Prolactin in relation to gestational diabetes and metabolic risk in pregnancy and postpartum: A systematic review and meta-analysis

Prolactin drives cortical neuron maturation and dendritic development during murine embryonic stem cell differentiation

Introduction

Prolactin (PRL) is a pleiotropic hormone implicated in various physiological processes; however, its contribution to neurodevelopment, particularly early corticogenesis, remains insufficiently characterized. In this study, we investigate PRL's regulatory influence on the initial stages of cortical development, with an emphasis on its effects on neuronal and astrocytic differentiation.

Methods

We employed a standardized in vitro differentiation protocol to generate cortical neurons from mouse embryonic stem cells (mESCs). Prolactin receptor (PRLr) expression was evaluated in pluripotent stem cells, neural stem cells (NSCs), immature neurons, and mature neurons using both PCR and immunofluorescence. These analyses revealed dynamic changes in PRLr expression throughout the differentiation process. Additionally, cells were treated with varying concentrations of PRL during early and late differentiation phases, enabling assessment of its impact on neuronal phenotypic distribution and morphological complexity.

Results

Early PRL administration significantly enhanced the population of β-tubulin III + immature neurons, promoting neuronal survival without altering NSC proliferation. Furthermore, PRL treatment increased the abundance of Tbr1 + and NeuN + neurons, augmented dendritic complexity, and accelerated neuronal maturation. In contrast, PRL exposure at later stages of neural differentiation did not yield comparable effects. Notably, PRL delayed the maturation of protoplasmic astrocytes, although the total astrocyte population was not affected.

Discussion

These findings highlight PRL's pivotal role as a regulator of early corticogenesis by modulating neuronal survival, dendritic development, and astrocyte maturation. PRL thus emerges as a potential key factor in neurodevelopment, underscoring its importance in the hormonal regulation of neural differentiation and maturation. These insights may have broader implications for understanding the molecular and cellular mechanisms underlying normal and pathological neurodevelopment.

Risk Assessment of Diabetes Mellitus During and After Pregnancy in Women With Prolactinomas

CONTEXT

Prolactin (PRL) is a crucial mediator of glucoinsulinemic metabolism.

OBJECTIVE

This work aims to dissect glucose metabolism during and after pregnancy in patients with prolactinomas.

METHODS

A total of 52 patients treated with cabergoline (CAB) were evaluated before conception, during pregnancy, and up to 10 years after delivery. During pregnancy, CAB was discontinued, while it was restarted in 57.7% of patients after delivery, due to recurrent hyperprolactinemia (RH). Hormonal (serum PRL) and metabolic (glycated hemoglobin A1c [HbA1c], fasting glucose [FG], glucose tolerance) parameters were assessed.

RESULTS

During pregnancy, PRL gradually increased, while FG remained stable. An inverse correlation between PRL and FG was found in the first (P = .032) and third (P = .048) trimester. PRL percentage increase across pregnancy was inversely correlated with third-trimester FG. Serum PRL before conception emerged as a predictive biomarker of third-trimester FG (t = 2.603; P = .048). Older patients with lower HbA1c in the first trimester and lower FG at 3 years post partum delivered infants with reduced birth weight. Breastfeeding up to 6 months correlated with lower FG at 4 and 10 years post partum. A positive correlation between BMI and FG at 10 years after delivery (P = .03) was observed, particularly in overweight/obese patients requiring higher CAB doses. Patients with RH who had to restart CAB showed shorter breastfeeding duration and higher FG at 2 years post partum.

CONCLUSION

Low PRL levels before pregnancy may be detrimental to FG during pregnancy. CAB duration and dose may influence long-term glucose tolerance, besides family history and BMI. Preconception metabolic management should be recommended to reduce the risk of gestational and type 2 diabetes mellitus.

Update on diabetic retinopathy during pregnancy

Diabetes mellitus (DM) leads to several vascular and neurological complications, including diabetic retinopathy (DR). As the population ages, health problems in certain groups, including children and pregnant women, are drawing more and more attention. Pregnancy is one of the independent risk factors for the development and progression of DR. Pregnancy-induced changes may contribute to or worsen DR, which can cause a tremendous burden on public health. It is essential for pregnant women with DR and their offspring to minimize the risk of vision loss from DR in this population and adverse outcomes by understanding the development and processes behind this process. Thus, we have updated the recent situation of epidemiology, evolution characteristics, risk factors, pathophysiology, pregnancy outcomes for a better understanding of the latest status of DR, helping to improve maternal and neonatal pregnancy outcomes, and promoting health for women with DR.

