Metformin, the aspirin of the 21st century: its role in gestational diabetes mellitus, prevention of preeclampsia and cancer, and the promotion of longevity

Specificity Protein Transcription Factors and Cancer: Opportunities for Drug Development

Specificity protein (Sp) transcription factors (TFs) such as Sp1 are critical for early development but their expression decreases with age and there is evidence that transformation of normal cells to cancer cells is associated with upregulation of Sp1, Sp3, and Sp4, which are highly expressed in cancer cells and tumors. Sp1 is a negative prognostic factor for pancreatic, colon, glioma, gastric, breast, prostate, and lung cancer patients. Functional studies also demonstrate that Sp TFs regulate genes responsible for cancer cell growth, survival, migration/invasion, inflammation and drug resistance, and Sp1, Sp3 and Sp4 are also nononcogene addiction (NOA) genes and important drug targets. The mechanisms of drug-induced downregulation of Sp TFs and pro-oncogenic Sp-regulated genes are complex and include ROS-dependent epigenetic pathways that initially decrease expression of the oncogene cMyc. Many compounds such as curcumin, aspirin, and metformin that are active in cancer prevention also exhibit chemotherapeutic activity and these compounds downregulate Sp TFs in cancer cell lines and tumors. The effects of these compounds on downregulation of Sp TFs in normal cells and the contribution of this response to their chemopreventive activity have not yet been determined. Cancer Prev Res; 11(7); 371-82. ©2018 AACR.

Gut microbiome and aging: Physiological and mechanistic insights

The development of human gut microbiota begins as soon as the neonate leaves the protective environment of the uterus (or maybe in-utero) and is exposed to innumerable microorganisms from the mother as well as the surrounding environment. Concurrently, the host responses to these microbes during early life manifest during the development of an otherwise hitherto immature immune system. The human gut microbiome, which comprises an extremely diverse and complex community of microorganisms inhabiting the intestinal tract, keeps on fluctuating during different stages of life. While these deviations are largely natural, inevitable and benign, recent studies show that unsolicited perturbations in gut microbiota configuration could have strong impact on several features of host health and disease. Our microbiota undergoes the most prominent deviations during infancy and old age and, interestingly, our immune health is also in its weakest and most unstable state during these two critical stages of life, indicating that our microbiota and health develop and age hand-in-hand. However, the mechanisms underlying these interactions are only now beginning to be revealed. The present review summarizes the evidences related to the age-associated changes in intestinal microbiota and vice-versa, mechanisms involved in this bi-directional relationship, and the prospective for development of microbiota-based interventions such as probiotics for healthy aging.

Prevention of obesity and diabetes in pregnancy: is it an impossible dream?

The obesity and diabetes epidemic is an unintended consequence of economic, social, and technological changes. In nonpregnancy, people identified as high risk to develop type 2 diabetes may delay progression by 30-70% with lifestyle interventions and pharmacological agents. In pregnancy, lifestyle interventions have been the primary focus to prevent fetal short- and long-term complications that may evolve into substantial weight gain and gestational diabetes mellitus. The dilemma for obstetricians is whether diabetes and obesity can be prevented and not simply treated after the fact. Interventions after women become pregnant may be too late to see the kinds of meaningful improvements in child and maternal health because there is a short interval from gestational diabetes mellitus diagnosis to delivery. Therefore, future efforts need to incorporate quality research, lifestyle interventions that designate time of initiation and duration during pregnancy, the preventative intervention of a prepregnant "fourth trimester," coupled with the concept of precision medicine so that there is the potential to make the impossible dream a reality.

