Inositol Phosphoglycan Research Articles

The Biomedical Uses of Inositols: A Nutraceutical Approach to Metabolic Dysfunction in Aging and Neurodegenerative Diseases.

Inositols are sugar-like compounds that are widely distributed in nature and are a part of membrane molecules, participating as second messengers in several cell-signaling processes. Isolation and characterization of inositol phosphoglycans containing myo- or d-chiro-inositol have been milestones for understanding the physiological regulation of insulin signaling. Other functions of inositols have been derived from the existence of multiple stereoisomers, which may confer antioxidant properties. In the brain, fluctuation of inositols in extracellular and intracellular compartments regulates neuronal and glial activity. Myo-inositol imbalance is observed in psychiatric diseases and its use shows efficacy for treatment of depression, anxiety, and compulsive disorders. Epi- and scyllo-inositol isomers are capable of stabilizing non-toxic forms of β-amyloid proteins, which are characteristic of Alzheimer’s disease and cognitive dementia in Down’s syndrome, both associated with brain insulin resistance. However, uncertainties of the intrinsic mechanisms of inositols regarding their biology are still unsolved. This work presents a critical review of inositol actions on insulin signaling, oxidative stress, and endothelial dysfunction, and its potential for either preventing or delaying cognitive impairment in aging and neurodegenerative diseases. The biomedical uses of inositols may represent a paradigm in the industrial approach perspective, which has generated growing interest for two decades, accompanied by clinical trials for Alzheimer’s disease.

Systematic analysis of the biological roles and pharmacological properties of D-chiro-inositol

D-chiroinositol (DCI) is one of the 9 inositol isomers that forms inositol phosphoglycans, which are mediators of the action of insulin. The metabolism of DCI and myo-inositol (MI) is impaired against the background of insulin resistance, including the patients with polycystic ovary syndrome (PCOS).
 Aim. Highlight the most characteristic pharmacological properties of DCI.
 Materials and methods. Systematic computer analysis of 45 600 publications on the biological roles of inositol by methods of the topological theory of pattern recognition and systems biology analysis of human proteome.
 Results. A complex of interactions between metabolic disorders of DCI, PCOS, ovulation disorders, obesity associated with numerous hormonal disorders is described. Supplements with DCI and MI increase the sensitivity of cells to insulin and normalize the metabolism of androgens. An important difference between DCI and MI is the presence of DCI in the composition of inositol phosphoglycans that mediate the action of insulin on cells, as well as its participation in the realization of the therapeutic effects of metformin. The use of the MI+DCI combination allows achieving positive dynamics in reducing excess body weight, normalizing blood lipids, glucose and insulin levels, restoring the ovulatory menstrual cycle, improving oocyte quality, and helps prevent gestational diabetes in pregnant women and macrosomia of the fetus. DCI is more effective than MI in reducing the risk of folate-resistant neural tube defects.
 Conclusion. The therapeutic potential of DCI in combination with MI for treating PCOS and hyperandrogenism is evident. Depending on the therapeutic expediency, various ratios of MI:DCI can be used for the treatment of PCOS and disorders of carbohydrate and lipid metabolism.A

Myo-Inositol and Its Derivatives: Their Emerging Role in the Treatment of Human Diseases.

Myo-inositol has been established as an important growth-promoting factor of mammalian cells and animals. The role of myo-inositol as a lipotropic factor has been proven, in addition to its involvement as co-factors of enzymes and as messenger molecules in signal transduction. Myo-inositol deficiency leads to intestinal lipodystrophy in animals and “inositol-less death” in some fungi. Of late, diverse uses of myo-inositol and its derivatives have been discovered in medicinal research. These compounds are used in the treatment of a variety of ailments from diabetes to cancer, and continued research in this direction promises a new future in therapeutics. In different diseases, inositols implement different strategies for therapeutic actions such as tissue specific increase or decrease in inositol products, production of inositol phosphoglycans (IPGs), conversion of myo-inositol (MI) to D-chiro-inositol (DCI), modulation of signal transduction, regulation of reactive oxygen species (ROS) production, etc. Though inositol pharmacology is a relatively lesser-known field, recent years of research has generated a critical mass of information on the subject. This review aims to summarize our current understanding on the role of inositol derivatives in ameliorating the symptoms of different diseases.