Screening and identification of key biomarkers associated with endometriosis using bioinformatics and next-generation sequencing data analysis

Background

Endometriosis is a common cause of endometrial-type mucosa outside the uterine cavity with symptoms such as painful periods, chronic pelvic pain, pain with intercourse and infertility. However, the early diagnosis of endometriosis is still restricted. The purpose of this investigation is to identify and validate the key biomarkers of endometriosis.

Methods

Next-generation sequencing dataset GSE243039 was obtained from the Gene Expression Omnibus database, and differentially expressed genes (DEGs) between endometriosis and normal control samples were identified. After screening of DEGs, gene ontology (GO) and REACTOME pathway enrichment analyses were performed. Furthermore, a protein–protein interaction (PPI) network was constructed and modules were analyzed using the Human Integrated Protein–Protein Interaction rEference database and Cytoscape software, and hub genes were identified. Subsequently, a network between miRNAs and hub genes, and network between TFs and hub genes were constructed using the miRNet and NetworkAnalyst tool, and possible key miRNAs and TFs were predicted. Finally, receiver operating characteristic curve analysis was used to validate the hub genes.

Results

A total of 958 DEGs, including 479 upregulated genes and 479 downregulated genes, were screened between endometriosis and normal control samples. GO and REACTOME pathway enrichment analyses of the 958 DEGs showed that they were mainly involved in multicellular organismal process, developmental process, signaling by GPCR and muscle contraction. Further analysis of the PPI network and modules identified 10 hub genes, including vcam1, snca, prkcb, adrb2, foxq1, mdfi, actbl2, prkd1, dapk1 and actc1. Possible target miRNAs, including hsa-mir-3143 and hsa-mir-2110, and target TFs, including tcf3 (transcription factor 3) and clock (clock circadian regulator), were predicted by constructing a miRNA-hub gene regulatory network and TF-hub gene regulatory network.

Conclusions

This investigation used bioinformatics techniques to explore the potential and novel biomarkers. These biomarkers might provide new ideas and methods for the early diagnosis, treatment and monitoring of endometriosis.

Pancreatic islet adaptation in pregnancy and postpartum

Pancreatic islets, particularly insulin-producing β-cells, are central regulators of glucose homeostasis capable of responding to a variety of metabolic stressors. Pregnancy is a unique physiological stressor, necessitating the islets to adapt to the complex interplay of maternal and fetal-placental factors influencing the metabolic milieu. In this review we highlight studies defining gestational adaptation mechanisms within maternal islets and emerging studies revealing islet adaptations during the early postpartum and lactation periods. These include adaptations in both β and in 'non-β' islet cells. We also discuss insights into how gestational and postpartum adaptation may inform pregnancy-specific and general mechanisms of islet responses to metabolic stress and contribute to investigation of gestational diabetes.

Increased BMI associated with decreased breastfeeding initiation in Million Veteran Program participants

Background

Breastfeeding has been associated with maternal and infant health benefits but has been inversely associated with body mass index (BMI) prepartum. Breastfeeding and BMI are both linked to socioeconomic factors.

Methods

Data from parous female participants with available breastfeeding information from the Million Veteran Program cohort was included. BMI at enrollment and earliest BMI available were extracted, and polygenic scores (PGS) for BMI were calculated. We modeled breastfeeding for one month or more as a function of BMI at enrollment; earliest BMI where available pre-pregnancy; and PGS for BMI. We conducted Mendelian randomization for breastfeeding initiation using PGS as an instrumental variable.

Results

A higher BMI predicted a lower likelihood of breastfeeding for one month or more in all analyses. A +5 kg/m 2 BMI pre-pregnancy was associated with a 24% reduced odds of breastfeeding, and a +5 kg/m 2 genetically predicted BMI was associated with a 17% reduced odds of breastfeeding.

Conclusions

BMI predicts a lower likelihood of breastfeeding for one month or longer. Given the high success of breastfeeding initiation regardless of BMI in supportive environments as well as potential health benefits, patients with elevated BMI may benefit from additional postpartum breastfeeding support.

