Multiple sclerosis and pregnancy

The protective role of interaction between vitamin D, sex hormones and calcium in multiple sclerosis

Multiple sclerosis (MS) is a neurological disorder that causes disability and paralysis, especially among young adults. Although interactions of several factors, such as viral infections, autoimmunity, genetic and environmental factors, performance a role in the beginning and progression of the disease, the exact cause of MS is unknown to date. Different immune cells such as Th1 and Th17 play an impressive role in the immunopathogenesis of MS, while, regulatory cells such as Th2 and Treg diminish the severity of the illness. Sex hormones have a vital role in many autoimmune disorders, including multiple sclerosis. Testosterone, estrogen and progesterone have various roles in the progress of MS, which higher prevalence of disease in women and more severe in men reveals the importance of sex hormones' role in this disease. Vitamin D after chemical changes in the body, as an active hormone called calcitriol, plays an important role in regulating immune responses and improves MS by modulating the immune system. The optimum level of calcium in the body with vitamin D modulates immune responses and calcium as an essential ion in the body plays a key role in the treatment of autoimmune diseases. The interaction between vitamin D and sex hormones has protective and therapeutic effects against MS and functional synergy between estrogen and calcitriol occurs in disease recovery. Moreover, vitamin D and calcium interact with each other to regulate the immune system and shift them to anti-inflammatory responses.

Progesterone: A Steroid with Wide Range of Effects in Physiology as Well as Human Medicine

Progesterone is a steroid hormone traditionally linked with female fertility and pregnancy. In current reproductive medicine, progesterone and its analogues play crucial roles. While the discovery of its effects has a long history, over recent decades, various novel actions of this interesting steroid have been documented, of which its neuro- and immunoprotective activities are the most widely discussed. Discoveries of the novel biological activities of progesterone have also driven research and development in the field of progesterone analogues used in human medicine. Progestogen treatment has traditionally and predominately been used in maintaining pregnancy, the prevention of preterm labor, various gynecological pathologies, and in lowering the negative effects of menopause. However, there are also various other medical fields where progesterone and its analogues could find application in the future. The aim of this work is to show the mechanisms of action of progesterone and its metabolites, the physiological and pharmacological actions of progesterone and its synthetic analogues in human medicine, as well as the impacts of its production and use on the environment.

Experimental and clinical evidence for the protective role of progesterone in motoneuron degeneration and neuroinflammation

Far beyond its role in reproduction, progesterone exerts neuro-protective, promyelinating, and anti-inflammatory effects in the nervous system. These effects are amplified under pathological conditions, implying that changes of the local environment sensitize nervous tissues to steroid therapy. The present survey covers our results of progesterone neuroprotection in a motoneuron neurodegeneration model and a neuroinflammation model. In the degenerating spinal cord of the Wobbler mouse, progesterone reverses the impaired expression of neurotrophins, increases enzymes of neurotransmission and metabolism, prevents oxidative damage of motoneurons and their vacuolar degeneration (paraptosis), and attenuates the development of mitochondrial abnormalities. After long-term treatment, progesterone also increases muscle strength and the survival of Wobbler mice. Subsequently, this review describes the effects of progesterone in mice with induced experimental autoimmune encephalomyelitis (EAE), a commonly used model of multiple sclerosis. In EAE mice, progesterone attenuates the clinical severity, decreases demyelination and neuronal dysfunction, increases axonal counts, reduces the formation of amyloid precursor protein profiles, and decreases the aberrant expression of growth-associated proteins. These actions of progesterone may be due to multiple mechanisms, considering that classic nuclear receptors, extranuclear receptors, and membrane receptors are all expressed in the spinal cord. Although many aspects of progesterone action in humans remain unsolved, data provided by experimental models makes getting to this objective closer than previously expected.