Pharmacological treatment of gestational diabetes mellitus: point/counterpoint

Controversies persist over the most efficacious pharmacologic treatment for gestational diabetes mellitus. For purposes of accuracy in this article, the individual American College of Obstetricians and Gynecologists Practice Bulletin and American Diabetes Association Standards of Medical Care positions on each issue are quoted and then deliberated with evidence of counter claims presented in point/counterpoint. This is a review of all the relevant evidence for the most holistic picture possible. The main issues are (1) which diabetic drugs cross the placenta, (2) the quality of evidence and data source validity, (3) the rationale for the designation of glucose control as the primary outcome in gestational diabetes mellitus, and (4) which drugs (metformin, glyburide, or insulin) are most effective in improving secondary outcomes. The concept that 1 drug fits all, whether it be insulin, glyburide, or metformin, is a fallacy. Different drugs provide certain benefits but not all the benefits and not to all patients. In addition, the steps in the gestational diabetes mellitus management decision path and the current cost of the use of insulin, glyburide, or metformin are addressed. In the future, we must consider studying the potential of diabetic drugs that currently are used in nonpregnancy and incorporating the concept of precision medicine in the decision tree to maximize pregnancy outcomes.

The effects of metformin on maternal haemodynamics in gestational diabetes mellitus: A pilot study

BACKGROUND

Gestational diabetes mellitus (GDM) is a major clinical challenge and is likely to remain so as the incidence of GDM continues to increase.

AIM

To assess longitudinal changes in maternal haemodynamics amongst women diagnosed with GDM requiring either metformin or dietary intervention in comparison to low-risk healthy controls.

METHODOLOGY

Fifty-six pregnant women attending their first appointment at the GDM clinic and 60 low-risk healthy pregnant controls attending their routine antenatal clinics were recruited and assigned to three groups: GDM Metformin (GDM-M), GDM Diet (GDM-D) and Control. Non-invasive assessment of maternal haemodynamics, using recognised measures of arterial stiffness and central blood pressure (Arteriograph®), were undertaken under controlled conditions within four gestational windows: antenatal; AN1 (26-28 weeks), AN2 (32-34 weeks) and AN3 (37-40 weeks), and postnatal (PN) (6-8 weeks after delivery). Data were analysed using a linear mixed model incorporating gestational age and other relevant predictors, including age, blood pressure (BP), baseline bodyweight and pulse as fixed effects, and patient as a random effect.

RESULTS

Fitted linear mixed models showed evidence of a two-way interaction effect between groups (GDM-D, GDM-M and Control) and stages of gestation (AN1, AN2, AN3 and PN) for maternal haemodynamic parameters: brachial artery augmentation index (AIx) (p = 0.004), aortic AIx (p = 0.008), and central systolic BP (p = 0.001). However, differences in respect of aortic pulse wave velocity (p = 0.001) and heart rate (p < 0.001) were only significant for gestational stage. At AN2, we did not observe any evidence that the mean brachial Aix in the GDM-M was different from the control group (p = 0.158).

CONCLUSION

AIx and central systolic BP measures of arterial stiffness are adversely affected by GDM in comparison to controls during pregnancy. The possible beneficial effects of metformin therapy seen at 32 to 34 weeks of gestation require further exploration.

Metformin-induced anticancer activities: recent insights

Metformin is a widely used antidiabetic drug, and there is evidence among diabetic patients that metformin is a chemopreventive agent against multiple cancers. There is also evidence in human studies that metformin is a cancer chemotherapeutic agent, and several clinical trials that use metformin alone or in combination with other drugs are ongoing. In vivo and in vitro cancer cell culture studies demonstrate that metformin induces both AMPK-dependent and AMPK-independent genes/pathways that result in inhibition of cancer cell growth and migration and induction of apoptosis. The effects of metformin in cancer cells resemble the patterns observed after treatment with drugs that downregulate specificity protein 1 (Sp1), Sp3 and Sp4 or by knockdown of Sp1, Sp3 and Sp4 by RNA interference. Studies in pancreatic cancer cells clearly demonstrate that metformin decreases expression of Sp1, Sp3, Sp4 and pro-oncogenic Sp-regulated genes, demonstrating that one of the underlying mechanisms of action of metformin as an anticancer agent involves targeting of Sp transcription factors. These observations are consistent with metformin-mediated effects on genes/pathways in many other tumor types.

