Gestational Diabetes Mellitus Subtypes Classified by Oral Glucose Tolerance Test and Maternal and Perinatal Outcomes: Results of a Mexican Multicenter Prospective Cohort Study "Cuido Mi Embarazo".

Purpose: This study explores the impact of gestational diabetes mellitus (GDM) subtypes classified by oral glucose tolerance test (OGTT) values on maternal and perinatal outcomes. Patients and Methods: This multicenter prospective cohort study (May 2019-December 2022) included participants from the Mexican multicenter cohort study Cuido mi Embarazo (CME). Women were classified into four groups per 75-g 2-h OGTT: 1) normal glucose tolerance (normal OGTT), 2) GDM-Sensitivity (isolated abnormal fasting or abnormal fasting in combination with 1-h or 2-h abnormal results), 3) GDM-Secretion (isolated abnormal values at 1-h or 2-h or their combination), and 4) GDM-Mixed (three abnormal values). Cesarean delivery, neonates large for gestational age (LGA), and pre-term birth rates were among the outcomes compared. Between-group comparisons were analyzed using either the t-test, chi-square test, or Fisher's exact test. Results: Of 2,056 Mexican pregnant women in the CME cohort, 294 (14.3%) had GDM; 53.7%, 34.4%, and 11.9% were classified as GDM-Sensitivity, GDM-Secretion, and GDM-Mixed subtypes, respectively. Women with GDM were older (p = 0.0001) and more often multiparous (p = 0.119) vs without GDM. Cesarean delivery (63.3%; p = 0.02) and neonate LGA (10.7%; p = 0.078) were higher in the GDM-Mixed group than the overall GDM group (55.6% and 8.4%, respectively). Pre-term birth was more common in the GDM-Sensitivity group than in the overall GDM group (10.2% vs 8.5%, respectively; p=0.022). At 6 months postpartum, prediabetes was more frequent in the GDM-Sensitivity group than in the overall GDM group (31.6% vs 25.5%). Type 2 diabetes was more common in the GDM-Mixed group than in the overall GDM group (10.0% vs 3.3%). Conclusion: GDM subtypes effectively stratified maternal and perinatal risks. GDM-Mixed subtype increased the risk of cesarean delivery, LGA, and type 2 diabetes postpartum. GDM subtypes may help personalize clinical interventions and optimize maternal and perinatal outcomes.

Premature ovarian insufficiency is associated with global alterations in the regulatory landscape and gene expression in balanced X-autosome translocations.

BACKGROUND: Patients with balanced X-autosome translocations and premature ovarian insufficiency (POI) constitute an interesting paradigm to study the effect of chromosome repositioning. Their breakpoints are clustered within cytobands Xq13-Xq21, 80% of them in Xq21, and usually, no gene disruption can be associated with POI phenotype. As deletions within Xq21 do not cause POI, and since different breakpoints and translocations with different autosomes lead to this same gonadal phenotype, a "position effect" is hypothesized as a possible mechanism underlying POI pathogenesis. OBJECTIVE AND METHODS: To study the effect of the balanced X-autosome translocations that result in POI, we fine-mapped the breakpoints in six patients with POI and balanced X-autosome translocations and addressed gene expression and chromatin accessibility changes in four of them. RESULTS: We observed differential expression in 85 coding genes, associated with protein regulation, multicellular regulation, integrin signaling, and immune response pathways, and 120 differential peaks for the three interrogated histone marks, most of which were mapped in high-activity chromatin state regions. The integrative analysis between transcriptome and chromatin data pointed to 12 peaks mapped less than 2 Mb from 11 differentially expressed genes in genomic regions not related to the patients' chromosomal rearrangement, suggesting that translocations have broad effects on the chromatin structure. CONCLUSION: Since a wide impact on gene regulation was observed in patients, our results observed in this study support the hypothesis of position effect as a pathogenic mechanism for premature ovarian insufficiency associated with X-autosome translocations. This work emphasizes the relevance of chromatin changes in structural variation, since it advances our knowledge of the impact of perturbations in the regulatory landscape within interphase nuclei, resulting in the position effect pathogenicity.

MIDO GDM: an innovative artificial intelligence-based prediction model for the development of gestational diabetes in Mexican women.

