Bachelor of Science, Stanford University, BIOL-BSH (2006)
Doctor of Philosophy, California Institute of Technology (2011)
Maxence Nachury, Postdoctoral Faculty Sponsor
Bardet-Biedl syndrome (BBS) is a recessive and genetically heterogeneous ciliopathy characterised by retinitis pigmentosa, obesity, kidney dysfunction, postaxial polydactyly, behavioural dysfunction and hypogonadism. 7 of the 17 BBS gene products identified to date assemble together with the protein BBIP1/BBIP10 into the BBSome, a protein complex that ferries signalling receptors to and from cilia.Exome sequencing performed on a sporadic BBS case revealed for the first time a homozygous stop mutation (NM_001195306: c.173T>G, p.Leu58*) in the BBIP1 gene. This mutation is pathogenic since no BBIP1 protein could be detected in fibroblasts from the patient, and BBIP1[Leu58*] is unable to associate with the BBSome subunit BBS4.These findings identify BBIP1 as the 18th BBS gene (BBS18) and suggest that BBSome assembly may represent a unifying pathomechanism for BBS.
View details for DOI 10.1136/jmedgenet-2013-101785
View details for Web of Science ID 000331191300009
View details for PubMedID 24026985
Autophagy and primary cilium assembly have long been known to be induced by the same conditions in cultured cells. Two recent studies in Nature-Tang et al. (2013) and Pampliega et al. (2013)-link the two processes, suggesting that a specialized autophagy pathway near the basal body regulates cilium assembly.
View details for DOI 10.1016/j.devcel.2013.10.013
View details for PubMedID 24176638
Neonatal jaundice results from an increased bilirubin production and decreased hepatic bilirubin conjugation and excretion. Severe hyperbilirubinemia is currently treated with phototherapy or exchange transfusion; however, its prevention by inhibiting bilirubin formation is a more logical strategy. Heme oxygenase (HO), with inducible (HO-1) and constitutive (HO-2) isoenzymes, is the rate-limiting enzyme in heme catabolism, producing equimolar amounts of bilirubin and carbon monoxide (CO). Metalloporphyrins (Mps) are heme derivatives that competitively inhibit HO and thereby suppress hyperbilirubinemia. No systematic studies have been reported evaluating whether the HO isoenzymes are inhibited differentially by various Mps. Identification of Mps that selectively inhibit the inducible HO-1 without affecting the 'housekeeping' HO-2 isoenzyme might be desirable in the clinical setting of hemolytic disease, in which the Hmox1 gene is greatly induced. Although bilirubin production is due to the activity of both HO-1 and HO-2, the inhibition of HO-1 with a relative sparing of HO-2 activity might provide the most selective approach for the treatment of hemolytic disease.We determined for the deutero-, proto-, meso- and bis-glycol porphyrins with zinc, tin and chromium as central atoms, respectively, the concentration needed for 50% inhibition (I(50)) of HO-1 and HO-2 activities in rat spleen and brain tissue.For a given Mp, HO-1 activity was less inhibited than that of HO-2. The order of inhibitor potency of each Mp was nearly identical for both isoenzymes. Tin mesoporphyrin was the most potent inhibitor for both isoenzymes. HO-2 selectivity was greatest for tin protoporphyrin. Conversely, the Zn compounds were least inhibitory toward HO-2. No Mp preferentially inhibited HO-1.Mps that produce a less inhibitory effect on HO-2, while limiting the response of the inducible HO-1, such as ZnPP, may be a useful clinical tool.
View details for DOI 10.1038/jp.2010.173
View details for Web of Science ID 000289236900006
View details for PubMedID 21448202