Rosuvastatin induces apoptosis in CD4+CD28null T cells in patients with acute coronary syndromes

Consideration of T-Cell Profile in the Examination of Statin Efficacy in Inflammatory Diseases, Neurodegeneration, and Neurocognitive Performance

Statins are a cornerstone in the medical management of cardiovascular disease, yet their efficacy varies greatly between individuals. In this commentary, we outline the evidence for the role of CD4+CD28null T-cell expansion as a critical moderator of the effects of statins in preventing cardiovascular events via the reduction of pathological inflammation. Given this relationship, we argue that T-cell profiles should be considered as a patient characteristic in clinical and preclinical studies examining statin efficacy in other age- and inflammation-related pathologies. We discuss the implications this may have for studies of statin use in numerous disease processes-notably, dementia and neurocognitive dysfunction-and the potential for T-cell profiles to be used as a prognosticator for statin efficacy in rheumatoid arthritis, Alzheimer's disease, and multiple sclerosis.

CD28null T cells in aging and diseases: From biology to assessment and intervention

CD28null T cells, an atypical subset characterized by the loss of CD28 costimulatory molecule expression, exhibit functional variants and progressively expand with age. Moreover, T cells with these phenotypes are found in both typical and atypical humoral immune responses. Consequently, they accumulate during infectious diseases, autoimmune disorders, cardiovascular conditions, and neurodegenerative ailments. To provide an in-depth review of the current knowledge regarding CD28null T cells, we specifically focus on their phenotypic and functional characteristics as well as their physiological roles in aging and diseases. While uncertainties regarding the clinical utility remains, we will review the following two crucial research perspectives to explore clinical translational applications of the research on this specific T cell subset: 1) addressing the potential utility of CD28null T cells as immunological markers for prognosis and adverse outcomes in both aging and disease, and 2) speculating on the potential of targeting CD28null T cells as an interventional strategy for preventing or delaying immune aging processes and disease progression.

Senescent T Cells in Age-Related Diseases

Age-induced alterations in human immunity are often considered deleterious and are referred to as immunosenescence. The immune system monitors the number of senescent cells in the body, while immunosenescence may represent the initiation of systemic aging. Immune cells, particularly T cells, are the most impacted and involved in age-related immune function deterioration, making older individuals more prone to different age-related diseases. T-cell senescence can impact the effectiveness of immunotherapies that rely on the immune system's function, including vaccines and adoptive T-cell therapies. The research and practice of using senescent T cells as therapeutic targets to intervene in age-related diseases are in their nascent stages. Therefore, in this review, we summarize recent related literature to investigate the characteristics of senescent T cells as well as their formation mechanisms, relationship with various aging-related diseases, and means of intervention. The primary objective of this article is to explore the prospects and possibilities of therapeutically targeting senescent T cells, serving as a valuable resource for the development of immunotherapy and treatment of age-related diseases.

Changes in natural killer and T lymphocyte phenotypes in response to cardiovascular risk management

The pro-inflammatory and regulatory roles of T lymphocytes in atherosclerosis are well established but less is known about natural killer (NK) cells and natural killer T (NKT)-like cells. The effects of cardiovascular risk management on the phenotypes of these cells are unknown. To assess changes in NK cell and lymphocyte phenotypes and circulating inflammatory proteins in response to cardiovascular risk management in patients with carotid atherosclerosis. Fifty patients were included in a prospective clinical study. Measurements were at baseline and after 12 months of cardiovascular risk management. Circulating NK, NKT-like and T lymphocyte subpopulations were phenotyped by multi-colour flow cytometry. Proximity extension assay was performed for 176 plasma proteins associated with inflammation and cardiovascular disease. At 12 months there were significant reductions in LDL (P = 0.001) and blood pressure (P = 0.028). NK cells responded with a reduction in pro-inflammatory (NKG2C+) cells (P = 0.0003), an increase in anti-inflammatory (NKG2A+) cells (P = 0.032), and a reduction in terminally differentiated (CD57+) NK cells. NKT-like cells showed a similar decrease in terminally differentiated subpopulations (P = 0.000002). Subpopulations of T helper cells exhibited a significant reduction in central memory (P = 1.09 × 10-8) and a significant increase in CD4+ naïve- (P = 0.0008) and effector memory T cells (P = 0.006). The protein analysis indicated that cardiovascular risk management affects proteins involved in the inflammatory NF-κB pathway. The consistent decrease in senescent phenotypes of NK, NKT-like and CD4+ cells with a concomitant increase in more naïve, phenotypes suggests a change towards a less pro-inflammatory lymphocyte profile in response to cardiovascular risk management.Trial registry name: CARotid MRI of Atherosclerosis (CARMA). ClinicalTrials.gov identifier NCT04835571 (08/04/2021). https://www.clinicaltrials.gov/study/NCT04835571 .

