Gender, hyperandrogenism and vitamin D deficiency related functional and morphological alterations of rat cerebral arteries

Hyperandrogenism is a risk factor of cerebrovascular diseases as androgens can alter markedly the regulation of cerebrovascular tone. We examined the combined impact of androgen excess and vitamin D deficiency (VDD), a common co-morbidity in hyperandrogenic disorders, on remodeling and testosterone-induced vascular responses of anterior cerebral arteries (ACA) in order to evaluate the interplay between androgens and VDD in the cerebral vasculature. Male and female Wistar rats were either fed with vitamin D deficient or vitamin D supplemented diet. Half of the female animals from both groups received transdermal testosterone treatment. After 8 weeks, vessel lumen, wall thickness and testosterone-induced vascular tone of isolated ACA were determined using pressure microangiometry and histological examination. Androgen receptor protein expression in the wall of cerebral arteries was examined using immunohistochemistry. In female rats only combined VDD and testosterone treatment decreased the lumen and increased the wall thickness of ACA. In males, however VDD by itself was able to decrease the lumen and increase the wall thickness. Vascular reactivity showed similar alterations: in females, testosterone constricted the ACA only after combined VDD and hyperandrogenism, whereas in males VDD resulted in increased testosterone-induced contractions in spite of decreased androgen receptor expression. In conclusion, a marked interplay between hyperandrogenism and VDD results in inward remodeling and enhanced testosterone-induced constrictions of cerebral arteries, which might compromise the cerebral circulation and thus, increase the risk of stroke in the long term. In addition, the early cerebrovascular manifestation of VDD appears to require androgen excess and thus, depends on gender

Practical guidelines for the supplementation of vitamin D and the treatment of deficits in Central Europe — recommended vitamin D intakes in the general population and groups at risk of vitamin D deficiency

Wstęp: Wyniki badań z ostatnich lat dokumentują wiele korzyści wynikających z działania witaminy D na organizm człowieka na wszystkichetapach jego życia. Większość badań epidemiologicznych sugeruje, że niedobór witaminy D jest powszechny wśród mieszkańców EuropyŚrodkowej. Naturalną konsekwencją tej sytuacji jest konieczność ciągłego uświadamiania społeczeństwu oraz środowisku medycznemu,jaką rolę odgrywa witamina D w rozwoju i funkcjonowaniu organizmu ludzkiego.Metody: Na podstawie przeglądu danych literaturowych Polski Zespół Wielodyscyplinarny opracował tezy dotyczące zasad suplementacjiwitaminą D, które przesłano do członków Komitetu Naukowego konferencji „Witamina D — minimum, maksimum, optimum”,19–20 Październik, 2012, Warszawa. W trakcie powyższej konferencji z udziałem 550 delegatów oraz Ekspertów różnych dziedzin medycynyomówiono i przedyskutowano propozycje wytycznych suplementacji witaminą D populacji Europy Środkowej.Wyniki: W efekcie przeprowadzonych dyskusji Zespół Ekspertów opracował wytyczne suplementacji witaminą D dla wszystkich grupwiekowych populacji Europy Środkowej. Określono również kryteria diagnostyczne charakteryzujące stan zaopatrzenia organizmu w witaminę D: deficyt witaminy D ustalono jako stężenie 25(OH)D < 20 ng/mL (< 50 nmol/L)], suboptymalne zaopatrzenie jako stężenie25(OH)D wynoszące 20–30 ng/mL (50–75 nmol/L), a stężenie 30–50 ng/mL (75–125 nmol/L) uznano za docelowe dla zapewnienia efektuplejotropowego witaminy D.Wnioski: Poprawa obecnego stanu zaopatrzenia witaminy D w grupach dzieci, młodzieży, osób aktywnych zawodowo i seniorówpowinna zostać włączona do priorytetów polityki zdrowotnej społeczeństw Europy Środkowej.Introduction: Adequate Vitamin D intake and its concentration in serum are important for bone health and calcium–phosphate metabolismas well as for optimal function of many organs and tissues. Documented trends in lifestyle, nutritional habits and physical activityappear to be associated with moderate or severe Vitamin D deficits resulting in health problems. Most epidemiological studies suggest thatVitamin D deficiency is prevalent among Central European populations. Concern about this problem led to the organising of a conferencefocused on overcoming Vitamin D deficiency.Methods: After reviewing the epidemiological evidence and relevant literature, a Polish multidisciplinary group formulated theses onrecommendations for Vitamin D screening and supplementation in the general population. These theses were subsequently sent to ScientificCommittee members of the ‘Vitamin D — minimum, maximum, optimum’ conference for evaluation based on a ten-point scale.With 550 international attendees, the meeting ‘Vitamin D — minimum, maximum, optimum’ was held on October 19–20, 2012 in Warsaw(Poland). Most recent scientific evidence of both skeletal and non-skeletal effects of Vitamin D as well as the results of panellists’ votingwere reviewed and discussed during eight plenary sessions and two workshops.Results: Based on many polemical discussions, including post-conference networking, the key opinion leaders established ranges ofserum 25-hydroxyVitamin D concentration indicating Vitamin D deficiency [< 20 ng/mL (< 50 nmol/L)], suboptimal status [20–30 ng/mL(50–75 nmol/L)], and target concentration for optimal Vitamin D effects [30–50 ng/mL (75–125 nmol/L)]. General practical guidelines regardingsupplementation and updated recommendations for prophylactic Vitamin D intakes in Central European neonates, infants, childrenand adolescents as well as in adults (including recommendations for pregnant and breastfeeding women and the elderly) were developed.Conclusions: Improving the Vitamin D status of children, adolescents, adults and the elderly must be included in the priorities of physicians,healthcare professionals and healthcare regulating bodies. The present paper offers elaborated consensus on supplementationguidance and population strategies for Vitamin D in Central Europe

