Polycystic ovary syndrome as a plausible evolutionary outcome of metabolic adaptation.

As a common endocrinopathy of reproductive-aged women, polycystic ovary syndrome (PCOS) is characterized by hyperandrogenism, oligo-anovulation and polycystic ovarian morphology. It is linked with insulin resistance through preferential abdominal fat accumulation that is worsened by obesity. Over the past two millennia, menstrual irregularity, male-type habitus and sub-infertility have been described in women and confirm that these clinical features of PCOS were common in antiquity. Recent findings in normal-weight hyperandrogenic PCOS women show that exaggerated lipid accumulation by subcutaneous (SC) abdominal stem cells during development to adipocytes in vitro occurs in combination with reduced insulin sensitivity and preferential accumulation of highly-lipolytic intra-abdominal fat in vivo. This PCOS phenotype may be an evolutionary metabolic adaptation to balance energy storage with glucose availability and fatty acid oxidation for optimal energy use during reproduction. This review integrates fundamental endocrine-metabolic changes in healthy, normal-weight PCOS women with similar PCOS-like traits present in animal models in which tissue differentiation is completed during fetal life as in humans to support the evolutionary concept that PCOS has common ancestral and developmental origins.

Loss of anti-Müllerian hormone (AMH) immunoactivity due to a homozygous AMH gene variant rs10417628 in a woman with classical polycystic ovary syndrome (PCOS).

Anti-Müllerian hormone (AMH) is produced by granulosa cells of pre-antral and small antral ovarian follicles. In polycystic ovary syndrome (PCOS), higher levels of serum AMH are usually encountered due to the ample presence of small antral follicles and a high AMH production per follicular unit which have led to the proposal of AMH as a serum diagnostic marker for PCOS or as a surrogate for polycystic ovarian morphology (PCOM). However, heterozygous coding mutations of the AMH gene with decreased in vitro bioactivity have been described in some women with PCOS. Such mutation carriers have a trend toward reduced serum AMH levels compared to noncarriers, although both types of women with PCOS have similar circulating gonadotropin and testosterone (T) levels. This report describes a normal-weight woman with PCOS by NIH criteria with severely reduced AMH levels (index woman with PCOS). Our objective was to examine the molecular basis for her reduced serum AMH levels and to compare her endocrine characteristics to similar-weight women with PCOS and detectable AMH levels. Twenty normoandrogenic ovulatory (control) and 13 age- and BMI-matched women with PCOS (19-35 years; 19-25 kg/m2) underwent transvaginal sonography and serum hormone measures including gonadotropins, sex hormone-binding globulin, total and free T, androstenedione, dehydroepiandrosterone sulfate, estrone, estradiol and AMH. The latter was measured by ELISA (Pico-AMH: Ansh Labs, Webster, TX, USA). Women with PCOS and detectable AMH had higher serum AMH (10.82 (6.74-13.40) ng/ml, median (interquartile range)), total and free T (total T: 55.5 (49.5-62.5) ng/dl; free T: 5.65 (4.75-6.6) pg/ml) levels and greater total antral follicle count (AFC) (46 (39-59) follicles) than controls (AMH: 4.03 (2.47-6.11) ng/ml; total T: 30 (24.5-34.5) ng/dl; free T: 2.2 (1.8-2.45) pg/ml; AFC 16 (14.5-21.5) follicles, P < 0.05, all values), along with a trend toward LH hypersecretion (P = 0.06). The index woman with PCOS had severely reduced serum AMH levels (∼0.1 ng/ml), although she also had a typical NIH-defined PCOS phenotype resembling that of the other women with PCOS and elevated AMH levels. All women with PCOS, including the index woman with PCOS, exhibited LH hypersecretion, hyperandrogenism, reduced serum estrogen/androgen ratios and PCOM. A homozygous Ala515Val variant (rs10417628) in the mature region of AMH was identified in the index woman with PCOS. Recombinant hAMH-515Val displayed normal processing and bioactivity, yet had severely reduced immunoactivity when measured by the commercial pico-AMH ELISA assay by Ansh Labs. In conclusion, homozygous AMH variant rs10417628 may severely impair serum AMH immunoactivity without affecting its bioactivity or PCOS phenotypic expression. Variants in AMH can interfere with serum AMH immunoactivity without affecting the phenotype in PCOS. This observation can be accompanied by discordance between AMH immunoactivity and bioactivity.

Mechanisms of intergenerational transmission of polycystic ovary syndrome.

