Effects of delivery on maternal & neonatal irisin levels in normal and preeclamptic pregnant women

Expression and Clinical Significance of Irisin in Serum and Placenta Tissues of Pregnant Women with Severe Preeclampsia

Objective

Preeclampsia (PE) is a serious pregnancy-specific disorder that poses significant risks to maternal and fetal health, with severe preeclampsia (SPE) being a particularly life-threatening complication. The objective of this study is to investigate the effects and clinical significance of irisin in pregnant women with severe preeclampsia (SPE). Irisin levels in the serum and placental tissues of healthy pregnant women and those with early- and late-onset SPE were measured and compared.

Methods

A total of 70 pregnant women treated at our hospital from January to November 2023 were selected for this study. The participants were divided into three groups: 20 women with early-onset severe preeclampsia (ES-PE group), 20 women with late-onset severe preeclampsia (LS-PE group), and 30 healthy pregnant women (control group). Fasting peripheral blood samples (5 mL) were collected from each participant, and placental tissues were obtained after delivery. Irisin levels in serum were measured using enzyme-linked immunosorbent assays (ELISA) with a commercial kit, and irisin expression in placental tissues was assessed by immunohistochemistry (IHC) with a rabbit anti-irisin antibody. The modes of delivery were also recorded.

Results

The concentrations of irisin in both serum and placental tissues were significantly higher among pregnant women in the control group compared to the ES-PE and LS-PE groups. There was a significant difference between the control group and the ES-PE and LS-PE groups in the mode of delivery. Additionally, a significant positive correlation was identified between the serum irisin concentration and its differential expression in placental tissues, while there was a significant negative correlation between irisin levels in both serum and placental tissue and systolic and/or diastolic blood pressure.

Conclusion

Reduced serum and placental irisin levels in pregnant women with SPE were associated with the onset and progression of SPE and may serve as a potential biological marker for SPE screening.

Irisin Improves Preeclampsia by Promoting Embryo Implantation and Vascular Remodeling

BACKGROUND

Preeclampsia is a pregnancy-specific disorder with unclear pathogenesis. Irisin, a recently identified exercise-induced factor, significantly influences lipid metabolism and cardiovascular function. Nonetheless, its role in trophoblast development during human placentation and the related intracellular signaling pathways remain poorly understood.

METHODS

We assessed peripheral blood irisin expression in early pregnancy among patients with preeclampsia and its correlation with key clinical indicators. In trophoblast cell lines and mice, we used exogenous irisin and viral knockdown to investigate functional changes. Phosphorylation-specific antibody arrays and dual-luciferase reporter assays were used to explore downstream molecular mechanisms, which were subsequently validated in trophoblast cell lines and relevant gene knockout mice.

RESULTS

In early pregnancy, patients with preeclampsia exhibit decreased peripheral blood irisin levels, occurring earlier than traditional predictive markers, such as PLGF (placental growth factor) and sFlt-1 (soluble fms-like tyrosine kinase-1). Furthermore, irisin concentration is positively correlated with proteinuria and abnormal blood pressure during pregnancy. Exogenous irisin significantly enhanced trophoblast cell migration, invasion, and proliferation while inhibiting apoptosis. It also increased STAT (signal transducers and activators of transcription) 4 phosphorylation and its binding to the GLUT (glucose transporter)-3 promoter, resulting in elevated GLUT-3 expression and glucose uptake in trophoblast cells. In vivo, increased peripheral irisin promoted embryo implantation, vascular remodeling, and enhanced glucose uptake, whereas reduced irisin resulted in a preeclampsia-like phenotype characterized by elevated blood pressure, proteinuria, renal-placental dysfunction, adipose accumulation, and restricted fetal growth.

CONCLUSIONS

Peripheral irisin improves preeclampsia by promoting embryo implantation and vascular remodeling through the activation of the STAT4/GLUT-3 pathway. Reduced peripheral irisin may contribute to preeclampsia-like pathologies. This study supports the advocacy for appropriate exercise during early pregnancy and provides new insights for preeclampsia prevention.

