61 research outputs found
Beneficial effects of naringenin and indomethacin on white and brown adipocytes
As obesity continues to grow and medical costs in the United States are estimated at $147 billion annually, novel ways to prevent and treat obesity are needed. One approach is to promote thermogenesis to improve energy balance by increasing the activities of thermogenic brown and beige adipocytes.
Naringenin, a citrus flavanone, has been shown to act as anti-inflammatory and lipid lowering agent as well as activate PPARgamma. However, it is unclear whether it can activate thermogenic activity in white adipocytes, i.e., promote formation of beige adipocytes. Indomethacin (INDO) is an FDA approved drug used to treat pain related to inflammation by inhibiting cyclooxygenase (COX). It has been demonstrated that INDO is a PPARgamma agonist and is protective against weight gain in mice fed a high fat and high sucrose diet. Whether INDO independently induces brown adipocyte differentiation has not been studied.
In this thesis, I investigated the effect of naringenin combined with isoproterenol, a beta- adrenergic receptor agonist on thermogenic activation of a common white adipocyte cell line, 3T3-L1. In addition, I investigated whether INDO induces brown adipocyte differentiation. 3T3- L1 cells were differentiated into mature adipocytes with a standard differentiation cocktail in the presence of naringenin and then stimulated with isoproterenol. While naringenin had little effect at the basal level, it significantly increased mRNA and protein expression of UCP-1 and PGC- 1alpha, browning marker genes. Moreover, naringenin increased mitochondrial DNA, which is indicative of increased mitochondrial biogenesis. The results suggest that in addition to increased UCP-1 expression, naringenin can promote up regulation of PGC-1alpha, leading to increased mitochondrial biogenesis in thermogenic activation of 3T3-L1.
To study the effects of INDO on brown adipocyte differentiation I differentiated brown preadipocytes in the presence of increasing doses of INDO using a modified differentiation protocol. INDO dose-dependently increased lipid accumulation and mRNA expression of brown specific marker genes PGC-1alpha, UCP-1 and PRDM16. Protein expression of PGC-1alpha and UCP-1 was confirmed by western analysis. Consistently, INDO dose-dependently increased mitochondrial biogenesis. Mechanistically, INDO increased PPAR responsive promoter activities. These results suggest that INDO may promote brown adipogenesis through activation of PPARgamma
Fairness Incentives for Myopic Agents
We consider settings in which we wish to incentivize myopic agents (such as
Airbnb landlords, who may emphasize short-term profits and property safety) to
treat arriving clients fairly, in order to prevent overall discrimination
against individuals or groups. We model such settings in both classical and
contextual bandit models in which the myopic agents maximize rewards according
to current empirical averages, but are also amenable to exogenous payments that
may cause them to alter their choices. Our notion of fairness asks that more
qualified individuals are never (probabilistically) preferred over less
qualified ones [Joseph et al].
We investigate whether it is possible to design inexpensive {subsidy} or
payment schemes for a principal to motivate myopic agents to play fairly in all
or almost all rounds. When the principal has full information about the state
of the myopic agents, we show it is possible to induce fair play on every round
with a subsidy scheme of total cost (for the classic setting with
arms, , and for the -dimensional linear contextual
setting ). If the principal has much more limited
information (as might often be the case for an external regulator or watchdog),
and only observes the number of rounds in which members from each of the
groups were selected, but not the empirical estimates maintained by the myopic
agent, the design of such a scheme becomes more complex. We show both positive
and negative results in the classic and linear bandit settings by upper and
lower bounding the cost of fair subsidy schemes
Compound heterozygote myocilin mutations in a pedigree with high prevalence of primary open-angle glaucoma
This article is an open access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License 3.0, which permits use, distribution, and reproduction in any medium, provided the original work is properly cited, the use is non commercial and is otherwise in compliance with the license.Purpose: To describe the phenotype of ocular hypertension and primary open-angle glaucoma in a family with individuals compound heterozygote for Gln368STOP and Thr377Met myocilin (MYOC) mutations.
Methods: Family members of the proband underwent comprehensive ocular clinical examination and DNA sequencing for MYOC mutations.
Results: A 34-year-old woman with marked ocular hypertension was found to carry Gln368STOP and Thr377Met MYOC mutations. Three other siblings carried both mutations, while one carried Gln368STOP alone. Three of five siblings had received treatment for ocular hypertension or early glaucoma, with the average age of diagnosis 28 years; one required trabeculectomy at age 27. The mother of the proband was found to be a carrier for Gln368STOP alone, which indicates that her offspring with both Gln368STOP and Thr377Met carry variants on opposing alleles.
