Project description:The non-coding genome, consisting of more than 98% of all genetic information in humans and once judged as 'Junk DNA', is increasingly moving into the spotlight in the field of human genetics. Non-coding regulatory elements (NCREs) are crucial to ensure correct spatio-temporal gene expression. Technological advancements have allowed to identify NCREs on a large scale, and mechanistic studies have helped to understand the biological mechanisms underlying their function. It is increasingly becoming clear that genetic alterations of NCREs can cause genetic disorders, including brain diseases. In this review, we concisely discuss mechanisms of gene regulation and how to investigate them, and give examples of non-coding alterations of NCREs that give rise to human brain disorders. The cross-talk between basic and clinical studies enhances the understanding of normal and pathological function of NCREs, allowing better interpretation of already existing and novel data. Improved functional annotation of NCREs will not only benefit diagnostics for patients, but might also lead to novel areas of investigations for targeted therapies, applicable to a wide panel of genetic disorders. The intrinsic complexity and precision of the gene regulation process can be turned to the advantage of highly specific treatments. We further discuss this exciting new field of 'enhancer therapy' based on recent examples.
Project description:The term skin fragility disorders describes a group of conditions in which the structural integrity of the skin is compromised and its resistance to external shear forces diminished. Skin fragility can have different causes, ranging from genetic variations to inflammatory or physical phenomena. The genetic skin fragility disorders, collectively called epidermolysis bullosa, serve as a paradigm for the study of causes and mechanisms of skin fragility. Recent biomedical research has revealed substantial genetic heterogeneity of the epidermolysis bullosa group, delivered ample new knowledge on its pathophysiology, and facilitated the design of evidence-based therapeutic strategies. The therapy development process extends from in vitro testing to preclinical validation in animal models, and clinical trials. This article reviews different approaches to curative and symptom-relief therapies, and appraises their status and perspectives for clinical implementation.
Project description:Genodermatoses are inherited disorders with skin manifestations and can present with multisystem involvement, resulting in challenges in diagnosis and treatment. To address this, the expertise of dermatology and clinical genetics through a multidisciplinary clinic (Genodermatoses Clinic) were combined. A retrospective cohort study of 45 children seen between March 2018 and February 2019 in the Genodermatoses Clinic at The Children's Hospital of Philadelphia was performed. Patient demographics, referral information, genetic testing modality, diagnoses, and patient satisfaction scores were evaluated to assess the clinic's impact. The majority of patients (42.2%) were referred from Dermatology and 86.7% were referred for diagnosis. Two-thirds of the patients were recommended genetic testing, and subsequently 73.3% completed testing. Nearly three-quarters, 26 out of 36 patients (72.2%), of our undiagnosed patients received a clinical and/or molecular diagnosis, which is imperative in managing their care. Twenty-two individuals pursued genetic testing. In eight individuals (36%), molecular testing was diagnostic. However, in two individuals the molecular diagnosis did not completely explain the phenotype. However, there are still obstacles to genetic testing, such as cost of testing and insurance barriers. Almost all (91.4%) rated the Genodermatoses Clinic as "Very Good," the top Press Ganey score. High patient satisfaction scores suggest a positive impact of the Genodermatoses clinic, emphasizing the importance to increase support for the clinical and administrative time needed for patients with genodermatoses.
Project description:Skin fragility refers to a large group of conditions in which the ability of the skin to provide protection against trivial mechanical trauma is diminished, resulting in the formation of blisters, erosions, wounds, or scars. Acquired and physiological skin fragility is common; genetic disorders are rare but give insight into the molecular mechanisms ensuring skin stability. The paradigm is represented by inherited epidermolysis bullosa. This review is focused on recent advances in understanding the molecular basis of genetic skin fragility, including emerging concepts, controversies, unanswered questions, and opinions of the author. In spite of the advanced knowledge on the genetic causes of skin fragility, the molecular pathology is still expanding. Open questions in understanding the molecular basis of genetic skin fragility are the following: what are the causes of phenotypes which remain genetically unsolved, and what are the molecular modifiers which might explain phenotypic differences among individuals with similar mutations? New mutational mechanisms and new genes have recently been discovered and are briefly described here. Comprehensive next-generation sequencing-based genetic testing improved mutation detection and facilitated the identification of the genetic basis of unclear and new phenotypes. Characterization of the biochemical and cell biological consequences of the genetic variants is challenging and laborious but may represent the basis for personalized therapeutic approaches. Molecular modifiers of skin fragility have been uncovered in particular animal and genetic models but not in larger cohorts of patients. This scientific progress is the basis for revisions of the epidermolysis bullosa classification and for innovative therapeutic approaches designed for this intractable condition.
