The impact of statins on biological characteristics of stem cells provides a novel explanation for their pleiotropic beneficial and adverse clinical effects

Aging of the eye: Lessons from cataracts and age-related macular degeneration

Aging is the greatest risk factor for chronic human diseases, including many eye diseases. Geroscience aims to understand the effects of the aging process on these diseases, including the genetic, molecular, and cellular mechanisms that underlie the increased risk of disease over the lifetime. Understanding of the aging eye increases general knowledge of the cellular physiology impacted by aging processes at various biological extremes. Two major diseases, age-related cataract and age-related macular degeneration (AMD) are caused by dysfunction of the lens and retina, respectively. Lens transparency and light refraction are mediated by lens fiber cells lacking nuclei and other organelles, which provides a unique opportunity to study a single aging hallmark, i.e., loss of proteostasis, within an environment of limited metabolism. In AMD, local dysfunction of the photoreceptors/retinal pigmented epithelium/Bruch's membrane/choriocapillaris complex in the macula leads to the loss of photoreceptors and eventually loss of central vision, and is driven by nearly all the hallmarks of aging and shares features with Alzheimer's disease, Parkinson's disease, cardiovascular disease, and diabetes. The aging eye can function as a model for studying basic mechanisms of aging and, vice versa, well-defined hallmarks of aging can be used as tools to understand age-related eye disease.

Prescription patterns of statins in cirrhotic patients: a survey among primary care physicians and cardiologists

Background

Statin therapy is widely utilized for preventing atherosclerotic cardiovascular disease, both as a primary and secondary measure. Despite the American Association for the Study of Liver Diseases' endorsement of statin use in cirrhotic patients, practitioners exhibit hesitancy, primarily due to concerns regarding hepatotoxicity. This study aimed to evaluate statin prescription patterns in cirrhotic patients by primary care physicians (PCPs) and cardiologists through a survey.

Methods

A voluntary survey via Survey Monkey with nine objective-type questions was sent to 220 PCPs and 75 cardiologists within Allegheny Health Network. Survey results were collected, and a chi square test was used to compare the two groups. A P value ≤ 0.05 was considered statistically significant.

Results

A total of 64 PCPs (29.1%) and 15 cardiologists (20%) completed the survey. Overall, 12.6% did not prescribe statins for primary prevention of atherosclerotic cardiovascular disease in compensated cirrhotic patients. While all cardiologists prescribed statins for secondary prevention, over 50% preferred lower-intensity options. Conversely, 14.1% of PCPs avoided statin prescriptions for secondary prevention. Cardiologists were significantly more inclined to prescribe statins, especially for cirrhosis due to metabolic dysfunction-associated steatotic liver disease compared to PCPs (73.3% vs 45.3%, P = 0.05).

Conclusions

Despite increasing evidence favoring use of statins in cirrhosis for improving portal hemodynamics and decreasing ascites, hepatic encephalopathy, the incidence of hepatocellular carcinoma, and mortality, there is still hesitation on the part of prescribers for the fear of worsening liver disease. Wider dissemination of current guidelines and education practices may help to bridge this gap.

Exploring the Relationship Between Atorvastatin and Memory Loss: A Comprehensive Analysis Integrating Real-World Pharmacovigilance and Mendelian Randomization

BACKGROUND AND OBJECTIVE

Atorvastatin is a drug widely used to prevent cardiovascular and cerebrovascular diseases. Current observational studies suggest that atorvastatin may be associated with cognitive dysfunction (especially memory loss). However, some studies have suggested that dyslipidemia may be an important factor in cognitive dysfunction. The purpose of this study was to perform a pharmacovigilance analysis using real-world data from the US Food and Drug Administration's Adverse Event Reporting System (FAERS) to assess whether memory loss is an adverse effect of atorvastatin and to further clarify its causality through Mendelian randomization (MR).

METHODS

We extracted real-world data from the FAERS database (Quarter 1 2004 to Quarter 1 2023). Disproportionality analysis methods and measures of association such as the reporting odds ratio (OR), proportional reporting ratio, Bayesian confidence interval progressive neural network, and polynomial Gamma Poisson distribution reduction were used to assess whether memory loss was an adverse effect of atorvastatin. In addition, we used MR to evaluate causality in depth.

RESULTS

In the pharmacovigilance analysis of atorvastatin, we extracted four datasets of clinical symptoms associated with memory loss from the FAERS database [Amnesia (n = 1196), Memory impairment (n = 840), Transient global amnesia (n = 38), and Retrograde amnesia (n = 9)]. The reporting OR, proportional reporting ratio, Bayesian confidence interval progressive neural network, and Gamma Poisson distribution reduction all showed positive results for amnesia, transient global amnesia, and retrograde amnesia, while the reporting OR and Bayesian confidence interval progressive neural network also showed positive results for memory disorders. Thus, memory loss was a frequent side effect of atorvastatin. The MR analyses were used to further evaluate the association between statins and memory loss. The results of the MR analysis (statins and memory loss) are as follows: Ivw (mre) (β = 0.11 [OR = 1.11], P = 0.01 < 0.05) and the OR and β directions of MR-Egger and weighted mode were the same. The results of the MR analysis (statins and mitochondrial DNA copy number) are as follows: Ivw(mre) (β = -0.03 [OR = 0.96], P < 0.01) and the OR and β direction of MR-Egger and weighted mode are the same. The results of the MR analysis (DNA copy number and memory loss) are as follows: Ivw(β = - 0.06 [OR = 0.94], P = 0.04 < 0.05) and the OR and β direction of MR-Egger and weighted mode were the same. The pleiotropy test did not find horizontal diversity in our results.

