The influence of CYP3A,PPARA, and POR genetic variants on the pharmacokinetics of tacrolimus and cyclosporine in renal transplant recipients

Purpose

Tacrolimus (Tac) and cyclosporine (CsA) are mainly metabolized by CYP3A4 and CYP3A5. Several studies have demonstrated an association between the CYP3A5 genotype and Tac dose requirements. Recently, CYP3A4, PPARA, and POR gene variants have been shown to influence CYP3A metabolism. The present study investigated potential associations between CYP3A5*3, CYP3A4*22, PPARA c.209-1003G>A and c.208?+?3819A>G, and POR*28 alleles and dose-adjusted concentrations (C/D) of Tac and CsA in 177 renal transplant patients early post-transplant.

Methods

All patients (n?=?177) were genotyped for CYP3A4*22, CYP3A5*3, POR*28, PPARA c.209-1003G>A, and PPARA c.208?+?3819A>G using real-time polymerase chain reaction (PCR) and melting curve analysis with allele-specific hybridization probes or PCR restriction fragment length polymorphisms (RFLP) methods. Drug concentrations and administered doses were retrospectively collected from patient charts at Oslo University Hospital, Rikshospitalet, Norway. One steady-state concentration was collected for each patient.

Results

We confirmed a significant impact of the CYP3A5*3 allele on Tac exposure. Patients with POR*28 and PPARA variant alleles demonstrated 15 % lower (P?=?0.04) and 19 % higher (P?=?0.01) Tac C₀/D respectively. CsA C₂/D was 53 % higher among CYP3A4*22 carriers (P?=?0.03).

Conclusion

The results support the use of pre-transplant CYP3A5 genotyping to improve initial dosing of Tac, and suggest that Tac dosing may be further individualized by additional POR and PPARA genotyping. Furthermore, initial CsA dosing may be improved by pre-transplant CYP3A4*22 determination.     

Influence of dietary (n-3)-polyunsaturated fatty acids on leukotriene B4 and prostaglandin E2 synthesis and course of experimental tuberculosis in guinea pigs

Summary In the present study eicosanoid synthesis was studied in macrophages of guinea pigs fed different amounts of (n-6)- and (n-3)-polyunsaturated fatty acids (PUFA). Three groups of weanling guinea pigs were fed by isocaloric diets differing only in their contents of PUFA: controls with 2.8 Cal% of linoleic acid (LA; 18:2(n-6)); (n-6)-rich fed animals with 15.4 Cal% of LA; and (n-3)-rich fed animals with 10.1 Cal% of LA, 1.4 Cal% of eicosapentaenoic acid (20:5(n-3)) and docosahexaenoic acid (22:6(n-3)). After 13 weeks half the number of animals from each group was infected i.m. by 180 colony forming units ofMycobacterium tuberculosis strain H37Rv. Seven weeks after infection the release of leukotriene (LT)B₄ and prostaglandin (PG)E₂ was quantified in calcium ionophore stimulated whole blood, peritoneal macrophage cultures and alveolar macrophages by immunoassays after high performance liquid chromatography. Synthesis of LTB₄ and PGE₂ was found to be reduced in (n-3)-rich fed guinea pigs (p<0.05), and equivalent between controls and (n-6)-rich fed animals. Controls and (n-6)-rich fed animals showed the same mycobacterial counts in the spleen whereas (n-3)-rich fed guinea pigs demonstrated an increased number of mycobacteria (p<0.05). Our results demonstrate that an increased dietary intake of (n-3)-PUFA suppress LTB₄ and PGE₂ synthesis. The increased number ofM. tuberculosis found in the spleens of (n-3)-rich fed animals could represent persistence of the experimental infection. It may be speculated that a functional relationship exists between the two findings.

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Einfluß einer Diät mit (n-3)-mehrfach ungesättigten Fettsäuren auf die Leukotrien B₄- und Prostaglandin E₂-Synthese und den Verlauf der experimentellen Tuberkulose bei Meerschweinchen