Irisin in Reproduction: Its Roles and Therapeutic Potential in Male and Female Fertility Disorders

The current study focused on identifying the potential of irisin in mammalian reproduction. The established role of irisin, a proteolytic product of FNDC5, in adipose tissue browning, energy metabolism, and thermogenesis suggests its role in reproductive health, often disturbed by metabolic imbalances. Various studies on mice demonstrated irisin's role in improving spermatogenesis, sperm count, and testosterone levels by influencing the hypothalamus-pituitary-gonadal axis. Moreover, in females, there is a fluctuation in levels of irisin during critical reproductive stages, including menstrual cycles, puberty, and pregnancy. Conditions like pregnancy complications, precocious puberty, and polycystic ovary syndrome (PCOS) are found to have an association with abnormal irisin levels. The potential role of irisin in endometrial receptivity and preventing endometritis is also discussed in this review. Overall, the influence of irisin on female and male reproduction is evident from various studies. However, further research is needed to elucidate irisin mechanism in reproduction and its potential as a therapeutic or diagnostic tool for reproductive dysfunctions and infertility.

Irisin as an emerging target in the regulation of reproductive functions in health and disease

Germ cells are highly conserved in the gonads, nurtured to either develop into a gamete or self-renew into a stem cell reserve. Preserving the germ cell pool and protecting the reproductive organs is essential for maintaining an individual's fertility. Several factors, including a sedentary lifestyle, pollutants, hormonal disruption, drugs, and a disease condition, have been shown to impair normal reproductive function. Irisin has recently been identified as an adipomyokine involved in modulating physiological functions based on the body's metabolic status. It is being studied for its role in various functions, including fertility. Findings show the localization of irisin in various parts of the reproductive axis, with the highest levels observed during puberty and pregnancy. This raises questions about its role and function in reproduction. Studies support irisin's role in protecting against disease-induced reproductive abnormalities and infertility. Therefore, the current review focuses on how irisin influences spermatogenesis and ovarian follicular development and plays a significant role in indirectly preserving the germ cell pool by protecting the gonads against oxidative stress and inflammation.

Physical exercise for a healthy pregnancy: the role of placentokines and exerkines

Complications such as diabetes and preeclampsia can occur during pregnancy. Moderate-intensity exercise can prevent such complications by releasing placentokines and exerkines, such as apelin, adiponectin, leptin, irisin, and chemerin. Exercise and apelin increase thermogenesis and glucose uptake in pregnancy by activating AMPK, PI3K, PGC-1α, AKT1, UCP3, and sarcolipin. Exercise increases apelin levels to reduce preeclampsia symptoms by increasing eNOS, NO, placental growth factor (PlGF), and VEGF and decreasing levels of fms-like tyrosine kinase 1 (sFlt-1), soluble endoglin (sEng), and oxidative stress. A negative relationship has been reported between plasma leptin and VO2peak/kg and VO2peak in women with gestational diabetes. In active women, decreases in leptin levels reduce the risk of preeclampsia by ~ 40%. Higher adiponectin levels are associated with greater physical activity and lead to increased insulin sensitivity. Increased adiponectin levels in preeclampsia and exercise counteract inflammatory and atherogenic activities while also having vascular protective effects. Exercise increases irisin levels that correlate negatively with fasting glucose, insulin concentration, and glycosylated hemoglobin levels. Irisin augments mRNA expression levels of UCP1 and cell death-inducing DNA fragmentation factor-like effector A (cidea) to cause browning of adipose tissue, increased thermogenesis, and increased energy consumption. Irisin concentrations in mothers with preeclampsia in the third trimester negatively correlate with systolic and diastolic blood pressure. Expression levels of chemerin, IL-6, and TNF-α are increased in gestational diabetes, and the increases in chemerin in late pregnancy positively correlate with the ratio of sFlt-1 to PlGF as a marker of preeclampsia. The effects of physical exercise on placentokines and exerkines in women at various stages of pregnancy remain poorly understood.