Given the barriers to early detection of gestational diabetes mellitus (GDM), this study aimed to develop an artificial intelligence (AI)-based prediction model for GDM in pregnant Mexican women. Data were retrieved from 1709 pregnant women who participated in the multicenter prospective cohort study 'Cuido mi embarazo'. A machine-learning-driven method was used to select the best predictive variables for GDM risk: age, family history of type 2 diabetes, previous diagnosis of hypertension, pregestational body mass index, gestational week, parity, birth weight of last child, and random capillary glucose. An artificial neural network approach was then used to build the model, which achieved a high level of accuracy (70.3%) and sensitivity (83.3%) for identifying women at high risk of developing GDM. This AI-based model will be applied throughout Mexico to improve the timing and quality of GDM interventions. Given the ease of obtaining the model variables, this model is expected to be clinically strategic, allowing prioritization of preventative treatment and promising a paradigm shift in prevention and primary healthcare during pregnancy. This AI model uses variables that are easily collected to identify pregnant women at risk of developing GDM with a high level of accuracy and precision.

Diagnostic Accuracy of Capillary Blood Glucometer Testing for Gestational Diabetes.

Purpose: Few pregnant women in low-resource settings are screened for gestational diabetes mellitus (GDM) using the gold standard oral glucose tolerance test (OGTT). This study compared capillary blood glucose testing with 2-h plasma glucose measurements obtained using the 75-g OGTT to screen for GDM at primary healthcare clinics in Mexico. Patients and Methods: Pregnant women who participated in a previous prospective multicenter longitudinal cohort study and who had not been previously diagnosed with diabetes were included. Participants were evaluated using the plasmatic 2-h 75-g OGTT with simultaneous capillary blood glucose measurements using a glucometer. The study endpoint was the comparability of the glucometer results to the gold standard OGTT when collected simultaneously. Sensitivity, specificity, and area under the curve of the glucose measurements obtained for capillary blood compared with venous plasma (gold standard) were calculated to determine diagnostic accuracy. Results: The study included 947 pregnant women who had simultaneous glucose measurements available (blood capillary [glucometer] and venous blood OGTT). Overall, capillary blood glucose testing was very sensitive (89.47%); the specificity was 66.58% and the area under the curve (95% confidence interval) was 0.78 (0.74-0.81). The sensitivity, specificity and area under the curve of each capillary measurement were: 89.47%, 66.58% and 0.78 (0.74-0.82) for the fasting measurement, 91.53%, 93.24% and 0.92 (0.88-0.96) for the one-hour measurement, and 89.80%, 93.32%, 0.91 (0.87-0.95) for the second-hour measurement, respectively. No adverse events were reported. Conclusion: Capillary OGTT is a valid alternative to the gold standard OGTT for screening of GDM in low-resource situations or in situations where there are other limitations to performing the OGTT as part of primary healthcare services.

Palmitoleic Acid Acts on Adipose-Derived Stromal Cells and Promotes Anti-Hypertrophic and Anti-Inflammatory Effects in Obese Mice.

Adipose tissue (AT) secretes adipokines, modulators of low-grade chronic inflammation in obesity. Molecules that induce the emergence of new and functional adipocytes in AT can alleviate or prevent inflammatory and metabolic disorders. The objective of this study was to investigate the role of palmitoleic acid (n7) in 3T3-L1 and primary pre-adipocyte differentiation and AT inflammation. C57BL/6j mice were submitted to a control or high-fat diet (HFD) for 8 weeks, and treated with n7 for 4 weeks. Mice consuming a HFD presented an increase in body weight, epididymal (Epi) fat mass, and Epi adipocytes size. N7 treatment attenuated the body weight gain and completely prevented the hypertrophy of Epi adipocytes, but not the increment in Epi mass induced by the HFD, suggesting a greater adipocytes hyperplasia in animals treated with n7. It was agreed that n7 increased 3T3-L1 proliferation and differentiation, as well as the expression of genes involved in adipogenesis, such as Cebpa, Pparg, aP2, Perilipin, and Scl2a4. Furthermore, n7 decreased the inflammatory cytokines Mcp1, Tnfa, Il6, Cxcl10, and Nos2 genes in Epi vascular stromal cells, but not in the whole AT. These findings show that n7 exerts anti-hypertrophic effects in adipocytes which influence the surrounding cells by attenuating the overexpression of pro-inflammatory cytokines triggered by a HFD.