Developmental origins of adult disease (DoHAD) refers to critical gestational ages during human fetal development and beyond when the endocrine metabolic status of the mother can permanently program the physiology and/or morphology of the fetus, modifying its susceptibility to disease after birth. The aim of this review is to address how DoHAD plays an important role in the phenotypic expression of polycystic ovary syndrome (PCOS), the most common endocrinopathy of women characterized by hyperandrogenism, oligo-anovulation and polycystic ovarian morphology. Clinical studies of PCOS women are integrated with findings from relevant animal models to show how intergenerational transmission of these central components of PCOS are programmed through an altered maternal endocrine-metabolic environment that adversely affects the female fetus and long-term offspring health. Prenatal testosterone treatment in monkeys and sheep have been particularly crucial in our understanding of developmental programming of PCOS because organ system differentiation in these species, as in humans, occurs during fetal life. These animal models, along with altricial rodents, produce permanent PCOS-like phenotypes variably characterized by LH hypersecretion from reduced steroid-negative feedback, hyperandrogenism, ovulatory dysfunction, increased adiposity, impaired glucose-insulin homeostasis and other metabolic abnormalities. The review concludes that DoHAD underlies the phenotypic expression of PCOS through an altered maternal endocrine-metabolic environment that can induce epigenetic modifications of fetal genetic susceptibility to PCOS after birth. It calls for improved maternal endocrine-metabolic health of PCOS women to lower their risks of pregnancy-related complications and to potentially reduce intergenerational susceptibility to PCOS and its metabolic derangements in offspring.

An Evolutionary Model for the Ancient Origins of Polycystic Ovary Syndrome.

Polycystic ovary syndrome (PCOS) is a common endocrinopathy of reproductive-aged women, characterized by hyperandrogenism, oligo-anovulation and insulin resistance and closely linked with preferential abdominal fat accumulation. As an ancestral primate trait, PCOS was likely further selected in humans when scarcity of food in hunter-gatherers of the late Pleistocene additionally programmed for enhanced fat storage to meet the metabolic demands of reproduction in later life. As an evolutionary model for PCOS, healthy normal-weight women with hyperandrogenic PCOS have subcutaneous (SC) abdominal adipose stem cells that favor fat storage through exaggerated lipid accumulation during development to adipocytes in vitro. In turn, fat storage is counterbalanced by reduced insulin sensitivity and preferential accumulation of highly lipolytic intra-abdominal fat in vivo. This metabolic adaptation in PCOS balances energy storage with glucose availability and fatty acid oxidation for optimal energy use during reproduction; its accompanying oligo-anovulation allowed PCOS women from antiquity sufficient time and strength for childrearing of fewer offspring with a greater likelihood of childhood survival. Heritable PCOS characteristics are affected by today's contemporary environment through epigenetic events that predispose women to lipotoxicity, with excess weight gain and pregnancy complications, calling for an emphasis on preventive healthcare to optimize the long-term, endocrine-metabolic health of PCOS women in today's obesogenic environment.

Interplay of Cortisol, Testosterone, and Abdominal Fat Mass in Normal-weight Women With Polycystic Ovary Syndrome.

Context: Ovarian and adrenal steroidogenesis underlie endocrine-metabolic dysfunction in polycystic ovary syndrome (PCOS). Adipocytes express aldo-keto reductase 1C3 and type 1 11ß-hydroxysteroid dehydrogenase, which modulate peripheral androgen and cortisol production. Objectives: To compare serum adrenal steroids, including 11-oxygenated androgens (11-oxyandrogens), cortisol, and cortisone between normal-weight women with PCOS and body mass index- and age-matched ovulatory women with normal-androgenic profiles (controls), and assess whether adrenal steroids associate with abdominal adipose deposition. Design: Prospective, cross-sectional, cohort study. Setting: Academic medical center. Patients: Twenty normal-weight women with PCOS and 20 body mass index-/age-matched controls. Interventions: Blood sampling, IV glucose tolerance testing, and total-body dual-energy x-ray absorptiometry. Main Outcome Measures: Clinical characteristics, hormonal concentrations, and body fat distribution. Results: Women with PCOS had higher serum total/free testosterone (T) and androstenedione (A4) levels and a greater android/gynoid fat mass than controls (androgens P < .001; android/gynoid fat mass ratio, P = .026). Serum total/free T and A4 levels correlated positively with android/gynoid fat mass ratio in all women combined (P < .025, all values). Serum 11ß-hydroxyA4, 11-ketoA4, 11ß-hydroxyT, 11-ketoT, cortisol, and cortisone levels were comparable between female types and unrelated to body fat distribution. Serum 11-oxyandrogens correlated negatively with % total body fat, but lost significance adjusting for cortisol. Serum cortisol levels, however, correlated inversely with android fat mass (P = .021), with a trend toward reduced serum cortisol to cortisone ratio in women with PCOS vs controls (P = .075), suggesting diminished 11ß-hydroxysteroid dehydrogenase activity. Conclusion: Reduced cortisol may protect against preferential abdominal fat mass in normal-weight PCOS women with normal serum 11-oxyandrogens.

