-
Photodiagnosis and Photodynamic Therapy Mar 2023Patients with erythropoietic protoporphyria (EPP) are hypersensitive to long wave ultraviolet (UVA) radiation and visible light and they experience severe skin pain by... (Randomized Controlled Trial)
Randomized Controlled Trial
BACKGROUND
Patients with erythropoietic protoporphyria (EPP) are hypersensitive to long wave ultraviolet (UVA) radiation and visible light and they experience severe skin pain by light exposure. The patients have very limited treatment options. Sunless skin tanning with dihydroxyacetone (DHA) is now being investigated as a possible treatment modality of skin photosensitivity in EPP.
METHODS
We simulated the theoretical light protection factor provided by DHA application. In addition, we present 19 cases with EPP who were treated at our department with DHA weekly during spring and summer from 2018 to 2021 inclusive.
RESULTS
The protection factor against UVA and visible light was estimated to approximately two. Out of the 19 patients with EPP who were treated with DHA in 2018, 11 patients experienced a sustained good effect and continued to use the treatment on a weekly basis in the spring and summer of 2019, 2020, and 2021.
CONCLUSION AND PERSPECTIVES
Both the theoretical estimates and the uncontrolled study suggest that sunless tanning with DHA reduces photosensitivity in patients with EPP. Our hypothesis is that skin treated with DHA can tolerate twice the daylight dose compared to untreated skin before onset of skin symptoms. To validate this conclusion, we plan a randomized clinical trial to determine the effect of DHA application to reduce photosensitivity in patients with EPP under controlled clinical conditions. The study protocol for this trial is presented in the paper.
Topics: Humans; Protoporphyria, Erythropoietic; Dihydroxyacetone; Photochemotherapy; Photosensitizing Agents; Light; Photosensitivity Disorders
PubMed: 36690194
DOI: 10.1016/j.pdpdt.2023.103302 -
Frontiers in Physiology 2022The heme biosynthesis (HB) involves eight subsequent enzymatic steps. Erythropoietic protoporphyria (EPP) is caused by loss-of-function mutations in the ferrochelatase...
The heme biosynthesis (HB) involves eight subsequent enzymatic steps. Erythropoietic protoporphyria (EPP) is caused by loss-of-function mutations in the ferrochelatase (FECH) gene, which in the last HB step inserts ferrous iron into protoporphyrin IX (PPIX) to form heme. The aim of this work was to for the first time analyze the mRNA expression of all HB genes in peripheral blood samples of patients with EPP having the same genotype FECH c.[215dupT]; [315-48T > C] as compared to healthy controls by highly sensitive and specific digital PCR assays (dPCR). We confirmed a decreased FECH mRNA expression in patients with EPP. Further, we found increased ALAS2 and decreased ALAS1, CPOX, PPOX and HMBS mRNA expression in patients with EPP compared to healthy controls. ALAS2 correlated with FECH mRNA expression (EPP: = 0.63, = 0.03 and controls: = 0.68, = 0.02) and blood parameters like PPIX (EPP: = 0.58 = 0.06). Our method is the first that accurately quantifies HB mRNA from blood samples with potential applications in the monitoring of treatment effects of mRNA modifying therapies , or investigation of the HB pathway and its regulation. However, our findings should be studied in separated blood cell fractions and on the enzymatic level.
PubMed: 35923227
DOI: 10.3389/fphys.2022.886194 -
ACS Omega Oct 2023Antisense oligonucleotides (ASOs) are short, single-stranded nucleic acid molecules that alter gene expression. However, their transport into appropriate cellular...
Antisense oligonucleotides (ASOs) are short, single-stranded nucleic acid molecules that alter gene expression. However, their transport into appropriate cellular compartments is a limiting factor in their potency. Here, we synthesized splice-switching oligonucleotides (SSOs) previously developed to treat the rare disease erythropoietic protoporphyria. Using chemical ligation-quantitative polymerase chain reaction (CL-qPCR), we quantified the SSOs in cells and subcellular compartments following free uptake. To drive nuclear localization, we covalently conjugated nuclear localization signal (NLS) peptides to a lead 2'--methoxyethyl phosphorothioate SSO using thiol-maleimide chemistry. The conjugates and parent SSO displayed similar RNA target-binding affinities. CL-qPCR quantification of the conjugates in cells and subcellular compartments following free uptake revealed one conjugate with better nuclear accumulation relative to the parent SSO. However, compared to the parent SSO, which altered the splicing of the target pre-mRNA, the conjugates were inactive at splice correction under free uptake conditions . Splice-switching activity could be conferred on the conjugates by delivering them into cells via cationic lipid-mediated transfection or by treating the cells into which the conjugates had been freely taken up with chloroquine, an endosome-disrupting agent. Our results identify the major barrier to the activity of the peptide-oligonucleotide conjugates as endosomal entrapment.