Simvastatin ameliorates testosterone-induced prostatic hyperplasia in rats via modulating IGF-1/PI3K/AKT/FOXO signaling

Benign prostatic hyperplasia (BPH) is characterized by non-malignant enlargement of prostate cells causing many lower urinary tract symptoms. BPH pathogenesis includes androgens receptors signaling pathways, oxidative stress, apoptosis, and possibly changes in IGF-1/PI3K/AKT/FOXO pathway. Altogether, modulating IGF-1/PI3K/AKT/FOXO signaling along with regulating oxidative stress and apoptosis might preserve prostatic cells from increased proliferation. Beyond statins' common uses, they also have anti-inflammatory, antioxidant, and anti-tumor effects. This study aims to determine simvastatin's beneficial effect on testosterone-induced BPH. Rats were randomly allocated into four groups, 9 rats each. The control group received olive oil subcutaneously and distilled water orally for 30 consecutive days. The second group received simvastatin (20 mg/kg, p.o.) dissolved in distilled water. The BPH-induced group received testosterone enanthate (3 mg/kg, s.c.) dissolved in olive oil, and the BPH-induced treated group received both simvastatin and testosterone. Testosterone significantly increased prostate index and severity of histopathological alterations in prostate tissues as well as 5-alpha reductase enzyme level in contrast to simvastatin treatment that reversed the testosterone-induced alterations in these parameters. Likewise, testosterone up-regulated IGF-1/PI3K/AKT signaling pathway and down-regulated FOXO transcription factor. It also decreased apoptotic markers level in prostatic tissue BAX, caspase-3, and caspase-9, while it elevated Bcl-2 level. In addition, it alleviated reduced GSH and GPX5 levels and SOD activity. Simvastatin treatment significantly opposed testosterone's effect on all aforementioned parameters. In conclusion, this study demonstrates that simvastatin is a possible treatment for BPH which may be attributed to its effect on IGF-1/PI3K/AKT/FOXO signaling pathway as well as anti-oxidant and apoptotic effects.

Effects of rosuvastatin/ezetimibe on senescence of CD8+ T-cell in type 2 diabetic patients with hypercholesterolemia: A study protocol

BACKGROUND

A decade ago, systemic inflammation became widely recognized as an etiology of type 2 diabetes mellitus (T2DM) and complications thereof. Senescent CD8 + T cells of T2DM patients exhibit increased secretion of pro-inflammatory cytokines and enhanced expression of cytotoxic molecules, contributing to systemic inflammation. Recently, many anti-inflammatory roles played by statins and ezetimibe (cholesterol-lowering drugs) have been reported. We will explore the effects of statin/ezetimibe therapy on CD8 + T cell senescence in patients with T2DM and hypercholesterolemia.

METHODS

This 2-group, parallel, randomized, controlled clinical trial will recruit 108 subjects with T2DM and low-density lipoprotein-cholesterol (LDL-C) levels ≥100 mg/dL and randomly assign them to rosuvastatin/ezetimibe and rosuvastatin groups at a 1:1 ratio. Blood samples will be drawn at baseline and after 12 weeks of medication. The primary outcomes will be the LDL-C-lowering effects after 12 weeks. The secondary outcomes will be changes in the senescent (CD28 - CD57+) CD8 + T cell proportions; the levels of circulating pro-inflammatory cytokines, cytotoxic molecules, interleukin-1, transforming growth factor-β, fasting glucose, and HbA1c; and biochemical indices of kidney, liver, and muscle function. Symptoms and signs of predictable adverse events (myopathy and hepatitis) will be routinely monitored.

DISCUSSION

We will evaluate the effects of statin/ezetimibe on CD8 + T cell senescence. Statin/ezetimibe may exert a beneficial immunomodulatory effect.