Modulation of gonadotrophin induced steroidogenic enzymes in granulosa cells by d-chiroinositol

d-chiroinositol (DCI) is a inositolphosphoglycan (IPG) involved in several cellular functions that control the glucose metabolism. DCI functions as second messenger in the insulin signaling pathway and it is considered an insulin sensitizer since deficiency in tissue availability of DCI were shown to cause insulin resistance (IR). Polycystic ovary syndrome (PCOS) is a pathological condition that is often accompanied with insulin resistance. DCI can positively affects several aspect of PCOS etiology decreasing the total and free testosterone, lowering blood pressure, improving the glucose metabolism and increasing the ovulation frequency. The purpose of this study was to evaluate the effects of DCI and insulin combined with gonadotrophins namely follicle-stimulating hormone (FSH) and luteinizing hormone (LH) on key steroidogenic enzymes genes regulation, cytochrome P450 family 19 subfamily A member 1 (CYP19A1) and cytochrome P450 side-chain cleavage (P450scc) in primary cultures of human granulosa cells (hGCs). We also investigated whether DCI, being an insulin-sensitizer would be able to counteract the expected stimulator activity of insulin on human granulosa cells (hGCs). Methods. The study was conducted on primary cultures of hGCs. Gene expression was evaluated by RT-qPCR method. Statistical analysis was performed applying student t-test, as appropriate (P < 0.05) set for statistical significance. Results. DCI is able to reduce the gene expression of CYP19A1, P450scc and insulin-like growth factor 1 receptor (IGF-1R) in dose–response manner. The presence of DCI impaired the increased expression of steroidogenic enzyme genes generated by the insulin treatment in gonadotrophin-stimulated hGCs. Conclusions. Insulin acts as co-gonadotrophin increasing the expression of steroidogenic enzymes genes in gonadotrophin-stimulated granulosa cells. DCI is an insulin-sensitizer that counteracts this action by reducing the expression of the genes CYP19A1, P450scc and IGF-1R. The ability of DCI to modulate in vitro ovarian activity of insulin could in part explain its beneficial effect when used as treatment for conditions associated to insulin resistance.

Preeclampsia and the 20th century: "Le siècle des Lumières".

The authors delineate seven quantum leap forward and, or revolutions having occurred during the 20th century in the understanding of the physiopathology of preeclampsia. First the discovery of the inflatable arm band permitting to measure blood pressure in 1896. Second, the discovery that eclamptic (convulsions), and later "pre"eclamptic (proteinuria) women presented hypertension in 1897 and confirmed in 1903, discovery of the hypertensive disorders of pregnancy. Third, the eight major textbooks published all along the 20th century by delineating risk factors of preeclampsia with the concept of "preeclampsia, disease of primigravidae". Fourth, the discovery in the 1970's that human trophoblast implantation was far deeper than in other mammalian species. Fifth, and a major step forward, description at the end of the 1980's that the maternal syndrome in preeclampsia (glomeruloendotheliosis, HELLP syndrome, eclampsia) could be unified in a global endothelial cell inflammation. Sixth, the epidemiological descriptions in the 1970-1990's that indeed preeclampsia was a disease of first pregnancies at the level of a couple ("primipaternity concept"), leading to an explosion in immunological research in the last decade, beginning in 1998. Seventh and finally, in the search for the "factor X" explaining the vascular inflammation in preeclamptic women (inositol phospho glycans P-type were described in 2000, while soluble Flt-1 and S-endoglins have been clearly predicted since 1997). The majority of the seeds or findings have been grounded or realized in the 20th century. Indeed, for preeclampsia, the 20th century has been le "Siècle des Lumières" (the Enlightments).

