A mechanism study on the synergistic effects of rifapentine and fluconazole against fluconazole-resistant Candida albicans in vitro.

Candida albicans (C. albicans) is one of the most common clinical isolates of systemic fungal infection. Long-term and inappropriate use of antifungal drugs can cause fungal resistance, which poses a great challenge to the clinical treatment of fungal infections. The combination of antifungal drugs and non-antifungal drugs to overcome the problem of fungal resistance has become a research hotspot in recent years. Our previous study found that the combination of rifapentine (RFT) and fluconazole (FLC) has a significant synergistic against FLC-resistant C. albicans. The present study aimed to further verify the synergistic effect between FLC and RFT against the FLC-resistant C. albicans 100, and explore the underlying mechanism. The growth curve and spot assay test not only showed the synergistic effect of FLC and RFT on FLC-resistant C. albicans in vitro but exhibited a dose-dependent effect on RFT, indicating that RFT may play a principal role in the synergic effect of the two drugs. Flow cytometry showed that the combined use of RFT and FLC arrested cells in the G2/M phase, inhibiting the normal division and proliferation of FLC-resistant C. albicans. Transmission electron microscopy (TEM) demonstrated that FLC at a low concentration could still cause a certain degree of damage to the cell membrane in the FLC-resistant C. albicans, as represented by irregular morphologic changes and some defects observed in the cell membrane. When FLC was used in combination with RFT, the nuclear membrane was dissolved and the nucleus was condensed into a mass. Detection of the intracellular drug concentration of fungi revealed that the intracellular concentration of RFT was 31-195 fold that of RFT alone when it was concomitantly used with FLC. This indicated that FLC could significantly increase the concentration of RFT in cells, which may be due to the damage caused to the fungal cell membrane by FLC. In short, the present study revealed a synergistic mechanism in the combined use of RFT and FLC, which may provide a novel strategy for the clinical treatment of FLC-resistant C. albicans.

Impact of polyphenol-loaded edible starch nanomaterials on antioxidant capacity and gut microbiota.

Starch nanoparticles (SNPs) have the capability to adsorb polyphenol components from apple pomace efficiently, forming bound polyphenols (P-SNPs). These bound polyphenols may have potential bioactivities to affect human health positively. Therefore, in-depth in vivo observation of the antioxidant activity and evaluation of its gut microbiota regulatory function are essential. The results revealed that P-SNPs indicated significant scavenging abilities against DPPH, ABTS, and hydroxyl radicals. Furthermore, the nanomaterials exhibited non-toxic properties, devoid of hepatorenal and intestinal damage, while concurrently stimulating the production of short-chain fatty acids (SCFAs) within the gastrointestinal tract. Notably, P-SNPs significantly enhanced antioxidant capacity in serum, liver, and kidney tissues, fostering the proliferation of beneficial bacteria (Lactobacillus, Bacillus, norank_f__Muribaculaceae) while suppressing pathogenic bacterial growth (Helicobacter, Odoribacter). This study proposes a novel research concept for the scientific use of polyphenols in promoting gut health.

Investigation the nutritional properties of Auricularia auricula pulp fermented with Lactobacillus strains and their effects on gut microbiota.

BACKGROUND: Auricularia auricula is rich in bioactive components, and microbial fermentation can further dramatically increase its content and bioavailability. However, there are few studies on the relationship between fermented A. auricula pulp (FAAP) and gut microbiota. In this study, standard strains Lactobacillus plantarum 21801 and 21805 purchased from the China Center of Industrial Culture Collection were used to ferment A. auricula pulp at a ratio of 2:1, with an inoculum of 5%, a fermentation temperature of 31 °C, and a fermentation time of 22 h. The nutritional properties, aroma, and color of FAAP and their effects on the body characteristics of mice and the structure and abundance of gut microbiota are discussed. RESULTS: The results showed that, compared with A. auricula pulp, FAAP significantly increased the nutritional properties while maintaining favorable sensory quality and flavor profiles. Among them, the content of total polyphenols and total flavonoids reached 22.04 µg mL-1 and 20.56 µg mL-1 respectively, and the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid free-radical scavenging rate increased to 73.21%. The consumption of FAAP had no negative effects on weight or liver and kidney function in mice and dramatically enhanced the antioxidant capacity in the liver and serum. The production of short-chain fatty acids in the gut was promoted, the relative abundance of beneficial bacteria (Lactobacillus, Bifidobacterium, norank_f__Muribaculaceae and unclassified_f__Lachnospiraceae) increased, and the growth of some pathogenic bacteria (Helicobacter, Mucispirillum, and Alloprevotella) was inhibited. CONCLUSION: These findings demonstrate that FAAP is rich in nutrients and has unique functional properties that promote host health and regulate the gut microbiota. © 2023 Society of Chemical Industry.

