Methylene-bridge tryptophan fatty acylation regulates PI3K-AKT signaling and glucose uptake.

Protein fatty acylation regulates numerous cell signaling pathways. Polyunsaturated fatty acids (PUFAs) exert a plethora of physiological effects, including cell signaling regulation, with underlying mechanisms to be fully understood. Herein, we report that docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) regulate PI3K-AKT signaling by modifying PDK1 and AKT2. DHA-administered mice exhibit altered phosphorylation of proteins in signaling pathways. Methylene bridge-containing DHA/EPA acylate δ1 carbon of tryptophan 448/543 in PDK1 and tryptophan 414 in AKT2 via free radical pathway, recruit both the proteins to the cytoplasmic membrane, and activate PI3K signaling and glucose uptake in a tryptophan acylation-dependent but insulin-independent manner in cultured cells and in mice. DHA/EPA deplete cytosolic PDK1 and AKT2 and induce insulin resistance. Akt2 knockout in mice abrogates DHA/EPA-induced PI3K-AKT signaling. Our results identify PUFA's methylene bridge tryptophan acylation, a protein fatty acylation that regulates cell signaling and may underlie multifaceted effects of methylene-bridge-containing PUFAs.

New types of ATP-grasp ligase are associated with the novel pathway for complicated mycosporine-like amino acid production in desiccation-tolerant cyanobacteria.

Mycosporine-like amino acids (MAAs) were widespread in diverse organisms to attenuate UV radiation. We recently characterized the large, complicated MAA mycosporine-2-(4-deoxygadusolyl-ornithine) in desert cyanobacterium Nostoc flagelliforme. Synthesis of this MAA requires the five-gene cluster mysABDC2C3. Here, bioinformatic analysis indicated that mysC duplication within five-gene mys clusters is strictly limited to drought-tolerant cyanobacteria. Phylogenic analysis distinguished these duplicated MysCs into two clades that separated from canonical MysCs. Heterologous expression of N. flagelliforme mys genes in Escherichia coli showed that MysAB produces 4-deoxygadusol. The ATP-grasp ligase of MysC3 catalyses the linkage of the δ- or ε-amino group of ornithine/lysine to 4-deoxygadusol, yielding mycosporine-ornithine or mycosporine-lysine respectively. The ATP-grasp ligase of MysC2 strictly condenses the α-amino group of mycosporine-ornithine to another 4-deoxygadusol. MysD (D-Ala-D-Ala ligase) functions following MysC2 to catalyse the formation of mycosporine-2-(4-deoxygadusolyl-ornithine). High arginine content likely provides a greater pool of ornithine over other amino acids during rehydration of desiccated N. flagelliforme. Duplication of ATP-grasp ligases is specific for the use of substrates that have two amino groups (such as ornithine) for the production of complicated MAAs with multiple chromophores. This five-enzyme biosynthesis pathway for complicated MAAs is a novel adaptation of cyanobacteria for UV tolerance in drought environments.

Prediction of Metabolic Disorders Using NMR-Based Metabolomics: The Shanghai Changfeng Study.

A metabolically healthy status, whether obese or not, is a transient stage with the potential to develop into metabolic disorders during the course of life. We investigated the incidence of metabolic disorders in 1078 metabolically healthy Chinese adults from the Shanghai Changfeng Study and looked for metabolites that discriminated the participants who would develop metabolic disorders in the future. Participants were divided into metabolically healthy overweight/obesity (MHO) and metabolically healthy normal weight (MHNW) groups according to their body mass index (BMI) and metabolic status. Their serum metabolomic profile was measured using a 1H nuclear magnetic resonance spectrometer (1H-NMR). The prevalence of diabetes, hypertriglyceridemia, hypercholesterolemia and metabolic syndrome was similar between the MHNW and MHO participants at baseline. After a median of 4.2 years of follow-up, more MHO participants became metabolically unhealthy than MHNW participants. However, a subgroup of MHO participants who remained metabolically healthy (MHO → MHO) had a similar prevalence of metabolic disorders as the MHNW participants at the follow-up examination, despite a significant reduction in their serum concentrations of high-density lipoprotein (HDL) and an elevation in valine, leucine, alanine and tyrosine. Further correlation analysis indicated that serum intermediate-density lipoprotein (IDL) and very low-density lipoprotein cholesterol (VLDL-CH) might be involved in the transition from metabolically healthy to unhealthy status and could be valuable to identify the MHNW and MHO with increased metabolic risks.