CONCLUSIONS

This study suggests that memory loss is a notable adverse event associated with atorvastatin and provides evidence indicating a potential causal relationship between atorvastatin and memory loss. We also found that statins may further affect memory by affecting mitochondrial function. Therefore, in the clinical use of atorvastatin, it is important to carefully monitor the changes in cognitive function of patients. Second, a pharmacovigilance analysis combined with MR was used in this study to provide a new approach for the study of adverse drug reactions. This comprehensive analysis method helps to evaluate the safety of drugs and the risk of adverse reactions more comprehensively and provides doctors with a more accurate clinical decision-making basis.

Highly variable biological effects of statins on cancer, non-cancer, and stem cells in vitro

Statins, the drugs used for the treatment of hypercholesterolemia, have come into the spotlight not only as chemoadjuvants, but also as potential stem cell modulators in the context of regenerative therapy. In our study, we compared the in vitro effects of all clinically used statins on the viability of human pancreatic cancer (MiaPaCa-2) cells, non-cancerous human embryonic kidney (HEK 293) cells and adipose-derived mesenchymal stem cells (ADMSC). Additionally, the effect of statins on viability of MiaPaCa-2 and ADMSC cells spheroids was tested. Furthermore, we performed a microarray analysis on ADMSCs treated with individual statins (12 μM) and compared the importance of the effects of statins on gene expression between stem cells and pancreatic cancer cells. Concentrations of statins that significantly affected cancer cells viability (< 40 μM) did not affect stem cells viability after 24 h. Moreover, statins that didn´t affect viability of cancer cells grown in a monolayer, induce the disintegration of cancer cell spheroids. The effect of statins on gene expression was significantly less pronounced in stem cells compared to pancreatic cancer cells. In conclusion, the low efficacy of statins on non-tumor and stem cells at concentrations sufficient for cancer cells growth inhibition, support their applicability in chemoadjuvant tumor therapy.

Association between the Use of Statins and Brain Tumors

This study aimed to investigate the effects of statin use on the incidence of brain tumors. The Korean National Health Insurance Service-National Sample Cohort from 2005 to 2019 was used. The 1893 patients who were diagnosed with brain tumors were matched with 7572 control patients for demographic variables. The history of dyslipidemia was collected, and their history of prescription of statins before diagnosis of brain tumor was examined. The participants without dyslipidemia were set as a reference population. Then, the odds for brain tumors were analyzed in dyslipidemia patients without statin use, dyslipidemia patients who were prescribed statins for less than 365 days, and dyslipidemia patients who were prescribed statins for 365 days or more. Propensity score overlap weighted multivariable logistic regression analysis was used and adjusted for demographics and comorbidities. Secondary analyses were conducted according to types of statins, malignancy of brain tumors, and histories of demographics or comorbidities. A total of 11.78% of brain tumor patients and 10.95% of control participants had histories of statin use for 365 days or more. Dyslipidemia patients with 365 days or more duration of statin use demonstrated 1.22 times higher odds for brain tumors than normal participants (95% confidence intervals [CI] = 1.06-1.14, p = 0.007). Dyslipidemia patients with less than 365 days of statin use had higher odds of brain tumors than other groups (odds ratio = 1.60, 95% CI = 1.36-1.87, p < 0.001). The higher odds for brain tumors in short-term statin users (<365 days) than in long-term statin users (≥365 days) were consistent in secondary analyses according to types of statins, malignancy of brain tumors, and histories of demographics or comorbidities. Long-term statin use in dyslipidemia patients was related to a lower risk of brain tumors than short-term statin use in patients with dyslipidemia.

Historical Review of the Use of Relative Risk Statistics in the Portrayal of the Purported Hazards of High LDL Cholesterol and the Benefits of Lipid-Lowering Therapy

The manner in which clinical trial investigators present their findings to healthcare providers and the public can have a substantial influence on their impact. For example, if a heart attack occurs in 2% of those in the placebo group and in 1% of those in the drug-treated group, the benefit to the treated population is only one percentage point better than no treatment. This finding is unlikely to generate much enthusiasm from the study sponsors and in the reporting of the findings to the public. Instead, trial directors can amplify the magnitude of the appearance of the treatment benefit by using the relative risk (RR) value of a 50% reduction of the risk of a heart attack, since one is 50% of two. By using the RR type of data analysis, clinical trial directors can promote the outcome of their trial in their publication and to the media as highly successful while minimizing or disregarding entirely the absolute risk (AR) reduction of only one percentage point. The practice of expressing the RR without the AR has become routinely deployed in the reporting of findings in many different areas of clinical research. We have provided a historical perspective on how this form of data presentation has become commonplace in the reporting of findings from randomized controlled trials (RCTs) on coronary heart disease (CHD) event monitoring and prevention over the past four decades. We assert that the emphasis on RR coupled with insufficient disclosure of AR in the reporting of RCT outcomes has led healthcare providers and the public to overestimate concerns about high cholesterol and to be misled as to the magnitude of the benefits of cholesterol-lowering therapy. The goal of this review is to prompt the scientific community to address this misleading approach to data presentation.

Statin therapy is not warranted for a person with high LDL-cholesterol on a low-carbohydrate diet

PURPOSE OF REVIEW

Although there is an extensive literature on the efficacy of the low carbohydrate diet (LCD) for weight loss and in the management of type 2 diabetes, concerns have been raised that the LCD may increase cardiovascular disease (CVD) risk by increasing the level of low-density lipoprotein cholesterol (LDL-C). We have assessed the value of LDL-C as a CVD risk factor, as well as effects of the LCD on other CVD risk factors. We have also reviewed findings that provide guidance as to whether statin therapy would be beneficial for individuals with high LDL-C on an LCD.

