Fungal systematics and evolution : FUSE 6

Fungal Systematics and Evolution (FUSE) is one of the journal series to address the “fusion” between morphological data and molecular phylogenetic data and to describe new fungal taxa and interesting observations. This paper is the 6th contribution in the FUSE series—presenting one new genus, twelve new species, twelve new country records, and three new combinations. The new genus is: Pseudozeugandromyces (Laboulbeniomycetes, Laboulbeniales). The new species are: Albatrellopsis flettioides from Pakistan, Aureoboletus garciae from Mexico, Entomophila canadense from Canada, E. frigidum from Sweden, E. porphyroleucum from Vietnam, Erythrophylloporus flammans from Vietnam, Marasmiellus boreoorientalis from Kamchatka Peninsula in the Russian Far East, Marasmiellus longistipes from Pakistan, Pseudozeugandromyces tachypori on Tachyporus pusillus (Coleoptera, Staphylinidae) from Belgium, Robillarda sohagensis from Egypt, Trechispora hondurensis from Honduras, and Tricholoma kenanii from Turkey. The new records are: Arthrorhynchus eucampsipodae on Eucampsipoda africanum (Diptera, Nycteribiidae) from Rwanda and South Africa, and on Nycteribia vexata (Diptera, Nycteribiidae) from Bulgaria; A. nycteribiae on Eucampsipoda africanum from South Africa, on Penicillidia conspicua (Diptera, Nycteribiidae) from Bulgaria (the first undoubtful country record), and on Penicillidia pachymela from Tanzania; Calvatia lilacina from Pakistan; Entoloma shangdongense from Pakistan; Erysiphe quercicola on Ziziphus jujuba (Rosales, Rhamnaceae) and E. urticae on Urtica dioica (Rosales, Urticaceae) from Pakistan; Fanniomyces ceratophorus on Fannia canicularis (Diptera, Faniidae) from the Netherlands; Marasmiellus biformis and M. subnuda from Pakistan; Morchella anatolica from Turkey; Ophiocordyceps ditmarii on Vespula vulgaris (Hymenoptera, Vespidae) from Austria; and Parvacoccum pini on Pinus cembra (Pinales, Pinaceae) from Austria. The new combinations are: Appendiculina gregaria, A. scaptomyzae, and Marasmiellus rodhallii. Analysis of an LSU dataset of Arthrorhynchus including isolates of A. eucampsipodae from Eucampsipoda africanum and Nycteribia spp. hosts, revealed that this taxon is a complex of multiple species segregated by host genus. Analysis of an SSU–LSU dataset of Laboulbeniomycetes sequences revealed support for the recognition of four monophyletic genera within Stigmatomyces sensu lato: Appendiculina, Fanniomyces, Gloeandromyces, and Stigmatomyces sensu stricto. Finally, phylogenetic analyses of Rhytismataceae based on ITS–LSU ribosomal DNA resulted in a close relationship of Parvacoccum pini with Coccomyces strobi.http://www.sydowia.at/index.htmpm2021Medical Virolog

