New genera and species with chloridium-like morphotype in the Chaetosphaeriales and Vermiculariopsiellales

In this study, we investigated the morphological and genetic variability of selected species belonging to the genus Chloridium sensu lato, some also referred to as chloridium-like asexual morphs and other undescribed morphologically similar fungi. These species do not conform to the revised generic concept and thus necessitate a re-evaluation in terms of taxonomy and phylogeny. The family Chaetosphaeriaceae (Chaetosphaeriales) encompasses a wide range of asexual morphotypes, and among them, the simplest form is represented by Chloridium sect. Chloridium. The morphological simplicity of the Chloridium morphotype has historically led to the amalgamation of numerous unrelated species, thereby creating a heterogeneous genus. By conducting phylogenetic reconstruction of four DNA loci and examining a set of 71 strains, including all available ex-type and other non-type strains as well as holotypes and other herbarium material, we were able to gain new insights into the relationships between these taxa. Phylogenetic analyses revealed that the studied species are distantly related to Chloridium sensu stricto and can be grouped into two orders in the Sordariomycetes. Within the Chaetosphaeriales, they formed nine well-separated genera in four clades, such as Cacumisporium, Caliciastrum gen. nov., Caligospora gen. nov., Capillisphaeria gen. nov., Curvichaeta, Fusichloridium, Geniculoseta gen. nov., Papillospora gen. nov., and Spicatispora gen. nov. We also established Chloridiopsiella gen. nov. and Chloridiopsis gen. nov. in Vermiculariopsiellales. Four new species and eight new combinations are proposed in these genera. Our study provides a clearer understanding of the genus Chloridium, its relationship to other morphologically similar fungi, and a new taxonomic treatment and molecular phylogeny to facilitate their accurate identification and classification in future research. Taxonomic novelties: New genera: Caliciastrum Réblová, Caligospora Réblová, Capillisphaeria Réblová, Chloridiopsiella Réblová, Chloridiopsis Réblová, Geniculoseta Réblová, Papillospora Réblová, Spicatispora Réblová; New species: Caliciastrum bicolor Réblová, Caligospora pannosa Réblová, Chloridiopsis syzygii Réblová, Gongromerizella silvana Réblová; New combinations: Caligospora dilabens (Réblová & W. Gams) Réblová, Capillisphaeria crustacea (Sacc.) Réblová, Chloridiopsiella preussii (W. Gams & Hol.-Jech.) Réblová, Chloridiopsis constrictospora (Crous et al.) Réblová, Geniculoseta preussii (W. Gams & Hol.-Jech.) Réblová, Papillospora hebetiseta (Réblová & W. Gams) Réblová, Spicatispora carpatica (Hol.-Jech. & Révay) Réblová, Spicatispora fennica (P. Karst.) Réblová; Epitypifications (basionyms): Chaetosphaeria dilabens Réblová & W. Gams, Chloridium cylindrosporum W. Gams & Hol.-Jech. Citation: Réblová M, Nekvindová J (2023). New genera and species with chloridium-like morphotype in the Chaetosphaeriales and Vermiculariopsiellales. Studies in Mycology 106: 199-258. doi: 10.3114/sim.2023.106.04.

Consolidation of Chloridium: new classification into eight sections with 37 species and reinstatement of the genera Gongromeriza and Psilobotrys

Chloridium is a little-studied group of soil- and wood-inhabiting dematiaceous hyphomycetes that share a rare mode of phialidic conidiogenesis on multiple loci. The genus has historically been divided into three morphological sections, i.e. Chloridium, Gongromeriza, and Psilobotrys. Sexual morphs have been placed in the widely perceived genus Chaetosphaeria, but unlike their asexual counterparts, they show little or no morphological variation. Recent molecular studies have expanded the generic concept to include species defined by a new set of morphological characters, such as the collar-like hyphae, setae, discrete phialides, and penicillately branched conidiophores. The study is based on the consilience of molecular species delimitation methods, phylogenetic analyses, ancestral state reconstruction, morphological hypotheses, and global biogeographic analyses. The multilocus phylogeny demonstrated that the classic concept of Chloridium is polyphyletic, and the original sections are not congeneric. Therefore, we abolish the existing classification and propose to restore the generic status of Gongromeriza and Psilobotrys. We present a new generic concept and define Chloridium as a monophyletic, polythetic genus comprising 37 species distributed in eight sections. In addition, of the taxa earlier referred to Gongromeriza, two have been redisposed to the new genus Gongromerizella. Analysis of published metabarcoding data showed that Chloridium is a common soil fungus representing a significant (0.3 %) proportion of sequence reads in environmental samples deposited in the GlobalFungi database. The analysis also showed that they are typically associated with forest habitats, and their distribution is strongly influenced by climate, which is confirmed by our data on their ability to grow at different temperatures. We demonstrated that Chloridium forms species-specific ranges of distribution, which is rarely documented for microscopic soil fungi. Our study shows the feasibility of using the GlobalFungi database to study the biogeography and ecology of fungi.

