Comprehensive circRNA-microRNA-mRNA network analysis revealed the novel regulatory mechanism of Trichosporon asahii infection.

BACKGROUND: Invasive Trichosporon asahii (T. asahii) infection frequently occurs with a high mortality in immunodeficient hosts, but the pathogenesis of T. asahii infection remains elusive. Circular RNAs (circRNAs) are a type of endogenous noncoding RNA that participate in various disease processes. However, the mechanism of circRNAs in T. asahii infection remains completely unknown. METHODS: RNA sequencing (RNA-seq) was performed to analyze the expression profiles of circRNAs, microRNAs (miRNAs), and mRNAs in THP-1 cells infected with T. asahii or uninfected samples. Some of the RNA-seq results were verified by RT-qPCR. Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were used to analyze the differentially expressed mRNAs. A circRNA-miRNA-mRNA network was constructed and verified by dual-luciferase reporter assay and overexpression experiments. RESULTS: A total of 46 circRNAs, 412 mRNAs and 47 miRNAs were differentially expressed at 12 h after T. asahii infection. GO and KEGG analyses showed that the differentially expressed mRNAs were primarily linked to the leukocyte migration involved in the inflammatory response, the Toll-like receptor signaling pathway, and the TNF signaling pathway. A competing endogenous RNA (ceRNA) network was constructed with 5 differentially expressed circRNAs, 5 differentially expressed miRNAs and 42 differentially expressed mRNAs. Among them, hsa_circ_0065336 was found to indirectly regulate PTPN11 expression by sponging miR-505-3p. CONCLUSIONS: These data revealed a comprehensive circRNA-associated ceRNA network during T. asahii infection, thus providing new insights into the pathogenesis of the T. asahii-host interactions.

Adipose tissue-derived stem cells ameliorates dermal fibrosis in a mouse model of scleroderma.

OBJECTIVE: To investigate the therapeutic potential of adipose-derived stem cells (ADSCs) for limited cutaneous scleroderma (LS) in mouse models. METHODS: ADSCs were isolated from pathogen-free female C57BL/6 mice and LS was induced in wild type (WT) C57BL/6 mice via daily injection of bleomycin (0.1 mL × 300 µg/mL) for 4 weeks; then the ADSCs were subcutaneously injected into the dorsal area in the model treatment group, and 100 µL of phosphate-buffered saline (PBS) solution was injected into the same site in the model control group. Green fluorescent protein (GFP) was used to track the cells using an in vivo imaging system on days 7, 14, 21, and 28 after transplantation. All mice were sacrificed and histologic analyses were performed after 4 weeks, and the skin thickness, collagen deposition and the total content of hydroxyproline were evaluated. Additionally, immunohistochemistry were performed to compare the tissue expression and distribution of TGF-ß1 and VEGF between the ADSCs treatment group and the treatment control group. RESULTS: WT C57BL/6 LS mouse model were successfully established and GFP in vivo fluorescence imaging showed that the translated ADSCs survived at the local for at least 4 weeks. Compared with the control group, the ADSCs treatment group significantly attenuated bleomycin-induced dermal fibrosis, reduced the skin thickness and the total content of hydroxyproline (P < 0.05). The ADSCs treatment group displayed significantly lower levels of TGF-ß1 and higher levels of VEGF than the control group (P < 0.05). CONCLUSIONS: ADSCs may provide a feasible and practical treatment for autoimmune diseases such as LS and ameliorate dermal fibrosis.

The antifungal effect of silver nanoparticles on Trichosporon asahii.

BACKGROUND/PURPOSE: Silver nanoparticles are receiving increasing attention in biomedical applications. This study aims at evaluating the antifungal properties of silver nanoparticles against the pathogenic fungus Trichosporon asahii. METHODS: The growth of T. asahii on potato dextrose agar medium containing different concentrations of silver nanoparticles was examined and the antifungal effect was evaluated using minimum inhibitory concentration. Scanning and transmission electron microscopy were also used to investigate the antifungal effect of silver nanoparticles on T. asahii. RESULTS: Silver nanoparticles had a significant inhibitory effect on the growth of T. asahii. The minimum inhibitory concentration of silver nanoparticles against T. asahii was 0.5 µg/mL, which was lower than amphotericin B, 5-flucytosine, caspofungin, terbinafine, fluconazole, and itraconazole and higher than voriconazole. Silver nanoparticles obviously damaged the cell wall, cell membrane, mitochondria, chromatin, and ribosome. CONCLUSION: Our results demonstrate that silver nanoparticles have good antifungal activity against T. asahii. Based on our electron microscopy observations, silver nanoparticles may inhibit the growth of T. asahii by permeating the fungal cell and damaging the cell wall and cellular components.