High-fat diet decreases H3K27ac in mice adipose-derived stromal cells.

OBJECTIVE: The study goal was to analyze the effects of a high-fat diet (HFD) on the histone 3 lysine 27 (H3K27) posttranscriptional modifications and the expression of histone-modifying enzymes in adipose-derived stromal cells (ASCs) from white adipose tissue (WAT). METHODS: Male C57BL/6J mice received control or HFD for 12 weeks. The ASCs were isolated from subcutaneous and visceral (epididymal) WAT, cultivated, and evaluated for expression of H3K27 trimethylation (H3K27me3) and H3K27 acetylation (H3K27ac) by Western blot. The transcription of histone-modifying enzymes was analyzed by real-time polymerase chain reaction. RESULTS: When compared with control, HFD ASCs showed a decrease in H3K27ac enrichment in subcutaneous and visceral WAT and ATP-citrate lyase expression in subcutaneous WAT. Curiously, the expression of CREB-binding protein was increased in visceral ASCs from HFD-fed mice. CONCLUSIONS: These results show that an HFD significantly reduces acetylation of H3K27 in ASCs and the expression of ATP-citrate lyase in subcutaneous ASCs, suggesting that, in this fat depot, the H3K27ac reduction could be partly due to lower acetyl-coenzyme A availability. H3K27ac is an epigenetic mark responsible for increasing the transcription rate and its reduction can have an important impact on ASC proliferation and differentiation potential.

Omega-3 Polyunsaturated Fatty Acids Prevent Nonalcoholic Steatohepatitis (NASH) and Stimulate Adipogenesis.

The increasing impact of obesity on global human health intensifies the importance of studies focusing on agents interfering with the metabolism and remodeling not only of the white adipose tissue (WAT) but also of the liver. In the present study, we have addressed the impact of n-3 PUFA in adipose cells' proliferation and adipogenesis, as well as in the hepatic lipid profile and morphology. Mice were induced to obesity by the consumption of a high-fat diet (HFD) for 16 weeks. At the 9th week, the treatment with fish oil (FO) was initiated and maintained until the end of the period. The FO treatment reduced the animals' body mass, plasma lipids, glucose, plasma transaminases, liver mass, triacylglycerol, and cholesterol liver content when compared to animals consuming only HFD. FO also decreased the inguinal (ing) WAT mass, reduced adipocyte volume, increased adipose cellularity (hyperplasia), and increased the proliferation of adipose-derived stromal cells (AdSCs) which corroborates the increment in the proliferation of 3T3-L1 pre-adipocytes or AdSCs treated in vitro with n-3 PUFA. After submitting the in vitro treated (n-3 PUFA) cells, 3T3-L1 and AdSCs, to an adipogenic cocktail, there was an increase in the mRNA expression of adipogenic transcriptional factors and other late adipocyte markers, as well as an increase in lipid accumulation when compared to not treated cells. Finally, the expression of browning-related genes was also higher in the n-3 PUFA treated group. We conclude that n-3 PUFA exerts an attenuating effect on body mass, dyslipidemia, and hepatic steatosis induced by HFD. FO treatment led to decreasing adiposity and adipocyte hypertrophy in ingWAT while increasing hyperplasia. Data suggest that FO treatment might induce recruitment (by increased proliferation and differentiation) of new adipocytes (white and/or beige) to the ingWAT, which is fundamental for the healthy expansion of WAT.

Fish Oil Enriched in EPA, but Not in DHA, Reverses the Metabolic Syndrome and Adipocyte Dysfunction Induced by a High-Fat Diet.

