p27kip1 (cyclin-dependent kinase inhibitor 1B) controls ovarian development by suppressing follicle endowment and activation and promoting follicle atresia in mice

In humans, the molecular mechanisms underlying ovarian follicle endowment and activation, which are closely related to the control of female reproduction, occurrence of menopause, and related diseases such as premature ovarian failure, are poorly understood. In the current study, we provide several lines of genetic evidence that the cyclin-dependent kinase (Cdk) inhibitor 1B (commonly known as p27(kip1) or p27) controls ovarian development in mice by suppressing follicle endowment and activation, and by promoting follicle death. In p27-deficient (p27(-/-)) mice, postnatal follicle assembly was accelerated, and the number of endowed follicles was doubled as compared with p27(+/+) mice. Moreover, in p27(-/-) ovaries the primordial follicle pool was prematurely activated once it was endowed, and at the same time the massive follicular death that occurs before sexual maturity was rescued by loss of p27. In early adulthood, however, the overactivated follicular pool in p27(-/-) ovaries was largely depleted, causing premature ovarian failure. Furthermore, we have extensively studied the molecular mechanisms underlying the above-mentioned phenotypes seen in p27(-/-) ovaries and have found that p27 controls follicular development by several distinct mechanisms at different stages of development of the ovary. For example, p27 controls oocyte growth by suppressing the functions of Cdk2/Cdc2-cyclin A/E1 in oocytes that are arrested at the diplotene stage of meiosis I. This function of p27 is distinct from its well-known role as a suppressor of cell cycle progression. In addition, we have found that p27 activates the caspase-9-caspase-3-caspase-7-poly (ADP-ribose) polymeraseapoptotic cascade by inhibiting Cdk2/Cdc2-cyclin A/B1 kinase activities in follicles, thereby inducing follicle atresia. Our results suggest that the p27 gene is important in determining mammalian ovarian development. This study therefore provides insight into ovary-borne genetic aberrations that cause defects in folliculogenesis and infertility in humans.     

Abnormalities in carbohydrate and lipid metabolisms in high-fructose dietfed insulin-resistant rats: amelioration by Catharanthus roseus treatments

High intake of dietary fructose has been shown to exert a number of adverse metabolic effects in humans and experimental animals. The present study was proposed to elucidate the effect of Catharanthus roseus (C. roseus) leaf powder treatment on alterations in carbohydrate and lipid metabolisms in rats fed with high-fructose diet. Male Wistar rats of body weight around 180 g were divided into four groups, two of these groups (groups C and C+CR) were fed with standard pellet diet and the other two groups (groups F and F+CR) were fed with high-fructose (66 %) diet. C. roseus leaf powder suspension in water (100 mg/kg body weight/day) was administered orally to group C+CR and group F+CR. At the end of a 60-day experimental period, biochemical parameters related to carbohydrate and lipid metabolisms were assayed. C. roseus treatment completely prevented the fructose-induced increased body weight, hyperglycemia, and hypertriglyceridemia. Hyperinsulinemia and insulin resistance observed in group F was significantly decreased with C. roseus treatment in group F+CR. The alterations observed in the activities of enzymes of carbohydrate and lipid metabolisms and contents of hepatic tissue lipids in group F rats were significantly restored to near normal values by C. roseus treatment in group F+CR. In conclusion, our study demonstrates that C. roseus treatment is effective in preventing fructose-induced insulin resistance and hypertriglyceridemia while attenuating the fructose-induced alterations in carbohydrate and lipid metabolisms. This study suggests that the plant can be used as an adjuvant for the prevention and/or management of insulin resistance and disorders related to it.     

A double blind, placebo-controlled, randomized crossover study of the acute metabolic effects of olanzapine in healthy volunteers

Background and Rationale

Atypical antipsychotics exhibit metabolic side effects including diabetes mellitus and obesity. The adverse events are preceded by acute worsening of oral glucose tolerance (oGTT) along with reduced plasma free fatty acids (FFA) and leptin in animal models. It is unclear whether the same acute effects occur in humans.