PubMed: 37929104
DOI: 10.1021/acsomega.3c05144 -
Molecular Medicine (Cambridge, Mass.) Jan 2019X-linked protoporphyria (XLP) (MIM 300752) is an erythropoietic porphyria due to gain-of-function mutations in the last exon (Ducamp et al., Hum Mol Genet 22:1280-88,...
BACKGROUND
X-linked protoporphyria (XLP) (MIM 300752) is an erythropoietic porphyria due to gain-of-function mutations in the last exon (Ducamp et al., Hum Mol Genet 22:1280-88, 2013) of the erythroid-specific aminolevulinate synthase gene (ALAS2). Five ALAS2 exon 11 variants identified by the NHBLI Exome sequencing project (p.R559H, p.E565D, p.R572C, p.S573F and p.Y586F) were expressed, purified and characterized in order to assess their possible contribution to XLP. To further characterize the XLP gain-of-function region, five novel ALAS2 truncation mutations (p.P561X, p.V562X, p.H563X, p.E569X and p.F575X) were also expressed and studied.
METHODS
Site-directed mutagenesis was used to generate ALAS2 mutant clones and all were prokaryotically expressed, purified to near homogeneity and characterized by protein and enzyme kinetic assays. Standard deviations were calculated for 3 or more assay replicates.
RESULTS
The five ALAS2 single nucleotide variants had from 1.3- to 1.9-fold increases in succinyl-CoA V and 2- to 3-fold increases in thermostability suggesting that most could be gain-of-function modifiers of porphyria instead of causes. One SNP (p.R559H) had markedly low purification yield indicating enzyme instability as the likely cause for XLSA in an elderly patient with x-linked sideroblastic anemia. The five novel ALAS2 truncation mutations had increased V values for both succinyl-CoA and glycine substrates (1.4 to 5.6-fold over wild-type), while the Ks for both substrates were only modestly changed. Of interest, the thermostabilities of the truncated ALAS2 mutants were significantly lower than wild-type, with an inverse relationship to V fold-increase.
CONCLUSIONS
Patients with porphyrias should always be assessed for the presence of the ALAS2 gain-of-function modifier variants identified here. A key region of the ALAS2 carboxyterminal region is identified by the truncation mutations studied here and the correlation of increased thermolability with activity suggests that increased molecular flexibility/active site openness is the mechanism of enhanced function of mutations in this region providing further insights into the role of the carboxyl-terminal region of ALAS2 in the regulation of erythroid heme synthesis.
Topics: 5-Aminolevulinate Synthetase; Enzyme Stability; Exons; Gain of Function Mutation; Kinetics; Polymorphism, Single Nucleotide
PubMed: 30678654
DOI: 10.1186/s10020-019-0070-9 -
The Tohoku Journal of Experimental... Oct 2023Erythropoietic protoporphyria (EPP) is a very rare disease with an estimated prevalence of 1 in 200,000 individuals. Decreased ferrochelatase activity causes the... (Review)
Review
Erythropoietic protoporphyria (EPP) is a very rare disease with an estimated prevalence of 1 in 200,000 individuals. Decreased ferrochelatase activity causes the accumulation of protoporphyrin in the body, and light exposure results in the generation of active oxygen, causing photosensitivity. Liver damage has the greatest influence on the prognosis, and liver transplantation is the only treatment option for patients with decompensated liver cirrhosis. We report a case of living-donor liver transplantation for decompensated liver cirrhosis associated with EPP. The patient was a 52-year-old male who led a normal life except for mild photosensitivity. When the patient was 37-year-old, hepatic dysfunction was noticed. At 48-year-old, high erythrocyte protoporphyrin levels, skin biopsy, and genetic tests resulted in a diagnosis of EPP. The patient underwent living- donor liver transplantation because of decompensated liver cirrhosis. In the operating room and intensive care unit, a special light-shielding film was applied to all light sources to block light with harmful wavelengths during treatment. Due to the need for special measures, a lecture on patients with EPP was given before surgery to deepen understanding among all medical professionals involved in the treatment. As a result, no adverse events occurred during the perioperative period, and the patient was discharged on the 46th post-operative day. Currently, the transplanted liver is functioning extremely well, and the patient is alive 3 years post-transplant. Herein, we describe a case of living donor liver transplantation for EPP with a brief literature review.