Accumulation of CD28null Senescent T-Cells Is Associated with Poorer Outcomes in COVID19 Patients

Coronavirus disease 2019 (COVID-19), a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes infectious disease, and manifests in a wide range of symptoms from asymptomatic to severe illness and even death. Severity of infection is related to many risk factors, including aging and an array of underlying conditions, such as diabetes, hypertension, chronic obstructive pulmonary disease (COPD), and cancer. It remains poorly understood how these conditions influence the severity of COVID-19. Expansion of the CD28null senescent T-cell populations, a common phenomenon in aging and several chronic inflammatory conditions, is associated with higher morbidity and mortality rates in COVID-19. Here, we summarize the potential mechanisms whereby CD28null cells drive adverse outcomes in disease and predispose patients to devastating COVID-19, and discuss possible treatments for individuals with high counts of CD28null senescent T-cells.

Statins: Neurobiological underpinnings and mechanisms in mood disorders

Statins (3-hydroxy-3-methylglutaryl-coenzyme A reductase inhibitors) treat dyslipidaemia and cardiovascular disease by inhibiting cholesterol biosynthesis. They also have immunomodulatory and anti-inflammatory properties. Beyond cardiovascular disease, cholesterol and inflammation appear to be components of the pathogenesis and pathophysiology of neuropsychiatric disorders. Statins may therefore afford some therapeutic benefit in mood disorders. In this paper, we review the pathophysiology of mood disorders with a focus on pharmacologically relevant pathways, using major depressive disorder and bipolar disorder as exemplars. Statins are discussed in the context of these disorders, with particular focus on the putative mechanisms involved in their anti-inflammatory and immunomodulatory effects. Recent clinical data suggest that statins may have antidepressant properties, however given their interactions with many known biological pathways, it has not been fully elucidated which of these are the major determinants of clinical outcomes in mood disorders. Moreover, it remains unclear what the appropriate dose, or appropriate patient phenotype for adjunctive treatment may be. High quality randomised control trials in concert with complementary biological investigations are needed if the potential clinical effects of statins on mood disorders, as well as their biological correlates, are to be better understood.

Peculiarities of Immune Regulation in Men of Perm Region with Atherosclerosis Related to Polymorphism of Candidate Genes

The study examined peculiarities of immune regulation and associated polymorphic variants of candidate genes in men with atherosclerosis in Perm region. The revealed deficiency of CD127 lymphocytes and Annexin V-FITC⁺7AAD^- cells, as well as enhanced level of CD3⁺CD4⁺ lymphocytes against the background of variant alleles of candidate genes FAS (rs1159120), CPOX (rs1131857) and wild-type alleles SULT1A1 (rs9282861), MMP9 (rs17576) are responsible for peculiar features of hereditary determination and pathogenesis of atherosclerosis in examined sample (p<0.05). The genetically determined degradation of extracellular matrix in vascular wall and implication of regulated Fas/APO1 apoptosis in the development of progressive atherosclerotic lesions indicate important role of immune system in atherogenesis. The revealed immunological and genetic features are recommended as the markers for early diagnosis of atherosclerosis and its prevention in men of Perm region.

Partial recovery of senescence in circulating follicular helper T cells after Dasatinib treatment

Cellular senescence is an irreversible arrest of cell proliferation triggered by different stimuli, including DNA damage, telomere shortening and oncogenic stress. Senescent cells, by releasing the senescence-associated-secretory-phenotype (SASP), contribute to various diseases pathogenesis. Human atherosclerotic plaque contains cells with multiple markers of senescence that associate with disease severity. We characterized the frequency of senescent cTfh cells and genes expressions before and after treatment with Dasatinib in patients with different degrees of stenosis. Twelve high (≥50%), and twelve low (<50%) stenosis patients and six healthy controls were enrolled. The percentage of senescent CD3⁺CD4⁺CXCR5⁺CD153⁺CD57⁺ cells was significantly decreased in Dasatinib treated cells from individuals with low and high stenosis (P = 0.0007 and P = 0.0002, respectively). However, the frequency of total lymphocytes, CD3⁺ and CD4⁺ T cells were not significantly different between the groups before and after treatment. The expression levels of P53 (P = 0.0003 and P = 0.0001), P16 (P = 0.0005 and P = 0.0002), p21 (P = 0.0002 and P < 0.0001), SENEX (P = 0.0005 and P < 0.0001) and BCL-2 (P = 0.0005 and P = 0.0002) were decreased in PBMCs of low and high stenosis groups after treatment with Dasatinib, respectively. The percentage of senescent cTfh cells positively correlated with cholesterol (P = 0.034; r = 0.671), C-reactive protein (CRP) (P = 0.029; r = 0.707), Erythrocyte sedimentation rate (ESR) levels (P = 0.030; r = 0.598) and neutrophil counts (P = 0.021; r = 0.799) in patients with high stenosis. The decreased frequency of senescent cTfh cells and the expression levels of senescence genes after Dasatinib treatment in patients with atherosclerosis suggest a role for Dasatinib in partial clearance or rejuvenation of senescent cTfh cells, which may decrease inflammatory mediators and attenuate disease progression.