Randomized clinical trial: effect of low-dose flutamide on abdominal adipogenic function in normal-weight women with polycystic ovary syndrome.

OBJECTIVE: To examine whether low-dose flutamide administration to normal-weight women with polycystic ovary syndrome (PCOS) reduces abdominal fat deposition, attenuates accelerated lipid accumulation in newly formed adipocytes derived from subcutaneous (SC) abdominal adipose stem cells (ASCs), and/or alters glucose-lipid metabolism. DESIGN: A double-blind, placebo-controlled randomized clinical trial. SETTING: An academic medical center. PATIENT(S): Twelve normal-weight women with PCOS and 12 age- and body mass index-matched controls. INTERVENTION(S): Women underwent circulating hormonal and metabolic determinations, intravenous glucose tolerance testing, total body dual-energy roentgenogram absorptiometry, and SC abdominal fat biopsy. Interventions were repeated in women with PCOS after 6-month administration of flutamide (125 mg orally daily) vs. placebo. MAIN OUTCOME MEASURE(S): Clinical parameters and lipid accumulation in newly formed adipocytes derived from SC abdominal ASCs in vitro were compared between controls and the women with PCOS receiving flutamide vs. placebo. RESULTS: Serum luteinizing hormone and androgen levels as well as lipid accumulation in newly formed SC abdominal adipocytes were greater in the women with PCOS than controls. Flutamide vs. placebo reduced percent android fat, lowered serum log low-density lipoprotein and log non-high-density lipoprotein levels, and increased fasting circulating glucose levels. In all women with PCOS, changes in percent android fat positively correlated with serum log non-high-density lipoprotein and log low-density lipoprotein levels, with correlations influenced by serum free testosterone levels. Flutamide vs. placebo also attenuated lipid accumulation in newly-formed PCOS SC abdominal adipocytes in vitro relative to controls, which was unrelated to serum lipid levels. CONCLUSION: Low-dose flutamide administration to normal-weight PCOS women reduces preferential abdominal fat deposition, attenuates accelerated lipid accumulation in newly-formed adipocytes derived from SC abdominal ASCs in vitro, and alters glucose-lipid homeostasis. CLINICAL TRIAL REGISTRATION NUMBER: NCT01889199 (URL, clinicaltrials.gov; date of registration, 6/28/2013; enrollment date of first subject, 6/28/2013).

Endothelial differentiation in multipotent cells derived from mouse and human white mature adipocytes.

White mature adipocytes give rise to multipotent cells, so-called de-differentiated fat (DFAT) cells, when losing their fat in culture. The objective of this study was to examine the ability of DFAT cells to give rise to endothelial cells (ECs) in vitro and vivo. We demonstrate that mouse and human DFAT cells, derived from adipose tissue and lipospirate, respectively, initially lack expression of CD34, CD31, CD146, CD45 and pericyte markers, distinguishing them from progenitor cells previously identified in adipose stroma. The DFAT cells spontaneously differentiate into vascular ECs in vitro, as determined by real-time PCR, fluorescence activated cell sorting, immunostaining, and formation of tube structures. Treatment with bone morphogenetic protein (BMP)4 and BMP9, important in regulating angiogenesis, significantly enhances the EC differentiation. Furthermore, adipocyte-derived cells from Green Fluorescent Protein-transgenic mice were detected in the vasculature of infarcted myocardium up to 6 weeks after ligation of the left anterior descending artery in mice. We conclude that adipocyte-derived multipotent cells are able to spontaneously give rise to ECs, a process that is promoted by BMPs and may be important in cardiovascular regeneration and in physiological and pathological changes in fat and other tissues.

Accelerated subcutaneous abdominal stem cell adipogenesis predicts insulin sensitivity in normal-weight women with polycystic ovary syndrome.

