Vitamin D3 reverses immune tolerance and enhances the cytotoxicity of effector T cells in coal pneumoconiosis.

Coal worker's pneumoconiosis (CWP) is a common occupational disease that coal miners are highly susceptible due to long-term exposure to coal dust particles (CDP). CWP can induce the accumulation of immune cells surrounding the bronchioles and alveoli in the lungs, resulting in pulmonary fibrosis and compromised immune function. Using single-cell RNA sequencing (scRNA-Seq), our previous studies disclose that CDP exposure triggers heterogeneity of transcriptional profiles in mouse pneumoconiosis, while Vitamin D3 (VitD3) supplementation reduces CDP-induced cytotoxicity; however, the mechanism by which how VitD3 regulates immune status in coal pneumoconiosis remains unclear. In this study, we elucidated the heterogeneity of pulmonary lymphocytes in mice exposed to CDP and demonstrated the therapeutic efficacy of VitD3 using scRNA-Seq dataset. The validation of key lymphocyte markers and their functional molecules was performed using immunofluorescence. The results demonstrated that VitD3 increased the number of naive T cells by modulating CD4 + T cell differentiation and decreased the number of Treg cells in CDP-exposed mice, thereby enhancing the cytotoxic activity of CD8 + effector T cells. These effects markedly alleviated lung fibrosis and symptoms. Taken together, the mechanism by which VitD3 regulates the functions of lymphocytes in CWP provides a new perspective for further research on the prevention and treatment of CWP.

Exploration study on serum metabolic profiles of Chinese male patients with artificial stone silicosis, silicosis, and coal worker's pneumoconiosis.

Long-term exposure to inhaled silica dust induces pneumoconiosis, which remains a heavy burden in developing countries. Modern industry provides new resources of occupational SiO2 leading to artificial stone silicosis especially in developed countries. This study aimed to characterize the serum metabolic profile of pneumoconiosis and artificial stone silicosis patients. Our case-control study recruited 46 pairs of pneumoconiosis patients and dust-exposed workers. Nontargeted metabolomics and lipidomics by ultra-high-performance liquid chromatography-tandem mass spectrometry platform were conducted to characterize serum metabolic profile in propensity score-matched (PSM) pilot study. 54 differential metabolites were screened, 24 of which showed good screening efficiency through receiver operating characteristics (ROC) in pilot study and validation study (both AUC > 0.75). 4 of the 24 metabolites can predict pneumoconiosis stages, which are 1,2-dioctanoylthiophosphatidylcholine, phosphatidylcholine(O-18:1/20:1), indole-3-acetamide and l-homoarginine. Kynurenine, N-tetradecanoylsphingosine 1-phosphate, 5-methoxytryptophol and phosphatidylethanolamine(22:6/18:1) displayed the potential as specific biomarkers for artificial stone silicosis. Taken together, our results confirmed that tryptophan metabolism is closely related to pneumoconiosis and may be related to disease progression. Hopefully, our results could supplement the biomarkers of pneumoconiosis and provide evidence for the discovery of artificial stone silicosis-specific biomarkers.

Colletotrichum Species Associated with Japanese Plum (Prunus salicina) Anthracnose in South Korea.

A total of 24 Colletotrichum isolates were isolated from diseased Japanese plum (Prunus salicina) fruits showing chlorotic regions with whitish-brown sunken necrotic lesions and phylogenetic relationships among the collected Colletotrichum isolates were determined. A subset of 11 isolates was chosen for further taxonomic study based on morphology and molecular characteristics identified using the internal transcribed spacer (ITS) and beta-tubulin (TUB2) genes. Isolates in the C. acutatum complex were analyzed using partial sequencing of five gene regions (ITS, GAPDH, ACT, TUB2, and CHS), and C. gloeosporioides sensu lato (s.l.) isolates were analyzed using seven gene regions (ITS, TUB2, GAPDH, ACT, CAL, CHS-1, and ApMat). Morphological assessments in combination with phylogenetic analysis delineated four species of Colletotrichum including C. gloeosporioides sensu stricto (s.s.), C. nymphaeae, C. foriniae, and C. siamense; these data identify Colletotrichum fioriniae and C. siamense two new species associated with plum anthracnose in South Korea. Finally, the pathogenicity of these four species in the development of plum anthracnose in South Korea was confirmed by inoculations of plum fruit.

Bacterial communities associated with anthracnose symptomatic and asymptomatic leaves of guarana, an endogenous tropical crop, and their pathogen antagonistic effects.

Plants are colonized by diverse microorganisms that can substantially impact their health and growth. Understanding bacterial diversity and the relationships between bacteria and phytopathogens may be key to finding effective biocontrol agents. We evaluated the bacterial community associated with anthracnose symptomatic and asymptomatic leaves of guarana, a typical tropical crop. Bacterial communities were assessed through culture-independent techniques based on extensive 16S rRNA sequencing, and cultured bacterial strains were evaluated for their ability to inhibit the growth of Colletotrichum sp. as well as for enzyme and siderophore production. The culture-independent method revealed that Proteobacteria was the most abundant phylum, but many sequences were unclassified. The emergence of anthracnose disease did not significantly affect the bacterial community, but the abundance of the genera Acinetobacter, Pseudomonas and Klebsiella were significantly higher in the symptomatic leaves. In vitro growth of Colletotrichum sp. was inhibited by 11.38% of the cultured bacterial strains, and bacteria with the highest inhibition rates were isolated from symptomatic leaves, while asymptomatic leaves hosted significantly more bacteria that produced amylase and polygalacturonase. The bacterial isolate Bacillus sp. EpD2-5 demonstrated the highest inhibition rate against Colletotrichum sp., whereas the isolates EpD2-12 and FD5-12 from the same genus also had high inhibition rates. These isolates were also able to produce several hydrolytic enzymes and siderophores, indicating that they may be good candidates for the biocontrol of anthracnose. Our work demonstrated the importance of using a polyphasic approach to study microbial communities from plant diseases, and future work should focus on elucidating the roles of culture-independent bacterial communities in guarana anthracnose disease.