This study aimed to investigate the effects of two commercially available fish oils (FOs) containing different proportions of two omega-3 fatty acids (FA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), on the metabolic and endocrine dysfunctions of white adipose tissue resulting from obesity. Male C57BL/6J mice, 8 weeks old, received a control or high-fat diet (CO and HF groups, with 9% and 59% energy from fat, respectively) for 8 weeks. The next 8 weeks, the HF group was subdivided into HF, HF+FO/E (HF+5:1 EPA:DHA), and HF+FO/D (HF+5:1 DHA:EPA). Supplementation was performed by gavage, three times a week. All groups that received the HF diet had lower food and caloric intake, but a higher fat intake, body weight (BW) gain, glucose intolerance, and a significant increase in inguinal (ING), retroperitoneal (RP), and epididymal (EPI) adipose tissues when compared to the CO group. Additionally, HF and HF+FO/D groups showed insulin resistance, adipocyte hypertrophy, increased lipolysis and secretion of TNF-α, resistin and IL-10 adipokines by ING and RP adipocytes, and adiponectin only by the HF+FO/D group in ING adipocytes. All of these effects were completely reversed in the HF+FO/E group, which also showed partial reversion in BW gain and glucose intolerance. Both the HF+FO/E and HF+FO/D groups showed a reduction in ING and RP adipose depots when compared to the HF group, but only HF+FO/E in the EPI depot. HF+FO/E, but not HF+FO/D, was able to prevent the changes triggered by obesity in TNF-α, Il-10, and resistin secretion in ING and RP depots. These results strongly suggest that different EPA:DHA ratios have different impacts on the adipose tissue metabolism, FO being rich in EPA, but not in DHA, and effective in reversing the changes induced by obesity.

Palmitoleic Acid Decreases Non-alcoholic Hepatic Steatosis and Increases Lipogenesis and Fatty Acid Oxidation in Adipose Tissue From Obese Mice.

We recently demonstrated that palmitoleic acid (C16:1n7), a monounsaturated fatty acid, increases the metabolic and oxidative capacity of 3T3-L1 adipocytes. Herein, the effect of 16:1n7 supplementation on metabolic parameters on white adipose tissue (WAT) and liver of obese mice induced by a high-fat diet (HFD) was addressed by analyzing metabolic (dys)function and altered genes expression in adipose tissue, as well as liver and serum biochemistry analysis. For this purpose, mice were induced to obesity for 8 weeks, and from the 5th week, they received 16:1n7 (300 mg/kg per day) or water for 30 days, by gavage. Subcutaneous inguinal (ING) and epididymal (EPI) WAT were removed for analysis of metabolic, (anti)inflammatory, adipogenic, and thermogenic genes expression by real-time reverse transcriptase-polymerase chain reaction. Additionally, metabolic activities of isolated adipocytes, such as glucose uptake, lipogenesis (triacylglycerol esterification), ß-oxidation, and lipolysis in ING adipocytes, were also assessed. Despite the higher fat intake, the HFD group showed lower food intake but higher body weight, increased glucose, significant dyslipidemia, and increased liver and adipose depot mass, accompanied by liver steatosis. The 16:1n7 supplementation slowed down the body mass gain and prevented the increase of lipids in the liver. HFD+n7 animals presented increased fatty acid oxidation and lipogenesis compared to control, but no effect was observed on lipolysis and glucose uptake in ING isolated adipocytes. Besides, 16:1n7 increased the content of the mRNA encoding FABP4, but partially prevented the expression of genes encoding ATGL, HSL, perilipin, lipin, C/EBP-α, PPAR-γ, C/EBP-ß, CPT1, NRF1, TFAM, PRDM16, and nitric oxide synthase 2 in ING depot from HFD group of animals. Finally, HFD increased Mcp1 and Tnfα expression, and 16:1n7 promoted a more marked increase in it. In summary, the data show that palmitoleic acid promotes metabolic changes and partially prevents the increase in gene expression on adipocytes triggered by obesity, suggesting that HFD+n7 animals do not require the same magnitude of metabolic adaptation to cope with energy demand from the HFD. In the long term, the effects of 16:1n7 may be more evident and beneficial for the function/dysfunction of WAT from an obese organism, with relevant repercussions in the systemic metabolic homeostasis.

LINE-1 specific nuclear organization in mice olfactory sensory neurons.