OBJECTIVE: To examine whether subcutaneous (SC) abdominal adipose stem cell differentiation into adipocytes in vitro predicts insulin sensitivity (Si) in vivo in normal-weight women with polycystic ovary syndrome (PCOS) and controls. DESIGN: Prospective cohort study. SETTING: Academic medical center. PATIENT(S): Eight normal-weight women with PCOS and 8 age- and body mass index-matched controls. INTERVENTION(S): Women underwent circulating hormone/metabolic determinations, intravenous glucose tolerance testing, total-body dual-energy x-ray absorptiometry, and SC abdominal fat biopsy. MAIN OUTCOME MEASURE(S): PPARγ and CEBPa gene expression and lipid content of adipocytes matured in vitro were compared between women with PCOS and control women, and correlated with patient characteristics, systemic Si, and adipose insulin resistance (adipose-IR). RESULT(S): Serum androgen levels, adipose-IR, and percentage of android fat were greater in women with PCOS than control women. Stem cell PPARγ and CEBPa gene expression increased maximally by day 12 without a female-type effect. In control cells, gene expression positively correlated with fasting serum insulin levels (both genes) and adipose-IR (CEBPa) and negatively correlated with Si (CEBPa). Conversely, CEBPa gene expression in PCOS cells negatively correlated with adipose-IR and serum free testosterone, whereas total lipid accumulation in these cells positively corelated with Si. CONCLUSION: In normal-weight women with PCOS, accelerated SC abdominal adipose stem cell differentiation into adipocytes in vitro favors Si in vivo, suggesting a role for hyperandrogenism in the evolution of metabolic thrift to enhance fat storage through increased cellular glucose uptake.

Serum Testosterone to Androstenedione Ratio Predicts Metabolic Health in Normal-Weight Polycystic Ovary Syndrome Women.

CONTEXT: Increased aldo-keto reductase 1C3 (AKR1C3)-mediated conversion of androstenedione (A4) to testosterone (T) promotes lipid storage in subcutaneous (SC) abdominal adipose in overweight/obese polycystic ovary syndrome (PCOS) women. OBJECTIVE: This work examines whether an elevated serum T/A4 ratio, as a marker of enhanced AKR1C3 activity in SC abdominal adipose, predicts metabolic function in normal-weight PCOS women. METHODS: This prospective cohort study took place in an academic center and comprised 19 normal-weight PCOS women and 21 age- and body mass index-matched controls. Interventions included circulating hormone/metabolic determinations, intravenous glucose tolerance testing, total body dual-energy x-ray absorptiometry, and SC abdominal fat biopsy. Serum T/A4 ratios, hormone/metabolic measures, and AKR1C3 expression of adipocytes matured in vitro were compared between female types; serum T/A4 ratios were correlated with serum lipids, adipose insulin resistance (adipose-IR), homeostatic model assessment of insulin resistance (HOMA-IR) and insulin sensitivity (Si). RESULTS: Increased serum T/A4 ratios (P = .040) and log adipose-IR values (P = .002) in PCOS women vs controls were accompanied by AKR1C3 messenger RNA overexpression of PCOS adipocytes matured in vitro (P = .016). Serum T/A4 ratios in PCOS women, but not controls, negatively correlated with log triglycerides (TGs: R = -0.65, P = .002) and the TG index (R = -0.57, P = .011). Adjusting for serum free T, serum T/A4 ratios in PCOS women remained negatively correlated with log TG (R = -0.57, P = .013) and TG index (R = -0.50, P = .036), respectively, without significant relationships with other metabolic measures. CONCLUSION: An elevated serum T/A4 ratio, as a marker of enhanced AKR1C3 activity in SC abdominal adipose, predicts healthy metabolic function in normal-weight PCOS women.

Endocrine-Metabolic Dysfunction in Polycystic Ovary Syndrome: an Evolutionary Perspective.

Polycystic ovary syndrome (PCOS) is characterized by hyperandrogenism, oligo-anovulation and polycystic ovarian morphology, with metabolic dysfunction from insulin resistance and abdominal fat accumulation worsened by obesity. As ancestral traits, these features could have favored abdominal fat deposition for energy use during starvation, but have evolved into different PCOS phenotypes with variable metabolic dysfunction. Adipose dysfunction in PCOS from hyperandrogenemia and hyperinsulinemia likely constrains subcutaneous (SC) fat storage, promoting lipotoxicity through ectopic lipid accumulation and oxidative stress, insulin resistance and inflammation in non-adipose tissue. Recent findings of inherently exaggerated SC abdominal stem cell development to adipocytes in women with PCOS, and PCOS-like traits in adult female monkeys with natural hyperandrogenemia, imply common ancestral origins of PCOS in both human and nonhuman primates.