Maternal serum AMP-activated protein kinase levels in mild and severe preeclampsia

OBJECTIVE

To investigate Phosphorylated adenosine monophosphate activated protein kinase (AMPK) levels in healthy pregnant women and pregnant women with preeclampsia (PE).

METHODS

Twenty-eight women with mild-PE, 22 with severe-PE, and 30 normotensive controls were included in this cross-sectional study. The serum AMPK levels of these patients were analyzed. The patients were followed up to delivery.

RESULTS

No statistically significant difference was found between the groups for age, gravida, parity, and gestational age at the time the blood samples were obtained (p > .05). No significant difference between the group with mild-PE and the control group was found, while in the severe-PE group, serum AMPK levels were significantly higher relative to both the mild-PE and control groups (p < .001 and p < .001, respectively). No correlation was detected between serum AMPK levels and age, body mass index (BMI), and gestational age at the time the blood samples were collected. A negative correlation was found between AMPK levels and gestational week and birthweight at delivery, while a positive correlation was detected between systolic and diastolic blood pressures and AMPK levels.

CONCLUSIONS

Serum AMPK was higher in patients with severe-PE compared with healthy pregnant women and patients with PE without severe features so it might be a new biomarker for the prediction of disease and its severity.

Chronic hypertension: first-trimester blood pressure control and likelihood of severe hypertension, preeclampsia, and small for gestational age

BACKGROUND

There is extensive evidence that prepregnancy chronic hypertension is associated with a high risk of development of severe hypertension and preeclampsia and birth of small-for-gestational-age neonates. However, previous studies have not reported whether antihypertensive use, blood pressure control, or normalization of blood pressure during early pregnancy influences the rates of these pregnancy complications.

OBJECTIVE

The purpose of this study was to stratify women with prepregnancy chronic hypertension according to the use of antihypertensive medications and level of blood pressure control at the first hospital visit during the first trimester of pregnancy and to examine the rates of severe hypertension, preeclampsia, and birth of small-for-gestational-age neonates according to such stratification.

STUDY DESIGN

We conducted a prospective study of 586 women with prepregnancy chronic hypertension, in the absence of renal or liver disease, that was booked at a dedicated clinic for the management of hypertension in pregnancy. The patients had singleton pregnancies and were subdivided according to findings in their first visit: group 1 (n=199), blood pressure <140/90 mm Hg without antihypertensive medication; group 2 (n=220), blood pressure <140/90 mm Hg with antihypertensive medication; and group 3 (n=167), systolic blood pressure ≥140 mm Hg and/or diastolic blood pressure ≥90 mm Hg, despite antihypertensive medication. In the subsequent management of these pregnancies, our policy was to maintain the blood pressure at 130-140/80-90 mm Hg with the use of antihypertensive medication; antihypertensive drugs were stopped if the blood pressure was persistently <130/80 mm Hg. The outcome measures were severe hypertension (systolic blood pressure ≥160 mm Hg and/or diastolic blood pressure ≥110 mm Hg), preterm and term preeclampsia (in addition to hypertension at least 1 of renal involvement, liver impairment, neurologic complications, or thrombocytopenia), and birth of small-for-gestational-age neonates (birthweight <5th percentile for gestational age). The incidence of these complications was compared in the 3 strata.

RESULTS

The median gestational age at presentation was 10.0 weeks (interquartile range, 9.1-11.0 weeks). In groups 2 and 3, compared with group 1, there was a significantly higher body mass index, incidence of black racial origin, and history of preeclampsia in a previous pregnancy. There was a significant increase from group 1 to group 3 in the incidence of severe hypertension (10.6%, 22.2%, and 52.1%), preterm preeclampsia with onset at <37 weeks of gestation (7.0%, 15.9%, and 20.4%), and small for gestational age (13.1%, 17.7%, and 21.1%), but not term preeclampsia with onset at ≥37 weeks of gestation (9.5%, 9.1%, and 6.6%).