New insights into early and late onset subgroups of preeclampsia from longitudinal versus cross-sectional analysis of urinary inositol-phosphoglycan P-Type

Most pre-eclampsia (PE) studies have used cross-sectional data to derive conclusions regarding the pathophysiology of the condition. This has led to the concept that there exists early (<34 weeks) and late-onset (>34 weeks) disease according to gestational age at diagnosis. Survival time models have predicted that if the pregnancy was to continue indefinitely, all women would develop PE. In this study we have performed a longitudinal analysis of the urinary biomarker, inositol phosphoglycan (IPG), in a cohort of women giving birth in Mauritius (n-920). We have analysed the PE data in the traditional cross-sectional manner for n = 77 women who developed PE and also then looked at the longitudinal data for 71/77 of the same women. The data allows us to use longitudinal values to calculate a date of onset (first presence of biomarker in urine) and compare that to date of clinical diagnosis (cross sectional). We find two populations for both analysis consistent with an early and late stage subgroup. The calculated date of onset had subgroups (early and late) at 28.4 ± 0.41 weeks and 35.37 ± 0.26 weeks and for clinical date of diagnosis, 32.3 ± 0.59 weeks and 37.04 ± 0.62 weeks, respectively. The presence of the same biomarker in both subgroups and its ability to predict clinical onset 2–4 weeks prior to clinical diagnosis suggest that both groups may have similar aetiology.

Historical evolution of ideas on eclampsia/preeclampsia: A proposed optimistic view of preeclampsia

Eclampsia (together with epilepsy) being the first disease ever written down since the beginning of writings in mankind 5000 years ago, we will make a brief presentation of the different major steps in comprehension of Pre-eclampsia. 1) 1840. Rayer, description of proteinuria in eclampsia, 2) 1897 Vaquez, discovery of gestational hypertension in eclamptic women, 3) In the 1970′s, description of the “double” trophoblastic invasion existing only in humans (Brosens & Pijnenborg,), 4) between the 1970′s and the 1990′s, description of preeclampsia being a couple disease. The “paternity problem” (and therefore irruption of immunology), 5) at the end of the 1980′s, a major step forward: Preeclampsia being a global endothelial cell disease (glomeruloendotheliosis, hepatic or cerebral endotheliosis, HELLP, eclampsia), inflammation (J.Roberts.C Redman, R Taylor), 6) End of the 1990′s: Consensus for a distinction between early onset preeclampsia EOP and late onset LOP (34 weeks gestation), EOP being rather a problem of implantation of the trophoblast (and the placenta), LOP being rather a pre-existing maternal problem (obesity, diabetes, coagulopathies etc…). LOP is predominant everywhere on this planet, but enormously predominant in developed countries: 90% of cases. This feature is very different in countries where women have their first child very young (88% of world births), where the fatal EOP (early onset) occurs in more than 30% of cases. 7) What could be the common factor which could explain the maternal global endotheliosis in EOP and LOP? Discussion about the inositol phospho glycans P type.

PKB/Akt and MAPK/ERK phosphorylation is highly induced by inositols: Novel potential insights in endothelial dysfunction in preeclampsia.

PKB/Akt and MAP/ERK are intracellular kinases regulating cell survival, proliferation and metabolism and as such hold a strategical role in preeclampsia. In fact intracellular pathways related to immunological alterations, endothelial dysfunction and insulin resistance in preeclampsia converge on these molecules. Inositol second messengers are involved in metabolic and cell signaling pathways and are highly expressed during preeclampsia. To evaluate the pathophysiological significance of this response, the effect of myo-inositol and d-chiro inositol on the activation of PKB/Akt and MAPK/ERK was assessed in human endothelial cells in vitro. Time-course and dose-response analyses of phosphorylation following incubation with inositols showed an approximately 6-fold and 15-fold increase for myo-inositol and d-chiro inositol (p<0.05), respectively. Both inositols promoted a significantly higher PKB/Akt and MAPK/ERK phosphorylation than insulin. Thus, exogenously administered inositols can activate PKB/Akt and MAPK/ERK in human endothelial cells in vitro. The increased production of d-chiro inositol phosphoglycans (IPG-P) during preeclampsia may thus represent a compensatory response, potentially promoting cell survival and metabolism.