Pharmacotherapy with 17β-estradiol and progesterone prevents development of mouse experimental autoimmune encephalomyelitis

BACKGROUND

Pregnant women with multiple sclerosis (MS) show disease remission in the third trimester concomitant with high circulating levels of sex steroids. Rodent experimental autoimmune encephalomyelitis (EAE) is an accepted model for MS. Previous studies have shown that monotherapy with estrogens or progesterone exert beneficial effects on EAE. The aim of the present study was to determine if estrogen and progesterone cotherapy of C57BL/6 female mice provided substantial protection from EAE.

METHODS

A group of mice received single pellets of progesterone (100 mg) and 17 β-estradiol (2.5 mg) subcutaneously 1 week before EAE induction, whereas another group were untreated before EAE induction. On day 16 we compared the two EAE groups and control mice in terms of clinical scores, spinal cord demyelination, expression of myelin basic protein and proteolipid protein, macrophage cell infiltration, neuronal expression of brain-derived neurotrophic factor mRNA and protein, and the number of glial fribrillary acidic protein (GFAP)-immunopositive astrocytes.

RESULTS

Clinical signs of EAE were substantially attenuated by estrogen and progesterone treatment. Steroid cotherapy prevented spinal cord demyelination, infiltration of inflammatory cells and GFAP+ astrogliocytes to a great extent. In motoneurons, expression of BDNF mRNA and protein was highly stimulated, indicating concomitant beneficial effects of the steroid on neuronal and glial cells.

CONCLUSIONS

Cotherapy with estrogen and progesterone inhibits the development of major neurochemical abnormalities and clinical signs of EAE. We suggest that a combination of neuroprotective, promyelinating and immuno-suppressive mechanisms are involved in these beneficial effects.

17β-Estradiol and 17α-estradiol induce rapid changes in cytoskeletal organization in cultured oligodendrocytes

Dramatic changes in the cytoskeleton and the morphology of oligodendrocytes (OLs) occur during various stages of the myelination process. OLs in culture produce large membrane sheets containing cytoskeletal veins of microtubules and actin filaments. We recently showed that estrogen receptors (ER) related to ERα/β were expressed in the membrane sheets of mature OLs in culture. Ligation of these or other membrane ERs in OLs with both 17β- and 17α-estradiol mediated rapid non-genomic signaling. Here, we show that estrogens also mediate rapid non-genomic remodeling of the cytoskeleton in mature OLs in culture. 17β-Estradiol caused a rapid loss of microtubules and the actin cytoskeleton in the OL membrane sheets. It also increased phosphorylation of the actin filament-severing protein cofilin, thus inactivating it. Staining for actin barbed ends with rhodamine-actin showed that it decreased the amount of actin barbed ends. 17α-Estradiol, on the other hand, increased the percentage of cells with abundant staining of actin filaments and actin barbed ends, suggesting that it stabilized and/or increased the dynamics of the actin cytoskeleton. The specific ERα and ERβ agonists, 4,4',4″-(4-propyl-(1H)-pyrazole-1,3,5-triyl) trisphenol (PPT) and diarylpropionitrile 2,3-bis(4-hydroxy-phenyl)-propionitrile (DPN), respectively, also caused the rapid phosphorylation of cofilin. Estrogen-induced phosphorylation of cofilin was inhibited by Y-27632, a specific inhibitor of the Rho-associated protein serine/threonine kinase (ROCK). The Rho/ROCK/cofilin pathway is therefore implicated in actin rearrangement via estrogen ligation of membrane ERs, which may include forms of ERα and ERβ. These results indicate a role for estrogens in modulation of the cytoskeleton in mature OLs, and thus in various processes required for myelinogenesis.