CD28 null CD4 T-cell expansions in autoimmune disease suggest a link with cytomegalovirus infection

Immunosenescence is thought to contribute to the increase of autoimmune diseases in older people. Immunosenescence is often associated with the presence of an expanded population of CD4 T cells lacking expression of CD28 (CD28 ^null). These highly cytotoxic CD4 T cells were isolated from disease-affected tissues in patients with rheumatoid arthritis, systemic lupus erythematosus, multiple sclerosis, or other chronic inflammatory diseases and their numbers appeared to be linked to disease severity. However, we recently demonstrated that the common herpes virus, cytomegalovirus (CMV), not ageing, is the major driver of this subset of cytotoxic T cells. In this review, we discuss how CMV might potentiate and exacerbate autoimmune disease through the expansion of CD28 ^null CD4 T cells.

T-cell senescence contributes to abnormal glucose homeostasis in humans and mice

Chronic inflammation is a driving force for the development of metabolic disease including diabetes and obesity. However, the functional characteristics of T-cell senescence in the abnormal glucose homeostasis are not fully understood. We studied the patients visiting a hospital for routine health check-ups, who were divided into two groups: normal controls and people with prediabetes. Gene expression profiling of peripheral blood mononuclear cells from normal controls and patients with type 2 diabetes was undertaken using microarray analysis. We also investigated the immunometabolic characteristics of peripheral and hepatic senescent T cells in the normal subjects and patients with prediabetes. Moreover, murine senescent T cells were tested functionally in the liver of normal or mice with metabolic deterioration caused by diet-induced obesity. Human senescent (CD28^-CD57⁺) CD8⁺ T cells are increased in the development of diabetes and proinflammatory cytokines and cytotoxic molecules are highly expressed in senescent T cells from patients with prediabetes. Moreover, we demonstrate that patients with prediabetes have higher concentrations of reactive oxygen species (ROS) in their senescent CD8⁺ T cells via enhancing capacity to use glycolysis. These functional properties of senescent CD8⁺ T cells contribute to the impairment of hepatic insulin sensitivity in humans. Furthermore, we found an increase of hepatic senescent T cells in mouse models of aging and diet-induced obesity. Adoptive transfer of senescent CD8⁺ T cells also led to a significant deterioration in systemic abnormal glucose homeostasis, which is improved by ROS scavengers in mice. This study defines a new clinically relevant concept of T-cell senescence-mediated inflammatory responses in the pathophysiology of abnormal glucose homeostasis. We also found that T-cell senescence is associated with systemic inflammation and alters hepatic glucose homeostasis. The rational modulation of T-cell senescence would be a promising avenue for the treatment or prevention of diabetes.

Cardiovascular disease after transplantation: an emerging role of the immune system

Cardiovascular disease (CVD) after transplantation remains a major concern. Little is known about what drives the increased cardiovascular risk in transplant recipients apart from traditional risk factors. The immune system is involved in the pathogenesis of hypertension, atherosclerosis, and coronary artery disease in the general population. Recently, inhibition of interleukin 1 - β by canakinumab versus placebo decreased the incidence of cardiovascular events. Emerging evidence points to a role of adaptive cellular immunity in the development of CVD. Especially, expansion of pro-inflammatory and antiapoptotic cytotoxic CD4⁺ CD28^null T cells is closely associated with incident CVD in various study populations including transplant recipients. The association of cytomegalovirus exposure with increased cardiovascular mortality might be explained by its capacity to upregulate these cytotoxic cells. Also, humoral immunity seems to be relevant for cardiovascular outcome in transplant recipients. Panel-reactive antibodies at baseline and donor-specific antibodies are independently associated with poor cardiovascular outcome after kidney transplantation. Cardiovascular effects of immunosuppressive drugs and statins do not only imply indirect positive or negative effects on traditional cardiovascular risk factors but also intrinsic immunological effects. How immunosuppressive drugs modify atherosclerosis largely remains elusive.