KL 16 Abnormal glucose signaling in trophoblast biology

Human trophoblast shows a peculiar carbohydrate metabolism during pregnancy with adaptive responses to systemic alterations that may occur during gestation. In fact, cells may adapt their metabolism to environmental changes driven by inflammatory cytokines, available nutrients and oxygen tension. An interesting adaptation of intracellular signaling occur in human trophoblast under healthy conditions throughout the pregnancy and in case of superimposed complications that alter the surrounding milieu. These modifications are not only passive responses but they may be considered as an active interaction and may be transferred to the mother through specific mediators as an attempt to modulate the maternal systemic reaction. In early gestation, trophoblast invades the endometrium (implantation) and gland secretions represent the initial form of nutrition for the conceptus (histiotrophic nutrition) prior to the complete development of the placenta. An alternative carbohydrate metabolism takes place in this setting that is characterized by low-oxygen tension, lipid and glycolipid secretion that represent the available nutrients, and high concentration of regulatory cytokines due to the immune system activation (fetal-placental interface). Inositol second messengers mediate this metabolic process of glucose non-oxidative use and storage and lipogenesis. Inositol phosphatides were shown to interact with leucocytes at membrane and intracellular level with a sort of reciprocal benefit during those weeks of rapid changes. Inositol phosphoglycans start to leak into maternal circulation to modulate physiological insulin resistance that occurs during healthy pregnancy. When an excessive systemic inflammation occurs like in preeclampsia, the fetal/placental unit pour out large amounts of D-chiro inositol mediators (IPG-P) into maternal circulation being favored by a more permissive placental membrane that show thinner glycocalyx and less tight junctions. These mediators were also shown to play a role in endothelial dysfunction, predisposition to seizures (eclampsia), and cardiovascular disease later in life.

Intracellular actions of inositol messengers and their relationship with the metabolic syndrome

Metabolic alterations occur along with immunological alterations, abnormal placental development and endothelial cell dysfunction in preeclampsia. Typical features of placental alterations are an inadequate/incomplete trophoblast invasion of maternal spiral arteries and acute atherosis. Phosphoinositide 3-kinase (PI3-K)/Akt signaling pathway holds a pivotal role in intracellular metabolic pathways as it regulates endothelial cell survival, migration, tube formation and nitric oxide production. The inositol second messenger system (myo- inositol and D-chiro inositol) is involved in metabolic and cell signaling pathways. Pyruvate dehydrogenase complex (PDC) is at the interface between glycolysis and the citric acid cycle and is crucial to the generation of ATP, acetyl CoA and NADH by mitochondria. We showed that the putative insulin mediator inositol phosphoglycan containing D-chiro inositol (IPG-P) has a sigmoidal inhibitory action on PDK in addition to its known linear stimulation of PDP. Thus, at critical levels of these mediators this sigmoidal/linear model amplifies the switchover from the inactive to active form of PDC, a ‘push- pull’ system that combined with the hormonal control of IPG-P, indicates a powerful regulatory function via inhibition of PDK. The presence of zinc is of interest in relation to our reported effects of zinc ions on PDP and PDH kinases, and in the context of the cardioprotective effects of zinc on vascular ischemia-reperfusion injury. This resetting of the PDC to the active non-phosphorylated state and formation of acetyl-CoA may be enhanced by the effect of zinc on the activation of enolase in the glycolytic pathway and by the regulation of the phosphorylation state of the insulin receptor and thus downstream pathways favouring the provision of pyruvate from glucose. The counter effect of zinc in depressing acetyl-CoA oxidation is obtained via inhibition of key enzymes of the tricarboxylic acid cycle driving acetyl-CoA towards the lipogenic route. Manganese is present in high concentrations in IPG-A type (containing myo-inositol) and coordinates lipid synthesis via manganese activation of different enzymes. Characterization of the intracellular action of inositol messengers in the context of a metabolic disease like preeclampsia helps to understand the underlying biochemical mechanisms that occur in placenta and endothelial cells.

Modulation of gonadotrophin induced steroidogenic enzymes in granulosa cells by d-chiroinositol

