Drew Tortoriello

Obesity in C57BL/6J mice is characterized by adipose tissue hypoxia and cytotoxic T-cell infiltration

Background:Obesity is currently viewed as a state of chronic low-grade inflammation in which there is a pro-inflammatory alteration in the serum adipocytokine profile as well as an infiltration of white adipose tissue by activated macrophages. The etiology of this inflammation, however, is poorly understood.Methods:Hypothesizing that local hypoxia within expanding white adipose tissue depots may contribute to obesity-related inflammation, we compared body composition, serum inflammatory marker concentrations and the expression of several hypoxia-regulated genes in white adipose tissue derived from lean, dietary-induced obese (DIO) and ob/ob male C57BL/6J mice. We also examined white adipose tissue for the presence of hypoxia using both a pimonidazole-based antibody system and a fiberoptic sensor for real-time pO2 quantification in vivo. Finally, using cell-specific leukocyte antibodies, we performed immunohistochemistry and flow cytometric analyses to further characterize the cellular nature of adipose inflammation.Results:We determined that obesity in male C57BL/6J mice is associated with increased expression of HIF (hypoxia-inducible factor) isoforms and GLUT-1, and that white adipose tissue hypoxia was present in the obese mice. Immunohistochemistry revealed hypoxic areas to colocalize predominantly with F4/80+ macrophages. Interestingly, CD3+ T cells were present in large numbers within the adipose of both DIO and ob/ob obese mice, and flow cytometry revealed their adipose to possess significantly more CD8+ T cells than their lean cohort.Conclusions:White adipose hypoxia and cytotoxic T-cell invasion are features of obesity in C57BL/6J mice and are potential contributors to their local and generalized inflammatory state.

Dietary Curcumin Significantly Improves Obesity-Associated Inflammation and Diabetes in Mouse Models of Diabesity

Obesity is a major risk factor for the development of type 2 diabetes, and both conditions are now recognized to possess significant inflammatory components underlying their pathophysiologies. We tested the hypothesis that the plant polyphenolic compound curcumin, which is known to exert potent antiinflammatory and antioxidant effects, would ameliorate diabetes and inflammation in murine models of insulin-resistant obesity. We found that dietary curcumin admixture ameliorated diabetes in high-fat diet-induced obese and leptin-deficient ob/ob male C57BL/6J mice as determined by glucose and insulin tolerance testing and hemoglobin A1c percentages. Curcumin treatment also significantly reduced macrophage infiltration of white adipose tissue, increased adipose tissue adiponectin production, and decreased hepatic nuclear factor-kappaB activity, hepatomegaly, and markers of hepatic inflammation. We therefore conclude that orally ingested curcumin reverses many of the inflammatory and metabolic derangements associated with obesity and improves glycemic control in mouse models of type 2 diabetes. This or related compounds warrant further investigation as novel adjunctive therapies for type 2 diabetes in man.

Genetic analysis of human embryos by metaphase comparative genomic hybridization (mCGH) improves efficiency of IVF by increasing embryo implantation rate and reducing multiple pregnancies and spontaneous miscarriages

OBJECTIVE To assess the benefit of selecting blastocysts for cryotransfer based upon prior comparative genomic hybridization (CGH) karyotyping of blastomeres derived from their cleaved embryos of origin. Implantation and birth rates per transfer of previtrified CGH-tested blastocysts were compared with those following the transfer of nonCGH-tested fresh and warmed embryos. DESIGN In vitro studies. SETTING Private infertility clinic. PATIENT(S) Women undergoing infertility treatment. INTERVENTION(S) Three groups of women with similar clinical and demographic characteristics were compared. Group A underwent transfer of warmed blastocysts derived from CGH-normal day 3 embryos. Group B underwent embryo transfer of warmed blastocysts derived from nonkaryotyped vitrified embryos. Group C underwent fresh transfers with non-CGH-tested blastocysts. MAIN OUTCOME MEASURE(S) Implantation and birth rates per embryo after the cryotransfer of CGH-tested blastocysts. RESULT(S) The birth rate per transferred blastocyst in group A was 48%, versus 15% for group B and 19% for group C. The birth rate per embryo transfer was 60% for group A, and 33% for group B and 36% for group C. The miscarriage rate was 4% in group A, 8% in group B, and 12% in group C. CONCLUSION(S) The transfer of previously vitrified blastocysts derived from CGH-normal embryos significantly improves implantation and birth rates per embryo transferred and reduces the miscarriage rate. Vitrification does not compromise this enhancement.