Reduced Estradiol-Induced Vasodilation and Poly-(ADP-Ribose) Polymerase (PARP) Activity in the Aortas of Rats with Experimental Polycystic Ovary Syndrome (PCOS)

Polycystic ovary syndrome (PCOS) is a complex endocrine disorder characterized by hyperandrogenism and insulin resistance, both of which have been connected to atherosclerosis. Indeed, an increased risk of clinical manifestations of arterial vascular diseases has been described in PCOS. On the other hand endothelial dysfunction can be detected early on, before atherosclerosis develops. Thus we assumed that vascular dysfunction is also related directly to the hormonal imbalance rather than to its metabolic consequences. To detect early functional changes, we applied a novel rodent model of PCOS: rats were either sham operated or hyperandrogenism was achieved by implanting subcutaneous pellets of dihydrotestosterone (DHT). After ten weeks, myograph measurements were performed on isolated aortic rings. Previously we described an increased contractility to norepinephrine (NE). Here we found a reduced immediate relaxation to estradiol treatment in pre-contracted aortic rings from hyperandrogenic rats. Although the administration of vitamin D3 along with DHT reduced responsiveness to NE, it did not restore relaxation to estradiol. Poly-(ADP-ribose) polymerase (PARP) activity was assessed by poly-ADP-ribose immunostaining. Increased PAR staining in ovaries and circulating leukocytes from DHT rats showed enhanced DNA damage, which was reduced by concomitant vitamin D3 treatment. Surprisingly, PAR staining was reduced in both the endothelium and vascular smooth muscle cells of the aorta rings from hyperandrogenic rats. Thus in the early phase of PCOS, vascular tone is already shifted towards vasoconstriction, characterized by reduced vasorelaxation and vascular dysfunction is concomitant with altered PARP activity. Based on our findings, PARP inhibitors might have a future perspective in restoring metabolic disorders in PCOS

Human anti-60 kD heat shock protein autoantibodies are characterized by basic features of natural autoantibodies

Anti-human Hsp60 autoantibodies--known risk factor of atherosclerosis--were investigated in a mouse model and in samples of healthy subjects: polyreactivity, presence in cord blood samples of healthy newborns and life-long stability were tested. In IgM hybridoma panel from mouse spleens, polyreactivity of anti-Hsp60 autoantibodies was studied. In healthy pregnant women, umbilical vein and maternal blood samples were collected after childbirth, anti-Hsp-60 and -65 IgM and IgG levels were measured. Life-long stability of anti-Hsp-60 levels was studied on healthy patients during 5 years. ELISA was used in all studies. Polyreactivity of IgM clones of newborn mice and lifelong stability of these autoantibodies in healthy adults were established. IgM anti-Hsp60 autoantibodies in cord blood of healthy human infants were present, however, there was no correlation between maternal and cord blood IgM anti-Hsp60 concentrations. It is proposed that presence of anti-Hsp60 autoantibodies--as part of the natural autoantibody repertoire--may be an inherited trait. Level of anti-Hsp60 autoantibodies may be an independent, innate risk factor of atherosclerosis for the adulthood

Statistical analysis confirmed the significant changes in PAR staining intensities in the three experimental groups.

<p>Slides from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0055589#pone-0055589-g002" target="_blank">Figure 2</a>. were evaluated using a 10-graded scale (PAR score) as described in Methods. Results from ovaries (A), circulating leukocytes (B), vascular endothelium (C) and vascular smooth muscle cells (D) are presented. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0055589#pone-0055589-g003" target="_blank">Figure 3</a>. A, B: Control vs. DHT (# = p<0.05), DHT vs. DHT+ D₃ (± = p<0.05). <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0055589#pone-0055589-g003" target="_blank">Figure 3</a>. C, D: Control vs. DHT, and Control vs. DHT+ D₃ (# = p<0.05).</p

Estradiol dependent vasorelaxation is weaker in experimental PCOS.