G protein-coupled receptor 30 contributes to improved remyelination after cuprizone-induced demyelination

Estrogen exerts neuroprotective and promyelinating actions. The therapeutic effect has been shown in animal models of multiple sclerosis, in which the myelin sheath is specifically destroyed in the central nervous system. However, it remains unproven whether estrogen is directly involved in remyelination via the myelin producing cells, oligodendrocytes, or which estrogen receptors are involved. In this study, we found that the membrane-associated estrogen receptor, the G protein-coupled receptor 30 (GPR30), also known as GPER, was expressed in oligodendrocytes in rat spinal cord and corpus callosum. Moreover, GPR30 was expressed throughout oligodendrocyte differentiation and promyelinating stages in primary oligodendrocyte cultures derived from rat spinal cords and brains. To evaluate the role of signaling via GPR30 in promyelination, a specific agonist for GPR30, G1, was administered to a rat model of demyelination induced by cuprizone treatment. Histological examination of the corpus callosum with oligodendrocyte differentiation stage-specific markers showed that G1 enhanced oligodendrocyte maturation in corpus callosum of cuprizone-treated animals. It also enhanced oligodendrocyte ensheathment of dorsal root ganglion (DRG) neurons in co-culture and myelination in cuprizone-treated animals. This study is the first evidence that GPR30 signaling promotes remyelination by oligodendrocytes after demyelination. GPR30 ligands may provide a novel therapy for the treatment of multiple sclerosis.

Progesterone down-regulates spinal cord inflammatory mediators and increases myelination in experimental autoimmune encephalomyelitis

In mice with experimental autoimmune encephalomyelitis (EAE) pretreatment with progesterone improves clinical signs and decreases the loss of myelin basic protein (MBP) and proteolipid protein (PLP) measured by immunohistochemistry and in situ hybridization. Presently, we analyzed if progesterone effects in the spinal cord of EAE mice involved the decreased transcription of local inflammatory mediators and the increased transcription of myelin proteins and myelin transcription factors. C57Bl/6 female mice were divided into controls, EAE and EAE receiving progesterone (100mg implant) 7 days before EAE induction. Tissues were collected on day 17 post-immunization. Real time PCR technology demonstrated that progesterone blocked the EAE-induced increase of the proinflammatory mediators tumor necrosis factor alpha (TNFα) and its receptor TNFR1, the microglial marker CD11b and toll-like receptor 4 (TLR4) mRNAs, and increased mRNA expression of PLP and MBP, the myelin transcription factors NKx2.2 and Olig1 and enhanced CC1+oligodendrocyte density respect of untreated EAE mice. Immunocytochemistry demonstrated decreased Iba1+microglial cells. Confocal microscopy demonstrated that TNFα colocalized with glial-fibrillary acidic protein+astrocytes and OX-42+microglial cells. Therefore, progesterone treatment improved the clinical signs of EAE, decreased inflammatory glial reactivity and increased myelination. Data suggest that progesterone neuroprotection involves the modulation of transcriptional events in the spinal cord of EAE mice.

Progesterone and autoimmune disease

Sexual dimorphism in human immune systems is most apparent in the female predominance of certain autoimmune diseases (ADs) like systemic lupus erythematosus (SLE). Epidemiologic, observational and experimental evidence strongly suggest sex steroids are important modulators of genetic risk in human AD. In this regard, the roles of progesterone (Pg), an immunomodulatory female sex steroid, are poorly understood. Several lines of investigation indicate Pg and synthetic progestins impact risk of AD and immune-mediated injury in different ways depending on their concentrations and their engagement of various Pg receptors expressed in immune organs, immune cells or tissues targeted by immune attack. At low physiologic levels, Pg may enhance interferon-alpha (IFN-α) pathways important in SLE pathogenesis. Commonly used synthetic progestins may have the opposite effect. At pregnancy levels, Pg may suppress disease activity in rheumatoid arthritis (RA) and multiple sclerosis (MS) via inhibition of T helper type 1 (Th1) and Th17 pathways and induction of anti-inflammatory molecules. Importantly, Pg's immunomodulatory effects differ from those of estrogens and androgens. An additional layer of complexity arises from apparent interdependence of sex hormone signaling pathways. Identifying mechanisms by which Pg and other sex steroids modulate risk of AD and immune-mediated injury will require clarification of their cellular and molecular targets in vivo. These future studies should be informed by recent genetic discoveries in human AD, particularly those revealing their sex-specific genetic associations.