Cognitive Impairment Induced by Gestational Diabetes: The Role of Oxidative Stress

BACKGROUND

Cognitive impairment is defined as a neurological condition that alters multiple cerebral functions such as reasoning, memory, concentration, and association, among others. It has found to be widely correlated with several factors such as oxidative stress. The latter could be induced by numerous pathological conditions characterized by increased levels of free radicals and decreased levels of antioxidants. Pregnancy is a period when women undergo a physiological state of oxidative stress due to hormonal changes and increased oxygen requirements to maintain pregnancy. However, when oxidative stress exceeds antioxidant capacity, this leads to cellular damage that promotes a diabetogenic state. Recent studies suggest a possible association between gestational diabetes and cognitive impairment, but the underlying mechanisms remain unclear.

AIMS

We aim to explore the pathophysiological relationship between cognitive impairment and oxidative stress, focusing on the possible involvement of oxidative stress as the inducing mechanism.

METHODS

We performed a comprehensive literature review through PubMed and Google Scholar. Our keywords were "neuroinflammation", "cognitive impairment", "gestational diabetes", "oxidative stress", "antioxidants", and "free radicals".

RESULTS

From the initial 400 records identified, a total of 78 studies were analyzed and included in our study.

CONCLUSION

Oxidative stress plays a fundamental role in the development of cognitive impairment. Understanding this correlation is essential to the development of targeted medical interventions and, ultimately, promote research and prevention that will benefit the mother-child binomial in the short and long term.

Impact of breastfeeding on risk of glucose intolerance in early postpartum after gestational diabetes

Aims

To determine the impact of breastfeeding on the risk of postpartum glucose intolerance in women with gestational diabetes.

Methods

Sub-analysis of two multi-centric prospective cohort studies (BEDIP-N and MELINDA) in 1008 women with gestational diabetes. Data were collected during pregnancy and at a mean of 12 weeks postpartum. Multivariate logistic regression was used to estimate the effect of breastfeeding on glucose intolerance, with adjustment for ethnicity, education, income, professional activity and BMI.

Results

Of all participants, 56.3% (567) breastfed exclusively, 10.1% (102) gave mixed milk feeding and 33.6% (339) did not breastfeed. Mean breastfeeding duration was 3.8 ± 2.4 and 3.7 ± 2.1 months in the breastfeeding and mixed milk feeding groups (p=0.496). The rate of glucose intolerance was lower in both the breastfeeding [22.3% (126)] and mixed milk feeding [25.5% (26)] groups compared to the no breastfeeding group [29.5% (100)], with an adjusted OR of 0.7 (95% CI 0.5-1.0) for glucose intolerance in the breastfeeding group compared to no breastfeeding group and an adjusted OR of 0.7 (95% CI 0.4-1.2) for the mixed milk feeding group compared to the no breastfeeding group. Postpartum, breastfeeding women had a lower BMI, less often postpartum weight retention, lower fasting triglycerides, less insulin resistance and a higher insulin secretion-sensitivity index-2 than the mixed milk feeding and no breastfeeding group. The mixed milk feeding group was more often from an non-White background, had a lower blood pressure and lower fasting triglycerides compared to the no breastfeeding group.

Conclusions

Breastfeeding (exclusive and mixed milk feeding) is associated with less glucose intolerance and a better metabolic profile in early postpartum in women with gestational diabetes.

Nutritional Profiles and Their Links to Insulin Resistance and Anthropometric Variables in a Female Cohort

This study investigates the relationship between dietary habits and metabolic health among women, emphasizing the role of anthropometric parameters as proxies for insulin resistance. We analyzed data from 443 women categorized into two groups based on the presence or absence of clinically diagnosed insulin resistance. Our assessments included dietary quality, socio-demographic characteristics, and a series of anthropometric measurements such as body weight, Body Mass Index (BMI), Waist-Hip Ratio (WHR), Abdominal Volume Index (AVI), and Body Adiposity Index (BAI). The results indicated significant disparities in these parameters, with the insulin-resistant group exhibiting higher average body weight (78.92 kg vs. 65.04 kg, p < 0.001), BMI (28.45 kg/m2 vs. 23.17 kg/m2, p < 0.001), and other related measures, suggesting a strong influence of dietary patterns on body composition and metabolic risk. The study underscores the importance of dietary management in addressing insulin resistance, advocating for personalized dietary strategies to improve metabolic health outcomes in women. This approach highlights the need for integrating dietary changes with lifestyle modifications and socio-demographic considerations to combat metabolic risks effectively.