Backgroundd-chiroinositol (DCI) is a inositolphosphoglycan (IPG) involved in several cellular functions that control the glucose metabolism. DCI functions as second messenger in the insulin signaling pathway and it is considered an insulin sensitizer since deficiency in tissue availability of DCI were shown to cause insulin resistance (IR). Polycystic ovary syndrome (PCOS) is a pathological condition that is often accompanied with insulin resistance. DCI can positively affects several aspect of PCOS etiology decreasing the total and free testosterone, lowering blood pressure, improving the glucose metabolism and increasing the ovulation frequency. The purpose of this study was to evaluate the effects of DCI and insulin combined with gonadotrophins namely follicle-stimulating hormone (FSH) and luteinizing hormone (LH) on key steroidogenic enzymes genes regulation, cytochrome P450 family 19 subfamily A member 1 (CYP19A1) and cytochrome P450 side-chain cleavage (P450scc) in primary cultures of human granulosa cells (hGCs). We also investigated whether DCI, being an insulin-sensitizer would be able to counteract the expected stimulator activity of insulin on human granulosa cells (hGCs).MethodsThe study was conducted on primary cultures of hGCs. Gene expression was evaluated by RT-qPCR method. Statistical analysis was performed applying student t-test, as appropriate (P < 0.05) set for statistical significance.ResultsDCI is able to reduce the gene expression of CYP19A1, P450scc and insulin-like growth factor 1 receptor (IGF-1R) in dose–response manner. The presence of DCI impaired the increased expression of steroidogenic enzyme genes generated by the insulin treatment in gonadotrophin-stimulated hGCs.ConclusionsInsulin acts as co-gonadotrophin increasing the expression of steroidogenic enzymes genes in gonadotrophin-stimulated granulosa cells. DCI is an insulin-sensitizer that counteracts this action by reducing the expression of the genes CYP19A1, P450scc and IGF-1R. The ability of DCI to modulate in vitro ovarian activity of insulin could in part explain its beneficial effect when used as treatment for conditions associated to insulin resistance.

Putative Key Role of Inositol Messengers in Endothelial Cells in Preeclampsia

Immunological alterations, endothelial dysfunction, and insulin resistance characterize preeclampsia. Endothelial cells hold the key role in the pathogenesis of this disease. The signaling pathways mediating these biological abnormalities converge on PKB/Akt, an intracellular kinase regulating cell survival, proliferation, and metabolism. Inositol second messengers are involved in metabolic and cell signaling pathways and are highly expressed during preeclampsia. Intracellular action of these molecules is deeply affected by zinc, manganese, and calcium. To evaluate the pathophysiological significance, we present the response of the intracellular pathways of inositol phosphoglycans involved in cellular metabolism and propose a link with the disease.

Is it time to consider patients suffering from endometriosis-related infertility as “novel candidates” for targeted peri-conceptional D-chiro inositol supplementation? Hypothesis, rationale and some considerations

Dear Editor, We read with great pleasure the interesting data reported by Piomboni et al. concerning several advantages patients affected by polycystic ovarian syndrome (PCOS) and undergoing controlled ovarian hyperstimulation (COH) with pre-treatment supplementation by D-chiro inositol and/or metformin treatment. [1] The demonstrat D-chiro inositol supplementation and metformin treatment were both shown to significantly improve the follicular fluid (FF) milieu by decreasing the oxidative damage (measured as free-SH groups levels) on FF proteins and, as a consequence, significantly increase the number of good quality MII oocytes. Although for many years it was known that the oxidative stress could have a negative effects on FF environment, recent evidence has suggested that good quality oocytes require a correct balance in FF pro-oxidative and anti-oxidative factors, [2] since an excess in pro-oxidative status is associated with poor quality oocytes, low fertilization and implantation rates while a deficit may be responsible for follicular atresia. [3, 4] Interestingly, several studies reported that women suffering from endometriosis frequently experience infertility and poor IVF outcomes (poor qualitative and quantitative ovarian response, low implantation rate), particularly when they have an imbalance in thiol-redox and oxidative status. [5–8] It is known that, frequently, abnormalities in oxidative status balance may reflect alterations in glucose and lipid metabolism. Similarly to PCOS patients, several studies noticed that patients suffering from endometriosis have abnormalities in both glucose and lipid metabolism. For example, McKinnon et al. found that in endometriotic lesions GLUT4 (glucose transporter-4) protein expression was enhanced, probably due to increase glucose availability in the growing lesions. [8] In contrast, Melo et al. report that patients affected by endometriosis frequently show “unfavourable” lipid profile (increase in low-density and reduction in high-density lipoprotein), potentially favouring the oxidative stress (via lipid peroxidation) typically increased in this cohort of women. [9–11] D-chiro inositol is a “dietary supplement” of Inositol, an essential component of the phospholipids that make up cellular membranes, detectable in every cell of the body. The available formulations for oral administration show good bioavailability, safe pharmacologic profiles and beneficial effects in improving spontaneous fertility (or success rate of ARTs) also after short-term treatment, particularly in patients affected by PCOS and anovulation. [11] Basically, oral formulations of D-chiro inositol appear to significantly reduce oxidative status as a result of its antioxidant properties that in turn lead to improvements in glucose metabolism (insulin-sensitizing effect mainly fulfilled by D-chiro inositol phosphoglycan via glycogen synthase activity) and a reduction in circulating levels of LDL and triglycerides in addition to BMI reduction. [12] The properties of D-chiro inositol in reducing the “unbalanced” oxidative status of PCOS patients without significant adverse effects prompts speculation as to whether patients suffering from endometriosis in association with hypo/infertility should be considered as “novel candidates” who may potentially benefit from this supplementation in a pre-conception period (or pre-treatment period when referred to ARTs). Our proposal warrants further investigation. Much effort is being made to improve the fertility of patients suffering from endometriosis, and more and more therapeutic strategies are targeted to oxidative stress reduction. [11, 12] In fact, several Authors [13] recently showed that pre-treatment administration of ultra-long GnRH agonist (1.8 mg s.c. every 28 days for three courses) was effective in balancing intra follicular oxidative stress (checked by 8-hydroxy-2-deoxyguanosine reduction and increase in melatonin levels) and in improving ARTs outcomes of women affected by endometriosis. Others [14] have proposed the use of statins for endometriosis targeted treatment. Despite the beneficial effects, potential adverse effects should not be underestimated. In the future both scientists and clinicians must join forces in seeking novel approaches to improve fertility in patients suffering from endometriosis reducing their “over” oxidative status. It is our opinion that the time has arrived to shift attention towards potential efficacy and safety of D-chiro inositol supplementation to balance the oxidative status of patients suffering from endometriosis, evaluating by appropriate studies the real cost-efficacy of peri-conceptional D-chiro inositol supplementation in this potential “novel candidate” cohort of patients.