Atorvastatin inhibits the immediate-early response gene EGR1 and improves the functional profile of CD4+T-lymphocytes in acute coronary syndromes

Background- Adaptive immune-response is associated with a worse outcome in acute coronary syndromes. Statins have anti-inflammatory activity beyond lowering lipid levels. We investigated the effects of ex-vivo and in-vivo atorvastatin treatment in acute coronary syndromes on CD4+T-cells, and the underlying molecular mechanisms.Approach and results- Blood samples were collected from 50 statin-naïve acute coronary syndrome patients. We assessed CD4+T-cell activation by flow-cytometry, the expression of 84 T-helper transcription-factors and 84 T-cell related genes by RT-qPCR, and protein expression by Western-blot, before and after 24-hours incubation with increasing doses of atorvastatin: 3-10-26 μg/ml (corresponding to blood levels achieved with doses of 10-40-80 mg, respectively). After incubation, we found a significant decrease in interferon-γ-producing CD4+CD28nullT-cells (P = 0.009) and a significant increase in interleukin-10-producing CD4+CD25highT-cells (P < 0.001). Atorvastatin increased the expression of 2 genes and decreased the expression of 12 genes (in particular, EGR1, FOS,CCR2 and toll like receptor-4; >3-fold changes).The in-vivo effects of atorvastatin were analyzed in 10 statin-free acute coronary syndrome patients at baseline, and after 24h and 48h of atorvastatin therapy (80 mg/daily): EGR1-gene expression decreased at 24h (P = 0.01) and 48h (P = 0.005); EGR1-protein levels decreased at 48h (P = 0.03).Conclusions-In acute coronary syndromes, the effects of atorvastatin on immune system might be partially related to the inhibition of the master regulator gene EGR1. Our finding might offer a causal explanation on why statins improve the early outcome in acute coronary syndromes.

Phenotypic characteristics of aged CD4+ CD28null T lymphocytes are determined by changes in the whole-genome DNA methylation pattern

Aging is associated with a progressive loss of the CD28 costimulatory molecule in CD4⁺ lymphocytes (CD28^null T cells), which is accompanied by the acquisition of new biological and functional properties that give rise to an impaired immune response. The regulatory mechanisms that govern the appearance and function of this cell subset during aging and in several associated inflammatory disorders remain controversial. Here, we present the whole‐genome DNA methylation and gene expression profiles of CD28^null T cells and its CD28⁺ counterpart. A comparative analysis revealed that 296 genes are differentially methylated between the two cell subsets. A total of 160 genes associated with cytotoxicity (e.g. GRZB,TYROBP, and RUNX3) and cytokine/chemokine signaling (e.g. CX3CR1,CD27, and IL‐1R) are demethylated in CD28^null T cells, while 136 de novo‐methylated genes matched defects in the TCR signaling pathway (e.g. ITK,TXK,CD3G, and LCK). TCR‐landscape analysis confirmed that CD28^null T cells have an oligo/monoclonal expansion over the polyclonal background of CD28⁺ T cells, but feature a Vβ family repertoire specific to each individual. We reported that CD28^null T cells show a preactivation state characterized by a higher level of expression of inflammasome‐related genes that leads to the release of IL‐1β when activated. Overall, our results demonstrate that CD28^null T cells have a unique DNA methylation landscape, which is associated with differences in gene expression, contributing to the functionality of these cells. Understanding these epigenetic regulatory mechanisms could suggest novel therapeutic strategies to prevent the accumulation and activation of these cells during aging.

Targeting T cells to treat atherosclerosis: odyssey from bench to bedside

More than 150 years from the initial description of inflammation in atherosclerotic plaques, randomized clinical trials to test anti-inflammatory therapies in atherosclerosis have recently been initiated. Lymphocytes and macrophages are main participants in the inflammatory response in atherosclerosis. T lymphocytes operate mainly by exerting strong influences on the function of many cells in the immune system and beyond, and co-ordinating their interactions. Importantly, T lymphocytes are not a homogenous population, but include several subsets with specialized functions that can either promote or suppress inflammation. The interactions between these T-lymphocyte subsets have critical consequences on the course and outcome of inflammation. The complexity of the inflammatory response in atherosclerosis poses significant challenges on translating experimental findings into clinical therapies and makes the journey from bench to bedside an arduous one. Here, we summarize recent advances on the role of CD4⁺ T cells in the inflammatory process in atherosclerosis and discuss potential therapies to modulate these lymphocytes that may provide future breakthroughs in the treatment of atherosclerosis.

The effect of statin therapy on thyroid autoimmunity in patients with Hashimoto's thyroiditis: A pilot study

BACKGROUND

Statins have been found to exert antiinflammatory and immunomodulatory properties. The aim of this study was to compare the effects of intensive and less aggressive statin treatment on thyroid autoimmunity and hypothalamic-pituitary-thyroid axis activity in patients with Hashimoto's thyroiditis.