Dynamic changes in chromatin accessibility, altered adipogenic gene expression, and total versus de novo fatty acid synthesis in subcutaneous adipose stem cells of normal-weight polycystic ovary syndrome (PCOS) women during adipogenesis: evidence of cellular programming.

BACKGROUND: Normal-weight polycystic ovary syndrome (PCOS) women exhibit adipose resistance in vivo accompanied by enhanced subcutaneous (SC) abdominal adipose stem cell (ASC) development to adipocytes with accelerated lipid accumulation per cell in vitro. The present study examines chromatin accessibility, RNA expression and fatty acid (FA) synthesis during SC abdominal ASC differentiation into adipocytes in vitro of normal-weight PCOS versus age- and body mass index-matched normoandrogenic ovulatory (control) women to study epigenetic/genetic characteristics as well as functional alterations of PCOS and control ASCs during adipogenesis. RESULTS: SC abdominal ASCs from PCOS women versus controls exhibited dynamic chromatin accessibility during adipogenesis, from significantly less chromatin accessibility at day 0 to greater chromatin accessibility by day 12, with enrichment of binding motifs for transcription factors (TFs) of the AP-1 subfamily at days 0, 3, and 12. In PCOS versus control cells, expression of genes governing adipocyte differentiation (PPARγ, CEBPα, AGPAT2) and function (ADIPOQ, FABP4, LPL, PLIN1, SLC2A4) was increased two-sixfold at days 3, 7, and 12, while that involving Wnt signaling (FZD1, SFRP1, and WNT10B) was decreased. Differential gene expression in PCOS cells at these time points involved triacylglycerol synthesis, lipid oxidation, free fatty acid beta-oxidation, and oxidative phosphorylation of the TCA cycle, with TGFB1 as a significant upstream regulator. There was a broad correspondence between increased chromatin accessibility and increased RNA expression of those 12 genes involved in adipocyte differentiation and function, Wnt signaling, as well as genes involved in the triacylglycerol synthesis functional group at day 12 of adipogenesis. Total content and de novo synthesis of myristic (C14:0), palmitic (C16:0), palmitoleic (C16:1), and oleic (C18:1) acid increased from day 7 to day 12 in all cells, with total content and de novo synthesis of FAs significantly greater in PCOS than controls cells at day 12. CONCLUSIONS: In normal-weight PCOS women, dynamic chromatin remodeling of SC abdominal ASCs during adipogenesis may enhance adipogenic gene expression as a programmed mechanism to promote greater fat storage.

Polycystic Ovary Syndrome: Impact of Lipotoxicity on Metabolic and Reproductive Health.

IMPORTANCE: Polycystic ovary syndrome (PCOS) is the most common endocrinopathy of reproductive-aged women. Women with PCOS are at increased risk of developing several metabolic and reproductive abnormalities, including metabolic syndrome. Underlying the combined metabolic and reproductive dysfunction is lipotoxicity, defined as the ectopic deposition of lipid in nonadipose tissue where it induces oxidative stress linked with insulin resistance and inflammation. OBJECTIVE: To examine what metabolic components underlie insulin resistance in PCOS, how lipotoxicity through insulin resistance impairs metabolism and reproduction in these women, and why evidence-based, individualized management is essential for their care. EVIDENCE ACQUISITION: PubMed search was performed using relevant terms to identify journal articles related to the subject. Relevant textbook chapters were also used. RESULTS: Polycystic ovary syndrome by Rotterdam criteria represents a complex syndrome of heterogeneous expression with variable adverse metabolic and reproductive implications. Women with classic PCOS are often insulin resistant and at greatest risk of developing metabolic syndrome with preferential fat accumulation and weight gain. Moreover, PCOS women may also have an altered capacity to properly store fat, causing ectopic lipid accumulation in nonadipose tissue, including the ovaries, where it can perpetuate insulin resistance and inflammation and harm the oocyte. CONCLUSIONS AND RELEVANCE: A personalized approach to managing PCOS is essential to improve the health of all PCOS women through cost-effective prevention and/or treatment, to minimize the risk of pregnancy complications in those individuals wishing to conceive, and to optimize the long-term health of PCOS women and their offspring.

Adipose Insulin Resistance in Normal-Weight Women With Polycystic Ovary Syndrome.