Elevated plasma ß-hydroxybutyrate predicts adverse outcomes and disease progression in patients with arrhythmogenic cardiomyopathy.

Sudden death could be the first symptom of patients with arrhythmogenic cardiomyopathy (AC), a disease for which clinical indicators predicting adverse progression remain lacking. Recent findings suggest that metabolic dysregulation is present in AC. We performed this study to identify metabolic indicators that predicted major adverse cardiac events (MACEs) in patients with AC and their relatives. Comparing explanted hearts from patients with AC and healthy donors, we identified deregulated metabolic pathways using quantitative proteomics. Right ventricles (RVs) from patients with AC displayed elevated ketone metabolic enzymes, OXCT1 and HMGCS2, suggesting higher ketone metabolism in AC RVs. Analysis of matched coronary artery and sinus plasma suggested potential ketone body synthesis at early-stage AC, which was validated using patient-derived induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) in vitro. Targeted metabolomics analysis in RVs from end-stage AC revealed a "burned-out" state, with predominant medium-chain fatty acid rather than ketone body utilization. In an independent validation cohort, 65 probands with mostly non-heart failure manifestations of AC had higher plasma ß-hydroxybutyrate (ß-OHB) than 62 healthy volunteers (P < 0.001). Probands with AC with MACE had higher ß-OHB than those without MACE (P < 0.001). Among 94 relatives of probands, higher plasma ß-OHB distinguished 25 relatives having suspected AC from nonaffected relatives. This study demonstrates that elevated plasma ß-OHB predicts MACE in probands and disease progression in patients with AC and their clinically asymptomatic relatives.

Deficiency of Gpr1 improves steroid hormone abnormality in hyperandrogenized mice.

BACKGROUND: Polycystic ovary syndrome (PCOS) is a complex genetic disease with multifarious phenotypes. Many researches use dehydroepiandrosterone (DHEA) to induce PCOS in pubertal mouse models. The aim of this study was to investigate the role of GPR1 in dehydroepiandrosterone (DHEA)-induced hyperandrogenized mice. METHODS: Prepubertal C57BL/6 mice (25 days of age) and Gpr1-deficient mice were each divided into two groups and injected daily with sesame oil with or without DHEA (6 mg/100 g) for 21 consecutive days. Hematoxylin and eosin (H&E) staining was performed to determine the characteristics of the DHEA-treated ovaries. Real-time PCR was used to examine steroid synthesis enzymes gene expression. Granulosa cell was cultured to explore the mechanism of DHEA-induced, GPR1-mediated estradiol secretion. RESULTS: DHEA treatment induced some aspects of PCOS in wild-type mice, such as increased body weight, elevated serum testosterone, increased number of small, cystic, atretic follicles, and absence of corpus luteum in ovaries. However, Gpr1 deficiency significantly attenuated the DHEA-induced weight gain and ovarian phenotype, improving steroidogenesis in ovaries and estradiol synthesis in cultured granulosa cells, partially through mTOR signaling. CONCLUSIONS: In conclusion, Gpr1 deficiency leads to the improvement of steroid synthesis in mice hyperandrogenized with DHEA, indicating that GPR1 may be a therapeutic target for DHEA-induced hyperandrogenism.

UV-B induced biosynthesis of a novel sunscreen compound in solar radiation and desiccation tolerant cyanobacteria.