The Mother-Child Dyad Adipokine Pattern: A Review of Current Knowledge

An important role in the network of interconnections between the mother and child is played by adipokines, which are adipose tissue hormones engaged in the regulation of metabolism. Alternations of maternal adipokines translate to the worsening of maternal insulin resistance as well as metabolic stress, altered placenta functions, and fetal development, which finally contribute to long-term metabolic unfavorable conditions. This paper is the first to summarize the current state of knowledge concerning the concentrations of individual adipokines in different biological fluids of maternal and cord plasma, newborn/infant plasma, milk, and the placenta, where it highlights the impact of adverse perinatal risk factors, including gestational diabetes mellitus, preeclampsia, intrauterine growth restriction, preterm delivery, and maternal obesity on the adipokine patterns in maternal-infant dyads. The importance of adipokine measurement and relationships in biological fluids during pregnancy and lactation is crucial for public health in the area of prevention of most diet-related metabolic diseases. The review highlights the huge knowledge gap in the field of hormones participating in the energy homeostasis and metabolic pathways during perinatal and postnatal periods in the mother-child dyad. An in-depth characterization is needed to confirm if the adverse outcomes of early developmental programming might be modulated via maternal lifestyle intervention.

Maternal serum irisin levels in normotensive and preeclamptic pregnancies: a systematic review and meta-analysis

BACKGROUND

Altered irisin levels have been reported in pregnancy-associated disorders, such as preeclampsia.

OBJECTIVE

A systematic review and meta-analysis were conducted to evaluate the changes in maternal circulatory irisin levels in preeclampsia as compared to normotensive healthy pregnant controls.

METHODS

Relevant studies were identified by searching PubMed and other databases. Random-effects model was used to obtain standardized mean differences (SMDs) and its 95% confidence intervals (CIs). The sub-group meta-regression analyses were conducted to explore heterogeneity. The presence of publication bias and the study robustness was tested using funnel plot and sensitivity analyses, respectively.

RESULTS

This meta-analysis finally included 14 observations from eight studies. Compared with controls, preeclampsia patients showed significantly decreased serum irisin levels (SMD: -1.13; 95% CI: -1.63 to -0.62, p < .0001). The sub-group analysis showed that this decrease in irisin is regardless of body mass index (BMI) and gestational age of preeclampsia patients. The meta-regression analysis indicated that blood pressure is significantly associated with the observed results. There was no significant publication bias as indicated by the funnel plot analysis followed by Begg's (p = .35) and Egger's tests (p = .39). The sensitivity analysis indicated that no single study had a significant influence on the overall outcome, suggesting the robustness of this meta-analysis.

CONCLUSIONS

This meta-analysis showed significantly decreased maternal serum irisin level in preeclampsia patients as compared to normotensive pregnant women. This study highlights the need for future studies evaluating the diagnostic utilities and associations of irisin with the fetal and neonatal outcomes in preeclampsia.

Hippocampal and Prefrontal Cortical Brain Tissue Levels of Irisin and GDF15 Receptor Subunits in Children

Cold-stress hormones (CSHs) stimulate thermogenesis and have direct neuroprotective effects on the brain. The obligatory receptor components of two new CSHs (irisin and growth differentiation factor-15 [GDF15]) were recently discovered. Irisin binds integrin-αV/β5 heterodimers while GDF-15 binds to the orphan receptor glial cell-derived neurotrophic factor (GDNF) family receptor α-like (GFRAL). In addition, integrin-αV/β5 was just identified as the key receptor mediating Zika virus infection in the CNS. We measured integrin-αV, integrin-β5, and GFRAL protein levels across 78 high-quality human male/female brain tissues in infants, toddlers, preschoolers, adolescent, and adults-providing the most robust analysis to date on their levels in the human cortex and hippocampus. We report that integrin-αV was detected at all ages in the prefrontal cortex with levels greatest in adults. Integrin-αV was also detected in the hippocampus in all age groups. In contrast, integrin-β5 was detected in cortex and hippocampus largely restricted to infants. Co-expression of integrin-αV/β5 in the human infant hippocampus and cortex suggests the possibility that irisin has a more robust effect on the developing vs. the adult brain and may have implications for Zika virus infection in infants and young children.