Methodology/Principal Findings

A double blind, randomized, placebo-controlled crossover trial was conducted to examine the potential metabolic effects of olanzapine in healthy volunteers. Participants included male (8) and female (7) subjects [18–30 years old, BMI 18.5–25]. Subjects received placebo or olanzapine (10 mg/day) for three days prior to oGTT testing. Primary endpoints included measurement of plasma leptin, oral glucose tolerance, and plasma free fatty acids (FFA). Secondary metabolic endpoints included: triglycerides, total cholesterol, high- and low-density lipoprotein cholesterol, heart rate, blood pressure, body weight and BMI. Olanzapine increased glucose Area Under the Curve (AUC) by 42% (2808±474 vs. 3984±444 mg/dl·min; P = 0.0105) during an oGTT. Fasting plasma leptin and triglycerides were elevated 24% (Leptin: 6.8±1.3 vs. 8.4±1.7 ng/ml; P = 0.0203) and 22% (Triglycerides: 88.9±10.1 vs. 108.2±11.6 mg/dl; P = 0.0170), whereas FFA and HDL declined by 32% (FFA: 0.38±0.06 vs. 0.26±0.04 mM; P = 0.0166) and 11% (54.2±4.7 vs. 48.9±4.3 mg/dl; P = 0.0184), respectively after olanzapine. Other measures were unchanged.

Conclusions/Significance

Olanzapine exerts some but not all of the early endocrine/metabolic changes observed in rodent models of the metabolic side effects, and this suggest that antipsychotic effects are not limited to perturbations in glucose metabolism alone. Future prospective clinical studies should focus on identifying which reliable metabolic alterations might be useful as potential screening tools in assessing patient susceptibility to weight gain and diabetes caused by atypical antipsychotics.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00741026","term_id":"NCT00741026"}}NCT00741026     

Combination of thidiazuron and 2-isopentenyladenine promotes highly efficient adventitious shoot regeneration from cotyledons of mature sunflower (Helianthus annuus L.) seeds

Genetic improvement of sunflower (Helianthus annuus L.) through the use of biotechnological tools requires a reliable in vitro shoot regeneration system. Tissue culture protocols reported to date for sunflower suffer from low efficiency, poor reproducibility, genotype dependence and a tendency for flowering in vitro. The present study describes an efficient protocol system for shoot regeneration via direct adventitious shoot organogenesis from cotyledons of mature seeds of sunflower. About 169 media combinations comprising 12 different growth regulator combinations in various concentrations were assessed for induction of shoots from cotyledons derived from mature seeds and also from seedling tissues of 2?C20-day-old seedlings. Appearance of shoots from seedling tissues was sporadic and the frequency of shoot regeneration was low. Cotyledon explants from mature seeds were consistent with regard to frequency of adventitious shoot regeneration and number of shoots per explant. A high frequency (93.86?%) of adventitious shoot regeneration was obtained within 2?weeks of culture initiation on Murashige and Skoog (MS) medium supplemented with 9.84???M 2-isopentenyladenine (2-iP), 2.85???M indole-3-acetic acid (IAA) and 0.45???M thidiazuron (TDZ). Use of 2-iP in the shoot induction and elongation media prevented precocious flowering. Statistical analysis revealed significant effects of explant orientation, age of seedlings, and genotype on adventitious organogenesis. Maximum shoot regeneration was obtained when cotyledons from 0 and 1-day-old seedlings were placed with their adaxial surface in contact with the medium surface. The protocol developed was tested on 42 genotypes and found to be applicable to a wide range of genotypes. Histological studies indicated that the shoots originated predominantly through adventive organogenesis from the sub-epidermal and cortical regions.     

Genetic engineering of sunflower (<Emphasis Type="Italic">Helianthus annuus</Emphasis> L.) for resistance to necrosis disease through deployment of the TSV coat protein gene