CONCLUSIONS

In women with prepregnancy chronic hypertension, the rates of development of severe hypertension, preterm preeclampsia, and small for gestational age are related to the use of antihypertensive medications and the level of blood pressure control at the first hospital visit during the first trimester of pregnancy.

Combining metformin and esomeprazole is additive in reducing sFlt-1 secretion and decreasing endothelial dysfunction - implications for treating preeclampsia

INTRODUCTION

The discovery of new treatments that prevent or treat preeclampsia would be a major advance. Antiangiogenic factors soluble fms-like tyrosine kinase-1 (sFlt-1) and soluble endoglin (sENG) are secreted in excess from the placenta, causing hypertension, endothelial dysfunction, and multiorgan injury. We recently identified metformin and esomeprazole as potential treatments for preeclampsia. Both reduce placental and endothelial secretion of sFlt-1 and soluble endoglin, and reduce endothelial dysfunction.

OBJECTIVES

We set out to assess whether combining metformin and esomeprazole would additively reduce sFlt-1 and soluble endoglin secretion and reduce endothelial dysfunction (verses drug alone). Metformin and esomeprazole were added to primary placental cells and tissues, and endothelial cells and their effects on sFlt-1 and soluble endoglin secretion were assessed in vitro. Tumor necrosis factor-α (TNF-α) was added to endothelial cells to induce dysfunction in vitro. We examined the ability of metformin + esomeprazole to rescue TNF-α induced vascular cell adhesion molecule-1 (VCAM-1) and Endothelin-1 (ET-1) expression, leukocyte adhesion (markers of endothelial dysfunction).

RESULTS

Combining metformin and esomeprazole was additive at reducing sFlt-1 secretion and expression of sFlt-1 e15a mRNA isoform in primary cytotrophoblast, placental explants and endothelial cells. In contrast, no additive reduction in sENG was observed with combined metformin and esomeprazole. The low-dose combination of metformin + esomeprazole additively reduced TNF-α-induced VCAM-1 mRNA, but not VCAM-1 protein expression. There was no additive reduction when combining metformin and esomeprazole on TNF-α induced PBMC adhesion to endothelial cells. However, combining metformin and esomeprazole additively reduced ET-1 mRNA expression.

CONCLUSIONS

In conclusion combining metformin and esomeprazole additively reduced secretion of sFlt-1, and markers of endothelial dysfunction. The combination of metformin and esomeprazole may provide a more effective treatment or prevention for preeclampsia compared to either as single agents.

Caloric Restriction Dramatically Stalls Lesion Growth in Mice With Induced Endometriosis

Caloric restriction (CR) has been demonstrated to have many health-beneficial effects in many species, but whether CR can impede the development of endometriosis is unknown. To test the hypothesis that CR can impede the growth of endometriotic lesions and fibrogenesis, we conducted 2 experiments. In experiment 1, 20 female Balb/C mice were randomly assigned to either ad libitum (AL) group that was fed AL or to CR group that was fed 30% less calories than that of AL mice. Two weeks after the implementation of the dietary intervention, endometriosis was induced by intraperitoneal injection of endometrial fragments. Two weeks after the induction, all mice were sacrificed and their lesion samples were evaluated. In experiment 2, another 20 mice were used and CR was implemented 2 weeks after induction of endometriosis and lasted for 4 weeks. Caloric restriction instituted before the induction of endometriosis reduced the lesion weight by 88.5%, whereas CR implemented well after lesions were established reduced the lesion weight by 93.0%. In both cases, CR significantly increased staining levels of markers of autophagy but reduced proliferation, angiogenesis, steroidogenesis, and fibrosis in lesions as compared with the AL group. Consequently, CR, instituted either before or after the induction of endometriosis, dramatically curbs the growth of endometriotic lesions and fibrogenesis through multiple mechanisms. Caloric restriction and CR mimetics, a family of compounds mimicking the beneficial effect of CR, even when instituted well after lesions are established, may stall the development of endometriosis. Given the scarcity in research on how lifestyle can impact on the development of endometriosis, our study should hopefully stimulate more research in this area.