RECENT FINDINGS

Multiple longitudinal trials have demonstrated the safety and effectiveness of the LCD, while also providing evidence of improvements in the most reliable CVD risk factors. Recent findings have also confirmed how ineffective LDL-C is in predicting CVD risk.

SUMMARY

Extensive research has demonstrated the efficacy of the LCD to improve the most robust CVD risk factors, such as hyperglycemia, hypertension, and atherogenic dyslipidemia. Our review of the literature indicates that statin therapy for both primary and secondary prevention of CVD is not warranted for individuals on an LCD with elevated LDL-C who have achieved a low triglyceride/HDL ratio.

Simvastatin and fluvastatin attenuate trauma-induced cell death and catabolism in human cartilage

Joint injuries are known to induce pathomechanisms that might lead to posttraumatic osteoarthritis (PTOA). In this regard, statins with their pleiotropic effects could represent potential therapeutic agents in preventing the development of PTOA. Therefore, we investigated the effects of simvastatin and fluvastatin in a drop-tower-based human ex vivo cartilage trauma model. After 7 days, a mechanical impact (0.59 J) resulted in a decrease of the cell viability and increased expression of catabolic enzymes in cartilage explants. Simvastatin and fluvastatin treatment of impacted cartilage demonstrated cell protective effects in a concentration dependent manner. Moreover, statin therapy exhibited chondroprotective effects as demonstrated by attenuated expression of MMP-2 and MMP-13 as well as subsequent breakdown of collagen type II (after impact). Further analysis indicated antioxidative properties of the statins by upregulating the gene expression of SOD2 and suppression that of NOX2 and NOX4. Despite its protective effects, simvastatin impaired the biosynthesis of collagen type II, which was confirmed during chondrogenic redifferentiation of high passage chondrocytes. However, while long-term administration of statins for 4 weeks impaired chondrogenic redifferentiation, addition of simvastatin at low concentrations for 1 week exhibited a slightly promoting effect. In conclusion, our data imply that simvastatin and fluvastatin are suitable in terms of initial harm reduction after cartilage trauma.

Comparison of toxic effects of atorvastatin and gemfibrozil on Daphnia magna

Atorvastatin (ATV) and gemfibrozil (GEM) are two typical lipid-lowering pharmaceuticals with different action modes, which are frequently detected in various water bodies owning to their wide usage. However, there is limited information about their effects on Daphnia magna. The present study addressed and compared the toxic effects of ATV and GEM on D. magna through determining the responses of the stress related genes (including Nrf2, Keap1, HO-1, GCLC, p53 and PIG3) in D. magna for 24 h and 48 h acute exposure and the changes of life history traits and swimming behaviors in a 21 days chronic exposure under different concentrations of ATV and GEM exposure (5 μg L^-1, 50 μg L^-1, 500 μg L^-1 and 5000 μg L^-1). Results showed that the expression of Nrf2, Keap1, HO-1, GCLC, p53 and PIG3 were induced to various degrees under the ATV exposure. There were similar performances for GEM. ATV and GEM caused the delay of first brooding and hatching time and decrease of eggs production number, especially in GEM exposure, reproduction of Daphnia was significantly inhibited, decreasing 38.51% compared to the control. ATV and GEM increased the heart rate of D. magna, and changed swimming behaviors of D. magna. In summary, two lipid-lowering pharmaceuticals caused oxidative stress on D. magna, subsequently brought about alterations in physiological traits. Comparatively, ATV pose more higher risks to D. magna than GEM, but the detailed action mechanisms of ATV and GEM on D. magna needs more investigations in future.

Effects of Lovastatin on Brain Cancer Cells

Although brain tumors occur less frequently than other forms of cancer, they have one of the bleakest prognoses with low survival rates. The conventional treatment for brain tumors includes surgery, radiotherapy, and chemotherapy. However, resistance to treatment remains a problem with recurrence shortly following. The resistance to treatment may be caused by cancer stem cells (CSCs), a subset of brain tumor cells with the affinity for self-renewal and differentiation into multiple cell lineages. An emerging approach to targeting CSCs in brain tumors is through repurposing the lipid-lowering medication, lovastatin. Lovastatin is a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor that impacts the mevalonate pathway. The inhibition of intermediates in the mevalonate pathway affects signaling cascades and oncogenes associated with brain tumor stem cells (BTSC). In this review, we show the possible mechanisms where lovastatin can target BTSC for different varieties of malignant brain tumors.

In search of elixir: Pharmacological agents against stem cell senescence

Stem cell senescence causes different complications. In addition to the aging phenomenon, stem cell senescence has been investigated in various concepts such as cancer, adverse drug effects, and as a limiting factor in cell therapy. This manuscript examines protective medicines and supplements which are capable of hindering stem cell senescence. We searched the databases such as EMBASE, PubMed, and Web of Science with the keywords "stem cell," "progenitor cell," "satellite," "senescence" and excluded the keywords "cancer," "tumor," "malignancy" and "carcinoma" until June 2020. Among these results, we chose 47 relevant studies. Our investigation indicates that most of these studies examined endothelial progenitor cells, hematopoietic stem cells, mesenchymal stem cells, adipose-derived stem cells, and a few others were about less-discussed types of stem cells such as cardiac stem cells, myeloblasts, and induced pluripotent stem cells. From another aspect, 17β-Estradiol, melatonin, metformin, rapamycin, coenzyme Q10, N-acetyl cysteine, and vitamin C were the most studied agents, while the main protective mechanism was through telomerase activity enhancement or oxidative damage ablation. Although many of these studies are in vitro, they are still worthwhile. Stem cell senescence in the in vitro expansion stage is an essential concern in clinical procedures of cell therapy. Moreover, in vitro studies are the first step for further in vivo and clinical studies. It is noteworthy to mention the fact that these protective agents have been used in the clinical setting for various purposes for a long time. Given that, we only need to examine their systemic anti-senescence effects and effective dosages.