Signalisation de la Sphingosine 1-phosphate dans la production de plaquettes

La Sphingosine 1-phosphate (S1P) est un médiateur bioactif produit lors de la phosphorylation de la sphingosine, un lipide de la membrane cellulaire, par deux kinases partiellement redondantes (Sphks 1 & 2). S1P coordonne l'homéostasie vasculaire et le trafic de cellules immunitaires via une famille de cinq récepteurs couplés aux protéines G dédiés (S1PR1-5). Le S1P est abondant dans le sang et la lymphe mais activement éliminé des fluides interstitiels, générant un gradient qui est utilisé par les lymphocytes pour trouver leur chemin vers la circulation. Il a également été proposé que le gradient vasculaire de S1P joue un rôle essentiel dans le trafic d'autres cellules hématopoïétiques ainsi que dans la production de plaquettes grâce au guidage des pro-plaquettes vers les sinusoïdes de la moelle osseuse. Nous avons utilisé des modèles génétiques pour altérer sélectivement l'apport de S1P à la lymphe et au sang séparément ou en combinaison et pour altérer sélectivement l'expression des récepteurs impliqués dans la détection du gradient S1P dans les lignées hématopoïétiques. L'analyse des cellules hématopoïétiques et de leurs progéniteurs dans la moelle osseuse, le sang périphérique et les rates de ces souris a confirmé que la S1P vasculaire est essentielle pour la sortie tissulaire des lymphocytes, mais pas pour la production de plaquettes. La thrombocytopénie n'a été observée ni avec la perte du gradient S1P ni avec l'ablation S1PR1 spécifiquement des mégacaryocytes (MK). Nous avons troué que l'expression et la signalisation de S1PR1 étaient indétectables dans les MK murins matures in situ. De manière concordante, ni la déficience génétique ni la modulation pharmacologique de S1PR1 n'ont eu d'impact sur l'activation des plaquettes murines. Ces observations soutiennent qu'il est peu probable que le ciblage S1PR1 altère l'hémostase et sont en accord avec les observations cliniques avec des médicaments immunosuppresseurs ciblant S1PR1. Bien que nous n'ayons pas confirmé l'implication du S1P sanguin dans la production de plaquettes, la numération plaquettaire périphérique était néanmoins sensible aux perturbations de la disponibilité locale de S1P dans la niche hématopoïétique. La carence panhématopoïétique en S1P a été associée à une augmentation modeste mais significative du nombre de plaquettes sanguines périphériques qui a également été observée avec une carence panhématopoïétique en S1PR1. Ainsi, S1PR1 inhibe plutôt que favorise la production de plaquettes. Nous avons également observé une thrombocytopénie avec une carence globale isolée en Sphk2. Celle-ci est restaurée via une déficience combinée de Sphk1 ou S1PR2, suggérant que la redistribution de la sphingosine de Sphk2 à Sphk1 peut augmenter l'exportation locale de S1P et altérer la production de plaquettes via l'activation de S1PR2. Sur la base de ces observations, nous avons examiné si la libération dérégulée de S1P dans la niche hématopoïétique pourrait expliquer la thrombocytopénie dans la maladie de Gaucher (MG), une maladie génétique associé à la production dérégulée de S1P. Pour cela, nous avons généré un modèle MG en altérant l'expression de la glucocérébrosidase en présence ou en l'absence de Sphk1. Les souris MG présentaient une augmentation de S1P sanguins et une réduction transitoire du nombre de plaquettes qui n'était plus observée avec une carence en composé de Sphk1. En conclusion, notre évaluation de l'importance de la détection du gradient S1P chez la souris nous a conduits à réévaluer le rôle de la signalisation S1P dans la production de plaquettes. En contraste direct avec le modèle dominant, nos observations soutiennent que le S1P sanguin est dispensable pour la production de plaquettes. Ces résultats peuvent avoir des implications pour la réorientation des modulateurs S1PR1 pour les indications cardiovasculaires aiguës et suggèrent que la production excessive de S1P dans la niche hématopoïétique peut constituer une cause de thrombocytopénie.Sphingosine 1-phosphate (S1P) is a bioactive lipid mediator produced by two partially redundant sphingosine kinases (Sphks 1&2) that coordinates vascular homeostasis and immune cell trafficking through a family of cognate G protein-coupled receptors (S1PR1-5). S1P is abundant in blood and lymph but actively removed from interstitial fluids, generating a concentration gradient that is used by lymphocytes to find their way into circulation. The vascular S1P gradient has also been proposed to play critical roles in the trafficking of other hematopoietic cells as well as in platelet production through the guidance of pro-platelets to bone marrow sinusoids. We used genetic models to selectively impair S1P provision to lymph and blood and to selectively impair the expression of receptors involved in S1P gradient sensing in hematopoietic lineages. Analysis of bone marrow, peripheral blood, and tissue hematopoietic cells and their progenitors in these mice confirmed a role for S1P gradient sensing in lymphocyte egress, but not in thrombopoiesis. Thrombocytopenia was observed neither with loss of the S1P gradient nor with S1PR1 ablation specifically from megakaryocytes (MKs). Further experiments showed that S1PR1 expression and signaling were both undetectable in mature murine MKs in situ. Concordantly, neither genetic deficiency nor pharmacological modulation of S1PR1 had any impact on the activation and spreading of murine platelets. These observations argue that S1PR1 targeting is unlikely to substantially impair hemostasis, and are in agreement with clinical observations with S1PR1-directed immunosuppressive drugs. Although we did not confirm a role for vascular S1P sensing in platelet production, peripheral blood platelet counts were nevertheless sensitive to disturbances in local S1P availability in the hematopoietic niche. Pan-hematopoietic S1P deficiency was associated with a modest but significant increase in peripheral blood platelet counts that was also observed with pan-hematopoietic S1PR1 deficiency. This was paralleled by a decrease in erythrocytes as well as a non-significant increase in MKs in bone marrow and spleen. Thus, instead of promoting platelet production, S1PR1 inhibits it, possibly by driving the differentiation of common MK-erythrocyte progenitors toward the erythroid fate. We also observed thrombocytopenia with isolated global deficiency in Sphk2. This phenotype was rescued by compound deficiency of Sphk1 or S1PR2, suggesting that redistribution of sphingosine from Sphk2 to Sphk1 can increase local S1P export and impair platelet production via S1PR2 activation. Based on these observations, we addressed if deregulated S1P release in the hematopoietic niche could explain thrombocytopenia in Gaucher Disease (GD), a genetic disorder associated with deregulated S1P production. To this end, we generated a GD model by impairing hematopoietic glucocerebrosidase expression in the presence or absence of hematopoietic Sphk1. GD mice displayed high circulating S1P levels and a transient reduction in platelet counts that was eliminated by compound deficiency of Sphk1. In conclusion, our studies of S1P gradient sensing in mice led us to reassess the role of S1P signaling in platelet production. In direct contrast to the prevailing model, our observations argue that blood S1P is dispensable for platelet production. Instead, S1P can suppress platelet production when sphingolipid metabolism is deregulated locally. These results may have implication for the repurposing of S1PR1 modulators for acute cardiovascular indications and suggest that excess S1P production in the hematopoietic niche can be a cause of thrombocytopenia