METHODS

The study included 38 adult women with Hashimoto's thyroiditis, who required statin therapy and were allocated into one of two groups. Patients at very high cardiovascular risk (n=16) received intensive statin treatment (rosuvastatin 20-40mg daily), while patients at moderate or moderately high cardiovascular risk (n=22) were treated with simvastatin (20-40mg daily) for the following 6 months. Serum levels of thyrotropin, total and free thyroid hormones, and high-sensitivity C-reactive protein (hsCRP), as well as titers of thyroid peroxidase and thyroglobulin antibodies were measured at the beginning and at the end of the study.

RESULTS

Thirty-six individuals completed the study and were included in the final analyses. Apart from improving plasma lipids and reducing circulating levels of hsCRP, intensive, but not less aggressive, statin therapy reduced thyroid peroxidase and thyroglobulin antibody titers, as well as tended to reduce circulating levels of thyrotropin. The effect of intensive statin therapy on thyroid antibody titers was lipid-independent but correlated with treatment-induced changes in thyrotropin and hsCRP.

CONCLUSIONS

Although 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors are able to reduce thyroid autoimmunity in women with Hashimoto's thyroiditis, intensive statin therapy is required to produce this effect.

T cell senescence and cardiovascular diseases

Age-related changes in the immune system, commonly termed "immunosenescence," contribute to deterioration of the immune response and fundamentally impact the health and survival of elderly individuals. Immunosenescence affects both the innate and adaptive immune systems; however, the most notable changes are in T cell immunity and include thymic involution, the collapse of T cell receptor (TCR) diversity, an imbalance in T cell populations, and the clonal expansion of senescent T cells. Senescent T cells have the ability to produce large quantities of proinflammatory cytokines and cytotoxic mediators; thus, they have been implicated in the pathogenesis of many chronic inflammatory diseases. Recently, an increasing body of evidence has suggested that senescent T cells also have pathogenic potential in cardiovascular diseases, such as hypertension, atherosclerosis, and myocardial infarction, underscoring the detrimental roles of these cells in various chronic inflammatory responses. Given that cardiovascular disease is the number one cause of death worldwide, there is great interest in understanding the contribution of age-related immunological changes to its pathogenesis. In this review, we discuss general features of age-related alterations in T cell immunity and the possible roles of senescent T cells in the pathogenesis of cardiovascular disease.

Proteasome-mediated reduction in proapoptotic molecule Bim renders CD4⁺CD28null T cells resistant to apoptosis in acute coronary syndrome

BACKGROUND

The number of CD4(+)CD28(null) (CD28(null)) T cells, a unique subset of T lymphocytes with proinflammatory and cell-lytic phenotype, increases markedly in patients with acute coronary syndrome (ACS). ACS patients harboring high numbers of CD28(null) T cells have increased risk of recurrent severe acute coronary events and unfavorable prognosis. The mechanisms that govern the increase in CD28(null) T cells in ACS remain elusive. We investigated whether apoptosis pathways regulating T-cell homeostasis are perturbed in CD28(null) T cells in ACS.

METHODS AND RESULTS

We found that CD28(null) T cells in ACS were resistant to apoptosis induction via Fas-ligation or ceramide. This was attributable to a dramatic reduction in proapoptotic molecules Bim, Bax, and Fas in CD28(null) T cells, whereas antiapoptotic molecules Bcl-2 and Bcl-xL were similar in CD28(null) and CD28(+) T cells. We also show that Bim is phosphorylated in CD28(null) T cells and degraded by the proteasome. Moreover, we demonstrate for the first time that proteasomal inhibition restores the apoptosis sensitivity of CD28(null) T cells in ACS.

CONCLUSIONS

We show that CD28(null) T cells in ACS harbor marked defects in molecules that regulate T-cell apoptosis, which tips the balance in favor of antiapoptotic signals and endows these cells with resistance to apoptosis. We demonstrate that the inhibition of proteasomal activity allows CD28(null) T cells to regain sensitivity to apoptosis. A better understanding of the molecular switches that control the apoptosis sensitivity of CD28(null) T cells may reveal novel strategies for targeted elimination of these T cells in ACS patients.

Statins for acute coronary syndrome

BACKGROUND

The early period following the onset of acute coronary syndrome (ACS) represents a critical stage of coronary heart disease, with a high risk of recurrent events and deaths. The short-term effects of early treatment with statins on patient-relevant outcomes in patients suffering from ACS are unclear. This is an update of a review previously published in 2011.