The role of statins in the differentiation and function of bone cells

BACKGROUND

Statins are 3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors blocking cholesterol biosynthesis in hepatic cells, thereby causing an increase in low-density lipoprotein (LDL) receptors resulting in enhanced uptake and clearance of atherogenic LDL-cholesterol (LDL-C) from the blood. Accordingly, statins decrease the risk of developing atherosclerosis and its acute complications, such as acute myocardial infarction and ischaemic stroke. Besides the LDL-C-lowering impact, statins also have other so-called pleiotropic effects. Among them, the ability to modulate differentiation and function of bone cells and exert direct effects on osteosynthesis factors. Specifically, earlier studies have shown that statins cause in vitro and in vivo osteogenic differentiation.

DESIGN

The most relevant papers on the bone-related 'pleiotropic' effects of statins were selected following literature search in databases and were reveiwed.

RESULTS

Statins increase the expression of many mediators involved in bone metabolism including bone morphogenetic protein-2 (BMP-2), glucocorticoids, transforming growth factor-beta (TGF-β), alkaline phosphatase (ALP), type I collagen and collagenase-1. As a result, they enhance bone formation and improve bone mineral density by modulating osteoblast and osteoclast differentiation.

CONCLUSION

This review summarizes the literature exploring bone-related 'pleiotropic' effects of statins and suggests an anabolic role in the bone tissue for this drug class. Accordingly, current knowledge encourages further clinical trials to assess the therapeutic potential of statins in the treatment of bone disorders, such as arthritis and osteoporosis.

Uterine Stem Cells and Benign Gynecological Disorders: Role in Pathobiology and Therapeutic Implications

Stem cells in the endometrium and myometrium possess an immense regenerative potential which is necessary to maintain the menstrual cycle and support pregnancy. These cells, as well as bone marrow stem cells, have also been implicated in the development of common benign gynecological disorders including leiomyomas, endometriosis and adenomyosis. Current evidence suggests the conversion of uterine stem cells to tumor initiating stem cells in leiomyomas, endometriosis stem cells, and adenomyosis stem cells, acquiring genetic and epigenetic alterations for the progression of each benign condition. In this comprehensive review, we aim to summarize the progress that has been made to characterize the involvement of stem cells in the pathogenesis of benign gynecologic conditions which, despite their enormous burden, are not yet fully understood. We focus on the stem cell characteristics and aberrations that contribute to the development of benign gynecological disorders and the possible clinical implications of what is known so far. Lastly, we discuss the role of uterine stem cells in the setting of regenerative medicine, particularly in the treatment of Asherman syndrome.Graphical abstract.

The influence of oxygen deprivation and donor age on the effect of statins on human mesenchymal stromal cells

To date, no study evaluated the effect of oxygen deprivation together with statins pretreatment on human mesenchymal stromal cells (MSCs). The aim of our study was to establish the influence of atorvastatin and rosuvastatin on MSC proliferation and cytotoxicity in different oxygenic conditions. Human MSCs isolated from the bone marrow (n = 12) were incubated with statins. The proliferation rate and cytotoxic effect were evaluated in normoxic (21 %O₂) and hypoxic (2%O₂) conditions, also in relation to donor age. The treatment with atorvastatin was associated with significantly higher proliferation rate compared to control, both in hypoxic (19 % median increase) and normoxic conditions (20 %), p = 0.02 and p = 0.04, respectively. Atorvastatin had no significant cytotoxic effect on MSCs. Treatment with rosuvastatin in hypoxia resulted in significantly higher proliferation rate (15 %, p = 0.02) comparing to control with no significant cytotoxicity. In atmospheric oxygen concentration, rosuvastatin was associated with no significant change in proliferation and higher cytotoxicity compared to untreated control (p = 0.042 and p = 0.015, for 0.04 μM and 1 μM solutions respectively). There were no differences in the effect of statins on MSC from young donors vs. aged donors. These results suggest that statins could support MSC-based therapy of acute myocardial infarction.

Looking for immortality: Review of phytotherapy for stem cell senescence

In this paper, we discussed natural agents with protective effects against stem cell senescence. Different complications have been observed due to stem cell senescence and the most important of them is "Aging". Senescent cells have not normal function and their secretary inflammatory factors induce chronic inflammation in body which causes different pathologies. Stem cell senescence also has been investigated in different diseases or as drug adverse effects. We searched databases such as Embase, Pubmed and Web of Science with keywords "stem cell", "progenitor cell", "satellite", "senescence" and excluded keywords "cancer", "tumor", "malignancy" and "carcinoma" without time limitation until May 2019. Among them we chose 52 articles that have investigated protective effects of natural agents (extracts or molecules) against cellular senescence in different kind of adult stem cells. Most of these studies were in endothelial progenitor cells, hematopoietic stem cells, mesenchymal stem cells, adipose-derived stem cells and few were about other kinds of stem cells. Most studied agents were resveratrol and ginseng which are also commercially available as supplement. Most protective molecular targets were telomerase and anti-oxidant enzymes to preserve genome integrity and reduce senescence-inducing signals. Due to the safe and long history of herbal usage in clinic, phytotherapy can be used for preventing stem cell senescence and their related complication. Resveratrol and ginseng can be the first choice for this aim due to their protective mechanisms in various kinds of stem cells and their long term clinical usage.