<p>Rats were treated with DHT for 70 days +/− vitamin D₃ when they were sacrificed and aorta rings were isolated for myography studies. Specimens were first precontracted with norepinephrine (5×10⁻⁸ M) and then treated with two different doses of estradiol as shown. Vasodilation is expressed as a percentage of difference between maximally contracted and maximally dilated tone of the vessels according to the following equation (percentage =  (tension after norepinephrine-tension after estradiol)/(tension after norepinephrine-baseline tension) * 100). The difference between control and DHT (# = p<0.01) or control vs. DHT+ D₃ animals (+ = p<0.01) were both significant. The difference between DHT and DHT+ D₃ was not significant.</p

PAR staining is reduced in both the endothelium and the smooth muscle cells of aortas in PCOS.

<p>Ovaries, aortas and circulating leukocytes were isolated from animals exposed to the three treatments (control, DHT, DHT+ D₃) as described previously. PAR immunohistochemistry was performed. Representative images were taken. PAR staining was augmented in ovaries and leukocytes, however was reduced in both the endothelial and the muscular layer of the aortas in the DHT animals. Vitamin D₃ reduced the augmented staining detected in ovaries and leukocytes, but did not alter the staining in the aortas. It is notable that the DHT treatment induced the morphological changes typical in PCOS.</p

Altered insulin-induced relaxation of aortic rings in a dihydrotestosterone-induced rodent model of polycystic ovary syndrome

OBJECTIVE: To clarify the effects of dihydrotestosterone (DHT)-induced polycystic ovary syndrome (PCOS) on the insulin-dependent vasodilatation of the thoracic aorta and the role of vitamin D in a rat model. DESIGN: Controlled experimental animal study. SETTING: Laboratory. ANIMAL(S): Thirty adolescent female Wistar rats. INTERVENTION(S): The PCOS model was induced by 10 weeks of DHT treatment (83 mug/d). One-half of the DHT-treated animals also received vitamin D (120 ng/kg/wk). MAIN OUTCOME MEASURE(S): The aortic rings of the control, DHT, and DHT plus vitamin D-treated animals were isolated. The insulin-dependent vasodilation of the isolated aortic rings was compared in Krebs-Ringer solution and under blockade of nitric oxide (NO) synthase or cyclooxygenase. RESULT(S): The insulin-dependent vasorelaxation decreased in both DHT-treated groups independently from the vitamin D treatment; NO-dependent and -independent relaxations were both impaired. In response to prostanoid, vasoconstriction was increased after DHT treatment. The NO-independent relaxation was partially improved by vitamin D treatment, which was neutralized by increased prostanoid-dependent vasoconstriction. CONCLUSION(S): Previously, we found that vitamin D treatment prevented systemic insulin resistance; however, in this study, we did not detect any influence on the vascular insulin resistance of the aorta that was induced by DHT treatment. Consequently, controlling insulin resistance with vitamin D alone did not resolve the aortic endothelial dysfunction caused by the hyperandrogenic state

Facilitation of Mitochondrial Outer and Inner Membrane Permeabilization and Cell Death in Oxidative Stress by a Novel Bcl-2 Homology 3 Domain Protein*

We identified a sequence homologous to the Bcl-2 homology 3 (BH3) domain of Bcl-2 proteins in SOUL. Tissues expressed the protein to different extents. It was predominantly located in the cytoplasm, although a fraction of SOUL was associated with the mitochondria that increased upon oxidative stress. Recombinant SOUL protein facilitated mitochondrial permeability transition and collapse of mitochondrial membrane potential (MMP) and facilitated the release of proapoptotic mitochondrial intermembrane proteins (PMIP) at low calcium and phosphate concentrations in a cyclosporine A-dependent manner in vitro in isolated mitochondria. Suppression of endogenous SOUL by diced small interfering RNA in HeLa cells increased their viability in oxidative stress. Overexpression of SOUL in NIH3T3 cells promoted hydrogen peroxide-induced cell death and stimulated the release of PMIP but did not enhance caspase-3 activation. Despite the release of PMIP, SOUL facilitated predominantly necrotic cell death, as revealed by annexin V and propidium iodide staining. This necrotic death could be the result of SOUL-facilitated collapse of MMP demonstrated by JC-1 fluorescence. Deletion of the putative BH3 domain sequence prevented all of these effects of SOUL. Suppression of cyclophilin D prevented these effects too, indicating that SOUL facilitated mitochondrial permeability transition in vivo. Overexpression of Bcl-2 and Bcl-xL, which can counteract the mitochondria-permeabilizing effect of BH3 domain proteins, also prevented SOUL-facilitated collapse of MMP and cell death. These data indicate that SOUL can be a novel member of the BH3 domain-only proteins that cannot induce cell death alone but can facilitate both outer and inner mitochondrial membrane permeabilization and predominantly necrotic cell death in oxidative stress