Long interspersed nuclear elements-1 (LINE-1) are mobile DNA elements that comprise the majority of interspersed repeats in the mammalian genome. During the last decade, these transposable sequences have been described as controlling elements involved in transcriptional regulation and genome plasticity. Recently, LINE-1 have been implicated in neurogenesis, but to date little is known about their nuclear organization in neurons. The olfactory epithelium is a site of continuous neurogenesis, and loci of olfactory receptor genes are enriched in LINE-1 copies. Olfactory neurons have a unique inverted nuclear architecture and constitutive heterochromatin forms a block in the center of the nuclei. Our DNA FISH images show that, even though LINE-1 copies are dispersed throughout the mice genome, they are clustered forming a cap around the central heterochromatin block and frequently occupy the same position as facultative heterochromatin in olfactory neurons nuclei. This specific LINE-1 organization could not be observed in other olfactory epithelium cell types. Analyses of H3K27me3 and H3K9me3 ChIP-seq data from olfactory epithelium revealed that LINE-1 copies located at OR gene loci show different enrichment for these heterochromatin marks. We also found that LINE-1 are transcribed in mouse olfactory epithelium. These results suggest that LINE-1 play a role in the olfactory neurons' nuclear architecture. SIGNIFICANCE STATEMENT: LINE-1 are mobile DNA elements and comprise almost 20% of mice and human genomes. These retrotransposons have been implicated in neurogenesis. We show for the first time that LINE-1 retrotransposons have a specific nuclear organization in olfactory neurons, forming aggregates concentric to the heterochromatin block and frequently occupying the same region as facultative heterochromatin. We found that LINE-1 at olfactory receptor gene loci are differently enriched for H3K9me3 and H3K27me3, but LINE-1 transcripts could be detected in the olfactory epithelium. We speculate that these retrotransposons play an active role in olfactory neurons' nuclear architecture.

Expression of genome defence protein members in proliferating and quiescent rat male germ cells and the Nuage dynamics.

During epigenetic reprogramming germ cells activate alternative mechanisms to maintain the repression retrotransposons. This mechanism involves the recruitment of genome defence proteins such as MAEL, PIWIL4 and TDRD9, which associate with piRNAs and promote Line-1 silencing. MAEL, PIWIL4 and TDRD9 form the piP-bodies, which organization and dynamics vary according to the stage of germ cell epigenetic reprogramming. Although these data have been well documented in mice, it is not known how this mechanism operates in the rat. Thus, the aim of this study was to describe the distribution and interaction of MAEL, PIWIL4, TDRD9 and DAZL during rat germ cell development and check whether specific localization of these proteins is related to the distribution of Line-1 aggregates. Rat embryo gonads at 15 days post-conception (dpc), 16dpc and 19dpc were submitted to MAEL, PIWIL4, TDRD9 and DAZL immunolabelling. The gonads of 19dpc embryos were submitted to the double-labelling of MAEL/DAZL, TDRD9/MAEL and PIWIL4/MAEL. The 19dpc gonads were submitted to co-immunoprecipitation assays and fluorescent in situ hybridization for Line-1 detection. MAEL and TDRD9 showed very similar localization at all ages, whereas DAZL and PIWIL4 showed specific distribution, with PIWIL4 showing shuttling from the nucleus to the cytoplasm by the end epigenetic reprogramming. In quiescent 19dpc gonocytes all proteins colocalized in a nuage adjacent to the nucleus. DAZL interacts with PIWIL4 and MAEL, suggesting that DAZL acts with these proteins to repress Line-1. TDRD9, however, does not interact with DAZL or MAEL despite their colocalization. Line-1 aggregates were detected predominantly in the nuclear periphery, although did not show homogeneous distribution as observed for the nuage. In conclusion, the nuage in quiescent rat gonocytes show a very distinguished organization that might be related to the organization of Line-1 clusters and describe the association of DAZL with proteins responsible for Line-1 repression.

Utilización del control prenatal en gestantes de la delegación Iztapa lapa distrito federal de México / Use of antenatal care in pregnant women of the delegation Iztapalapa federal district of México

Objetivo: determinar la utilización adecuada del control prenatal en gestantes de la delegación Iztapalapa del Distrito Federal de México. Materiales y métodos: estudio descriptivo, retrospectivo (entre diciembre 2014 y abril de 2015), en la delegación de Iztapalapa del Distrito Federal de México, con una muestra de 135 mujeres. Para recolectar la información fue utilizada una encuesta para datos sociodemográficos basada en la ENSANUT, un cuestionario de caracterización familiar, que incluyó el APGAR familiar, para medir la percepción de la funcionalidad familiar, y un cuestionario de satisfacción con los servicios de salud recibidos. Resultados: fueron incluidas en el estudio 135 mujeres embarazadas, con un promedio de edad de 26,7 años, la media de controles prenatales fue de 5, la razón principal de asistir es la de detectar alteraciones tempranas, además se sienten satisfechas con la atención brindada por el personal de salud y perciben un adecuado apoyo familiar. Conclusiones: la utilización del control prenatal mejora entre las mujeres primíparas, que conviven en familias nucleares y normofuncionales..(AU)