Is there a role for placental senescence in the genesis of obstetric complications and fetal growth restriction?

The placenta ages as pregnancy advances, yet its continued function is required for a successful pregnancy outcome. Placental aging is a physiological phenomenon; however, there are some placentas that show signs of aging earlier than others. Premature placental senescence and aging are implicated in a number of adverse pregnancy outcomes, including fetal growth restriction, preeclampsia, spontaneous preterm birth, and intrauterine fetal death. Here we discuss cellular senescence, a state of terminal proliferation arrest, and how senescence is regulated. We also explore the role of physiological placental senescence and how aberrant placental senescence alters placental function, contributing to the pathophysiology of fetal growth restriction, preeclampsia, spontaneous preterm labor/birth, and unexplained fetal death.

Targeting of stress response pathways in the prevention and treatment of cancer

The hallmarks of tumor tissue are not only genetic aberrations but also the presence of metabolic and oxidative stress as a result of hypoxia and lactic acidosis. The stress activates several prosurvival pathways including metabolic remodeling, autophagy, antioxidant response, mitohormesis, and glutaminolysis, whose upregulation in tumors is associated with a poor survival of patients, while their activation in healthy tissue with statins, metformin, physical activity, and natural compounds prevents carcinogenesis. This review emphasizes the dual role of stress response pathways in cancer and suggests the integrative understanding as a basis for the development of rational therapy targeting the stress response.

First-trimester screening for early and late preeclampsia using maternal characteristics, biomarkers, and estimated placental volume

BACKGROUND

Preeclampsia is a major cause of perinatal morbidity and mortality. First-trimester screening has been shown to be effective in selecting patients at an increased risk for preeclampsia in some studies.

OBJECTIVE

We sought to evaluate the feasibility of screening for preeclampsia in the first trimester based on maternal characteristics, medical history, biomarkers, and placental volume.

STUDY DESIGN

This is a prospective observational nonintervention cohort study in an unselected US population. Patients who presented for an ultrasound examination between 11-13+6 weeks' gestation were included. The following parameters were assessed and were used to calculate the risk of preeclampsia: maternal characteristics (demographic, anthropometric, and medical history), maternal biomarkers (mean arterial pressure, uterine artery pulsatility index, placental growth factor, pregnancy-associated plasma protein A, and maternal serum alpha-fetoprotein), and estimated placental volume. After delivery, medical records were searched for the diagnosis of preeclampsia. Detection rates for early-onset preeclampsia (<34 weeks' gestation) and later-onset preeclampsia (≥34 weeks' gestation) for 5% and 10% false-positive rates using various combinations of markers were calculated.

RESULTS

We screened 1288 patients of whom 1068 (82.99%) were available for analysis. In all, 46 (4.3%) developed preeclampsia, with 13 (1.22%) having early-onset preeclampsia and 33 (3.09%) having late-onset preeclampsia. Using maternal characteristics, serum biomarkers, and uterine artery pulsatility index, the detection rate of early-onset preeclampsia for either 5% or 10% false-positive rate was 85%. With the same protocol, the detection rates for preeclampsia with delivery <37 weeks were 52% and 60% for 5% and 10% false-positive rates, respectively. Based on maternal characteristics, the detection rates for late-onset preeclampsia were 15% and 48% for 5% and 10%, while for preeclampsia at ≥37 weeks' gestation the detection rates were 24% and 43%, respectively. The detection rates for late-onset preeclampsia and preeclampsia with delivery at >37 weeks' gestation were not improved by the addition of biomarkers.

CONCLUSION

Screening for preeclampsia at 11-13+6 weeks' gestation using maternal characteristics and biomarkers is associated with a high detection rate for a low false-positive rate. Screening for late-onset preeclampsia yields a much poorer performance. In this study the utility of estimated placental volume and mean arterial pressure was limited but larger studies are needed to ultimately determine the effectiveness of these markers.