Topics: Male; Humans; Middle Aged; Adult; Protoporphyria, Erythropoietic; Liver Transplantation; Living Donors; Protoporphyrins; Ferrochelatase; Liver Diseases; Liver Cirrhosis
PubMed: 37495523
DOI: 10.1620/tjem.2023.J061 -
Pharmacology Research & Perspectives Jun 2023Dersimelagon (formerly MT-7117) is a novel, orally administered nonpeptide small molecule selective agonist for melanocortin 1 receptor currently being investigated for...
Absorption, metabolism, and excretion of [ C]dersimelagon, an investigational oral selective melanocortin 1 receptor agonist, in preclinical species and healthy volunteers.
Dersimelagon (formerly MT-7117) is a novel, orally administered nonpeptide small molecule selective agonist for melanocortin 1 receptor currently being investigated for the treatment of erythropoietic protoporphyria, X-linked protoporphyria, and diffuse cutaneous systemic sclerosis (dcSSc). Findings of studies evaluating the absorption, distribution, metabolism, and excretion (ADME) of dersimelagon following a single dose of [ C]dersimelagon in healthy adult volunteers (N = 6) who participated in phase 1, single-center, open-label, mass balance study (NCT03503266), and in preclinical animal models are presented. Rapid absorption and elimination were observed following oral administration of [ C]dersimelagon in clinical and nonclinical studies, with a mean T of 30 min in rats and 1.5 h in monkeys, and a median T of 2 h in humans. In rats, there was a widespread distribution of [ C]dersimelagon-related material, but little or no radioactivity was detected in the brain or fetal tissues. In humans, elimination of radioactivity in urine was negligible (excretion of radioactivity into the urine: 0.31% of dose), and the primary route of excretion was feces, with more than 90% of the radioactivity recovered through 5 days postdose. Based on these findings, dersimelagon is not retained in the human body. Findings from humans and animals suggest dersimelagon is extensively metabolized to the glucuronide in the liver, which is eliminated in bile, and hydrolyzed to unchanged dersimelagon in the gut. The results to date for this orally administered agent elucidate the ADME of dersimelagon in human and animal species and support its continued development for the treatment of photosensitive porphyrias and dcSSc.
Topics: Adult; Animals; Humans; Rats; Bile; Feces; Healthy Volunteers; Liver; Receptor, Melanocortin, Type 1
PubMed: 37078227
DOI: 10.1002/prp2.1084 -
Journal of Photochemistry and... Mar 2021In the knowledge that human ultra-weak photon emission (UPE) is mainly due to the metabolic oxidative stress processes that the skin cells undergo in the presence of... (Review)
Review
In the knowledge that human ultra-weak photon emission (UPE) is mainly due to the metabolic oxidative stress processes that the skin cells undergo in the presence of reactive oxygen species (ROS), external stressors (like UV radiation), but also internal stressors (like diseases or brain activity) might strongly influence the UPE. This manuscript revises the scientific advances focused on the influence of internal factors on the human UPE. According to literature, the UPE seems to be influenced by some diseases (including diabetes, hemiparesis, protoporphyria, or a typical cold), and even by the cerebral intention/relaxation (brain activity/meditation). These allow to consider UPE as a natural and promising non-invasive spectroscopic tool for helping during the diagnosis of a variety of illnesses or stress- / mood-state disorders. Nonetheless, further research is required for answering some still unresolved controversial points.
Topics: Brain; Diabetes Mellitus; Humans; In Vitro Techniques; Luminescent Measurements; Meditation; Paresis; Photons; Reactive Oxygen Species; Skin; Ultraviolet Rays
PubMed: 33540236
DOI: 10.1016/j.jphotobiol.2021.112141 -
Genetics in Medicine : Official Journal... Jan 2021Erythropoietic protoporphyria (EPP), characterized by painful cutaneous photosensitivity, results from pathogenic variants in ferrochelatase (FECH). For 96% of patients,...