Objective: to determinate the use of antenatal care in pregnant women of the delegation Iztapalapa in the Federal District of Mexico. Materials and methods: sudy descriptive, retrospective (December 2014 to April of 2015), in the delegation of Iztapalapa of the District Federal of Mexico, it shows was constituted by 135 women. To collect the information is used a survey to data socio-demographic and characterization family based in the ENSANUT. Also used the instrument of assessment of family functionality (APGAR family) and satisfaction with the services. Data were coded in an array of data in the Microsoft Excel program and its analysis was performed by descriptive statistics using the statistical software SPSS version 23. Results: were included in the study, 135 women pregnant women, with an average age of 26,7 years, prenatal median was 5, the main reason to attend is the detecting early alterations, also they are satisfied with the care provided by health personnel and they have adequate family support. Conclusions: the use of the control prenatal is greater among primiparous women, that living nuclear families and that perceived their families as functional..(AU)

Discovery of potent and selective PPARα/δ dual antagonists and initial biological studies.

We previously published on the design and synthesis of novel, potent and selective PPARα antagonists suitable for either i.p. or oral in vivo administration for the potential treatment of cancer. Described herein is SAR for a subsequent program, where we set out to identify selective and potent PPARα/δ dual antagonist molecules. Emerging literature indicates that both PPARα and PPARδ antagonism may be helpful in curbing the proliferation of certain types of cancer. This dual antagonism could also be used to study PPARs in other settings. After testing for selective and dual potency, off-target counter screening, metabolic stability, oral bioavailability and associated toxicity, compound 11, the first reported PPARα/δ dual antagonist was chosen for more advanced preclinical evaluation.

Combining In Vivo and In Vitro Approaches To Identify Human Odorant Receptors Responsive to Food Odorants.

Olfactory perception plays an important role in food flavor. Humans have around 400 odorant receptors (ORs), which can be activated by an enormous number of odorants in a combinatorial fashion. To date, only a few odorant receptors have been linked to their respective odorants, due to the difficulties in expressing these receptor proteins in heterologous cell systems. In vivo approaches allow for the analysis of odorant-receptor interactions in their native environment and have the advantage that the complete OR repertoire is simultaneously tested. Once mouse odorant-receptor pairs are defined, one can search for the corresponding human orthologues, which can be validated against the odorants in heterologous cells. Thus, the combination of in vivo and in vitro methods should contribute to the identification of human ORs that recognize odorants of interest, such as key food odorants.

In vitro and in vivo pharmacology of NXT629, a novel and selective PPARα antagonist.

Peroxisome-proliferator activated receptors (PPAR) are members of the nuclear hormone receptor superfamily which regulate gene transcription. PPARα is a key regulator of lipid homeostasis and a negative regulator of inflammation. Under conditions of metabolic stress such as fasting or glucose deprivation, PPARα is upregulated in order to control gene expression necessary for processing alternate fuel sources (e.g. fatty acid oxidation) and thereby promote maintenance of cell viability. Clinically, PPARα expression is upregulated in diseased tissues such as melanoma, chronic lymphocytic leukemia, ovarian and prostate cancer. This may allow for cellular proliferation and metastasis. Importantly, genetic knockouts of PPARα have been shown to be protected against tumor growth in a variety of syngeneic tumors models. We hypothesized that a potent and selective PPARα antagonist could represent a novel cancer therapy. Early in our discovery research, we identified NXT629 (Bravo et al., 2014). Herein we describe the pharmacology of NXT629 and demonstrate that it is a potent and selective PPARα antagonist. We identify NXT629 as a valuable tool for use in in vivo assessment of PPARα due to its good systemic exposure following intraperitoneal injection. We explore the in vivo pharmacology of NXT629 and demonstrate that it is efficacious in pharmacodynamic models that are driven by PPARα. Finally, we probe the efficacy of NXT629 in disease models where PPARα knockouts have shown to be protected. We believe that PPARα antagonists will be beneficial in diseases such as ovarian cancer and melanoma where PPARα and fatty acid oxidation may be involved.