OBJECTIVES

To assess the effects, both harms and benefits, of early administered statins in patients with ACS, in terms of mortality and cardiovascular events.

SEARCH METHODS

We updated the searches of CENTRAL (2013, Issue 3), MEDLINE (Ovid) (1946 to April Week 1 2013), EMBASE (Ovid) (1947 to 2013 Week 14), and CINAHL (EBSCO) (1938 to 2013) on 12 April 2013. We applied no language restrictions. We supplemented the search by contacting experts in the field, by reviewing the reference lists of reviews and editorials on the topic, and by searching trial registries.

SELECTION CRITERIA

Randomized controlled trials (RCTs) comparing statins with placebo or usual care, with initiation of statin therapy within 14 days following the onset of ACS, follow-up of at least 30 days, and reporting at least one clinical outcome.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed risk of bias and extracted data. We calculated risk ratios (RRs) for all outcomes in the treatment and control groups and pooled data using random-effects models.

MAIN RESULTS

Eighteen studies (14,303 patients) compared early statin treatment versus placebo or no treatment in patients with ACS. The new search did not identify any new studies for inclusion. There were some concerns about risk of bias and imprecision of summary estimates. Based on moderate quality evidence, early statin therapy did not decrease the combined primary outcome of death, non-fatal myocardial infarction, and stroke at one month (risk ratio (RR) 0.93, 95% confidence interval (CI) 0.80 to 1.08) or four months (RR 0.93, 95% CI 0.81 to 1.06) of follow-up when compared to placebo or no treatment. There were no statistically significant risk reductions from statins for total death, total myocardial infarction, total stroke, cardiovascular death, revascularization procedures, and acute heart failure at one month or at four months, although there were favorable trends related to statin use for each of these endpoints. Moderate quality evidence suggests that the incidence of unstable angina was significantly reduced at four months following ACS (RR 0.76, 95% CI 0.59 to 0.96). There were nine individuals with myopathy (elevated creatinine kinase levels more than 10 times the upper limit of normal) in statin-treated patients (0.13%) versus one (0.015%) in the control groups. Serious muscle toxicity was mostly limited to patients treated with simvastatin 80 mg.

AUTHORS' CONCLUSIONS

Based on moderate quality evidence, due to concerns about risk of bias and imprecision, initiation of statin therapy within 14 days following ACS does not reduce death, myocardial infarction, or stroke up to four months, but reduces the occurrence of unstable angina at four months following ACS. Serious side effects were rare.

Update on the efficacy of statin treatment in acute coronary syndromes

BACKGROUND

The natural history of atherosclerosis might involve coronary plaque rupture/erosion, thrombus formation and vessel lumen occlusion, clinically recognized as acute coronary syndrome (ACS). International guidelines strongly recommend early statin administration in patients admitted for ACS. In addition to lowering circulating levels of low-density lipoprotein cholesterol (LDL-c), statin treatment was shown to promote plaque stabilization or regression in several ways, including reduction in necrotic lipid core, anti-inflammatory effects and improvement in endothelial function. The aim of this review is to summarize clinical evidence on the role of statins in secondary prevention of ACS.

MATERIALS AND METHODS

This narrative review is based on the material found on medline and pubmed up to August 2013. We looked for the terms 'statin, acute coronary syndromes' in combination with 'atherosclerosis, acute myocardial infarction, pathophysiology'.

RESULTS

This review article emphasizes the relevance of the timing of statin administration to improve the outcomes after ACS. Early and continuous statin administration has emerged as key features to prevent adverse events, especially in patients admitted for ACS undergoing percutaneous coronary intervention. Clinical trials matching the improved clinical outcome with the imaging of atherosclerotic plaque stabilization/regression, further supporting the effectiveness of statin therapy. However, the achievement of these goals requires high dose of statins, thus increasing the risk of adverse events.

CONCLUSIONS

Although clinical trials and meta-analyses have provided conflicting results, it is likely that in clinical practice, the rate of adverse events is higher, so that many concerns still remain about a statin high-dose approach in ACS patients.

Substantial proliferation of human renal tubular epithelial cell-reactive CD4+CD28null memory T cells, which is resistant to tacrolimus and everolimus

BACKGROUND

In spite of maintenance treatment with immunosuppressive drugs, tubulitis still occurs and can lead to structural kidney graft damage. We hypothesize that human renal tubular epithelial cells (TECs) trigger selective proliferation of recipient T-cell subsets with variable sensitivity to immunosuppressive drugs.