XB130 inhibits healing of diabetic skin ulcers through the PI3K/Akt signalling pathway.

BACKGROUND: Diabetic skin ulcers, a significant global healthcare burden, are mainly caused by the inhibition of cell proliferation and impaired angiogenesis. XB130 is an adaptor protein that regulates cell proliferation and migration. However, the role of XB130 in the development of diabetic skin ulcers remains unclear. AIM: To investigate whether XB130 can regulate the inhibition of proliferation and vascular damage induced by high glucose. Additionally, we aim to determine whether XB130 is involved in the healing process of diabetic skin ulcers, along with its molecular mechanisms. METHODS: We conducted RNA-sequencing analysis to identify the key genes involved in diabetic skin ulcers. We investigated the effects of XB130 on wound healing using histological analyses. In addition, we used reverse transcription-quantitative polymerase chain reaction, Western blot, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling staining, immunofluorescence, wound healing, and tubule formation experiments to investigate their effects on cellular processes in human umbilical vein endothelial cells (HUVECs) stimulated with high glucose. Finally, we performed functional analysis to elucidate the molecular mechanisms underlying diabetic skin ulcers. RESULTS: RNA-sequencing analysis showed that the expression of XB130 was up-regulated in the tissues of diabetic skin ulcers. Knockdown of XB130 promoted the healing of skin wounds in mice, leading to an accelerated wound healing process and shortened wound healing time. At the cellular level, knockdown of XB130 alleviated high glucose-induced inhibition of cell proliferation and angiogenic impairment in HUVECs. Inhibition of the PI3K/Akt pathway removed the proliferative effects and endothelial protection mediated by XB130. CONCLUSION: The findings of this study indicated that the expression of XB130 is up-regulated in high glucose-stimulated diabetic skin ulcers and HUVECs. Knockdown of XB130 promotes cell proliferation and angiogenesis via the PI3K/Akt signalling pathway, which accelerates the healing of diabetic skin ulcers.

Succinylation modification provides new insights for the treatment of immunocompromised individuals with drug-resistant Aspergillus fumigatus infection.

Invasive Aspergillus fumigatus infection poses a serious threat to global human health, especially to immunocompromised individuals. Currently, triazole drugs are the most commonly used antifungals for aspergillosis. However, owing to the emergence of drug-resistant strains, the effect of triazole drugs is greatly restricted, resulting in a mortality rate as high as 80%. Succinylation, a novel post-translational modification, is attracting increasing interest, although its biological function in triazole resistance remains unclear. In this study, we initiated the screening of lysine succinylation in A. fumigatus. We discovered that some of the succinylation sites differed significantly among strains with unequal itraconazole (ITR) resistance. Bioinformatics analysis showed that the succinylated proteins are involved in a broad range of cellular functions with diverse subcellular localizations, the most notable of which is cell metabolism. Further antifungal sensitivity tests confirmed the synergistic fungicidal effects of dessuccinylase inhibitor nicotinamide (NAM) on ITR-resistant A. fumigatus. In vivo experiments revealed that treatment with NAM alone or in combination with ITR significantly increased the survival of neutropenic mice infected with A. fumigatus. In vitro experiments showed that NAM enhanced the killing effect of THP-1 macrophages on A. fumigatus conidia. Our results suggest that lysine succinylation plays an indispensable role in ITR resistance of A. fumigatus. Dessuccinylase inhibitor NAM alone or in combination with ITR exerted good effects against A. fumigatus infection in terms of synergistic fungicidal effect and enhancing macrophage killing effect. These results provide mechanistic insights that will aid in the treatment of ITR-resistant fungal infections.

Serum metabolomics combined with 16S rRNA sequencing to reveal the effects of Lycium barbarum polysaccharide on host metabolism and gut microbiota.

Gut microbes and microbial metabolites derived from polysaccharides mediate beneficial effects related to polysaccharides consumption. Lycium barbarum polysaccharide (LBP) is the main bioactive components in L. barbarum fruits and possesses considerable health-promoting effects. In the present study, we aimed to investigate whether LBP supplementation influenced host metabolic responses and gut microbiota in healthy mice, and to identify bacterial taxa associated with the observed beneficial effects. Our results indicated that mice supplied with LBP at 200 mg/kg BW showed lower serum total cholesterol (TC), triglyceride (TG), and liver TG levels. LBP supplementation strengthened the antioxidant capacity of liver, supported the growth of Lactobacillus and Lactococcus, and stimulated short-chain fatty acids (SCFAs) production. Serum metabolomic analysis revealed that fatty acid degradation pathways were enriched, and RT-PCR further confirmed that LBP up-regulated the expression of liver genes involved in fatty acid oxidation. The Spearman's correlation analysis indicated that some serum and liver lipid profiles and hepatic SOD activity were associated with Lactobacillus, Lactococcus, Ruminococcus, Allobaculum and AF12. Collectively, these findings provide new evidence for the potential preventive effect of LBP consumption on hyperlipidemia and nonalcoholic fatty liver disease.