Synergistic mixtures of chitosan and Mentha piperita L. essential oil to inhibit Colletotrichum species and anthracnose development in mango cultivar Tommy Atkins.

This study assessed the efficacy of chitosan (CHI) and Mentha piperita L. essential oil (MPEO) alone or in combination to control the mycelial growth of five different Colletotrichum species, C. asianum, C. dianesei, C. fructicola, C. tropicale and C. karstii, identified as potential anthracnose-causing agents in mango (Mangifera indica L.). The efficacy of coatings of CHI and MPEO mixtures in controlling the development of anthracnose in mango cultivar Tommy Atkins was evaluated. CHI (2.5, 5, 7.5 and 10 mg/mL) and MPEO (0.3, 0.6, 1.25, 2.5 and 5 µL/mL) alone effectively inhibited mycelial growth of all tested Colletotrichum strains in synthetic media. Mixtures of CHI (5 or 7.5 mg/mL) and MPEO (0.3, 0.6 or 1.25 µL/mL) strongly inhibited mycelial growth and showed additive or synergistic inhibitory effects on the tested Colletotrichum strains based on the Abbott index. The application of coatings of CHI (5 or 7.5 mg/mL) and MPEO (0.6 or 1.25 µL/mL) mixtures that presented synergistic interactions decreased anthracnose lesion severity in mango artificially contaminated with either of the tested Colletotrichum strains over 15 days of storage at 25 °C. The anthracnose lesion severity in mango coated with the mixtures of CHI and MPEO was similar or lower than those observed in mango treated with the synthetic fungicides thiophanate-methyl (10 µg a.i./mL) and difenoconazole (0.5 µg a.i./mL). The application of coatings containing low doses of CHI and MPEO may be an effective alternative for controlling the postharvest development of anthracnose in mango cultivar Tommy Atkins.

Novel approach for suppressing cutting dust using foam on a fully mechanized face with hard parting.

The cutting dust created by the shearer drum is the main source of dust on a fully mechanized coal face. However, overexposure to respirable dust may cause pneumoconiosis in coal workers, while coal dust may lead to serious explosions. The fully mechanized face known as II1051 Face, found at the Zhuxianzhuang Coal Mine located in east China, generates dust by way of the drum on a high-power shear. The coal seam involves hard rock parting so there is a high concentration of cutting dust when the shearer is working. Thus, we developed a new foam dust suppression method with an air self-suction system based on an analysis of the dust generation characteristics that suppressed the shearer cutting dust level. The new foam system was evaluated in a field test where the dust concentration was measured at two points. The results showed that the foam reduced the cutting dust concentration significantly. The respirable dust exposure levels were reduced from 378.4 mg/m(3)to 53.5 mg/m(3)and the visibility was enhanced dramatically. Thus, we conclude that our new foam system is highly efficient at capturing cutting dust, and it has a much lower water consumption. [Supplementary materials are available for this article. Go to the publisher's online edition of Journal of Occupational and Environmental Hygiene for the following free supplemental resource: Contact angle of cutting dust sample, migration trajectory of cutting dust, technological process for suppressing shearer cutting dust using foam, the layout of the foam dust suppression system on coal face, real object of the air self-suction type foam generator, the special foam nozzle used for shearers, relevant experimental results of the air self-suction foam system.].

Laboratory studies of the impact of calcite on in vitro and in vivo effects of coal dust: a potential preventive agent for coal workers' pneumoconiosis?

BACKGROUND: Bioavailable iron (BAI) in coal, which may play a key role in causing coal workers' pneumoconiosis (CWP), is present at relatively high levels in Appalachian coals. Calcite decreases BAI and is more plentiful in Western coals than in Appalachian coals, possibly explaining the lower CWP prevalence among Western miners. METHODS: We measured effects of calcite on BAI in non-cellular and cellular systems involving Pennsylvania (PA) coal dust. We also tested in vivo effects of calcite on transferrin receptor and markers of epithelial mesenchymal transition (EMT) and inflammation in mice exposed to PA coal. RESULTS: Calcite rapidly eliminated BAI in an aqueous suspension of PA coal. Ferritin induction in human lung epithelial cells exposed to PA coal was effectively eliminated by calcite. Mouse lung tissue markers indicated increased EMT after exposure to PA coal dust, but not after exposure to PA coal plus calcite. Markers of inflammation increased following exposure to PA coal alone, but not following exposure to PA coal plus calcite. CONCLUSION: Additional research may lead to the use of supplemental calcite in coal mining as a safe and effective way to prevent CWP among Appalachian coal miners.