Zusammenfassung In der vorliegenden Studie wurde die Eikosanoidsynthese in Makrophagen von Meerschweinchen untersucht, die mit unterschiedlichen Gehalten (n-6)- und (n-3)-mehrfach ungesättigten Fettsäuren (PUFA) gefüttert wurden. Drei Gruppen entwöhnter Meerschweinchen wurden mit isokalorischen Diäten gefüttert, die sich nur in ihrem Gehalt an PUFA unterschieden: Kontrollen mit 2,8 Cal% Linolsäure (LA. (18:2(n-6)); Tiere mit (n-6)-angereichertem Futter mit 15,4 Cal% LA und Tiere mit (n-3)-angereichertem Futter mit 10,1 Cal% LA, 1,4 Cal% Eikosapentaensäure (20:5(n-3)) und 0,9 Cal% Dokosahexaensäure (22:6(n-3)). Nach 13 Wochen wurde die Hälfte der Tiere aus jeder Gruppe mit 180 Kolonie-bildenden Einheiten des StammesMycobacterium tuberculosis H37Rv i.m. infiziert. Sieben Wochen nach Infektion wurde die Freisetzung von LTB₄ und PGE₂ in Kalzium-Ionophor stimuliertem Vollblut, Peritonealmakrophagen und Alveolarmakrophagen mittels Immunoassays nach Hochdruckflüssigkeitschromatographie quantifiziert. Die Synthese von LTB₄ und PGE₂ war reduziert bei den (n-3)-reich gefütterten Meerschweinchen (p<0,05) und äquivalent bei den Kontrollen und (n-6)-reich gefütterten Tieren. Kontrolltiere und (n-6)-reich gefütterte Meerschweinchen wiesen die gleiche Zahl von Mykobakterien in der Milz auf, während sich bei den (n-3)-gefütterten Tieren eine erhöhte Zahl von Mykobakterien zeigte (p<0,05). Unsere Ergebnisse zeigen, daß eine höhere diätetische Zufuhr von (n-3)-PUFA die Synthese von LTB₄ und PGE₂ unterdrückt. Die erhöhte Zahl vonM. tuberculosis in den Milzen von (n-3)-gefütterten Tieren spricht für eine Persistenz der experimentellen Tuberkulose unter diesen Bedingungen. Möglicherweise existiert zwischen beiden Befunden ein funktioneller Zusammenhang.

     

肝炎病毒利用DC-SIGN逃逸机体免疫作用

DC-SIGN是DC表面识别多种病原微生物的受体.一方面,DC借助DC-SIGN对固有免疫及适应性免疫发挥免疫调节作用;另一方面,DC-SIGN又成为某些病原微生物如肝炎病毒借以逃逸机体免疫防御功能的靶分子.我们就DC-SIGN的结构及功能、与病毒的相互作用等方面进行阐述.     

An interstitial deletion of 7.1 Mb in chromosome band 6p22.3 associated with developmental delay and dysmorphic features including heart defects, short neck, and eye abnormalities

Seven cases with an interstitial deletion of the short arm of chromosome 6 involving the 6p22 region have previously been reported. The clinical phenotype of these cases includes developmental delay, brain-, heart-, and kidney defects, eye abnormalities, short neck, craniofacial malformations, hypotonia, as well as clinodactyly or syndactyly. Here, we report a patient with a 7.1 Mb interstitial deletion of chromosome band 6p22.3, detected by genome-wide screening array CGH. The patient is a 4-year-old girl with developmental delay and dysmorphic features including eye abnormalities, short neck, and a ventricular septum defect. The deleted region at 6p22.3 in our patient overlaps with six out of the seven previously reported cases with a 6p22–24 interstitial deletion. This enabled us to further narrow down the critical region for the 6p22 deletion phenotype to 2.2 Mb. Twelve genes are mapped to the overlapping deleted region, among them the gene encoding the ataxin-1 protein, the ATXN1 gene. Mice with homozygous deletions in ATXN1 are phenotypically normal but show cognitive delay. Haploinsufficiency of ATXN1 may therefore contribute to the learning difficulties observed in the patients harboring a 6p22 deletion.     

Fluorescence imaging with near-infrared light: new technological advances that enable in vivo molecular imaging

A recent development in biomedical imaging is the non-invasive mapping of molecular events in intact tissues using fluorescence. Underpinning to this development is the discovery of bio-compatible, specific fluorescent probes and proteins and the development of highly sensitive imaging technologies for in vivo fluorescent detection. Of particular interest are fluorochromes that emit in the near infrared (NIR), a spectral window, whereas hemoglobin and water absorb minimally so as to allow photons to penetrate for several centimetres in tissue. In this review article we concentrate on optical imaging technologies used for non-invasive imaging of the distribution of such probes. We illuminate the advantages and limitations of simple photographic methods and turn our attention to fluorescence-mediated molecular tomography (FMT), a technique that can three-dimensionally image gene expression by resolving fluorescence activation in deep tissues. We describe theoretical specifics, and we provide insight into its in vivo capacity and the sensitivity achieved. Finally, we discuss its clinical feasibility. Electronic Publication