Vitrification of human embryos subjected to blastomere biopsy for pre-implantation genetic screening produces higher survival and pregnancy rates than slow freezing

PurposeCryopreservation of blastocysts, especially those subjected to the trauma due to blastomere biopsy for the purposes of pre-implantation genetic screening (PGS), requires significant optimization. Laboratory and clinical outcomes were compared to determine the effect of two different cryopreservation techniques on the development of human pre-implantation embryos that underwent blastomere biopsy and blastocoel drainage prior to cryopreservation.DesignRetrospective clinical study.Patient(s)Women who requested cryotransfer of supernumerary blastocysts were analyzed by FISH.ResultsThe main outcome measures were post-thaw survival (SR), pregnancy (PR), and implantation (IR). The SR of slowly frozen blastocysts was 83% compared to 97% for vitrified blastocysts. In 160 cases where biopsied embryos were cryotransferred, the results for slowly frozen versus vitrified blastocysts were: SR (71% vs. 95%), PR (23% vs. 37%), and IR (26% vs. 36%, P < 0.05), respectively.ConclusionThe results revealed that vitrified blastocysts provided higher SR, PR and IR as compared to slowly frozen counterparts.

Increased expression of hypothalamic leptin receptor and adiponectin accompany resistance to dietary- induced obesity and infertility in female C57BL/6J mice

Background:Obesity is strongly associated with female infertility, but the mechanisms underlying this relationship are largely unknown.Methods:We investigated the effect of increasing dietary fat percentage upon body mass, hypothalamic neuropeptide gene expression, adipose hormone secretion and fertility in females of the inbred mouse strains C57BL/6J and DBA/2J. To assess the effect of obesity independent of dietary influence, we also compared these parameters in wild-type female C57BL/6J mice to those congenic for the obesogenic mutations ob/ob and Ay/a.Results:After 24 weeks, rather than exhibiting an obese, leptin-resistant phenotype like their female DBA/2J counterparts, wild-type female C57BL/6J mice remained lean, fertile and manifested increased hypothalamic LEPR-B expression. Although both mutant genotypes were associated with obesity and subfertility, ob/ob mice demonstrated significantly increased hypothalamic LEPR-B expression, whereas Ay/a mice had a significant reduction. Interestingly, wild-type female C57BL/6J mice were noted to manifest significantly higher and lower levels of adiponectin and tissue plasminogen activator inhibitor-1 (tPAI-1), respectively, than weight-matched wild-type female DBA/2J mice.Conclusions:We conclude that (1) resistance to the obese-infertile phenotype in female C57BL/6J mice is associated with increased hypothalamic leptin receptor expression and alterations in adipokine levels consistent with decreased adipose tissue inflammation and (2) that long-standing hyperleptinemic obesity in mice is associated with a downregulation of the hypothalamic leptin receptor.

Reanalysis of human blastocysts with different molecular genetic screening platforms reveals significant discordance in ploidy status

ObjectiveThe objective of this study is to determine mosaicism and its effect on blastocysts; abnormal blastocysts determined by molecular testing were sequentially biopsied and retested.Material and methodWe re-biopsied 37 blastocyst-stage abnormal embryos from eight patients, which were reanalyzed to determine the level of concordance between biopsies and inter-laboratory congruence between reputable commercial PGS laboratories.ResultsThe main outcome measures were intra-embryo variation between sequential embryo biopsies and inter-laboratory variation between two PGS laboratories. The compatibility between both aCGH and NGS was found to be 11 % (3/27). Importantly, 9/27 (33 %) of embryos originally reported to be aneuploid, upon repeat assessment, were found to be euploid. The concurrence for SNP array and NGS was 50 % (3/6), and 17 % (1/6) of these abnormal embryos tested normal upon re-evaluation with NGS. NGS resulted 41 % (11/27) normal results when 27 of CGH abnormal embryos were retested. Concordance between aCGH and NGS was 4 % (1/27) whereas in three instances, gender discrepancy was observed with NGS when aCGH abnormal embryos were reanalyzed.ConclusionsThe results of these studies reinforce the prevalence of inconsistencies during PGS evaluation of trophectoderm biopsies possibly due to variations in platform sensitivity and heightening concerns over the clinical tractability of such technology in human ARTs..