Evaluation of serum levels of chemokines during interferon-β treatment in multiple sclerosis patients: a 1-year, observational cohort study

BACKGROUND

The molecules that provide access to activated T cells in the CNS, including chemokines, have been considered to be a crucial step in the pathogenesis of multiple sclerosis (MS).

AIMS

In this study, we investigated serial serum chemokine levels in patients with relapsing-remitting MS over 1 year and the association of these chemokine levels with treatment regimens, lesions on MRI and patients' characteristics.

METHODS

Serum CXCL9, CXCL10, CCL2, CCL4 and CCL5 levels were evaluated using ELISA every 2 months for a year in 28 healthy controls and 28 MS patients during their treatment with interferon (IFN)-β. Patients underwent MRI and were evaluated using the Expanded Disability Status Scale (EDSS) at the first and final evaluations.

RESULTS

CXCL10 serum levels were higher in MS patients compared with controls, were positively correlated with T2 lesions on MRI and were slightly increased during relapses. Treatment with IFNβ-1a or IFNβ-1b was associated with increased CXCL10 levels when evaluated more than 36 hours after subcutaneous injection. The CXCL9 levels were higher after MS relapse. There was significant variability in CCL4 and CCL5 levels in the serial evaluations, associated with gender and treatment. CCL2 levels were higher in treated MS patients than healthy controls, particularly among those patients with a stable form of the disease.

CONCLUSION

Serum is a feasible resource for searching for an immunological marker in MS. Peripheral chemokine levels correlated in different ways with IFNβ therapy and with disease and patient characteristics.

CLINICAL TRIAL REGISTRATION NUMBER

ISRCTN45526724.

Progesterone attenuates demyelination and microglial reaction in the lysolecithin-injured spinal cord

Progesterone treatment of mice with experimental autoimmune encephalomyelitis has shown beneficial effects in the spinal cord according to enhanced clinical, myelin and neuronal-related parameters. In the present work, we report progesterone effects in a model of primary demyelination induced by the intraspinal injection of lysophospatidylcholine (LPC). C57Bl6 adult male mice remained steroid-untreated or received a single 100 mg progesterone implant, which increased circulating steroid levels to those of mouse pregnancy. Seven days afterwards mice received a single injection of 1% LPC into the dorsal funiculus of the spinal cord. A week after, anesthetized mice were perfused and paraffin embedded sections of the spinal cord stained for total myelin using Luxol Fast Blue (LFB) histochemistry, for myelin basic protein (MBP) immunohistochemistry and for determination of OX-42+ microglia/macrophages. Cryostat sections were also prepared and stained for oligodendrocyte precursors (NG2+ cells) and mature oligodendrocytes (CC1+ cells). A third batch of spinal cords was prepared for analysis of the microglial marker CD11b mRNA using qPCR. Results showed that progesterone pretreatment of LPC-injected mice decreased by 50% the area of demyelination, evaluated by either LFB staining or MBP immunostaining, increased the density of NG2+ cells and of mature, CC1+ oligodendrocytes and decreased the number of OX-42+ cells, respect of steroid-untreated LPC mice. CD11b mRNA was hyperexpressed in LPC-treated mice, but significantly reduced in LPC-mice receiving progesterone. These results indicated that progesterone antagonized LPC injury, an effect involving (a) increased myelination; (b) stimulation of oligodendrocyte precursors and mature oligodendrocytes, and (c) attenuation of the microglial/macrophage response. Thus, use of a focal demyelination model suggests that progesterone exerts promyelinating and anti-inflammatory effects at the spinal cord level.