Methylation analysis of tumour suppressor genes in ovarian cancer using MS-MLPA

Epigenetic changes are considered to be a frequent event during tumour development. Hypermethylation of promoter CpG islands represents an alternative mechanism for inactivation of tumour suppressor genes, DNA repair genes, cell cycle regulators and transcription factors. The aim of this study was to investigate promoter methylation of specific genes in ovarian cancer by comparison with normal ovarian tissue. To search for epigenetic events we used methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) to compare the methylation status of 69 tissue samples of ovarian cancer with 40 control samples. Using a 15% cut-off for methylation, we observed significantly higher methylation in genes MGMT, PAX5, CDH13, WT1, THBS1, GATA5 in the ovarian cancer group, while in the ESR1 gene we observed significantly higher methylation in the control group compared with the ovarian cancer group. These findings could potentially be used in screening of ovarian cancer and may have implications for future chemotherapy based on epigenetic changes.

Inhibition of human liver microsomal cytochrome P450 activities by adefovir and tenofovir

Adefovir (PMEA) and tenofovir (PMPA) and their prodrugs, adefovir dipivoxil (bisPOM-PMEA) and tenofovir disoproxil (bisPOC-PMPA), were subjected to a detailed study of their potential to inhibit the activities of human liver microsomal cytochromes P450 (CYP). The inhibition of marker enzyme activities of CYP1A2, CYP2A6, CYP2B6, CYP2C9, CYP2D6, CYP2E1 and CYP3A4 was examined with high-performance liquid chromatography (HPLC) or spectroscopic (fluorescence, luminescence) detection. Adefovir and adefovir dipivoxil did not significantly influence activities of most CYP enzymes. The activity of CYP3A4 was inhibited by adefovir dipivoxil at concentrations over 100 microM. Adefovir and its prodrug inhibited CYP2C9 at concentrations below 100 microM; inhibition by adefovir was of the uncompetitive (at the lower inhibitor concentrations) or of the competitive nature with a Ki = 420 microM. Tenofovir and tenofovir disoproxil influenced the activity of CYP2C9, and competitive inhibition was found with Ki = 580 and 395 microM, respectively. Tenofovir disoproxil was shown to inhibit microsomal CYP2E1 activities by a mixed-type inhibition with Ki values at about 140 microM. The results indicate the possibility of an influence of the compounds tested on the respective CYP activities when used at high doses.

In vivo study of the effect of antiviral acyclic nucleotide phosphonate (R)-9-[2-(phosphonomethoxy)propyl]adenine (PMPA, tenofovir) and its prodrug tenofovir disoproxil fumarate on rat microsomal cytochrome P450

The total content of rat liver microsomal cytochrome P450 (CYP) significantly decreased after repeated i.p. administration of the antiviral agent tenofovir ((R)-9-[2-(phosphonomethoxy)propyl] adenine) and tenofovir disoproxil at a daily dose 25 mg/kg, although the content of liver microsomal protein did not change. The decrease of the CYP content was accompanied by concomitant increase of the amount of inactive CYP form, cytochrome P420. This effect was confirmed by a parallel study of the activities of selected CYP forms, CYP2E1 (p-nitrophenol hydroxylation) and CYP1A2 (7-ethoxyresorufin deethylation). The activity (expressed relatively to the protein content) of both CYP forms decreased significantly following the decrease of the total CYP. On the other hand, the CYP2E1 activity expressed relatively to the decreasing total CYP content remained unchanged. However, CYP1A2 activity also decreased when calculated relatively to the total native CYP content indicating lower stability of this form. Semiquantitative RT-PCR showed no significant changes in expression of major rat liver microsomal CYP forms after tenofovir treatment. In conclusion, repeated administration of tenofovir in higher doses led to significant decrease of the relative proportion of active liver microsomal CYPs accompanied by a conversion of these enzymes to the inactive form (CYP420) maintaining the sum of CYP proteins unchanged.

Interactions of food and dietary supplements with drug metabolising cytochrome P450 enzymes

Drug side effects and toxicity and often the drug efficacy are highly dependent on drug metabolism determining the activation and/or elimination of the respective compound. In humans, cytochromes P450 are the most important drug metabolizing enzymes of the first phase of drug biotransformation. Their activity can vary due to interindividual genetic differences, but it can be changed also by inhibition or induction of the enzymes by their substrates or other compounds that are not only drugs themselves and/or drugs taken concomitantly. Often, influence on drug metabolism by compounds that occur in the environment, most remarkably in the food, is forgotten. Some commonly used herbs, fruits as well as e.g. alcohol may cause failure of the therapy up to serious alterations of the patient's health. This review presents a brief overview of potentially dangerous nutrition factors including herbs (incl. teas, infusions) that should be considered when indicating individual drug therapy. Examples include primarily grapefruits, pomelo, star fruit, pomegranates and some other fruits, St John's Wort (Hypericum perforatum), caffeine, as well as alcohol and cigarette smoking.