The small-molecule sunscreen compounds, mycosporine-like amino acids (MAAs), have strong ultraviolet (UV) absorption and can protect cyanobacteria against UV-B damage. However, the molecular mechanism underlying UV-B signaling and MAA chemical diversity remain largely unclear. Here, we identified a five-gene cluster for MAA biosynthesis in the solar radiation and desiccation tolerant cyanobacterium Nostoc flagelliforme. A LuxR family protein OrrA was identified as a positive UV-B responsive regulator binding to the promoter region of this gene cluster. OrrA functions as an activator mediating the UV-B induced MAA biosynthesis. Overexpression of orrA strengthened its UV-B tolerance during desiccation, and enhanced the photosynthetic recovery upon rehydration. Heterologous expression of this gene cluster in Anabaena PCC 7120 produces the same MAA as that in field samples of N. flagelliforme. The MAA structure is assigned as mycosporine-2-(4-deoxygadusolyl-ornithine) with a molecular weight of 756 Da, the structurally unique MAA compound reported to date. This MAA was catalyzed by mysD-mysC2-mysC1 encoding proteins from 4-deoxygadusol, which was synthesized through the catalysis of mysA-mysB products. Thus, we elucidated the transcriptional mechanism for a novel type MAA biosynthesis in solar radiation and desiccation tolerant cyanobacteria, which shed light on the identification of other components for UV-B signaling in cyanobacteria.

Sensing and Transmitting Intracellular Amino Acid Signals through Reversible Lysine Aminoacylations.

Amino acids are known regulators of cellular signaling and physiology, but how they are sensed intracellularly is not fully understood. Herein, we report that each aminoacyl-tRNA synthetase (ARS) senses its cognate amino acid sufficiency through catalyzing the formation of lysine aminoacylation (K-AA) on its specific substrate proteins. At physiologic levels, amino acids promote ARSs bound to their substrates and form K-AAs on the ɛ-amine of lysines in their substrates by producing reactive aminoacyl adenylates. The K-AA marks can be removed by deacetylases, such as SIRT1 and SIRT3, employing the same mechanism as that involved in deacetylation. These dynamically regulated K-AAs transduce signals of their respective amino acids. Reversible leucylation on ras-related GTP-binding protein A/B regulates activity of the mammalian target of rapamycin complex 1. Glutaminylation on apoptosis signal-regulating kinase 1 suppresses apoptosis. We discovered non-canonical functions of ARSs and revealed systematic and functional amino acid sensing and signal transduction networks.

Assessment of the effect of different vitrification solutions on human ovarian tissue after short-term xenotransplantation onto the chick embryo chorioallantoic membrane.

Chemotherapy can lead to the loss of fertility and premature ovarian failure in young women who suffer from malignant diseases. Freezing ovarian tissue by vitrification allows for the preservation of a large number of follicles prior to treatment, yet no established protocols have been optimized with respect to the vitrification solution. The aim of the present study was to evaluate the early stage of human ovarian tissue xenotransplantated onto the chick embryo chorioallantoic membrane after vitrification, and to determine the effect of different vitrification solutions on ovarian tissue quality-as defined by morphology and viability of follicles, neovascularization, cell proliferation, and apoptosis. Each vitrification protocol had a different impact on ovarian tissue at the early transplantation stage; one process using the lowest concentrations of ethylene glycol and dimethylsulfoxide, plus sucrose, demonstrated a moderate advantage compared to the other protocols. We also demonstrated that the chorioallantoic membrane model can be a useful alternative for short-term xenotransplantation studies of angiogenesis into human ovarian cortical tissue.

[Investigation on the prevalence of high risk human papillomavirus and cervical cancer among adult women, in Shenzhen].

