Immune profile in relation to sex steroid cyclicity in healthy women and women with multiple sclerosis

Revisiting the role of sexual hormones in the demyelinated central nervous system

Sex-related differences characterize multiple sclerosis, an autoimmune, inflammatory and neurodegenerative disease displaying higher incidence in females as well as discrepancies in susceptibility and progression. Besides clinical specificities, molecular and cellular differences related to sex hormones were progressively uncovered improving our understanding of the mechanisms involved in this disabling disease. The most recent findings may give rise to the identification of novel therapeutic perspectives that could meet the urgent need for a treatment preventing the transition from the recurrent- to the progressive form of the disease. The present review is an update of our current knowledge about progestagens, androgens and estrogens in the context of CNS demyelination including their synthesis, the impact of their dysregulation, the preclinical and clinical data presently available, the main molecular dimorphisms related to these hormones and their age-related changes and relationship with failure of spontaneous remyelination, likely impacting the inexorable progression of multiple sclerosis towards irreversible disabilities.

The effects of menstrual cycle phases on immune function and inflammation at rest and after acute exercise: A systematic review and meta-analysis

The immune system plays an important role in mediating exercise responses and adaptations. However, whether fluctuating hormone concentrations across the menstrual cycle may impact these processes remains unknown. The aim of this systematic review with meta-analysis was to compare baseline concentrations as well as exercise-induced changes in immune and inflammatory parameters between menstrual cycle phases. A systematic literature search was conducted according to the PRISMA guidelines using Pubmed/MEDLINE, ISI Web of Science, and SPORTDiscus. Of the 159 studies included in the qualitative synthesis, 110 studies were used for meta-analysis. Due to the designs of the included studies, only the follicular and luteal phase could be compared. The estimated standardized mean differences based on the random-effects model revealed higher numbers of leukocytes (-0.48 [-0.73; -0.23], p < 0.001), monocytes (-0.73 [-1.37; -0.10], p = 0.023), granulocytes (-0.85 [-0.1.48; -0.21], p = 0.009), neutrophils (-0.32 [-0.52; -0.12], p = 0.001), and leptin concentrations (-0.37 [-0.5; -0.23], p = 0.003) in the luteal compared to the follicular phase at rest. Other parameters (adaptive immune cells, cytokines, chemokines, and cell adhesion molecules) showed no systematic baseline differences. Seventeen studies investigated the exercise-induced response of these parameters, providing some indications for a higher pro-inflammatory response in the luteal phase. In conclusion, parameters of innate immunity showed cycle-dependent regulation at rest, while little is known on the exercise responses. Due to a large heterogeneity and a lack of cycle phase standardization among the included studies, future research should focus on comparing at least three distinct hormonal profiles to derive more specific recommendations for exercise prescription.

Rat Ovarian Function Is Impaired during Experimental Autoimmune Encephalomyelitis

Multiple sclerosis (MS) is an autoimmune disease affecting the CNS and occurring far more prevalently in women than in men. In both MS and its animal models, sex hormones play important immunomodulatory roles. We have previously shown that experimental autoimmune encephalomyelitis (EAE) affects the hypothalamic-pituitary-gonadal axis in rats of both sexes and induces an arrest in the estrous cycle in females. To investigate the gonadal status in female rats with EAE, we explored ovarian morphometric parameters, circulating and intraovarian sex steroid levels, and the expression of steroidogenic machinery components in the ovarian tissue. A prolonged state of diestrus was recorded during the peak of EAE, with maintenance of the corpora lutea, elevated intraovarian progesterone levels, and increased gene and protein expression of StAR, similar to the state of pseudopregnancy. The decrease in CYP17A1 protein expression was followed by a decrease in ovarian testosterone and estradiol levels. On the contrary, serum testosterone levels were slightly increased. With unchanged serum estradiol levels, these results point at extra-gonadal sites of sex steroid biosynthesis and catabolism as important regulators of their circulating levels. Our study suggests alterations in the function of the female reproductive system during central autoimmunity and highlights the bidirectional relationships between hormonal status and EAE.

Environmental level bisphenol A accelerates alterations of the reno-cardiac axis by the MAPK cascades in male diabetic rats: An analysis based on transcriptomic profiling and bioinformatics

In humans and animal models, the kidneys and cardiovascular systems are negatively affected by BPA from the environment. It is considered that BPA have some potential estrogen-like and non-hormone-like properties. In this study, RNA-sequencing and its-related bioinformatics was used as the basic strategy to clarify the characteristic mechanisms of kidney-heart axis remodeling and dysfunction in diabetic male rats under BPA exposure. We found that continuous BPA exposure in diabetic rats aggravated renal impairment, and caused hemodynamic disorders and dysfunctions. There were 655 and 125 differentially expressed genes in the kidney and heart, respectively. For the kidneys, functional annotation and enrichment, and gene set enrichment analyses identified bile acid secretion related to lipid synthesis and transport, and MAPK cascade pathways. For the heart, these bioinformatics analyses clearly pointed to MAPKs pathways. A total of 12 genes and another total of 6 genes were identified from the kidney tissue and heart tissue, respectively. Western blotting showed that exposure to BPA activated MAPK cascades in both organs. In this study, the exacerbated remodeling of diabetic kidney-heart axis under BPA exposure and diabetes might occur through hemodynamics, metabolism disorders, and the immune-inflammatory response, as well as continuous estrogen-like stimulation, with focus on the MAPK cascades.

