The characterization of the flavin-containing monooxygenase gene family of man

Flavin-containing monooxygenases (FMO) are a family of enzymes that metabolise a variety of foreign compounds such as pesticides, pharmaceuticals and toxicants. They are found in most tissues of all mammals. Five FMO isoforms (FMO1, 2, 3, 4 and 5) have been identified. Analysis of human genomic DNA by Southern blot hybridization with cDNAs encoding the different FMO isoforms gave simple patterns of hybridization suggesting that a single gene encodes each protein. Northern blot hybridization analyses and RNase protection assays showed that each FMO has a distinct tissue specific pattern of expression. This pattern differs between man and other species. The skin is a major portal of entry for a variety of chemicals and environmental pollutants. FMOs 1, 3 and 5 were found to be the major forms present in human skin. In situ hybridization demonstrated that FMOs 1, 3, 4 and 5 are expressed in the sebaceous gland and the epidermis. Western blotting analysis of FMOs in whole skin homogenates and microsomes was unsuccessful due to a high degree of cross-reactivity of the polyclonal antibodies used with other skin proteins. The methimazole assay was used to determine the presence of FMO activity in skin. The expression of FMOs in an immortalised human keratinocyte (HaCaT) cell line was also studied. These cells could offer an alternative system for biotransformation studies; this is possible only if HaCaT cells express a similar range of FMOs as the skin or primary human keratinocyte cultures. Primary cultures of human keratinocytes expressed FMOs 1, 2, and 3 to varying degrees, whereas HaCaT cells, expressed only FMOs 1, 4 and 5. An analysis of cytochromes P450 in whole human skin, primary keratinocyte cultures and HaCaT cells was undertaken. Regional localisation of CYP2As, CYP2B6 and CYP3As in the skin was the same as for FMOs

Living with trimethylaminuria and body and breath malodour: personal perspectives

BACKGROUND: Many people suffer from body and breath malodour syndromes. One of these is trimethylaminuria, a condition characterized by excretion in breath and bodily fluids of trimethylamine, a volatile and odorous chemical that has the smell of rotting fish. Trimethylaminuria can be primary, due to mutations in the gene encoding flavin-containing monooxygenase 3, or secondary, due to various causes. To gain a better understanding of problems faced by United Kingdom residents affected by body and breath malodour conditions, we conducted a survey. METHODS: Two anonymous online surveys, one for adults and one for parents/guardians of affected children, were conducted using the Opinio platform. Participants were invited via a trimethylaminuria advisory website. Questions were a mix of dropdown, checkbox and open-ended responses. Forty-four adults and three parents/guardians participated. The dropdown and checkbox responses were analysed using the Opinio platform. RESULTS: All participants reported symptoms of body/breath odour. However, not all answered every question. Twenty-three respondents experienced difficulties in being offered a diagnostic test for trimethylaminuria. Problems encountered included lack of awareness of the disorder by medical professionals and reluctance to recognise symptoms. Of those tested, 52% were diagnosed with trimethylaminuria. The main problems associated with living with body/breath malodours were bullying, harassment and ostracism in either the workplace (90%) or in social settings (88%). All respondents thought their condition had disadvantaged them in their daily lives. Open-ended responses included loss of confidence, stress, exclusion, isolation, loneliness, depression and suicidal thoughts. Respondents thought their lives could be improved by greater awareness and understanding of malodour conditions by medical professionals, employers and the general public, and appreciation that the malodour was due to a medical condition and not their fault. CONCLUSIONS: Breath and body malodour conditions can cause immense hardship and distress, both mentally and socially, having devastating effects on quality of life. It would be advantageous to establish a standardised pathway from primary care to a specialist unit with access to a robust and reliable test and diagnostic criteria. There is a need to recognise malodour disorders as a disability, giving affected individuals the same rights as those with currently recognised disabilities

Functional convergence of signalling by GPI-anchored and anchorless forms of a salamander protein implicated in limb regeneration

The GPI-anchor is an established determinant of molecular localisation and various functional roles have been attributed to it. The newt GPI-anchored three-finger protein (TFP) Prod1 is an important regulator of cell behaviour during limb regeneration, but it is unclear how it signals to the interior of the cell. Prod1 was expressed by transfection in cultured newt limb cells and activated transcription and expression of matrix metalloproteinase 9 (MMP9) by a pathway involving ligand-independent activation of epidermal growth factor receptor (EGFR) signalling and phosphorylation of extracellular regulated kinase 1 and 2 (ERK1/2). This was dependent on the presence of the GPI-anchor and critical residues in the α-helical region of the protein. Interestingly, Prod1 in the axolotl, a salamander species that also regenerates its limbs, was shown to activate ERK1/2 signalling and MMP9 transcription despite being anchorless, and both newt and axolotl Prod1 co-immunoprecipitated with the newt EGFR after transfection. The substitution of the axolotl helical region activated a secreted, anchorless version of the newt molecule. The activity of the newt molecule cannot therefore depend on a unique property conferred by the anchor. Prod1 is a salamander-specific TFP and its interaction with the phylogenetically conserved EGFR has implications for our view of regeneration as an evolutionary variable

Challenges in cardiovascular pharmacogenomics implementation: a viewpoint from the European Society of Cardiology Working Group on Cardiovascular Pharmacotherapy

Abstract Pharmacogenomics promises to advance cardiovascular therapy, but there remain pragmatic barriers to implementation. These are particularly important to explore within Europe, as there are differences in the populations, availability of resources, and expertise, as well as in ethico-legal frameworks. Differences in healthcare delivery across Europe present a challenge, but also opportunities to collaborate on pharmacogenomics implementation. Clinical workforce upskilling is already in progress but will require substantial input. Digital infrastructure and clinical support tools are likely to prove crucial. It is important that widespread implementation serves to narrow rather than widen any existing gaps in health equality between populations. This viewpoint supplements the working group position paper on cardiovascular pharmacogenomics to address these important themes.</jats:p

The role of pharmacogenomics in contemporary cardiovascular therapy: a position statement from the European Society of Cardiology Working Group on Cardiovascular Pharmacotherapy

Abstract There is a strong and ever-growing body of evidence regarding the use of pharmacogenomics to inform cardiovascular pharmacology. However, there is no common position taken by international cardiovascular societies to unite diverse availability, interpretation, and application of such data, nor is there recognition of the challenges of variation in clinical practice between countries within Europe. Aside from the considerable barriers to implementing pharmacogenomic testing and the complexities of clinically actioning results, there are differences in the availability of resources and expertise internationally within Europe. Diverse legal and ethical approaches to genomic testing and clinical therapeutic application also require serious thought. As direct-to-consumer genomic testing becomes more common, it can be anticipated that data may be brought in by patients themselves, which will require critical assessment by the clinical cardiovascular prescriber. In a modern, pluralistic and multi-ethnic Europe, self-identified race/ethnicity may not be concordant with genetically detected ancestry and thus may not accurately convey polymorphism prevalence. Given the broad relevance of pharmacogenomics to areas, such as thrombosis and coagulation, interventional cardiology, heart failure, arrhythmias, clinical trials, and policy/regulatory activity within cardiovascular medicine, as well as to genomic and pharmacology subspecialists, this position statement attempts to address these issues at a wide-ranging level.</jats:p