METHODS

Recipient peripheral blood mononuclear cells were cocultured with donor-derived TECs for 7 days. The proliferation of the total CD4 T-cell pool was assessed. Next, we analyzed which CD4 T-cell subset proliferated and how this response was affected by tacrolimus, everolimus, prednisolone, and mycophenolic acid (MPA) in clinically relevant concentrations.

RESULTS

CD4 T-cell proliferation upon TEC encounter was mainly executed by memory T cells. Interestingly, 38%±7% of the proliferating CD4 T-cell pool showed a CD28 phenotype. These proliferating CD4CD28 memory T cells produced high levels of interferon-γ, tumor necrosis factor-α, and the cytolitic protease granzyme B. TEC-reactive CD4 T-cell proliferation was significantly suppressed by tacrolimus, everolimus, prednisolone, and MPA (P<0.05). Surprisingly and in contrast to prednisolone and MPA, neither tacrolimus nor everolimus could inhibit the CD4CD28 T-cell proliferative response.

CONCLUSION

Our data show substantial proliferation of TEC-reactive CD4CD28 memory T cells, which are resistant to tacrolimus and everolimus. This phenomenon might play an important mechanistic role during cellular rejection under full immunosuppression.

Genotoxicity evaluation of HMG CoA reductase inhibitor rosuvastatin

The genotoxic potential of rosuvastatin as one of the statin drugs was assessed by chromosomal aberrations (CAs), micronucleus (MN) and DNA damage by comet assay in the human peripheral blood lymphocytes. Rosuvastatin was used at concentrations of 0.0625, 0.125, 0.25, 0.5 and 1 µg/mL for these in vitro assays. In all assays, a negative and positive control were also included. CA frequencies were significantly increased in all concentrations at 24 hours and significantly increased in all concentrations except 0.0625 µg/mL at 48 hours, compared to the negative control. Rosuvastatin has a decreased mitotic index (MI) at 0.5- and 1-µg/mL concentrations at 24 hours and at 0.25, 0.5 and 1 µg/mL at 48 hours. A significant increase was observed for induction of MN in all treatments, compared to the negative control. Cytokinesis-block proliferation indices were not affected by treatments with rosuvastatin. In the comet assay, significant increases in comet tail length and tail moment were observed at 0.0625-, 0.5- and 1-µg/mL concentrations. Comet intensity was significantly increased in all concentrations except 0.0625 µg/mL. According to these results, rosuvastatin is cytotoxic and clastogenic/aneugenic in human peripheral lymphocytes. Further studies should be conducted in other test systems to evaluate the full genotoxic potential of rosuvastatin.

Statins, Bcl-2, and apoptosis: cell death or cell protection?

Statins have proven their effectiveness in the treatment of cardiovascular disease. This class of drugs has also attracted attention as a potential treatment for dissimilar diseases such as certain types of cancers and neurodegenerative diseases. What appears to be a contradiction is that, in the case of cancer, it has been suggested that statins increase apoptosis and alter levels of Bcl-2 family members (e.g., reduce Bcl-2 and increase Bax), whereas studies mainly using noncancerous cells report opposite effects. This review examined studies reporting on the effects of statins on Bcl-2 family members, apoptosis, cell death, and cell protection. Much, but not all, of the evidence supporting the pro-apoptotic effects of statins is based on data in cancer cell lines and the use of relatively high drug concentrations. Studies indicating an anti-apoptotic effect of statins are fewer in number and generally used much lower drug concentrations and normal cells. Those conclusions are not definitive, and certainly, there is a need for additional research to determine if statin repositioning is justified for noncardiovascular diseases.

Pathogenic features of CD4+CD28- T cells in immune disorders

Aging of the immune system contributes to the increased morbidity and mortality of the elderly population and may occur prematurely in patients with immune disorders. One of the main characteristics of immunosenescence is the expansion of CD4(+)CD28(-) T cells in the blood. These cells are effector memory T cells with cytotoxic capacity, and have been recently described to have pathogenic potential in a variety of immune disorders. Interestingly, CD4(+)CD28(-) T cells have now been found to infiltrate target tissues of patients with multiple sclerosis, rheumatoid arthritis, myopathies, acute coronary syndromes, and other immune-related diseases. In this review, we discuss potential factors and mechanisms that may induce the expansion of these cells, as well as their putative pathogenic mechanisms in immune disorders.