CONTEXT: Normal-weight women with polycystic ovary syndrome (PCOS) may have adipose tissue insulin resistance (adipose-IR). OBJECTIVE: To examine whether adipose-IR and subcutaneous (SC) abdominal adipose stem cell (ASC) gene expression are altered in normal-weight women with PCOS and correlated with hyperandrogenemia and/or whole-body IR. DESIGN: Prospective cohort study. SETTING: Academic medical center. PATIENTS: Ten normal-weight women with PCOS and 18 control subjects matched for age and body mass index. INTERVENTION(S): Women underwent circulating hormone and metabolic measurements, IV glucose tolerance testing, total-body dual-energy x-ray absorptiometry, and SC abdominal fat biopsy. MAIN OUTCOME MEASURE(S): Adipose-IR (fasting insulin × total fatty acid levels) and SC abdominal ASC gene expression were compared between groups and correlated with clinical outcomes. RESULTS: Adipose-IR was greater in women with PCOS than in control subjects (P < 0.01), with 29 pmol/L × mmol/L providing 94% specificity and 80% sensitivity in discriminating the two groups (P < 0.001). Adipose-IR positively correlated with serum androgen and log of fasting triglyceride (TG) levels, percentage of small adipocytes (P < 0.01, all correlations), and acute insulin response to glucose (P < 0.05); and negatively correlated with insulin sensitivity (Si; P < 0.025) and serum adiponectin levels (P < 0.05). Adjusting for serum androgens, adipose-IR correlations with Si and log TG levels remained significant. ASC genes were differentially expressed by the two groups. Expression of functionally critical genes was associated with serum testosterone and/or fasting insulin levels. CONCLUSION: Normal-weight women with PCOS have increased adipose-IR and altered ASC gene expression related to hyperandrogenism and IR.

Precocious subcutaneous abdominal stem cell development to adipocytes in normal-weight women with polycystic ovary syndrome.

OBJECTIVE: To examine whether abnormal subcutaneous (SC) abdominal adipose stem cell (ASC) development to adipocytes in polycystic ovary syndrome (PCOS) correlates with hyperandrogenism. DESIGN: Prospective cohort study. SETTING: Academic medical center. PATIENT(S): Eight normal-weight women with PCOS and eight normoandrogenic ovulatory (control) women matched for age and body mass index. INTERVENTION(S): Circulating hormone and metabolic measurements, intravenous glucose tolerance testing, total body dual-energy X-ray absorptiometry, and SC abdominal fat biopsy. MAIN OUTCOME MEASURE(S): In vitro ASC commitment to preadipocytes (ZFP423 protein expression, day 0.5), preadipocyte differentiation to adipocytes (PPARγ gene expression, day 3) and adipocyte lipid content (Oil-Red-O fluorescence, day 12) comparisons correlated with clinical outcomes. RESULT(S): In women with PCOS, SC abdominal ASCs compared with those of control women showed exaggerated commitment to preadipocytes and had greater lipid content in newly formed adipocytes after in vitro maturation. In all women combined, ZFP423 protein expression negatively correlated with fasting plasma glucose levels whereas the lipid content of newly formed adipocytes positively correlated with both PPARγ gene expression and serum free testosterone levels. CONCLUSION(S): In normal-weight women with PCOS compared with the control group, exaggerated SC abdominal ASC commitment to preadipocytes and enhanced adipocyte lipid content during maturation in vitro negatively and positively correlate with circulating fasting glucose and androgen levels, respectively, as a possible mechanism to maintain glucose-insulin homeostasis when fat accretion is accelerated.

Reproductive and metabolic determinants of granulosa cell dysfunction in normal-weight women with polycystic ovary syndrome.

OBJECTIVE: To determine the degree to which E2 hyperresponsiveness to FSH and antimüllerian hormone (AMH) overproduction in normal-weight women with polycystic ovary syndrome (PCOS) correlate with increased antral follicle number (AFN), hyperandrogenism, and/or metabolic dysfunction. DESIGN: Prospective cohort study. SETTING: Academic medical center. PATIENT(S): Seven normal-weight women with PCOS (1990 National Institutes of Health criteria) ages 20-34 years and 13 age- and body mass index- (BMI-; 18.5-25 kg/m2) matched normoandrogenic ovulatory women were studied. INTERVENTION(S): All women underwent basal serum hormone and metabolic measurements, FSH stimulation testing with transvaginal ovarian sonography, frequently sampled IV glucose tolerance testing, and whole-body dual-energy x-ray absorptiometry. MAIN OUTCOME MEASURE(S): Serum hormone/metabolite levels, 24-hour serum E2 response to 150 IU recombinant human (rh) FSH infusion, AFN, insulin sensitivity, and body mass measurements. RESULT(S): Serum E2 responsiveness to rhFSH and AMH levels were greater in women with PCOS than in BMI- and age-matched control women, as were serum androgen levels, AFN, and abdominal fat mass. In all women combined, serum E2 responsiveness to rhFSH was associated with AFN. Serum AMH levels, however, positively correlated with AFN but remained positively correlated with serum LH and free T levels and negatively correlated with total body fat and percent body fat, adjusting for AFN. CONCLUSION(S): In normal-weight women with PCOS, serum E2 hyperresponsiveness to rhFSH represents increased AFN, while elevated serum AMH levels reflect opposing effects of stimulatory reproductive (hyperandrogenism and increased AFN) versus inhibitory metabolic (body fat) factors. Given the small number of subjects reported, additional follow-up studies are required to confirm these data.