The Role of the Adipokines in the Most Common Gestational Complications

Adipocytokines are hormonally active molecules that are believed to play a key role in the regulation of crucial biological processes in the human body. Numerous experimental studies established significant alterations in the adipokine secretion patterns throughout pregnancy. The exact etiology of various gestational complications, such as gestational diabetes, preeclampsia, and fetal growth abnormalities, needs to be fully elucidated. The discovery of adipokines raised questions about their potential contribution to the molecular pathophysiology of those diseases. Multiple studies analyzed their local mRNA expression and circulating protein levels. However, most studies report conflicting results. Several adipokines such as leptin, resistin, irisin, apelin, chemerin, and omentin were proposed as potential novel early markers of heterogeneous gestational complications. The inclusion of the adipokines in the standard predictive multifactorial models could improve their prognostic values. Nonetheless, their independent diagnostic value is mostly insufficient to be implemented into standard clinical practice. Routine assessments of adipokine levels during pregnancy are not recommended in the management of both normal and complicated pregnancies. Based on the animal models (e.g., apelin and its receptors in the rodent preeclampsia models), future implementation of adipokines and their receptors as new therapeutic targets appears promising but requires further validation in humans.

Study on the relationship between the levels of irisin in umbilical cord blood and neonatal growth in China

Objective: The results of the study on the relationship between obesity and cord blood irisin were far apart. The aim of this study was to explore the relationship between cord blood irisin levels and neonatal growth in China.Methods: A cross-sectional study of 400 neonates and their mothers was conducted in the obstetrics department of Shandong provincial hospital in China. Neonates were divided into a fetal macrosomia group and a normal birth weight group based on customized birth-weight standards and divided into non-high-ponderal index group and high ponderal index group based on ponderal index. Levels of irisin in umbilical cord blood were measured by enzyme-linked immunosorbent assay.Results: Irisin concentrations in the fetal macrosomia group were significantly higher than in the normal birth weight group (p = .032). Irisin levels in the high ponderal index group were significantly higher compared with the non-high-ponderal index group (p = .032). After adjustment for confounding variables, logistic regression analysis identified macrosomia affected factors include weight gained during pregnancy (OR = 1.15, p = .028), infant's sex (OR = 9.73, p = .001) and found that affected factors of high ponderal index include weight gained during pregnancy (OR = 1.08, p = .025), maternal age (OR = 1.10, p = .018). Compared with the reference category (<108.62 ng/ml), infants with a cord blood irisin level above 241.44 ng/ml had significantly elevated risk of macrosomia (OR = 8.57, p = .010) and had significantly elevated risk of high birth ponderal index (PI) (OR = 3.15, p = .002). A nonlinear relationship was observed between irisin levels and fetal macrosomia. The higher the concentration of irisin, the greater the risk of fetal macrosomia.Conclusions: We found that as the cord blood irisin increased, the risk of having fetal macrosomia was greater. Weight gained during pregnancy and high cord blood irisin levels were independent predictors of fetal adiposity.