Conclusions: This pedigree is the first report with individuals compound heterozygote for the two most common glaucoma-causing MYOC variants. The combination of mutations manifests a more severe phenotype than either alone. Identification of gene changes associated with glaucoma within the family has enabled unaffected members to stratify their risk of future disease and institute closer monitoring and early treatment.CERA receives Operational Infrastructure Support from the Victorian Government. The Australian and New Zealand Registry of Advanced Glaucoma is funded by the RANZCO Eye Foundation. KPB and JEC are funded by a Career Development Award and Practitioner Fellowship from the National Health and Medical Research Council of Australia, respectively
CYP1B1 copy number variation is not a major contributor to primary congenital glaucoma
This article is published under a Creative Commons Attribution-NonCommercial-NoDerivatives License 3.0, or CC BY-NC-ND 3.0 (see http://creativecommons.org/licenses/by-nc-nd/3.0/ for license terms). The authors retain copyright and grant Molecular Vision an irrevocable, royalty-free, perpetual license to publish and distribute the article, in all formats now known or later developed, and to identify Molecular Vision as the original publisher.Purpose: To evaluate the prevalence and the diagnostic utility of testing for CYP1B1 copy number variation (CNV) in primary congenital glaucoma (PCG) cases unexplained by CYP1B1 point mutations in The Australian and New Zealand Registry of Advanced Glaucoma.
Methods: In total, 50 PCG cases either heterozygous for disease-causing variants or with no CYP1B1 sequence variants were included in the study. CYP1B1 CNV was analyzed by Multiplex Ligation-dependent Probe Amplification (MLPA).
Results: No deletions or duplications were found in any of the cases.
Conclusion: This is the first study to report on CYP1B1 CNV in PCG cases. Our findings show that this mechanism is not a major contributor to the phenotype and is of limited diagnostic utility
Biallelic CPAMD8 Variants Are a Frequent Cause of Childhood and Juvenile Open-Angle Glaucoma
© 2020 by the American Academy of Ophthalmology. This is an open access article under the CC BY-NC-ND licensePurpose
Developmental abnormalities of the ocular anterior segment in some cases can lead to ocular hypertension and glaucoma. CPAMD8 is a gene of unknown function recently associated with ocular anterior segment dysgenesis, myopia, and ectopia lentis. We sought to assess the contribution of biallelic CPAMD8 variants to childhood and juvenile open-angle glaucoma.
Design
Retrospective, multicenter case series.
Participants
A total of 268 probands and their relatives with a diagnosis of childhood or juvenile open-angle glaucoma.
Purpose
Developmental abnormalities of the ocular anterior segment in some cases can lead to ocular hypertension and glaucoma. CPAMD8 is a gene of unknown function recently associated with ocular anterior segment dysgenesis, myopia, and ectopia lentis. We sought to assess the contribution of biallelic CPAMD8 variants to childhood and juvenile open-angle glaucoma.
Methods
Patients underwent a comprehensive ophthalmic assessment, with DNA from patients and their relatives subjected to genome, exome, or capillary sequencing. CPAMD8 RNA expression analysis was performed on tissues dissected from cadaveric human eyes.
Main Outcome Measures
Diagnostic yield within a cohort of childhood and juvenile open-angle glaucoma, prevalence and risk of ophthalmic phenotypes, and relative expression of CPAMD8 in the human eye.
Results
We identified rare (allele frequency < 4×10−5) biallelic CPAMD8 variants in 5.7% (5/88) of probands with childhood glaucoma and 2.1% (2/96) of probands with juvenile open-angle glaucoma. When including family members, we identified 11 individuals with biallelic variants in CPAMD8 from 7 unrelated families. Nine of these individuals were diagnosed with glaucoma (9/11, 81.8%), with a mean age at diagnosis of 9.22±14.89 years, and all individuals with glaucoma required 1 or more incisional procedures to control high intraocular pressure. Iris abnormalities were observed in 9 of 11 individuals, cataract was observed in 8 of 11 individuals (72.7%), and retinal detachment was observed in 3 of 11 individuals (27.3%). CPAMD8 expression was highest in neural crest–derived tissues of the adult anterior segment, suggesting that CPAMD8 variation may cause malformation or obstruction of key drainage structures.