Encapsulated peritoneal sclerosis

Encapsulating peritoneal sclerosis (EPS) also known as abdominal cacoon is a rare cause of acute or subacute small bowel obstruction. It is characterized by total or partial encasement of the small bowel within a thick fibrocollagenous membrane which may be formed in response to prolonged, repetitive, and severe insult to the peritoneal mesothelium. This is frequently seen in the setting of peritoneal dialysis. However other causes may include chronic inflammation. We present a case of EPS in a male with infrequent abdominal pain, nausea and fever.... Continu

Bioactive lipids and cancer metastasis to bone

Bioactive lipids constitute a large family of molecules considered as inflammatory mediators. Among them, lysophosphatidic acid (LPA), sphingosine 1-phosphate (S1P), and eicosanoids (prostanoids such as PGE2 and leukotrienes such as LTB4, LTC4, and LTD4) play a central role in the pathophysiology of several inflammatory diseases. However, it has long been known that these bioactive lipids are also involved in cancer, mainly because of their ability to control the pro-inflammatory microenvironment of tumors as well as their ability to act directly on tumor cells promoting cell proliferation, migration, and survival. Recently, there has been increased interest in determining how these lipid mediators orchestrate tumor development and metastasis. Bone metastases result from a complex dialogue between tumor cells and bone cells. Recent findings demonstrate that all these bioactive lipids can profoundly affect bone metabolism by acting positively or negatively on both osteoblasts and osteoclasts. This review gives an overview of previous findings demonstrating direct involvement of LPA, S1P, and PGE2 in bone metastasis. This review also emphasizes the recent findings that characterize the activity of these bioactive lipids directly on bone cells and how these activities could be integrated into the complex molecular mechanisms leading to bone metastasis formation and progression