Irisin level and neonatal birthweight: A systematic review and meta-analysis

Irisin is an important crosstalk myokine between adipose and muscle tissue. Disorders in irisin secretion can lead to fetal growth abnormalities and even lead to metabolic syndromes in adult life. This study aimed to evaluate the association between irisin level in umbilical cord blood and maternal serum with neonatal birthweight. The Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) statement and the Meta-analysis of Observational Studies in Epidemiology (MOOSE) guideline were followed. A comprehensive search of eight databases (PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials, CBM, CNKI, WANFANG and VIP) was performed from inception to November 2019. Studies with original date reporting irisin levels in newborns of small for gestational age (SGA) and newborns of large for gestational age (LGA) were included. Additionally, studies reporting correlation coefficients of irisin with birthweight were analyzed. Newcastle-Ottawa score system and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach were applied. Seventeen studies with 1866 participants were included. Pooled analysis indicated decreased cord irisin levels in SGA newborns (MD -10.57, 95 % CI -13.41 to -7.73) and increased irisin levels in LGA newborns (MD 3.80, 95 % CI 1.91-5.70). Umbilical cord irisin level was positively correlated with neonatal birthweight (r = 0.41 95 %CI 0.04 to 0.68). The pooled correlation coefficient of maternal serum irisin with birthweight has no statistical significance. This meta-analysis suggested that the umbilical cord irisin levels were impaired in fetal growth abnormalities. Umbilical cord blood irisin level was positively correlated with birthweight.

The role of serum adipokine levels in preeclampsia: A systematic review

BACKGROUND

Preeclampsia represents a major pregnancy complication, associated with high rates of perinatal morbidity. The aim of this systematic review is to accumulate current literature evidence in order to examine the pattern of serum adipokine levels among preeclamptic women and asses their potential efficacy in the prediction of the disease.

METHODS

Medline, Scopus, CENTRAL, Clinicaltrials.gov and Google Scholar databases were systematically searched from inception. All observational studies reporting serum adipokine values among preeclamptic and healthy pregnant women were held eligible.

RESULTS

A total of 163 studies were included, comprising 23,482 women. Leptin was evaluated in 91 studies and its values were found to be significantly elevated in preeclamptic women during all pregnancy trimester, independently of disease onset and severity. Preeclampsia was also associated with increased serum fatty acid binding protein-4 and chemerin levels, when measured both during the 1st and 3rd trimester. Data concerning the rest adipokines were either conflicting or limited to reach firm conclusions. Quality of evidence was evaluated to be high for leptin, moderate for serum fatty acid binding protein-4 and chemerin and low for the other adipokines.

CONCLUSIONS

The existing evidence suggests that preeclampsia is linked to increased levels of leptin, chemerin and fatty acid binding protein-4 in all pregnancy trimesters and forms of the disease. Inconsistent data currently exists concerning the role of the other adipokines. Large-scale prospective studies should longitudinally evaluate the serum concentration of novel adipokines and define the optimal threshold and timing of measurement to be widely applied in clinical practice.

Irisin Maternal Plasma and Cord Blood Levels in Mothers with Spontaneous Preterm and Term Delivery

Irisin, an adipomyokine identified in 2012, has been investigated in association with common pregnancy complications, including gestational diabetes mellitus, preeclampsia, and intrauterine growth restriction. The objective of this study is to examine the potential role of irisin in preterm birth (PTB) by comparing its level between mothers with term and preterm labor. Maternal peripheral blood and cord blood samples were collected from 30 mothers who delivered prematurely and from 35 mothers who delivered at term. Irisin concentrations were measured in all samples using ELISA, and four common single nucleotide polymorphisms in the irisin gene were determined (rs16835198, rs726344, rs3480, and rs1746661). Univariable and multivariable regression modeling was applied to evaluate maternal and cord blood irisin concentrations in relation to preterm/term labor. Irisin concentration in umbilical cord blood was found to be associated with PTB in the univariable model (p = 0.046). On the other hand, no differences in maternal blood irisin levels between mothers with preterm and term deliveries were established. To the best of our knowledge, this is the first study determining irisin levels in term and preterm deliveries in maternal peripheral blood and umbilical cord blood. Our study shows a possible association between cord blood irisin concentration and PTB occurrence.