Monogenic and Monoallelic Expression of Odorant Receptors.

Odorant receptors (ORs) belong to a large gene family of rhodopsin-like G protein-coupled receptors (GPCRs). The mouse OR gene family is composed of ∼1000 OR genes, and the human OR gene family is composed of ∼400 OR genes. The OR genes are spread throughout the genome, and can be found in clusters or as solitary genes in almost all chromosomes. These chemosensory GPCRs are expressed in highly specialized cells, the olfactory sensory neurons of the nose. Each one of these neurons expresses a single OR gene out of the complete repertoire of genes. In addition, only one of the two homologous alleles of the chosen OR gene, the maternal or the paternal, is expressed per neuron. Here we review recent findings that help to elucidate the mechanisms underlying monogenic and monoallelic expression of OR genes.

Antagonizing Peroxisome Proliferator-Activated Receptor α Activity Selectively Enhances Th1 Immunity in Male Mice.

Females exhibit more robust Th1 responses than males. Our previous work suggested that this sex disparity is a consequence of higher activity of the androgen-induced gene peroxisome proliferator-activated receptor α (PPARα) in male CD4(+) T cells. The objective of this study was to elucidate the cellular and molecular mechanism of how PPARα inhibits Th1 responses in male mice. In this study, we found that PPARα functions within CD4(+) and CD8(+) T lymphocytes and NKT cells to negatively regulate IFN-γ responses in male mice and identified Ifng as the gene target of PPARα repression. Treatment of male CD4(+) T cells with the PPARα agonist fenofibrate induced the recruitment of PPARα and the nuclear receptor-interacting protein, nuclear receptor corepressor 1, to specific cis-regulatory elements in the Ifng locus. This recruitment associated with reduced histone acetylation at these sites. Knockdown of nuclear receptor corepressor 1 in primary male T cells abolished the effect of fenofibrate in reducing IFN-γ production. In contrast, treatment of male T cells with IS001, a novel antagonist of PPARα, increased Ifng gene expression and histone acetylation across the Ifng locus. Finally, we investigated the effects of IS001 on IFN-γ responses in mice during infection with the Th1-associated pathogen Listeria monocytogenes and observed that IS001 enhanced IFN-γ production by NKT, CD4(+), and CD8(+) T cells and improved the survival of male, but not female, mice. Our findings provide a novel mechanism of why IFN-γ responses are more robust in females and introduce a small-molecule IS001 that can be used to enhance Th1 immunity in males.

A Selective Novel Peroxisome Proliferator-Activated Receptor (PPAR)-α Antagonist Induces Apoptosis and Inhibits Proliferation of CLL Cells In Vitro and In Vivo.

Tumor-specific metabolic changes can reveal new therapeutic targets. Our findings implicate a supporting role for fatty acid metabolism in chronic lymphocytic leukemia (CLL) cell survival. Peroxisome proliferator-activated receptor (PPAR)-α, a major transcriptional regulator of fatty acid oxidation, was recently shown to be upregulated in CLL. To evaluate PPARα as a potential therapeutic target, we developed a highly selective, potent small molecule antagonist of PPARα, NXT629. NXT629 inhibited agonist-induced transcription of PPARα-regulated genes, demonstrating target engagement in CLL cells. Furthermore, NXT629 induced apoptosis of CLL cells even in the presence of a protective microenvironment. To mimic the proliferative lymphoid compartment of CLL, we examined the activity of NXT629 on CLL cells that were stimulated to proliferate in vitro. NXT629 reduced the number of leukemia cells undergoing cell division. In addition, in two xenograft mouse models of CLL (one a model for nondividing and one for dividing CLL), NXT629 reduced the number of viable CLL cells in vivo. Overall, these results suggest that fatty acid metabolism promotes survival and proliferation of primary CLL cells and that inhibiting PPARα gene regulation could be a new therapeutic approach to treating CLL.

Identification of the first potent, selective and bioavailable PPARα antagonist.

The discovery and SAR of a novel series of potent and selective PPARα antagonists are herein described. Exploration of replacements for the labile acyl sulfonamide linker led to a biaryl sulfonamide series of which compound 33 proved to be suitable for further profiling in vivo. Compound 33 demonstrated excellent potency, selectivity against other nuclear hormone receptors, and good pharmacokinetics in mouse.