Leucoagaricus fragilis sp. nov. (Agaricaceae) from Punjab, Pakistan

Niazi, Muhammad Asif Abdul Rehman, Izhar, Aiman, Khalid, Abdul Nasir, Bashir, Hira (2021): Leucoagaricus fragilis sp. nov. (Agaricaceae) from Punjab, Pakistan. Phytotaxa 501 (1): 140-150, DOI: 10.11646/phytotaxa.501.1.5, URL: http://dx.doi.org/10.11646/phytotaxa.501.1.

First report of Agaricus sect. Brunneopicti from Pakistan with descriptions of two new species

International audienceAgaricus is a genus of saprophytic fungi in the Basidiomycota. As part of ongoing studies on the genus Agaricus in Pakistan, we here describe and discuss two new species, A. pakistanicus sp. nov. and A. sparsisquamosus sp. nov. Morphological characters and phylogenetic analysis of ITS sequences were used to clarify their taxonomic affinities. Phylogenetic analysis indicated that both species belong to A. sect. Brunneopicti. This palaeotropical section, which has been recently reconstructed, is reported in Pakistan for the first time. Interestingly, these two new species exhibit a reddish or brown discoloration. With these two new species, the distribution of this section, which was previously restricted to tropical and subtropical humid regions, now extends to semi-arid and desert climate regions and the total number of species in the section increases to 20, including eight unnamed species

Clitopilus cretoalbus sp. nov. (Entolomataceae, Agaricales), a new species from Pakistan

A new species, Clitopilus cretoalbus A.Izhar, Zaman, M.Asif, H.Bashir, Niazi & Khalid sp. nov., is described herein based on several collections from Punjab, Pakistan. It is characterized by a clitocyboid to somewhat omphaloid stature combined with a white pileus, decurrent lamellae, an almost central to slightly eccentric whitish relatively long stipe, the occurrence of cheilocystidia, and basidiospores with 6 to 9 ridges in polar view. Molecular phylogenetic analyses of nrITS and nrLSU performed using the maximum likelihood method supported the novelty of this Pakistani species and its placement within the genus Clitopilus section Scyphoides. A comparison with other morpho-anatomically close species confirmed that the newly described species is distinct from others

An overview of Agaricus section Hondenses and Agaricus section Xanthodermatei with description of eight new species from Pakistan

Abstract In a recent revision of the genus Agaricus, A. section Xanthodermatei was split into two sections A. sect. Hondenses and A. sect. Xanthodermatei. Our objectives were to investigate the species diversity of both sections in Pakistan and to give an overview of the major clades. Phylogenetic analyses based on the combined nucLSU, ITS and TEF1 dataset from 35 specimens of both sections revealed three major clades. Analyses based on ITS dataset and 106 specimens, including 33 from Pakistan, reveal eight new species and one new record species. These nine species are described in detail. It is noteworthy that intraspecific variability as well as interspecific variability between closely related species were very low in ITS sequences in many cases. In the case of the two new species A. xanthochromaticus and A. griseovariegatus, TEF1 sequence data were much more efficient than ITS to distinguish these species from each other. The other new species are A. atroumbonatus, A. fumidicolor, A. macropeplus, A. parviniveus, A. swaticus and A. bambusetorum. The latter is the only new species of A. sect. Hondenses in which it is morphologically atypical and also the unique (sub)tropical species. Agaricus gregariomyces is recorded for the first time in Pakistan. In addition, brief descriptions are provided not only for A. bisporiticus, A. endoxanthus and A. punjabensis, which are reported again in Pakistan, but also for A. californicus, which is reported for the first time in Spain and outside North America. In total 12 species of both sections were reported in Pakistan and half of them were from subtropical climatic areas, underlining the contribution of the climatic diversity to the high species richness in this country