Current Insights in Prolactin Signaling and Ovulatory Function

Prolactin (PRL) is a pleiotropic hormone released from lactotrophic cells of the anterior pituitary gland that also originates from extrapituitary sources and plays an important role in regulating lactation in mammals, as well as other actions. Acting in an endocrine and paracrine/autocrine manner, PRL regulates the hypothalamic-pituitary-ovarian axis, thus influencing the maturation of ovarian follicles and ovulation. This review provides a detailed discussion of the current knowledge on the role of PRL in the context of ovulation and ovulatory disorders, particularly with regard to hyperprolactinemia, which is one of the most common causes of infertility in women. Much attention has been given to the PRL structure and the PRL receptor (PRLR), as well as the diverse functions of PRLR signaling under normal and pathological conditions. The hormonal regulation of the menstrual cycle in connection with folliculogenesis and ovulation, as well as the current classifications of ovulation disorders, are also described. Finally, the state of knowledge regarding the importance of TIDA (tuberoinfundibular dopamine), KNDγ (kisspeptin/neurokinin B/dynorphin), and GnRH (gonadotropin-releasing hormone) neurons in PRL- and kisspeptin (KP)-dependent regulation of the hypothalamic-pituitary-gonadal (HPG) axis in women is reviewed. Based on this review, a rationale for influencing PRL signaling pathways in therapeutic activities accompanying ovulation disorders is presented.

Recent progress in metabolic reprogramming in gestational diabetes mellitus: a review

Gestational diabetes mellitus is a prevalent metabolic disease that can impact the normal course of pregnancy and delivery, leading to adverse outcomes for both mother and child. Its pathogenesis is complex and involves various factors, such as insulin resistance and β-cell dysfunction. Metabolic reprogramming, which involves mitochondrial oxidative phosphorylation and glycolysis, is crucial for maintaining human metabolic balance and is involved in the pathogenesis and progression of gestational diabetes mellitus. However, research on the link and metabolic pathways between metabolic reprogramming and gestational diabetes mellitus is limited. Therefore, we reviewed the relationship between metabolic reprogramming and gestational diabetes mellitus to provide new therapeutic strategies for maternal health during pregnancy and reduce the risk of developing gestational diabetes mellitus.

Prolactin in Pregnancies Affected by Pre-Existing Maternal Metabolic Conditions: A Systematic Review

Women affected by maternal pregestational diabetes mellitus (type 1 or type 2) or by polycystic ovary syndrome experience an increased risk of pregnancy complications, as well as suboptimal lactation outcomes. The hormone prolactin plays important roles in pregnancy and postpartum, both as a metabolic and lactogenic hormone. We aimed to explore, through a systematic review, the relationship between pregestational maternal metabolic conditions and prolactin levels in pregnancy and postpartum. MEDLINE via OVID, CINAHL Plus, and Embase were searched from inception to 9 May 2022. Eligible studies included women who were pregnant or up to 12 months postpartum and had a pre-existing diagnosis of type 1 or type 2 diabetes mellitus or polycystic ovary syndrome; with reporting of at least one endogenous maternal serum prolactin level during this time. Two independent reviewers extracted the data. Eleven studies met the eligibility criteria. The studies were too diverse and heterogeneous to enable meta-analysis. Overall, prolactin levels appeared to be lower in pregnancies affected by type 1 diabetes mellitus. There was little data in polycystic ovary syndrome or type 2 diabetes pregnancy, but prolactin increment across pregnancy in polycystic ovary syndrome emerged as an area for future study. During postpartum, lactation difficulties in women with metabolic disease present before pregnancy are well-described, but the relationship to prolactin remains unclear. Overall, preliminary evidence suggests that pre-existing maternal metabolic disease may alter prolactin dynamics in pregnancy and postpartum. Further well-designed studies in modern cohorts, with standardised collection and serial sampling across pregnancy and postpartum, are required to clarify these associations.