OBJECTIVE: To investigate the prevalence of high risk human papillomavirus (HPV) genital infection and cervical cancer in adult women from Shenzhen. METHODS: Cluster sampling was used to investigate the prevalence of HPV infection and cervical cancer from women aged 20 - 59 years old living in Luohu, Futian, Nanshan, Longgang and Baoan districts in Shenzhen from April 2006 to April 2010. All women were detected for liquid-based cytology test (LCT) or Thinprep cytologic test (TCT) and high-risk HPV-DNA test with hybrid capture II (HC-II). All women with ≥ ASC-US by cytology and/or a positive HC-II test were asked to return for colposcopy and four-quadrant biopsy. Endocervical curettage was performed. Pathological finding were used as the gold standard of the diagnosis of cervical intraepithelial neoplasia. RESULTS: 10 210 women were involved in the study and 10 017 of them having completed data. The overall positive rate of high-risk HPV-DNA was 16.29%. HPV positive rates in 20-, 30-, 35-, 40-, 45-, 50-59 age groups were 17.37%, 15.59%, 16.33%, 14.74%, 17.16% and 17.98%, respectively. The curve of HPV infection rates in different age groups appeared a 'W' shape. HPV infection rates in the 25-years-olds and 50-59 year-olds groups were significantly higher than the other age groups (χ(2) = 4.50, P = 0.03). The overall prevalence rate of cervical intraepithelial lesions (CIN) was 7.52%, of which the prevalence rates of low-grade cervical intraepithelial lesions (CIN I) was 5.32% high-grade cervical intraepithelial lesions (CIN II/III) was 2.21%, cervical cancer was 0.12%. The prevalence of CIN I was significantly higher than the CIN II/III (χ(2) = 134.15, P < 0.001). The prevalence of cervical cancer in 45-age group was 0.12%, the highest. HPV infection rates increased with the grades of cervical lesions including women without CIN as 44.31%, in CINI as 70.73%, in CINII as 86.73%, and in CIN III as 96.75% and in cancer as 100.00%. The HPV infection rates were different in districts (χ(2) = 17.81, P = 0.03), with Futian and Luohu higher than those of Nanshan, Longgang and Baoan district. The prevalence rate of CIN in Baoan was lower than other districts. The CIN prevalence rates were not significantly different among the other districts of Shenzhen (χ(2) = 4.84, P = 0.18). CONCLUSION: The prevalence of cervical cancer was low in adult women living in Shenzhen, with cervical lesions still in the early stage. Prevention of HPV infection and treatment of CIN were the key points for the prevention of cervical cancer.

Metabolic alterations in the hamster co-infected with Schistosoma japonicum and Necator americanus.

Co-infection with hookworm and schistosomes is a common phenomenon in sub-Saharan Africa, as well as in parts of South America and southeast Asia. As a first step towards understanding the metabolic response of a hookworm-schistosome co-infection in humans, we investigated the metabolic consequences of co-infection in an animal model, using a nuclear magnetic resonance (NMR)-based metabolic profiling technique, combined with multivariate statistical analysis. Urine and serum samples were obtained from hamsters experimentally infected with 250 Necator americanus infective L(3) and 100 Schistosoma japonicum cercariae simultaneously. In the co-infection model, similar worm burdens were observed as reported for single infection models, whereas metabolic profiles of co-infection represented a combination of the altered metabolite profiles induced by single infections with these two parasites. Consistent differences in metabolic profiles between the co-infected and non-infected control hamsters were observed from 4 weeks p.i. onwards. The predominant metabolic alterations in co-infected hamsters consisted of depletion of amino acids, tricarboxylic acid cycle intermediates (e.g. citrate and succinate) and glucose. Moreover, alterations of a series of gut microbial-related metabolites, such as decreased levels of hippurate, 3-hydroxyphenylpropionic acid, 4-hydroxyphenylpropionic acid and trimethylamine-N-oxide, and increased concentrations of 4-cresol glucuronide and phenylacetylglycine were associated with co-infection. Our results provide a first step towards understanding the metabolic response of an animal host to multiple parasitic infections.

[Human papillomavirus infection and cervical intraepithelial neoplasia morbidity of women from different occupations in Shenzhen city, China].

OBJECTIVE: To investigate the human papillomavirus (HPV) infection and cervical intraepithelial neoplasia (CIN) morbidity of women from different occupations in Shenzhen city. METHODS: 2045 women of five kinds of occupation in Shenzhen city, including 130 teachers, 385 workers, 316 service women, 199 poverish women, 420 doctors or nurses and 595 general residents were included. We screened these women by methods of detecting high risk HPV of hc2 combing with LCT. Women with screening positive results were diagnosed CIN by colposcopic biopsy. RESULTS: (1) High risk factors on HPV infection rate in different occupations were different with the highest in service occupation (19.3%) while the lowest appeared in medical workers (11.9%). (2) In those 2045 women, we found 199 cervical lesions including pathological HPV infection, CIN1, 2, 3 and cervical cancers, with morbidity rates as 4.11%, 3.28%, 1.67%, 0.54% and 0.15% respectively. Along with the progress of the cervical lesions, the morbidity decreased. (3) The morbidity rates of CIN in different occupations were different, with the highest of HSIL in service occupation and the lowest in teachers. CONCLUSION: Women of different occupations in Shenzhen city had different high risk HPV infection rates and CIN morbidity. The HPV infection rate and HSIL morbidity were highest among women having service related jobs.