PURPOSE
Erythropoietic protoporphyria (EPP), characterized by painful cutaneous photosensitivity, results from pathogenic variants in ferrochelatase (FECH). For 96% of patients, EPP results from coinheriting a rare pathogenic variant in trans of a common hypomorphic variant c.315-48T>C (minor allele frequency 0.05). The estimated prevalence of EPP derived from the number of diagnosed individuals in Europe is 0.00092%, but this may be conservative due to underdiagnosis. No study has estimated EPP prevalence using large genetic data sets.
METHODS
Disease-associated FECH variants were identified in the UK Biobank, a data set of 500,953 individuals including 49,960 exome sequences. EPP prevalence was then estimated. The association of FECH variants with EPP-related traits was assessed.
RESULTS
Analysis of pathogenic FECH variants in the UK Biobank provides evidence that EPP prevalence is 0.0059% (95% confidence interval [CI]: 0.0042-0.0076%), 1.7-3.0 times more common than previously thought in the UK. In homozygotes for the common c.315-48T>C FECH variant, there was a novel decrement in both erythrocyte mean corpuscular volume (MCV) and hemoglobin.
CONCLUSION
The prevalence of EPP has been underestimated secondary to underdiagnosis. The common c.315-48T>C allele is associated with both MCV and hemoglobin, an association that could be important both for those with and without EPP.
Topics: Biological Specimen Banks; Europe; Ferrochelatase; Humans; Mutation; Protoporphyria, Erythropoietic; United Kingdom
PubMed: 32873934
DOI: 10.1038/s41436-020-00951-8 -
Scientific Reports Apr 2022Liver damage affects the prognosis of patients with erythropoietic protoporphyria (EPP). However, there is no radical cure for EPP patients with severe liver damage....
Liver damage affects the prognosis of patients with erythropoietic protoporphyria (EPP). However, there is no radical cure for EPP patients with severe liver damage. This study aims to investigate the effectiveness of phlebotomy in patients with severe liver damage. We examined seven patients diagnosed with EPP and liver damage between 2010 and 2020. Of the 7 cases, phlebotomy was performed in 3 cases with severe hepatic disorder, and the improvement effect of hepatic disorder was observed in all cases. In addition, as an additional study, we also investigated the mechanism by which liver damage becomes more severe. Liver biopsy samples were stained with hematoxylin and eosin and immunohistochemistry was used to examine the expression of adenosine triphosphate-binding transporter G2 (ABCG2). Liver biopsies were performed in 3 of 7 patients with EPP. Of these three patients, ABCG2 expression was low in two patients, especially in the protoporphyrin (PP) deposition area. Two patients with reduced ABCG2 expression subsequently developed severe liver damage. However, the causal relationship between the decreased expression of ABCG2 and the exacerbation of liver damage has not been directly proved, and further investigation is required in the future. This study demonstrated the effectiveness of phlebotomy in EPP patients with severe liver damage.
Topics: Ferrochelatase; Humans; Liver; Phlebotomy; Porphyria, Erythropoietic
PubMed: 35414164
DOI: 10.1038/s41598-022-10089-z -
Biochemical Pharmacology Aug 2018Erythropoietic protoporphyria (EPP) is a genetic disease that results from the defective mutation in the gene encoding ferrochelatase (FECH), the enzyme that converts...
Erythropoietic protoporphyria (EPP) is a genetic disease that results from the defective mutation in the gene encoding ferrochelatase (FECH), the enzyme that converts protoporphyrin IX (PPIX) to heme. Liver injury and even liver failure can occur in EPP patients because of PPIX accumulation in the liver. The current study profiled the liver metabolome in an EPP mouse model caused by a Fech mutation (Fech-mut). As expected, we observed the accumulation of PPIX in the liver of Fech-mut mice. In addition, our metabolomic analysis revealed the accumulation of bile acids and ceramide (Cer) in the liver of Fech-mut mice. High levels of bile acids and Cer are toxic to the liver. Furthermore, we found that the major phosphatidylcholines (PC) in the liver and the ratio of total PC to PPIX in the bile were decreased in Fech-mut mice compared to wild type mice. A decrease of the ratio of PC to PPIX in the bile can potentiate the accumulation of PPIX in the liver because PC increases PPIX solubility and excretion. These metabolomic findings suggest that the accumulation of PPIX, together with the disruption of the homeostasis of bile acids, Cer, and PC, contributes to EPP-associated liver injury.
Topics: Animals; Disease Models, Animal; Liver; Male; Metabolomics; Mice; Mice, Transgenic; Protoporphyria, Erythropoietic
PubMed: 29906468
DOI: 10.1016/j.bcp.2018.06.011