Effects of statins on the biological features of mesenchymal stem cells and therapeutic implications

Statins are well-known lipid-lowering drugs. The pleiotropic effects of statins have brought about some beneficial effects on improving the therapeutic outcomes of cell therapy and tissue engineering approaches. In this review, the impact of statins on mesenchymal stem cell behaviors including differentiation, apoptosis, proliferation, migration, and angiogenesis, as well as molecular pathways which are responsible for such phenomena, are discussed. A better understanding of pathways and mechanisms of statin-mediated effects on mesenchymal stem cells will pave the way for the expansion of statin applications. Furthermore, since designing a suitable carrier for statins is required to maintain a sufficient dose of active statins at the desired site of the body, different systems for local delivery of statins are also reviewed.

Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is considered the hepatic manifestation of the metabolic syndrome (MetS) and comprises one of the largest health threats of the twenty-first century. In this chapter, we review the current state of knowledge of NAFLD and underline the striking similarities with atherosclerosis. We first describe current epidemiological data showing the staggering increase of NAFLD numbers and its related clinical and economic costs. We then provide an overview of pathophysiological hepatic processes in NAFLD and highlight the systemic aspects of NAFLD that point toward metabolic crosstalk between organs as an important cause of metabolic disease. Finally, we end by highlighting the currently investigated therapeutic approaches for NAFLD, which also show strong similarities with a range of treatment options for atherosclerosis.

A framework for identification of on- and off-target transcriptional responses to drug treatment

Owing to safety concerns or insufficient efficacy, few drug candidates are approved for marketing. Drugs already on the market may be withdrawn due to adverse effects (AEs) discovered after market introduction. Comprehensively investigating the on-/off-target effects of drugs can help expose AEs during the drug development process. We have developed an integrative framework for systematic identification of on-/off-target pathways and elucidation of the underlying regulatory mechanisms, by combining promoter expression profiling after drug treatment with gene perturbation of the primary drug target. Expression profiles from statin-treated cells and HMG-CoA reductase knockdowns were analyzed using the framework, allowing for identification of not only reported adverse effects but also novel candidates of off-target effects from statin treatment, including key regulatory elements of on- and off-targets. Our findings may provide new insights for finding new usages or potential side effects of drug treatment.

Statin Toxicity

There is now overwhelming evidence to support lowering LDL-c (low-density lipoprotein cholesterol) to reduce cardiovascular morbidity and mortality. Statins are a class of drugs frequently prescribed to lower cholesterol. However, in spite of their wide-spread use, discontinuation and nonadherence remains a major gap in both the primary and secondary prevention of atherosclerotic cardiovascular disease. The major reason for statin discontinuation is because of the development of statin-associated muscle symptoms, but a range of other statin-induced side effects also exist. Although the mechanisms behind these side effects have not been fully elucidated, there is an urgent need to identify those at increased risk of developing side effects as well as provide alternative treatment strategies. In this article, we review the mechanisms and clinical importance of statin toxicity and focus on the evaluation and management of statin-associated muscle symptoms.

Concise Review: Reduction of Adverse Cardiac Scarring Facilitates Pluripotent Stem Cell-Based Therapy for Myocardial Infarction

Pluripotent stem cells (PSCs) are an attractive, reliable source for generating functional cardiomyocytes for regeneration of infarcted heart. However, inefficient cell engraftment into host tissue remains a notable challenge to therapeutic success due to mechanical damage or relatively inhospitable microenvironment. Evidence has shown that excessively formed scar tissues around cell delivery sites present as mechanical and biological barriers that inhibit migration and engraftment of implanted cells. In this review, we focus on the functional responses of stem cells and cardiomyocytes during the process of cardiac fibrosis and scar formation. Survival, migration, contraction, and coupling function of implanted cells may be affected by matrix remodeling, inflammatory factors, altered tissue stiffness, and presence of electroactive myofibroblasts in the fibrotic microenvironment. Although paracrine factors from implanted cells can improve cardiac fibrosis, the transient effect is insufficient for complete repair of an infarcted heart. Furthermore, investigation of interactions between implanted cells and fibroblasts including myofibroblasts helps the identification of new targets to optimize the host substrate environment for facilitating cell engraftment and functional integration. Several antifibrotic approaches, including the use of pharmacological agents, gene therapies, microRNAs, and modified biomaterials, can prevent progression of heart failure and have been developed as adjunct therapies for stem cell-based regeneration. Investigation and optimization of new biomaterials is also required to enhance cell engraftment of engineered cardiac tissue and move PSCs from a laboratory setting into translational medicine.

Atherosclerosis is a vascular stem cell disease caused by insulin

The present article proposes the hypothesis that when multipotent vascular stem cells are exposed to excessive insulin in a rhythmic pattern of sharply rising and falling concentrations, their differentiation is misdirected toward adipogenic and osteogenic cell lineages. This results in plaque-like accumulation of adipocytes with fat and cholesterol deposition from adipocyte debris, and osteogenic (progenitor) cells with a calcified matrix in advanced lesions. The ingrowth of capillaries and infiltration with macrophages, which upon uptake of lipids turn into foam cells, are unspecific pro-resolving reactions. Epidemiological, histopathological, pharmacological, and experimental evidence in favour of this hypothesis is summarised.

Performing a Better Bone Marrow Aspiration

Bone marrow aspiration (BMA) is increasingly being used to harvest stem cells for use in regenerative medicine. The focus of BMA in interventional orthopedics is to maximize the yield of mesenchymal stem cells. The authors present an improved method for BMA that involves fluoroscope or ultrasound guidance combined with anesthesia; in the authors' experience, it produces the highest possible stem cell yield and is well tolerated by patients. The authors provide a step-by-step guide to the process, along with a discussion of technical and other considerations and quick reference guides for ultrasound- and fluoroscope-guided BMA.