Thyroid-stimulating autoantibodies in Graves disease preferentially recognize the free A subunit, not the thyrotropin holoreceptor.

Graves disease is directly caused by thyroid-stimulating autoantibodies (TSAb's) that activate the thyrotropin receptor (TSHR). We observed upon flow cytometry using intact cells that a mouse mAb (3BD10) recognized the TSHR ectodomain with a glycosidylphosphatidylinositol (ECD-GPI) anchor approximately tenfold better than the same ectodomain on the wild-type TSHR, despite the far higher level of expression of the latter. The 3BD10 epitope contains the N-terminal cysteine cluster critical for TSAb action. Consequently, we hypothesized and confirmed that TSAb (but not thyrotropin-blocking autoantibodies [TBAb's]) also poorly recognize the wild-type TSHR relative to the ECD-GPI. Despite poor recognition by TSAb of the holoreceptor, soluble TSHR A subunits (known to be shed from surface TSHR) fully neutralized autoantibody-binding activity. These data indicate that the epitope(s) for TSAb's, but not for TBAb's, are partially sterically hindered on the holoreceptor by the plasma membrane, the serpentine region of the TSHR, or by TSHR dimerization. However, the TSAb epitope on the soluble A subunit is freely accessible. This observation, as well as other evidence, supports the concept that A subunit shedding either initiates or amplifies the autoimmune response to the TSHR, thereby causing Graves disease in genetically susceptible individuals.

Pluripotent nontumorigenic multilineage differentiating stress enduring cells (Muse cells): a seven-year retrospective.

Multilineage differentiating stress enduring (Muse) cells, discovered in the spring of 2010 at Tohoku University in Sendai, Japan, were quickly recognized by scientists as a possible source of pluripotent cells naturally present within mesenchymal tissues. Muse cells normally exist in a quiescent state, singularly activated by severe cellular stress in vitro and in vivo. Muse cells have the capacity for self-renewal while maintaining pluripotent cell characteristics indicated by the expression of pluripotent stem cell markers. Muse cells differentiate into cells representative of all three germ cell layers both spontaneously and under media-specific induction. In contrast to embryonic stem and induced pluripotent stem cells, Muse cells exhibit low telomerase activity, a normal karyotype, and do not undergo tumorigenesis once implanted in SCID mice. Muse cells efficiently home into damaged tissues and differentiate into specific cells leading to tissue regeneration and functional recovery as described in different animal disease models (i.e., fulminant hepatitis, muscle degeneration, skin ulcers, liver cirrhosis, cerebral stroke, vitiligo, and focal segmental glomerulosclerosis). Circulating Muse cells have been detected in peripheral blood, with higher levels present in stroke patients during the acute phase. Furthermore, Muse cells have inherent immunomodulatory properties, which could contribute to tissue generation and functional repair in vivo. Genetic studies in Muse cells indicate a highly conserved cellular mechanism as seen in more primitive organisms (yeast, Saccharomyces cerevisiae, Caenorhabditis elegans, chlamydomonas, Torpedo californica, drosophila, etc.) in response to cellular stress and acute injury. This review details the molecular and cellular properties of Muse cells as well as their capacity for tissue repair and functional recovery, highlighting their potential for clinical application in regenerative medicine.

Evidence that human thyroid cells express uncleaved, single-chain thyrotropin receptors on their surface.