The putative metabolic role of d-chiro inositol phosphoglycan in human pregnancy and preeclampsia

Immunological alterations, systemic inflammation, endothelial dysfunction, and insulin resistance are prominent features of preeclampsia, although the reciprocal relationship between them is poorly understood. The metabolic syndrome that occurs during preeclampsia can be exacerbated by the systemic inflammation and linked to placental metabolism/development and endothelial dysfunction. Under healthy conditions, insulin and insulin-like growth factor-integrated pathways not only promote cell metabolism and proliferation, but also regulate endothelial synthesis and release of vasodilators (e.g., nitric oxide, NO) and opposing vasoconstrictors (e.g., endothelin-1) to maintain vascular homeostasis. d-chiro inositol phosphoglycans (DCI), second messengers of insulin, are increased during preeclampsia and contribute directly to insulin resistance. The dynamic balanced control of vascular function may be altered by excessive DCI that impairs the PI3-kinase-dependent pathway and may result in reduced bioavailability of NO, contributing to elevated peripheral vascular resistance and hypertension.

Fourteen years of debate and workshops on the immunology of preeclampsia. Where are we now after the 2012 workshop?

This paper depicts an overview of debates that have taken place during the 14 years of the International Workshops on Reproductive Immunology/Immunological Tolerance and Immunology of Preeclampsia. This 8th event in 2012 (Reunion island, overseas department of France in the Indian Ocean) witnessed a consensus among immunologists on the key role of regulatory T-cells in the orchestration of trophoblastic invasion at the maternal–fetal interface, while they represent some 10% of the immunological cellular repertoire at the site of implantation (NK cells representing 70%). On the vascular side, the upregulation of carbon monoxide CO, metabolite of heme oxygenase-1 (HO-1; by inhibiting soluble Flt-1, SFlt-1, and soluble endoglin, SEng, release), explains the very promising protective and potentially therapeutic effect of pravastatin in preeclampsia and the paradoxical strong protective effect of cigarette smoking on preeclampsia. Finally, there was, through a study performed on Mauritius island a great interest in the inositol phosphoglycans P-type (IPG-P) as a reliable, cheap, and predictive urinary test in preeclamptic women (a few weeks before the clinical onset of the disease). Besides the interest of a specific test, IPG-P may also partially explain the global endothelial cell disease encountered in preeclampsia. Furthermore, the Appendix of this paper lists the programs of all the workshops that have taken place since 1998.