Influence of cholesterol/caveolin-1/caveolae homeostasis on membrane properties and substrate adhesion characteristics of adult human mesenchymal stem cells

BACKGROUND

Adult mesenchymal stem cells (MSCs) are an important resource for tissue growth, repair, and regeneration. To utilize MSCs more effectively, a clear understanding of how they react to environmental cues is essential. Currently, relatively little is known about how the composition of the plasma membranes affects stem cell phenotype and properties. The presence of lipid molecules, including cholesterol in particular, in the plasma membrane plays a crucial role in regulating a variety of physiological processes in cells. In this study, we examined the effects of perturbations in cholesterol/caveolin-1 (CAV-1)/caveolae homeostasis on the membrane properties and adhesive characteristics of MSCs. Findings from this study will contribute to the understanding of how cholesterol/CAV-1/caveolae regulates aspects of the cell membrane important to cell adhesion, substrate sensing, and microenvironment interaction.

METHODS

We generated five experimental MSC groups: 1) untreated MSCs; 2) cholesterol-depleted MSCs; 3) cholesterol-supplemented MSCs; 4) MSCs transfected with control, nonspecific small interfering (si)RNA; and 5) MSCs transfected with CAV-1 siRNA. Each cell group was analyzed for perturbation of cholesterol status and CAV-1 expression by performing Amplex Red cholesterol assay, filipin fluorescence staining, and real-time polymerase chain reaction (PCR). The membrane fluidity in the five experimental cell groups were measured using pyrene fluorescence probe staining followed by FACS analysis. Cell adhesion to collagen and fibronectin as well as cell surface integrin expression were examined.

RESULTS

Cholesterol supplementation to MSCs increased membrane cholesterol, and resulted in decreased membrane fluidity and localization of elevated numbers of caveolae and CAV-1 to the cell membrane. These cells showed increased expression of α1, α4, and β1 integrins, and exhibited higher adhesion rates to fibronectin and collagen. Conversely, knockdown of CAV-1 expression or cholesterol depletion on MSCs caused a parallel decrease in caveolae content and an increase in membrane fluidity due to decreased delivery of cholesterol to the cell membrane. Cells with depleted CAV-1 expression showed decreased cell surface integrin expression and slower adhesion to different substrates.

CONCLUSIONS

Our results demonstrate that perturbations in cholesterol/CAV-1 levels significantly affect the membrane properties of MSCs. These findings suggest that modification of membrane cholesterol and/or CAV-1 and caveolae may be used to manipulate the biological activities of MSCs.

Concise Review: Optimized Strategies for Stem Cell-Based Therapy in Myocardial Repair: Clinical Translatability and Potential Limitation

Ischemic heart diseases (IHDs) remain major public health problems with high rates of morbidity and mortality worldwide. Despite significant advances, current therapeutic approaches are unable to rescue the extensive and irreversible loss of cardiomyocytes caused by severe ischemia. Over the past 16 years, stem cell-based therapy has been recognized as an innovative strategy for cardiac repair/regeneration and functional recovery after IHDs. Although substantial preclinical animal studies using a variety of stem/progenitor cells have shown promising results, there is a tremendous degree of skepticism in the clinical community as many stem cell trials do not confer any beneficial effects. How to accelerate stem cell-based therapy toward successful clinical application attracts considerate attention. However, many important issues need to be fully addressed. In this Review, we have described and compared the effects of different types of stem cells with their dose, delivery routes, and timing that have been routinely tested in recent preclinical and clinical findings. We have also discussed the potential mechanisms of action of stem cells, and explored the role and underlying regulatory components of stem cell-derived secretomes/exosomes in myocardial repair. Furthermore, we have critically reviewed the different strategies for optimizing both donor stem cells and the target cardiac microenvironments to enhance the engraftment and efficacy of stem cells, highlighting their clinical translatability and potential limitation. Stem Cells 2018;36:482-500.

Chemical and Physical Approaches to Extend the Replicative and Differentiation Potential of Stem Cells

Cell therapies using mesenchymal stem cells (MSCs) and endothelial progenitor cells (EPCs) are increasing in regenerative medicine, with applications to a growing number of aging-associated dysfunctions and degenerations. For successful therapies, a certain mass of cells is needed, requiring extensive ex vivo expansion of the cells. However, the proliferation of both MSCs and EPCs is limited as a result of telomere shortening-induced senescence. As cells approach senescence, their proliferation slows down and differentiation potential decreases. Therefore, ways to delay senescence and extend the replicative lifespan these cells are needed. Certain proteins and pathways play key roles in determining the replicative lifespan by regulating ROS generation, damage accumulation, or telomere shortening. And, their agonists and gene activators exert positive effects on lifespan. In many of the treatments, importantly, the lifespan is extended with the retention of differentiation potential. Furthermore, certain culture conditions, including the use of specific atmospheric conditions and culture substrates, exert positive effects on not only the proliferation rate, but also the extent of proliferation and differentiation potential as well as lineage determination. These strategies and known underlying mechanisms are introduced in this review, with an evaluation of their pros and cons in order to facilitate safe and effective MSC expansion ex vivo.

Use of Statins in Patients with Chronic Liver Disease and Cirrhosis: Current Views and Prospects

PURPOSE OF REVIEW

The purpose of this study is to analyze the current evidence regarding the use of statins in patients with chronic liver disease and cirrhosis.

RECENT FINDINGS

Chronic liver disease (CLD), cirrhosis, and its complications, including hepatocellular carcinoma (HCC), are significant public health problems. The use of statins in patients with CLD has been a matter of concern, and physicians are often reluctant to its prescription in these patients. This mainly relates to the potential occurrence of drug-induced liver injury. However, newer evidence from pre-clinical and clinical research has shown that statins are drugs with a potentially beneficial impact on the natural history of cirrhosis, on portal hypertension, and in HCC prevention. In this review, we summarize current evidence regarding the influence of statins in endothelial dysfunction in CLD, their ability to modulate hepatic fibrogenesis, and their vasoprotective effects in portal hypertension; we also focus on existing data about the impact of statins in cirrhosis development, progression, and complications and critically assess the current concerns about its use in patients with CLD.