Project description:The field of science and medicine has experienced a flood of data and technology associated with the human genome project. Over 10,000 human diseases have been genetically defined, but little progress has been made with respect to the clinical application of this knowledge. A notable exception to this exists for pachyonychia congenita (PC), a rare, dominant-negative keratin disorder. The establishment of a non-profit organization, PC Project, has led to an unprecedented coalescence of patients, scientists, and physicians with a unified vision of developing novel therapeutics for PC. Utilizing the technological by-products of the human genome project, such as RNA interference (RNAi) and quantitative RT-PCR (qRT-PCR), physicians and scientists have collaborated to create a candidate siRNA therapeutic that selectively inhibits a mutant allele of KRT6A, the most commonly affected PC keratin. In vitro investigation of this siRNA demonstrates potent inhibition of the mutant allele and reversal of the cellular aggregation phenotype. In parallel, an allele-specific quantitative real-time RT-PCR assay has been developed and validated on patient callus samples in preparation for clinical trials. If clinical efficacy is ultimately demonstrated, this "first-in-skin" siRNA may herald a paradigm shift in the treatment of dominant-negative genetic disorders.
Project description:In men, the level of testosterone decreases with age. At the skin level, the result is observed as a decrease in density and in a lower elasticity. Identifying compounds that are able to increase the level of testosterone appears to be an attractive strategy to develop new antiaging bioactive ingredients for men. Reverse pharmacognosy was successfully applied to identify new natural compounds able to modulate testosterone levels. Among several in silico hits, honokiol was retained as a candidate as it has the greatest potential to become an active ingredient. This result was then validated in vitro on aromatase and 5-alpha-reductase type 1 and 2, which are two types of enzymes implicated in the degradation of free testosterone. Indeed, honokiol was identified as an inhibitor of aromatase, with a half-maximal inhibitory concentration (IC(50)) of about 50 μM. In addition, honokiol was shown to be an inhibitor of 5-alpha-reductase type 1, with an IC(50) of about 75 μM. Taken together, these data indicate that honokiol modulates testosterone levels, and its structure has the potential to serve as a lead for future designs of highly selective inhibitors of 5-alpha-reductase type 1.
Project description:ObjectivesThere is evidence from observational studies that human microbiota is linked to skin appendage Disorders (SADs). Nevertheless, the causal association between microbiota and SADs is yet to be fully clarified.MethodsA comprehensive two-sample Mendelian randomization (MR) was first performed to determine the causal effect of skin and gut microbiota on SADs. A total of 294 skin taxa and 211 gut taxa based on phylum, class, order, family, genus, and ASV level information were identified. Summary data of SADs and eight subtypes (acne vulgaris, hidradenitis suppurativa, alopecia areata, rogenic alopecia, rosacea, rhinophyma, seborrhoeic dermatitis, and pilonidal cyst) were obtained from the FinnGen consortium. We performed bidirectional MR to determine whether the skin and gut microbiota are causally associated with multiple SADs. Furthermore, sensitivity analysis was conducted to examine horizontal pleiotropy and heterogeneity.ResultsA total of 65 and 161 causal relationships between genetic liability in the skin and gut microbiota with SADs were identified, respectively. Among these, we separately found 5 and 11 strong causal associations that passed Bonferroni correction in the skin and gut microbiota with SADs. Several skin bacteria, such as Staphylococcus, Streptococcus, and Propionibacterium, were considered associated with multiple SADs. As gut probiotics, Bifidobacteria and Lactobacilli were associated with a protective effect on SAD risk. There was no significant heterogeneity in instrumental variables or horizontal pleiotropy.ConclusionsOur MR analysis unveiled bidirectional causal relationships between SADs and the gut and skin microbiota, and had the potential to offer novel perspectives on the mechanistic of microbiota-facilitated dermatosis.
Project description:The conserved nature of the ATP-binding site of the > 500 human kinases renders the development of specific inhibitors a challenging task. A widely used chemical genetic strategy to overcome the specificity challenge exploits a large-to-small mutation of the gatekeeper residue (a conserved hydrophobic amino acid) and the use of a bulky inhibitor to achieve specificity via shape complementarity. However, in a number of cases, introduction of a glycine or alanine gatekeeper results in diminished kinase activity and ATP affinity. A new chemical genetic approach based on covalent complementarity between an engineered gatekeeper cysteine and an electrophilic inhibitor was developed to address these challenges. This strategy was evaluated with Src, a proto-oncogenic tyrosine kinase known to lose some enzymatic activity using the shape complementarity chemical genetic strategy. We found that Src with a cysteine gatekeeper recapitulates wild type activity and can be irreversibly inhibited both in vitro and in cells. A cocrystal structure of T338C c-Src with a vinylsulfonamide-derivatized pyrazolopyrimidine inhibitor was solved to elucidate the inhibitor binding mode. A panel of electrophilic inhibitors was analyzed against 307 kinases and MOK (MAPK/MAK/MRK overlapping kinase), one of only two human kinases known to have an endogenous cysteine gatekeeper. This analysis revealed remarkably few off-targets, making these compounds the most selective chemical genetic inhibitors reported to date. Protein engineering studies demonstrated that it is possible to increase inhibitor potency through secondary-site mutations. These results suggest that chemical genetic strategies based on covalent complementarity should be widely applicable to the study of protein kinases.