D-chiro-inositol phosphoglycan expression in human placenta at term in diabetes

We present a histological assessment of diabetic placenta for the localization of some insulin mediators that were reported to play a major role for lipid/glycogen metabolism in human placenta. Placental metabolism is fundamental to fetal wellbeing. In fact, all maternal metabolic alterations have a profound effect on placental development with a subsequent definite impact on pregnancy outcome and fetal growth [1]. We have previously reported abnormalities in expression and activation of specific insulin-like growth factor-I receptor signaling molecules and multiple members of the MAP kinase family in human placentas of fetuses with intra-uterine growth restriction [2]. Subsequent studies on placental metabolism have focused on a family of insulin mediators, namely inositol phosphoglycans that were found to be highly expressed in diabetic and preeclamptic placentas [3]. These molecules play a major role in the regulation of the disposal of glucose by oxidative and non-oxidative routes of storage by glycogen synthesis [4]. In fact, the complexity and specificity of insulin action are determined by an integrated signaling network of independent intracellular pathways with several downstream effectors that have been shown to modulate the signal amplitude and frequency for both shortand longterm effects. Specific acquired alterations in activation of proteins involved in insulin signaling in preeclamptic placenta were shown to be associated with the accumulation of D-chiro-inositol phosphoglycan and to play a role in the insulin-resistant state that occurs in preeclampsia [5]. A disturbed insulin signaling was demonstrated in these cases and associated to low activation of insulin receptor effectors through multiple serine phosphorylations in both IRS-1 and IRS-2 [5]. In this study, placental specimens from six healthy and diabetic women at term were assessed for chiro-inositol using antibodies (mouse anti-D-chiro-inositol phosphoglycan), kindly provided by Professor Eduardo Martinez (Pamplona, Spain). A standard procedure was used for the immunohistochemical staining. The primary anti-D-chiroinositol phosphoglycan antibody was diluted 1:100 in antibody diluent (Dako, USA) and incubated for 60 min at room temperature. The percentage of positive stained controls was used as a reference for comparison. In control cases (Fig. 1a), a clear immunostaining of the syncytiotrophoblast was found (p = 0.11) with a little activity within the villous stroma (p = 0.43). The endothelium of placental vessels shows a localization of D-chiro-inositol phosphoglycan in normal placenta while in diabetic samples is weakly stained (p \ 0.01, Fig. 1b). The extravillous trophoblast in the basal plate of diabetic cases reveals also staining (p = 0.23, Fig. 1c, d). In both cases, a weak staining was found in maternal plasma, while a strong staining was found in fetal plasma. According to these findings, we may hypothesize that the placenta uptakes D-chiro inositol phosphoglycan from M. Scioscia (&) Department of Obstetrics and Gynecology, Sacro Cuore Don Calabria General Hospital, Via Don A. Sempreboni, 5, 37024 Negrar, VR, Italy e-mail: marco.scioscia@sacrocuore.it

Know your Enemy: The Rationale of Using Inositol in the Treatment of Polycystic Ovary Syndrome