Aspirin for Evidence-Based Preeclampsia Prevention trial: influence of compliance on beneficial effect of aspirin in prevention of preterm preeclampsia

BACKGROUND

The Aspirin for Evidence-Based Preeclampsia Prevention trial was a multicenter study in women with singleton pregnancies. Screening was carried out at 11-13 weeks' gestation with an algorithm that combines maternal factors and biomarkers (mean arterial pressure, uterine artery pulsatility index, and maternal serum pregnancy-associated plasma protein A and placental growth factor). Those with an estimated risk for preterm preeclampsia of >1 in 100 were invited to participate in a double-blind trial of aspirin (150 mg/d) vs placebo from 11-14 until 36 weeks' gestation. Preterm preeclampsia with delivery at <37 weeks' gestation, which was the primary outcome, occurred in 1.6% (13/798) participants in the aspirin group, as compared with 4.3% (35/822) in the placebo group (odds ratio in the aspirin group, 0.38; 95% confidence interval, 0.20 to 0.74).

OBJECTIVE

We sought to examine the influence of compliance on the beneficial effect of aspirin in prevention of preterm preeclampsia in the Aspirin for Evidence-Based Preeclampsia Prevention trial.

STUDY DESIGN

This was a secondary analysis of data from the trial. The proportion of prescribed tablets taken was used as an overall measure of compliance. Logistic regression analysis was used to estimate the effect of aspirin on the incidence of preterm preeclampsia according to compliance of <90% and ≥90%, after adjustment for the estimated risk of preterm preeclampsia at screening and the participating center. The choice of cut-off of 90% was based on an exploratory analysis of the treatment effect. Logistic regression analysis was used to investigate predictors of compliance ≥90% among maternal characteristics and medical history.

RESULTS

Preterm preeclampsia occurred in 5/555 (0.9%) participants in the aspirin group with compliance ≥90%, in 8/243 (3.3%) of participants in the aspirin group with compliance <90%, in 22/588 (3.7%) of participants in the placebo group with compliance ≥90%, and in 13/234 (5.6%) of participants in the placebo group with compliance <90%. The odds ratio in the aspirin group for preterm preeclampsia was 0.24 (95% confidence interval, 0.09-0.65) for compliance ≥90% and 0.59 (95% confidence interval, 0.23-1.53) for compliance <90%. Compliance was positively associated with family history of preeclampsia and negatively associated with smoking, maternal age <25 years, Afro-Caribbean and South Asian racial origin, and history of preeclampsia in a previous pregnancy.

CONCLUSION

The beneficial effect of aspirin in the prevention of preterm preeclampsia appears to depend on compliance.

Women's Health Endocrine Update

The clinical update serves as a brief review of recently published, high-impact, and potentially practice changing journal articles summarized for our readers. Topics include menopause, sexual dysfunction, breast health, contraception, osteoporosis, and cardiovascular disease. In this clinical update, we selected four recent high-impact publications related to endocrine issues in women. We have chosen to highlight research on subclinical hypothyroidism during pregnancy and adverse pregnancy outcomes, including cognitive outcomes in offspring; the progression of metabolic syndrome severity during the menopausal transition; and the association of diabetes and metformin use with cancer risk and mortality.

Translational geroscience: A new paradigm for 21st century medicine

Advances in geroscience are allowing scientists and clinicians, for the first time, to consider interventions aimed at directly targeting the hallmarks of aging. Unlike disease-specific approaches, such interventions have the potential to prevent multiple diseases of aging simultaneously, thereby greatly enhancing healthspan for most individuals. Initial clinical data indicates that geroprotective compounds such as rapamycin and metformin may be effective at delaying or reversing age-related disease in otherwise healthy elderly people and companion animals. Here I will provide an overview of the field of translational geroscience, which I believe will become the paradigm for the practice of medicine in the 21^st century.