A comprehensive review on the role of chemokines in the pathogenesis of multiple sclerosis

Multiple sclerosis (MS) as a chronic inflammatory disorder of the central nervous system (CNS) is thought to be caused by the abnormal induction of immune responses. Chemokines as molecules that can engage leukocytes into the location of inflammation, actively participate in the pathogenesis of MS. Several members of this family of chemo attractants have been shown to be dysregulated in the peripheral blood, cerebrospinal fluid or CNS lesions of MS patients. Studies in animal models of MS particularly experimental autoimmune encephalomyelitis have indicated the critical roles of chemokines in the pathophysiology of MS. In the current review, we summarize the data regarding the role of CCL2, CCL3, CCL4, CCL11, CCL20, CXCL1, CXCL2, CXCL8, CXCL10, CXCL12 and CXCL13 in the pathogenesis of MS.

The sex-specific patterns of changes in hypothalamic-pituitary-gonadal axis during experimental autoimmune encephalomyelitis

Multiple sclerosis develops during reproductive years in a sex-specific manner. Various neuroendocrine changes have been described in this inflammatory, demyelinating, and debilitating disease. We here aimed to determine the extent and sex specificity of alterations in the hypothalamic-pituitary-gonadal axis in the rat model of multiple sclerosis named experimental autoimmune encephalomyelitis. During the disease course, the hypothalamic tissue showed transient upregulation of inflammatory marker genes Gfap, Cd68, Ccl2, and Il1b in both sexes, but accompanied by sex-specific downregulation of Kiss1 (in females only) and Gnrh1 (in males only) expression. In females, the expression of gonadotrope-specific genes Lhb, Cga, and Gnrhr was also inhibited, accompanied by decreased basal but not stimulated serum luteinizing hormone levels and a transient arrest of the estrous cycle. In contrast, Fshb expression and serum progesterone levels were transiently elevated, findings consistent with the maintenance of the corpora lutea, and elevated immunohistochemical labeling of ovarian StAR, a rate limiting protein in steroidogenic pathway. In males, downregulation of Gnrhr expression and basal and stimulated serum luteinizing hormone and testosterone levels were accompanied by inhibited testicular StAR protein expression. We propose that inflammation of hypothalamic tissue downregulates Kiss1 and Gnrh1 expression in females and males, respectively, leading to sex-specific changes downstream the axis.

Rhythmic Fluctuations in Levels of Liver Enzymes During Menstrual Cycles of Healthy Women and Effects of Body Weight

BACKGROUND & AIMS

Female sex hormones affect several non-reproductive organs, but little is known about their effects on the liver during a normal menstrual cycle. We aimed to investigate the association between sex hormones and liver enzymes in healthy menstruating women.

METHODS

We performed a post-hoc analysis of data from the BioCycle study, a longitudinal cohort study designed to determine the association of sex hormones with markers of oxidative stress during the menstrual cycle. We analyzed data collected from 259 menstruating women, over 1-2 menstrual cycles, who had as many as 16 separate office visits, timed by fertility monitors. Levels of liver enzymes, including alanine aminotransferase (ALT), aspartate aminotransferase, and alkaline phosphatase (ALKP), bilirubin, and lipids were measured by laboratory assays.

RESULTS

We found a natural cyclic pattern for liver enzymes, with transaminases and ALKP peaking in the mid-follicular phase and reaching a trough in the late luteal phase; the peak to trough differences were 4.0 ± 4.9 U/L for ALT and 8.8 ± 4.0 U/L for ALKP. Levels of ALT were significantly and negatively associated with levels of progesterone on the preceding visit (P = 5x10^-4), whereas level of ALKP was negatively associated with level of estrogen (P = .007) and progesterone (P = 1x10^-11). Food and alcohol intake did not modify the association. The amplitude of ALT fluctuation was greater in African Americans and decreased with age. Fluctuations in levels of ALT were smaller in women with body mass indices >30 kg/m² (P = .03). During menstrual fluctuation, 49% of participants had ALT values both above and below the normal cut-off value (19 U/L).

CONCLUSIONS

Levels of liver enzymes fluctuate during the normal menstrual cycle, possibly mediated by progesterone, and the fluctuation varies with age and body mass index. These findings indicate the importance of accounting for phase of menstrual cycle when interpreting liver enzyme measurements in menstruating women.

Ovarian and endometrial immunity during the ovarian cycle

Immune tolerance is crucial for the successful pregnancy, while immune effectors and their products are required to safeguard a fetus from the infectious pathogens. The key immune effectors, such as T, B, and natural killer (NK) cells, monocytes, macrophages, and dendritic cells take part in regulating the immune responses at the maternal-fetal interface. The immune effectors become involved in intraovarian reproductive processes as well, such as ovulation, production of corpus luteum (CL) and its degeneration and determine the quality and evolution of the oocyte during the folliculogenesis. In the cycling endometrium, NK cells are rapidly infiltrated into the endometrium after ovulation and participate in angiogenesis and spiral artery remodeling process. In this study, we reviewed the characteristics and action mechanisms of immune effectors and their products in the peripheral blood, ovary, and endometrium during the ovarian cycle, since a comprehensive understanding of immune responses during the ovarian cycle and the time of implantation can help us to predict the pregnancy outcome and take effective measures for the prevention of potential obstetrical complications.