The role of mast cells and macrophages in amiodarone induced pulmonary fibrosis and the possible attenuating role of atorvastatin

Amiodarone (AM) is an effective anti-arrhythmic drug. We investigated the role of mast cells and macrophages on AM induced pulmonary fibrosis and the action of atorvastatin on this fibrosis. Rats were allocated into four groups; negative control (1), positive control (2), 30 mg/kg body weight/day AM (3) and AM + 10 mg/kg/day atorvastatin (4). Lungs were harvested and prepared for histology and immunohistochemistry. Hematoxylin and eosin stained sections of group 3 exhibited disorganized lung architecture. We found cellular debris in the lumen of both intrapulmonary bronchi and bronchioles with partial disruption of the thickened epithelial lining and mononuclear cellular infiltration into the lamina propria. We also observed thickening of the epithelial lining and the smooth muscle layer. Congested, dilated and thickened blood capillaries and thickened inter-alveolar septa were observed with mononuclear cellular infiltrates in the lung of group 3. Most alveoli were collapsed, but some dilated ones were detected. In some alveoli, type ІІ pneumocytes were increased, while type I cells were decreased. We observed significant increases in the amount of collagen in the thickened inter-alveolar septa, around bronchioles and around blood capillaries in sections from group 3. We found a significant increase in mast cells and alveolar macrophages in group 3 compared to group 1. Mast cells and macrophages appear to play important roles in AM induced pulmonary fibrosis. Atorvastatin appears to attenuate this condition.

Hypolipidemic effect of XH601 on hamsters of Hyperlipidemia and its potential mechanism

BACKGROUND

The novel compound XH601 is a synthesized derivative of formononetin. The present study was to investigate the hypolipidemia effect and potential mechanism of XH601.

METHODS

Male Golden Syrian hamsters were induced by high-fat diet (HFD) for eight weeks and the hyperlipidemic model was established successfully. After XH601 treatment, serum and hepatic biochemistry parameters of hamsters were detected and the effect of XH601 on adipose tissue was also analyzed. Furthermore, 3 T3-L1 cell differentiation by Oil-Red-O staining was observed and the mRNA and protein expression of peroxisome proliferator-activated receptors (PPARs) were measured by qRT-PCR and Western-blot in mature adipocytes.

RESULTS

The in vivo results suggest that XH601 significantly decreased the adipose weight and levels of serum triglyceride (TG), total cholesterol (TC), low-density lipoprotein (LDL-C), apolipoprotein B (Apo-B), apolipoprotein E (Apo-E), while increased serum high-density lipoprotein (HDL-C). The in vitro results implied that XH601 up-regulated the mRNA and protein expression of both PPARα and PPARβ/δ in a dose-dependent manner.

CONCLUSIONS

The study suggests that XH601 exhibited strong ability to improve the dyslipidemia in hamsters fed with high-fat diet. The potential mechanism of XH601 was associated with the up-regulation of PPARα and PPARβ/δ mRNA and protein expression.

Effects of statins on the development of sepsis and organ dysfunction in hospitalized older patients in China

This study aimed to evaluate the protective role of statins on the development of sepsis and infection-related organ dysfunction and mortality in a hospitalized older Chinese population with bacterial infections. In this retrospective cohort study, 257 older patients with bacterial infection were divided into two groups: a statin group, those who had received statin therapy for ≥1 month before admission and continued receiving statin during hospitalization; and a non-statin group, those who had never received statin or used statin for <1 month prior to admission. A multivariate logistic regression analysis was performed to identify risk and protective factors for severe sepsis. A significantly lower incidence of organ dysfunction was found in the statin group, as compared with the non-statin group (13.3% vs 31.1%, respectively; p = 0.002), corresponding to adjusted rates ratio of 0.32 (95% confidence interval [CI], 0.13–0.75; p = 0.009). No significant difference was found between statin and non-statin groups in 30-day sepsis-related mortality (4.4% vs 10.2%, respectively; p = 0.109), incidence of intensive care unit admission (13.3% vs 16.8%, respectively; p = 0.469), or length of hospital stay (20.5 vs 25.9 days, respectively; p = 0.61). Statins significantly reduced the development of sepsis and infection-related organ dysfunction in hospitalized older Chinese patients but did not reduce 30-day mortality, ICU admission incidence, or length of hospital stay.

Statin non-adherence and residual cardiovascular risk: There is need for substantial improvement

Although statin therapy has proven to be the cornerstone for prevention and treatment of cardiovascular disease (CVD), there are many patients for whom long-term therapy remains suboptimal. The aims of this article are to review the current complex issues associated with statin use and to explore when novel treatment approaches should be considered. Statin discontinuation as well as adherence to statin therapy remain two of the greatest challenges for lipidologists. Evidence suggests that between 40 and 75% of patients discontinue their statin therapy within one year after initiation. Furthermore, whilst the reasons for persistence with statin therapy are complex, evidence shows that low-adherence to statins negatively impacts clinical outcomes and residual CV risk remains a major concern. Non-adherence or lack of persistence with long-term statin therapy in real-life may be the main cause of inadequate low density lipoprotein cholesterol lowering with statins. There is a large need for the improvement of the use of statins, which have good safety profiles and are inexpensive. On the other hand, in a non-cost-constrained environment, proprotein convertase subtilisin/kexin type 9 inhibitors should arguably be used more often in those patients in whom treatment with statins remains unsatisfactory.

Statin-associated myopathy and the quest for biomarkers: can we effectively predict statin-associated muscle symptoms?