Nitrogen is a major driver of plant growth and the nitrogen source can be critical to good growth in vitro. A response surface methodology mixture-component design and a data mining algorithm were applied to nitrogen (N) nutrition for improving the micropropagation of Prunus armeniaca Lam. Data taken on shoot cultures included a subjective quality rating, shoot number, shoot length, leaf characteristics and physiological disorders. Data were analyzed using the Classification and Regression Tree data mining algorithm. The best overall shoot quality as well as leaf color were on medium with NO₃^??>?25 mM and NH₄⁺/Ca⁺ >?0.8. Improving shoot length to15 mm required 25?<?NO₃^? ≤?35 mM with NH₄⁺/Ca²⁺ ≤?2.33. The most shoots (11.6) were produced with NO₃^? >?25 mM and NH₄⁺/Ca²⁺ ≤ 0.8, but there were 5–10 shoots at other NO₃^? concentrations regardless of NH₄⁺/Ca²⁺ proportion. Leaves increased in size with higher NO₃^? concentrations (>?55 mM). Physiological disorders were also influenced by the nitrogen components. Shoot tip necrosis was rarely present with NO₃^? > 45 mM. Callus production decreased somewhat with NH₄⁺/Ca²⁺ >?2.33. Suggested concentrations for an improved medium considering all of these growth characteristics would be 25?<?NO₃^? ≤?35 mM and NH₄⁺/Ca⁺ ≤ 0.8. Validation experiments comparing WPM and three trial media showed improvements in several shoot growth parameters on medium with optimized mesos and optimized nitrogen components.     

Infertility caused by retardation of follicular development in mice with oocyte-specific expression of Foxo3a

In recent years, mammalian oocytes have been proposed to have important roles in the orchestration of ovarian follicular development and fertility. To determine whether intra-oocyte Foxo3a, a component of the phosphatidylinositol 3-kinase (PI3K) signaling pathway, influences follicular development and female fertility, a transgenic mouse model was generated with constitutively active Foxo3a expressed in oocytes. We found that the female transgenic mice were infertile, which was caused by retarded oocyte growth and follicular development, and anovulation. Further mechanistic studies revealed that the constitutively active Foxo3a in oocytes caused a dramatic reduction in the expression of bone morphogenic protein 15 (Bmp15), connexin 37 and connexin 43, which are important molecules for the establishment of paracrine and gap junction communications in follicles. Foxo3a was also found to facilitate the nuclear localization of p27(kip1) in oocytes, a cyclin-dependent kinase (Cdk) inhibitor that may serve to inhibit oocyte growth. The results from the current study indicate that Foxo3a is an important intra-oocyte signaling molecule that negatively regulates oocyte growth and follicular development. Our study may therefore give some insight into oocyte-borne genetic aberrations that cause defects in follicular development and anovulation in human diseases, such as premature ovarian failure.     

Dosimetric predictors of acute bone marrow toxicity in carcinoma cervix — experience from a tertiary cancer centre in India

BackgroundThe objective of this study was To determine the dose volume parameters predicting acute haematological toxicity in carcinoma cervix patients undergoing concurrent chemoradiotherapy.Materials and methodsAll patients that presented to the hospital between Jan 2019 and Dec 2019 were prospectively analyzed. Patients diagnosed to have Carcinoma Cervix and planned for concurrent chemoradiation by volumetric modulated arc therapy (VMAT) were included for analysis. Patients were assessed at baseline and every week during treatment for acute haematological toxicities. Dose volume parameters from treatment plans were correlated with RTOG grade of haematological toxicities.ResultsA total of 34 patients diagnosed to have squamous cell carcinoma of cervix were treated by radical radiotherapy by VMAT technique and concurrent chemotherapy. The most common stage of presentation was stage IIB (61.7%). 29 patients (85.2%) completed five cycles of weekly cisplatin. Statistical analysis for sensitivity and specificity of dosimetric parameters was performed using receiver operating characteristic (ROC) curve. The probability of developing bone marrow toxicity was analyzed using T test. Mean dose to bone marrow exceeding 28.5 Gy was significantly associated with bone marrow toxicity (sensitivity — 82.4%, specificity — 70.6%). On analyzing dose volume parameters, volume of bone marrow receiving 20 Gy, 30 Gy and 40 Gy (V20, V30 and V40) more than 71.75%, and 49.75% and 22.85%, respectively, was significantly associated with bone marrow toxicity.ConclusionsOur study concludes that mean dose to bone marrow exceeding 28.5 Gy has high sensitivity and specificity for predicting bone marrow toxicity in patients receiving IMRT. Volume of bone marrow receiving 20 Gy, 30 Gy and 40 Gy significantly correlated with acute haematological toxicity.