Post-translational modifications confer amphotericin B resistance in Candida krusei isolated from a neutropenic patient.

Neutropenia is a common complication in the treatment of hematological diseases and the most common predisposing factor for invasion by fungi, such as Candida krusei. Recent studies have shown that C. krusei, a life-threatening pathogen, has developed resistance to amphotericin B (AMB). However, the mechanisms that led to the rapid emergence of this AMB-resistant phenotype are unclear. In this study, we found the sensitivity for AMB could be promoted by inhibiting histone acyltransferase activity and western blot analysis revealed differences in the succinylation levels of C. krusei isolated from immunocompromised patients and of the corresponding AMB-resistant mutant. By comparative succinyl-proteome analysis, we identified a total of 383 differentially expressed succinylated sites in with 344 sites in 134 proteins being upregulated in the AMB-resistant mutant, compared to 39 sites in 23 proteins in the wild-type strain. These differentially succinylated proteins were concentrated in the ribosome and cell wall. The critical pathways associated with these proteins included those involved in glycolysis, gluconeogenesis, the ribosome, and fructose and mannose metabolism. In particular, AMB resistance was found to be associated with enhanced ergosterol synthesis and aberrant amino acid and glucose metabolism. Analysis of whole-cell proteomes, confirmed by parallel reaction monitoring, showed that the key enzyme facilitating lysine acylation was significantly upregulated in the AMB-resistant strain. Our results suggest that lysine succinylation may play an indispensable role in the development of AMB resistance in C. krusei. Our study provides mechanistic insights into the development of drug resistance in fungi and can aid in efforts to stifle the emergence of AMB-resistant pathogenic fungi.

Preparation of edible starch nanomaterials for the separation of polyphenols from fruit pomace extract and determination of their adsorption properties.

Apple polyphenols are abundantly present in apple pomace, and their applications are limited by the low efficiency of traditional extraction methods and the tendency to pollute the environment. Starch nanoparticles (SNPs) have received much attention due to their renewable, low cost and biocompatibility. The aim of this study was to prepare SNPs of different sizes from corn starch using ultrasonic-assisted chemical precipitation with adsorption of apple polyphenols, investigate the relationship between particle size and adsorption, while experiments were performed to assess antioxidant activity, simulate in vivo digestion and polyphenol release. The results showed that the smaller the particle size of SNPs the higher the adsorption of polyphenols, and the combination of characterization and adsorption kinetics showed that this adsorption was a physicochemical binding process. DPPH radical scavenging activity showed that polyphenols bound to SNPs were more stable than free polyphenols. In vitro simulation of digestion and release processes, SNPs loaded with polyphenols showed better anti-digestive properties, polyphenols are released in small amounts in gastric juices and continuously in intestinal juices. Our results provide a theoretical basis for the direct separation of polyphenols from fruit pomace polyphenol extracts using nanomaterials and the industrial utilization of polyphenol products.

Genotypic diversity and antifungal susceptibility of Scedosporium species from clinical settings in China.

BACKGROUND: Scedosporium species have drawn significant interest as inhabitants of polluted soil and water and as cause of high mortality in near-drowning patients. So far, most cases have been reported from Europe and Australia, while knowledge on their prevalence and genotypic diversity from Asia is scant. OBJECTIVES: To increase the knowledge of the genetic diversity and in vitro antifungal susceptibility of Scedosporium species involved in human infections from China. METHODS: Here, we applied the ISHAM-MLST consensus scheme for molecular typing of Scedosporium species and revealed both high species diversity and high genotypic diversity among 45 Chinese clinical Scedosporium isolates. RESULTS: Among the five species, Scedosporium boydii (n = 22) was the most common, followed by S. apiospermum (n = 18), S. aurantiacum (n = 4) and S. dehoogii (n = 1). S. aurantiacum was reported for the first time from clinical samples in China. The predominant sequence types (STs) were ST17 in S. apiospermum, ST4 in S. boydii and ST92 in S. aurantiacum, including four novel STs (ST40, ST41, ST42 and ST43) in S. apiospermum. Based on the CLSI-M38 A2 criterion, voriconazole was the only antifungal compound with low MIC values (MIC90 ≤ 1 µg/ml) for all Scedosporium isolates in our study. CONCLUSIONS: The genetic diversity of clinical isolates of Scedosporium species from China is extremely high, with S. boydii being predominant and S. aurantiacum being firstly reported here. VOR was the only antifungal compound with low MIC values for all Scedosporium isolates in our study, which should be recommended as the firstline antifungal treatment against scedosporiosis in China.