The Polycystic Ovary Syndrome (PCOS) is defined, according to Rotterdam’s criteria proposed by the European Society for Human Reproduction and Embryology and the American Society for Reproductive Medicine [1,2], by the identification of two out of following parameters: oligo-anovulation; hyperandrogenism (clinical or biochemical); the presence of 12 or more follicles in each ovary measuring 2÷9 mm in diameter, and/or an increased ovarian volume (>10 ml). PCOS affects about 4÷8% of the women in reproductive age [3], causing anovulatory cycles in the 74% of the cases, insulinresistance in the 42% and hyperandrogenism in the 48% [4]. PCOS in our opinion could be considered as the result of concurrent endocrinological alterations, which affects each other. First of all, obesity affects the 35% of PCOS patients [5] and provoke multiple metabolic and endocrine dysfunctions: fatty tissue, in fact, behaves as non-classical endocrine organs and secretes specific cytokines and chemokines [6] which stimulate the androgens production by adrenal cortex and ovaries [7]; on the other hands, adipocytes’ mediators seems to alter thehypothalamus-hypophisis-gonads regulation system, causing high and constant production of Luteinizing Hormone (LH). This may accounts, at least in part, for the typical inhibition of the ovarian follicular maturation in PCOS patients [8]. Moreover, metabolic profile is strictly connected to gonadal function [9]: in PCOS patient’s insulinresistance is commonly associated with hyperinsulinemia [10], and the latter acts synergistically with LH to enhance the androgen production of theca cells [11]. Furthermore, it is able to reduce circulating levels of Sex Hormone Binding Globulin (SHBG), leading to increased levels of free testosterone [12]. Considered altogether, these evidences led to the use of insulin sensitizing drugs to stem the symptoms of this pathology. To date, different Inositol isoforms seems to increase insulin action on various tissues and, in this way to improve the ovulatory function and to inhibit or limit the production of testosterone [13]. Moreover, the use of Inositol may improve the possibility of spontaneous ovulation and regular menstrual cycles, as well as to increase the production of progesterone in the luteal phase of female infertile patients with PCOS [14]. Inositol is a polyalcohol classified as insulin sensitizer and existing as nine stereoisomers, two of which, D-Chiro-inositol [15-18] and Myo-Inositol [14,19-22], are currently used in PCOS treatment. Myo-Inositol, which is the most abundant form of inositol in humans, is converted to D-Chiro-inositol by an insulin-dependent epimerase [23]. These two stereoisomer showed an insulin-like action in vivo exerting the function of insulin mediators as inositolphosphoglycans (IPGs) [24]. In our experience, both Inositol isoforms are effective in improving ovarian function and metabolism of patients with PCOS, although Myo-Inositol shows the most marked effect on the metabolic profile, whereas D-Chiro-Inositol reduces more hyperandrogenism [25].

Differential insulin response to myo-inositol administration in obese polycystic ovary syndrome patients

Polycystic ovary syndrome (PCOS) is characterized by hyperandrogenism, chronic anovulation, polycystic ovaries at ultrasound evaluation, and quite frequently by insulin resistance or compensatory hyperinsulinemia. Attention has been given to the role of inositol-phosphoglycan (IPG) mediators of insulin action and growing evidences suggest that a deficiency of d-chiro-inositol (DCI) containing IPG might be at the basis of insulin resistance, frequent in PCOS patients. On such basis, we investigated the efficacy on insulin sensitivity and hormonal parameters of 8 weeks treatment with myo-inositol (MYO) (Inofert, ItalPharmaco, Milano, Italy) at the dosage of 2 g day in a group (n = 42) of obese PCOS patients,. After the treatment interval body mass index (BMI) and insulin resistance decreased together with luteinizing hormone (LH), LH/FSH and insulin. When subdividing the patients according to their fasting insulin levels, Group A (n = 15) insulin below 12 µU/ml and Group B (n = 27) insulin above 12 µU/ml, MYO treatment induced similar changes in both groups but only patients of Group B showed the significant decrease of both fasting insulin plasma levels (from 20.3 ± 1.8 to 12.9 ± 1.8 µU/ml, p < 0.00001) and of area under the curve (AUC) of insulin under oral glucose tolerance test (OGTT). In conclusion, our study supports the hypothesis that MYO administration is more effective in obese patients with high fasting insulin plasma levels.

L15. Biological aspects of inositol phosphoglycans in human pregnancy and preeclampsia

L15. Biological aspects of inositol phosphoglycans in human pregnancy and preeclampsia

Inositol phosphoglycans and preeclampsia: from bench to bedside

The metabolic syndrome that occurs in preeclampsia reflects the complex interactions between immunological alterations and the systemic inflammation that have been shown to take place during this complication of human pregnancy. Inositol phosphoglycans play a definite role in the insulin resistance in preeclampsia with a higher production and urinary excretion of this molecule before and during preeclampsia. Recent researches suggest that the feto-placental glucose metabolism in the first and early second trimester is mainly linked to the nonoxidative pathway of glycogen catabolism supporting the pivotal role of the inositol phosphoglycan P-type. In this article we present the results of a case-control study carried out in the first trimester to evaluate the potential of urinary P-IPG release as a early marker of the disease. A single mid-stream sample of maternal urine was collected at 11 weeks of gestation for this single centre retrospective study. Twenty-seven patients out of 331 women recruited (8.1%) went on to develop preeclampsia but no sample attained positivity. Further details about the development of the metabolic syndrome during preeclampsia were retrieved also from other studies to implement our knowledge about the pathophysiology of this syndrome and to identify biochemical aspects that could help in clinical practice.