm discontinued the study drug due to side effects. They were analyzed in their assigned study arm according to the intention-to-treat principle. Overall, the median PSA change after the intervention did not differ between the atorvastatin and placebo arms (median change -0.4; IQR -1.4-0.1 and -0.2; IQR -1.1-0.4 in the atorvastatin and placebo arm, respectively), p for interaction 0.150. However, among the high-grade cases (n=35), PSA decreased among all men in the atorvastatin arm (median change -0.6, IQR -2[[Unsupported Character - Codename &amp;shy;]]- -0.2), but not in the placebo arm (median change 0, IQR -0.6-0.4); p for interaction 0.024. Overall, intraprostatic inflammation score did not differ between the study arms (p for difference 0.772). Result was similar for separate tissue compartments. Conclusions: Short-term high-dose atorvastatin therapy before radical prostatectomy lowers serum PSA values in high-grade cases but not in low-grade cases, indicating that atorvastatin intervention affects the prostate in such cases. Future clinical trials testing statins in prostate cancer patients should aim to enroll patients with Gleason score at least 4+3. Citation Format: Teemu J. Murtola, Jarno Riikonen, Heimo Syvälä, Teemu Tolonen, Juha Koskimäki, Tomi Pakarainen, Antti Kaipia, Taina Isotalo, Paula Kujala, Teuvo Tammela. Atorvastatin and prostate cancer - a phase 2 clinical trial [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT133. doi:10.1158/1538-7445.AM2017-CT133