Epidemiology of fungal infections in China.

With the increasing number of immunocompromised hosts, the epidemiological characteristics of fungal infections have undergone enormous changes worldwide, including in China. In this paper, we reviewed the existing data on mycosis across China to summarize available epidemiological profiles. We found that the general incidence of superficial fungal infections in China has been stable, but the incidence of tinea capitis has decreased and the transmission route has changed. By contrast, the overall incidence of invasive fungal infections has continued to rise. The occurrence of candidemia caused by Candida species other than C. albicans and including some uncommon Candida species has increased recently in China. Infections caused by Aspergillus have also propagated in recent years, particularly with the emergence of azole-resistant Aspergillus fumigatus. An increasing trend of cryptococcosis has been noted in China, with Cryptococcus neoformans var. grubii ST 5 genotype isolates as the predominant pathogen. Retrospective studies have suggested that the epidemiological characteristics of Pneumocystis pneumonia in China may be similar to those in other developing countries. Endemic fungal infections, such as sporotrichosis in Northeastern China, must arouse research, diagnostic, and treatment vigilance. Currently, the epidemiological data on mycosis in China are variable and fragmentary. Thus, a nationwide epidemiological research on fungal infections in China is an important need for improving the country's health.

Comparison of the in vitro activities of newer triazoles and established antifungal agents against Trichophyton rubrum.

One hundred eleven clinical Trichophyton rubrum isolates were tested against 7 antifungal agents. The geometric mean MICs of all isolates were, in increasing order: terbinafine, 0.03 mg/liter; voriconazole, 0.05 mg/liter; posaconazole, 0.11 mg/liter; isavuconazole, 0.13 mg/liter; itraconazole, 0.26 mg/liter; griseofulvin, 1.65 mg/liter; and fluconazole, 2.12 mg/liter.

T cell CD40LG gene expression and the production of IgG by autologous B cells in systemic lupus erythematosus.

CD40 ligand (CD40LG), encoded on the X chromosome, has been reported to be overexpressed on lupus T cells. Herein, we investigated the effect of DNA demethylation on T cell CD40LG expression and the production of IgG by autologous B cells in lupus. We found normal human T cells transfected with CD40LG induced autologous B cell activation and plasma cell differentiation. Both female lupus CD4+ T cells and demethylating agents treated CD4+ T cells overexpressed CD40LG mRNA. Further, lupus T cells from both genders or demethylated CD4+ T cells from healthy women overstimulated autologous B cells, and this could be reversed with anti-CD40LG Ab in only females. We demonstrated that female lupus CD4+ T cells and demethylated CD4+ T cells express high level of CD40LG and overstimulate B cells to produce IgG. This is due to DNA demethylation and thereby reactivation of the inactive X chromosome in female.

Abnormal histone modification patterns in lupus CD4+ T cells.

OBJECTIVE: To investigate alterations in histone modifications in patients with systemic lupus erythematosus (SLE). METHODS: Global histone H3/H4 acetylation and H3K4/H3K9 methylation in CD4+ T cells from 20 SLE patients and 10 healthy control subjects were assayed using the EpiQuik global histone H3/H4 acetylation and H3K4/H3K9 methylation assay kits. mRNA levels of 12 members of 3 classes of chromatin modifier genes were measured by real-time quantitative polymerase chain reaction. RESULTS: Global histone H3 and H4 hypoacetylation was observed in active lupus CD4+ T cells compared with controls (p = 0.002 and p = 0.009, respectively). The degree of histone H3 acetylation correlated negatively with increased disease activity in lupus patients as measured by SLEDAI (r = -0.889, p = 0.044). We found global histone H3K9 hypomethylation in both active and inactive lupus CD4+ T cells, compared with controls (p = 0.001, p = 0.003, respectively). However, global levels of H3K4 methylation were not different between patients and controls. SIRT1 mRNA levels were significantly increased in active lupus CD4+ T cells compared with controls (p < 0.001), while mRNA levels of CREBBP, P300, HDAC2, HDAC7, SUV39H2, and EZH2 were significantly downregulated in patients with active lupus (p < 0.001, p < 0.001, p = 0.01, p < 0.001, p = 0.003, p = 0.001, respectively). CONCLUSION: Histone modifications appear abnormal in CD4+ T cells in SLE.