Over the past three decades, statins have become the cornerstone of prevention and treatment of atherosclerotic cardiovascular and metabolic diseases. Albeit generally well tolerated, these drugs can elicit a variety of muscle-associated symptoms that represent the most important reason for treatment discontinuation. Statin-associated myopathy has been systematically underestimated by randomized controlled trials as compared with the incidence observed in clinical practice and obtained from patient registries. There are several reasons for this discrepancy, among which the lack of reliable diagnostic tests and a validated questionnaire to assess muscle symptoms are recognized as unmet needs. Here, we review the cellular and molecular mechanisms underlying statin-associated myopathy and discuss the experimental and clinical data on various biomarkers to diagnose and predict muscle-related complaints.

Drug repurposing for vascular dementia: overview and current developments

Antidementive drugs have made Alzheimer's disease a symptomatically treatable condition but have essentially bypassed vascular dementia. The complexity of its pathology, the variable pathognomonic manifestations, the absence of validated biomarkers and the continuum with Alzheimer's disease that makes vascular dementia a comparatively small market are the major contributing factors. This report discusses how drug repurposing can be harnessed to identify new therapeutic opportunities, where such efforts are already yielding promising results, and which ones must be considered failures. Most investigations address obvious aspects cerebral small vessel disease, but some early-stage developments attempt changes in gene expression or modulation of complex biological pathways. A stronger focus on the nature and dynamics of white matter lesions should yield additional molecular targets.

Innovation in medicine: Ignaz the reviled and Egas the regaled

In our current climate of rapid technological progress, it seems counterintuitive to think that modern science can learn anything of ethical value from the dark recesses of the nineteenth century or earlier. However, this happens to be quite true, with plenty of knowledge and wisdom to be gleaned by studying our scientific predecessors. Presently, our journals are flooded with original concepts and potential breakthroughs, a continuous stream of ideas pushing the frontiers of knowledge ever forward. Some ideas flourish while others flounder; but what sets the two apart? The distinguishing feature between success and failure within this context is the ability to discern the appropriate time to accept an innovation with open arms, versus when to take a more cautious approach. And the primary arbiters for whether an idea will catch on or not are the professional audience. I illustrate this concept by comparing the initial reception of two innovative ideas from Medicine's past: sterile technique, and prefrontal lobotomy. Sterile technique was first introduced by Dr. Ignaz Semmelweis and was initially ridiculed and rejected, with Semmelweis eventually dying in exile. Conversely, lobotomy was accepted and lauded and its inventor, Dr. Egas Moniz, won the Nobel Prize for his "discovery". This begs the question: why was a technique with the potential to save millions of lives initially rejected, whereas paradoxically, one that compromised and sometimes destroyed lives, accepted? Here I explore and analyze the potential reasons why, suggest how we can learn from these mistakes of the past and apply new insight to some current ethical dilemmas.

Skin Metabolite, Farnesyl Pyrophosphate, Regulates Epidermal Response to Inflammation, Oxidative Stress, and Migration

Skin produces cholesterol and a wide array of sterols and non-sterol mevalonate metabolites, including isoprenoid derivative farnesyl pyrophosphate (FPP). To characterize FPP action in epidermis, we generated transcriptional profiles of primary human keratinocytes treated with zaragozic acid (ZGA), a squalene synthase inhibitor that blocks conversion of FPP to squalene resulting in endogenous accumulation of FPP. The elevated levels of intracellular FPP resulted in regulation of epidermal differentiation and adherens junction signaling, insulin growth factor (IGF) signaling, oxidative stress response and interferon (IFN) signaling. Immunosuppressive properties of FPP were evidenced by STAT-1 downregulation and prominent suppression of its nuclear translocation by IFNγ. Furthermore, FPP profoundly downregulated genes involved in epidermal differentiation of keratinocytes in vitro and in human skin ex vivo. Elevated levels of FPP resulted in induction of cytoprotective transcriptional factor Nrf2 and its target genes. We have previously shown that FPP functions as ligand for the glucocorticoid receptor (GR), one of the major regulator of epidermal homeostasis. Comparative microarray analyses show significant but not complete overlap between FPP and glucocorticoid regulated genes, suggesting that FPP may have wider transcriptional impact. This was further supported by co-transfection and chromatin immunoprecipitation experiments where we show that upon binding to GR, FPP recruits β-catenin and, unlike glucocorticoids, recruits co-repressor GRIP1 to suppress keratin 6 gene. These findings have many clinical implications related to epidermal lipid metabolism, response to glucocorticoid therapy as well as pleiotropic effects of cholesterol lowering therapeutics, statins. J. Cell. Physiol. 231: 2452-2463, 2016. © 2016 Wiley Periodicals, Inc.

Innovative Target Therapies Are Able to Block the Inflammation Associated with Dysfunction of the Cholesterol Biosynthesis Pathway

The cholesterol pathway is an essential biochemical process aimed at the synthesis of bioactive molecules involved in multiple crucial cellular functions. The end products of this pathway are sterols, such as cholesterol, which are essential components of cell membranes, precursors of steroid hormones, bile acids and other molecules such as ubiquinone. Several diseases are caused by defects in this metabolic pathway: the most severe forms of which cause neurological involvement (psychomotor retardation and cerebellar ataxia) as a result of a variety of cellular impairments, including mitochondrial dysfunction. These pathologies are induced by convergent mechanisms in which the mitochondrial unit plays a pivotal role contributing to defective apoptosis, autophagy and mitophagy processes. Unraveling these mechanisms would contribute to the development of effective drug treatments for these disorders. In addition, the development of biochemical models could have a substantial impact on the understanding of the mechanism of action of drugs that act on this pathway in multifactor disorders. In this review we will focus in particular on inhibitors of cholesterol synthesis, mitochondria-targeted drugs and inhibitors of the inflammasome.