Angiotensin II stimulates melanogenesis via the protein kinase C pathway.

Melanogenesis is a physiological process that results in the synthesis of melanin pigments, which serve a crucial function in hyperpigmentation. The aim of the present study was to determine the effects of angiotensin II (Ang II) on melanogenesis and to elucidate the molecular events of Ang II-induced melanogenesis. Experiments were performed on human melanocytes to elucidate the pigmenting effect of Ang II and the underlying mechanisms. The elements involved in melanogenesis, including melanin content, tyrosinase (TYR) activity, and microphthalmia-associated transcription factor (MITF) and TYR expression at the mRNA and protein levels were evaluated. Melanin content and TYR activity increased in response to Ang II treatment in a concentration-dependent manner. MITF and TYR mRNA and protein expression levels were increased significantly in response to Ang II in a concentration-dependent manner. The Ang II-induced increase in melanin synthesis was reduced significantly in response to co-treatment with Ro-32-0432, a protein kinase C (PKC) inhibitor, whereas co-treatment with H-89, a PKA inhibitor, did not attenuate the Ang II-induced increase in melanin levels. These results suggest that PKC is required for Ang II-induced pigmentation in human melanocytes and that the mechanism involves the PKC pathway and MITF upregulation.

Targeting the TGF-ß receptor with kinase inhibitors for scleroderma therapy.

Scleroderma (systemic sclerosis) is a connective tissue disease that affects various organ systems; the treatment of scleroderma is still difficult and remains a challenge to the clinician. Recently, kinase inhibitors have shown great potential against fibrotic diseases and, specifically, the transforming growth factor-ß receptor (TGF-ßR) was found as a new and promising target for scleroderma therapy. In the current study, we propose that the large pool of existing kinase inhibitors could be exploited for inhibiting the TGF-ßR to suppress scleroderma. In this respect, we developed a modeling protocol to systematically profile the inhibitory activities of 169 commercially available kinase inhibitors against the TGF-ßR, from which five promising candidates were selected and tested using a standard kinase assay protocol. Consequently, two molecular entities, namely the PKB inhibitor MK-2206 and the mTOR C1/C2 inhibitor AZD8055, showed high potency when bound to the TGF-ßR, with IC50 values of 97 and 86 nM, respectively, which are close to those of the recently developed TGF-ßR selective inhibitors SB525334 and LY2157299 (IC50 = 14.3 and 56 nM, respectively). We also performed atomistic molecular dynamics simulations and post-molecular mechanics/Poisson-Boltzmann surface area analyses to dissect the structural basis and energetic properties of intermolecular interactions between the TGF-ßR kinase domain and these potent compounds, highlighting intensive nonbonded networks across the tightly packed interface of non-cognate TGF-ßR-inhibitor complexes.

Slowly progressive cutaneous, rhinofacial, and pulmonary mucormycosis caused by Mucor irregularis in an immunocompetent woman.

We herein report a case of slowly progressive cutaneous, rhinofacial, and pulmonary mucormycosis caused by Mucor irregularis in an immunocompetent woman who was successfully managed by combined surgical debridement and antifungal therapy. Slow progression, pulmonary involvement, occurrence in an immunocompetent patient, and good prognosis are unusual features of our case.

[Significance of IGS1, ITS and D1/D2 regions in molecular identification of Trichosporon species and genotype of T. asahii in China].

OBJECTIVE: To compare the sensitivity and specificity in molecular identification in different DNA regions of Trichosporon species and to study the genotype of T. asahii isolated from clinical specimens in China. METHODS: DNA was extracted from the cells of all experimental strains by using a method of glass bead method. The D1/D2, ITS and IGS1 regions were amplified by PCR with specific primers, the PCR products were cloned and sequenced. The sequences were referred to GenBank and compared with the other sequences of the Trichosporon species from GenBank by the software CLUSTAL X 1.83. Phylogenetic trees were constructed and genotypes were determined. RESULTS: The D1/D2 regions in T. asahii (CBS2479), T. dermatis, and T. laibachii were 640, 639, and 637 bp in length respectively, the ITS regions were 541, 528, and 531 bp respectively in length, and the IGS1 regions were 643, 515, and 411 bp respectively. The sequence similarity of the D1/D2 region was 89% - 99%, that of ITS and IGS1 regions were 85% - 99% and 11% - 95% respectively. The clinically isolated strains BZP07001, BZP07002, BZP07004, and BZP07005 belonged to genotype I, and the strain BZP07003 to genotype IV. CONCLUSION: The sensitivity and specificity of the IGS1 region was higher than those of the D1/D2 and ITS regions in identification of phylogenetically closely related Trichosporon species. T. asahii isolated from clinical specimens in China belongs to either genotype I or genotype IV.