Conclusions
Biallelic CPAMD8 variation was associated with a highly heterogeneous phenotype and in our cohorts was the second most common inherited cause of childhood glaucoma after CYP1B1 and juvenile open-angle glaucoma after MYOC. CPAMD8 sequencing should be considered in the investigation of both childhood and juvenile open-angle glaucoma, particularly when associated with iris abnormalities, cataract, or retinal detachment
Author Correction: Cross-ancestry genome-wide association analysis of corneal thickness strengthens link between complex and Mendelian eye diseases.
Emmanuelle Souzeau, who contributed to analysis of data, was inadvertently omitted from the author list in the originally published version of this Article. This has now been corrected in both the PDF and HTML versions of the Article
Prevalence of FOXC1 Variants in Individuals With a Suspected Diagnosis of Primary Congenital Glaucoma
© 2019 American Medical Association. Reproduced in accordance with the publisher's Public Access policy.
This author accepted manuscript is made available following 12 month embargo from date of publication (January 2019) in accordance with the publisher’s archiving policyImportance Both primary and secondary forms of childhood glaucoma have many distinct causative mechanisms, and in many cases a cause is not immediately clear. The broad phenotypic spectrum of secondary glaucoma, particularly in individuals with variants in FOXC1 or PITX2 genes associated with Axenfeld-Rieger syndrome, makes it more difficult to diagnose patients with milder phenotypes. These cases are occasionally classified and managed as primary congenital glaucoma.
Objective To investigate the prevalence of FOXC1 variants in participants with a suspected diagnosis of primary congenital glaucoma.
Design, Setting, and Participants Australian and Italian cohorts were recruited from January 1, 2007, through March 1, 2016. Australian individuals were recruited through the Australian and New Zealand Registry of Advanced Glaucoma and Italian individuals through the Genetic and Ophthalmology Unit of l’Azienda Socio–Sanitaria Territoriale Grande Ospedale Metropolitano Niguarda in Milan, Italy. We performed exome sequencing, in combination with Sanger sequencing and multiplex ligation-dependent probe amplification, to detect variants of FOXC1 in individuals with a suspected diagnosis of primary congenital glaucoma established by their treating specialist. Data analysis was completed from June 2015 to November 2017.
Main Outcome and Measures Identification of single-nucleotide and copy number variants in FOXC1, along with phenotypic characterization of the individuals who carried them.
Results A total of 131 individuals with a suspected diagnosis of primary congenital glaucoma were included. The mean (SD) age at recruitment in the Australian cohort was 24.3 (18.1) years; 37 of 84 Australian participants (44.0%) were female, and 71 of 84 (84.5%) were of European ancestry. The mean (SD) age at recruitment was 22.5 (18.4) years in the Italian cohort; 21 of 47 Italian participants (44.7%) were female, and 45 of 47 (95.7%) were of European ancestry. We observed rare, predicted deleterious FOXC1 variants in 8 of 131 participants (6.1%), or 8 of 166 participants (4.8%) when including those explained by variants in CYP1B1. On reexamination or reinvestigation, all of these individuals had at least 1 detectable ocular and/or systemic feature associated with Axenfeld-Rieger syndrome.
Conclusions and Relevance These data highlight the genetic and phenotypic heterogeneity of childhood glaucoma and support the use of gene panels incorporating FOXC1 as a diagnostic aid, especially because clinical features of Axenfeld-Rieger syndrome can be subtle. Further replication of these results will be needed to support the future use of such panels
Cross-ancestry genome-wide association analysis of corneal thickness strengthens link between complex and Mendelian eye diseases
Central corneal thickness (CCT) is a highly heritable trait associated with complex eye diseases such as keratoconus and glaucoma. We perform a genome-wide association meta-analysis of CCT and identify 19 novel regions. In addition to adding support for known connective tissue-related pathways, pathway analyses uncover previously unreported gene sets. Remarkably, >20% of the CCT-loci are near or within Mendelian disorder genes. These included FBN1, ADAMTS2 and TGFB2 which associate with connective tissue disorders (Marfan, Ehlers-Danlos and Loeys-Dietz syndromes), and the LUM-DCN-KERA gene complex involved in myopia, corneal dystrophies and cornea plana. Using index CCT-increasing variants, we find a significant inverse correlation in effect sizes between CCT and keratoconus (r =-0.62, P = 5.30 × 10-5) but not between CCT and primary open-angle glaucoma (r =-0.17, P = 0.2). Our findings provide evidence for shared genetic influences between CCT and keratoconus, and implicate candidate genes acting in collagen and extracellular matrix regulation
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