The localization and non-genomic function of the membrane-associated estrogen receptor in oligodendrocytes

There is general acceptance that the estrogen receptor can act as a transcription factor. However, estrogens can also bind to receptors that are located at the plasma membrane and stimulate rapid intracellular signaling processes. We recently showed that a membrane-associated estrogen receptor (mER) is present within myelin and at the oligodendrocyte (OL) plasma membrane. To understand the physiological function of mER in OLs, we investigated its cellular localization and involvement in rapid signaling in CG4 cells and OL primary cultures. An ERalpha was expressed along the lacy network of veins in the membrane sheets and in the perikaryon and nucleus in OLs. ERbeta was located in the nucleus, and to a lesser extent along the veins. The expression of ERalpha and ERbeta in OL membranes was confirmed by Western analysis of isolated membranes. OL membranes mainly had truncated forms of ERalpha, 53 and 50 kDa, in addition to some 65 kDa form, whereas ERbeta was a 54 kDa form. CG4 cells and OLs were pulsed with 17alpha- and 17beta-estradiol for various times and the total lysates were analyzed for phosphorylated kinases. Both 17alpha- and 17beta-estradiol elicited rapid phosphorylation of p42/44MAPK, Akt, and GSK-3beta within 8 min. This rapid signaling is consistent with estradiol ligation of a membrane form of ER. Since 17alpha-estradiol is produced at higher concentrations than 17beta-estradiol in the brain of both sexes, signaling via 17alpha-estradiol-liganded mER may have an important function in OLs.

Effects of progesterone in the spinal cord of a mouse model of multiple sclerosis

The spinal cord is a target of progesterone (PROG), as demonstrated by the expression of intracellular and membrane PROG receptors and by its myelinating and neuroprotective effects in trauma and neurodegeneration. Here we studied PROG effects in mice with experimental autoimmune encephalomyelitis (EAE), a model of multiple sclerosis characterized by demyelination and immune cell infiltration in the spinal cord. Female C57BL/6 mice were immunized with a myelin oligodendrocyte glycoprotein peptide (MOG(40-54)). One week before EAE induction, mice received single pellets of PROG weighing either 20 or 100 mg or remained free of steroid treatment. On average, mice developed clinical signs of EAE 9-10 days following MOG administration. The spinal cord white matter of EAE mice showed inflammatory cell infiltration and circumscribed demyelinating areas, demonstrated by reductions of luxol fast blue (LFB) staining, myelin basic protein (MBP) and proteolipid protein (PLP) immunoreactivity (IR) and PLP mRNA expression. In motoneurons, EAE reduced the expression of the alpha 3 subunit of Na,K-ATPase mRNA. In contrast, EAE mice receiving PROG showed less inflammatory cell infiltration, recovery of myelin proteins and normal grain density of neuronal Na,K-ATPase mRNA. Clinically, PROG produced a moderate delay of disease onset and reduced the clinical scores. Thus, PROG attenuated disease severity, and reduced the inflammatory response and the occurrence of demyelination in the spinal cord during the acute phase of EAE.

Mannose-binding lectin levels during pregnancy: a longitudinal study

BACKGROUND

Pregnancy is associated with changes in the immune system. Although previous studies have focussed mainly on adaptive immunity, there are indications that components of innate immunity, such as mannose-binding lectin (MBL), are associated with pregnancy outcome. Although this would suggest that pregnancy also involves adaptations in innate immunity, there are few studies in this area. Therefore, we aimed to determine whether MBL concentrations and the following steps in complement pathway activation are influenced by pregnancy.

METHODS

MBL and Ficolin-2 concentrations, MBL-MBL-associated serine protease (MASP) complex activity, MBL pathway activity and classical complement pathway activity were determined by enzyme-linked immunosorbent assay (ELISA) in sera from pregnant women (n=32) during each trimester and post-partum. MBL genotyping was performed by PCR.

RESULTS

During pregnancy, MBL concentrations increased to 140% [interquartile range (IQR) 116-181%, P < 0.0001]. This increase was already present at 12 weeks of pregnancy and was most pronounced in the high-production AA-genotype. Directly Post-partum MBL concentrations dropped to 57% of baseline (IQR 44-66%, P < 0.0001). Variations in MBL levels were reflected by similar changes in the following steps of complement activation, r > 0.93 (P < 0.01). Ficolin-2 levels and classical complement pathway activity were not similarly influenced by pregnancy.

CONCLUSIONS

Pregnancy and the post-partum period profoundly influence MBL serum concentration and MBL complement pathway activity.