The prevailing concept is that, in human thyroid tissue in vivo, all cell-surface TSH receptors (TSHR) cleave into disulfide linked A and B subunits. Because this viewpoint is based on studies using homogenized thyroid tissue and because of TSHR fragility, we studied TSHR subunit structure in intact thyroid cells, primary human thyrocyte cultures, FRTL-5 rat thyroid cells, and WRO (follicular) and NPA (papillary) thyroid cancer cell lines. To overcome the handicap of very low TSHR expression in thyroid cells, we generated a TSHR-expressing adenovirus (TSHR-Ad-RGD) with an integrin-binding RGD motif enabling efficient entry into cells lacking the coxsackie-adenovirus receptor. Two days after TSHR-Ad-RGD infection, [125I]TSH cross-linking to intact cells revealed uncleaved, single-chain TSHR as well as cleaved TSHR A subunits on the surface of all four thyroid cell types. The extent of TSHR cleavage, which is independent of the level of TSHR expression, was consistently lower in the human thyroid cancer cell lines than in the other cell lines. In flow cytometry studies after TSHR-Ad-RGD infection, strong signals were detected in all four thyroid cell types using a monoclonal antibody that primarily recognizes the uncleaved TSHR. Finally, using the same monoclonal antibody, confocal microscopy confirmed the presence of single-chain TSHR on TSHR-Ad-RGD-infected thyroid cells. In summary, TSH covalent cross-linking, flow cytometry, and confocal microscopy demonstrate the presence of uncleaved TSHR on the human thyrocyte surface. These data provide stronger evidence for this alternative than the contrary view based on the finding of only cleaved TSHR in homogenized thyroid cells.

Muse Cells: Nontumorigenic Pluripotent Stem Cells Present in Adult Tissues-A Paradigm Shift in Tissue Regeneration and Evolution.

Muse cells are a novel population of nontumorigenic pluripotent stem cells, highly resistant to cellular stress. These cells are present in every connective tissue and intrinsically express pluripotent stem markers such as Nanog, Oct3/4, Sox2, and TRA1-60. Muse cells are able to differentiate into cells from all three embryonic germ layers both spontaneously and under media-specific induction. Unlike ESCs and iPSCs, Muse cells exhibit low telomerase activity and asymmetric division and do not undergo tumorigenesis or teratoma formation when transplanted into a host organism. Muse cells have a high capacity for homing into damaged tissue and spontaneous differentiation into cells of compatible tissue, leading to tissue repair and functional restoration. The ability of Muse cells to restore tissue function may demonstrate the role of Muse cells in a highly conserved cellular mechanism related to cell survival and regeneration, in response to cellular stress and acute injury. From an evolutionary standpoint, genes pertaining to the regenerative capacity of an organism have been lost in higher mammals from more primitive species. Therefore, Muse cells may offer insight into the molecular and evolutionary bases of autonomous tissue regeneration and elucidate the molecular and cellular mechanisms that prevent mammals from regenerating limbs and organs, as planarians, newts, zebrafish, and salamanders do.

Cumulus Cell Mitochondrial Resistance to Stress In Vitro Predicts Oocyte Development During Assisted Reproduction.

CONTEXT: Complex cumulus cell-oocyte interactions govern energy utilization during oocyte development. OBJECTIVE: This study investigates the relationship of cumulus cell mitochondria with oocyte development during ovarian stimulation for in vitro fertilization (IVF). DESIGN: This is a prospective cohort study. SETTING: The setting was an academic center. PATIENTS: Thirty women underwent ovarian stimulation for IVF. INTERVENTION(S): Pooled cumulus cells were collected; numbers of total and mature oocytes and two-pronuclear (day 1), six- to eight-cell cleavage (day 3), and blastocyst (day 5) embryos were recorded. MAIN OUTCOME MEASURE(S): A mitochondrial bioassay was developed with Jurkat cells and used with cumulus cells from IVF patients to correlate mitochondrial membrane potential resistance to carbonyl cyanide 3-chlorophenylhydrazone (CCCP) stress with oocyte development and embryogenesis. RESULTS: Adjusting for FSH administered and maternal age, cumulus cell mitochondrial membrane potential resistance to CCCP positively correlated with numbers of total (P < .025) and mature (P < .025) oocytes retrieved. The highest oocyte numbers that correlated with cumulus cell mitochondrial membrane potential occurred in women with the greatest ovarian response to FSH (mitochondrial membrane potential resistance to CCCP-log FSH interactions: total oocytes P < .025; mature oocytes P < .05). Multiple regression modeling of mature oocyte numbers, age, and cumulus cell mitochondrial membrane potential resistance to CCCP showed that numbers of mature oocytes best correlated with numbers of embryos at all stages (P < .0001). CONCLUSION: During ovarian stimulation for IVF, cumulus cell mitochondrial membrane potential resistance to stress correlates with numbers of total and mature oocytes retrieved, suggesting that cumulus cell-oocyte interactions involving energy facilitate oocyte development.