Case report: A case of pulmonary mucormycosis caused by Rhizopus azygosporus infection complicated by type 2 diabetes mellitus.

A case of pulmonary mucormycosis (PM) caused by Rhizopus azygosporus infection complicated by type 2 diabetes mellitus is reported. An adult male patient had a productive cough for more than 10 days, aggravated by blood in the sputum for 9 days. Laboratory examination confirmed that he had had type 2 diabetes mellitus and diabetic ketosis for more than 3 years, and his chest computed tomography (CT) scan showed lesions, cavities, and a small effusion in the right lower lobe. The lavage fluid was taken by bronchoscope for bacterial culture and mNGS, which indicated Rhizopus azygosporus growth. Mucormycosis was diagnosed. The patient was given amphotericin B cholesterol sulfate complex for 30 days, and his renal function was closely monitored. After that, his right lower lobe was resected. To date, the patient has recovered well.

N-Acetylcysteine overcomes epalrestat-mediated increase of toxic 4-hydroxy-2-nonenal and potentiates the anti-arthritic effect of epalrestat in AIA model.

Epalrestat, an aldose reductase inhibitor (ARI), has been clinically adopted in treating diabetic neuropathy in China and Japan. Apart from the involvement in diabetic complications, AR has been implicated in inflammation. Here, we seek to investigate the feasibility of clinically approved ARI, epalrestat, for the treatment of rheumatoid arthritis (RA). The mRNA level of AR was markedly upregulated in the peripheral blood mononuclear cells (PBMCs) of RA patients when compared to those of healthy donors. Besides, the disease activity of RA patients is positively correlated with AR expression. Epalrestat significantly suppressed lipopolysaccharide (LPS) induced TNF-α, IL-1ß, and IL-6 in the human RA fibroblast-like synoviocytes (RAFLSs). Unexpectedly, epalrestat treatment alone markedly exaggerated the disease severity in adjuvant induced arthritic (AIA) rats with elevated Th17 cell proportion and increased inflammatory markers, probably resulting from the increased levels of 4-hydroxy-2-nonenal (4-HNE) and malondialdehyde (MDA). Interestingly, the combined treatment of epalrestat with N-Acetylcysteine (NAC), an anti-oxidant, to AIA rats dramatically suppressed the production of 4-HNE, MDA and inflammatory cytokines, and significantly improved the arthritic condition. Taken together, the anti-arthritic effect of epalrestat was diminished or even overridden by the excessive accumulation of toxic 4-HNE or other reactive aldehydes in AIA rats due to AR inhibition. Co-treatment with NAC significantly reversed epalrestat-induced upregulation of 4-HNE level and potentiated the anti-arthritic effect of epalrestat, suggesting that the combined therapy of epalrestat with NAC may sever as a potential approach in treating RA. Importantly, it could be regarded as a safe intervention for RA patients who need epalrestat for the treatment of diabetic complications.

Age-related self-DNA accumulation may accelerate arthritis in rats and in human rheumatoid arthritis.

The incidence of rheumatoid arthritis (RA) is increasing with age. DNA fragments is known to accumulate in certain autoimmune diseases, but the mechanistic relationship among ageing, DNA fragments and RA pathogenesis remain unexplored. Here we show that the accumulation of DNA fragments, increasing with age and regulated by the exonuclease TREX1, promotes abnormal activation of the immune system in an adjuvant-induced arthritis (AIA) rat model. Local overexpression of TREX1 suppresses synovial inflammation in rats, while conditional genomic deletion of TREX1 in AIA rats result in higher levels of circulating free (cf) DNA and hence abnormal immune activation, leading to more severe symptoms. The dysregulation of the heterodimeric transcription factor AP-1, formed by c-Jun and c-Fos, appear to regulate both TREX1 expression and SASP induction. Thus, our results confirm that DNA fragments are inflammatory mediators, and TREX1, downstream of AP-1, may serve as regulator of cellular immunity in health and in RA.

Pomiferin targets SERCA, mTOR, and P-gp to induce autophagic cell death in apoptosis-resistant cancer cells, and reverses the MDR phenotype in cisplatin-resistant tumors in vivo.

Drug resistance in cancer has been classified as innate resistance or acquired resistance, which were characterized by apoptotic defects and ABC transporters overexpression respectively. Therefore, to preclude or reverse these resistance mechanisms could be a promising strategy to improve chemotherapeutic outcomes. In this study, a natural product from Osage Orange, pomiferin, was identified as a novel autophagy activator that circumvents innate resistance by triggering autophagic cell death via SERCA inhibition and activation of the CaMKKß-AMPK-mTOR signaling cascade. In addition, pomiferin also directly inhibited the P-gp (MDR1/ABCB1) efflux and reversed acquired resistance by potentiating the accumulation and efficacy of the chemotherapeutic agent, cisplatin. In vivo study demonstrated that pomiferin triggered calcium-mediated tumor suppression and exhibited an anti-metastatic effect in the LLC-1 lung cancer-bearing mouse model. Moreover, as an adjuvant, pomiferin potentiated the anti-tumor effect of the chemotherapeutic agent, cisplatin, in RM-1 drug-resistant prostate cancer-bearing mouse model by specially attenuating ABCB1-mediated drug efflux, but not ABCC5, thereby promoting the accumulation of cisplatin in tumors. Collectively, pomiferin may serve as a novel effective agent for circumventing drug resistance in clinical applications.

Inhibition of the CDK9-cyclin T1 protein-protein interaction as a new approach against triple-negative breast cancer.

Cyclin-dependent kinase 9 (CDK9) activity is correlated with worse outcomes of triple-negative breast cancer (TNBC) patients. The heterodimer between CDK9 with cyclin T1 is essential for maintaining the active state of the kinase and targeting this protein-protein interaction (PPI) may offer promising avenues for selective CDK9 inhibition. Herein, we designed and generated a library of metal complexes bearing the 7-chloro-2-phenylquinoline CˆN ligand and tested their activity against the CDK9-cyclin T1 PPI. Complex 1 bound to CDK9 via an enthalpically-driven binding mode, leading to disruption of the CDK9-cyclin T1 interaction in vitro and in cellulo. Importantly, complex 1 showed promising anti-metastatic activity against TNBC allografts in mice and was comparably active compared to cisplatin. To our knowledge, 1 is the first CDK9-cyclin T1 PPI inhibitor with anti-metastatic activity against TNBC. Complex 1 could serve as a new platform for the future design of more efficacious kinase inhibitors against cancer, including TNBC.

Biological Evaluation in Resistant Cancer Cells and Study of Mechanism of Action of Arylvinyl-1,2,4-Trioxanes.

1,2,4-trioxane is a pharmacophore, which possesses a wide spectrum of biological activities, including anticancer effects. In this study, the cytotoxic effect and anticancer mechanism of action of a set of 10 selected peroxides were investigated on five phenotypically different cancer cell lines (A549, A2780, HCT8, MCF7, and SGC7901) and their corresponding drug-resistant cancer cell lines. Among all peroxides, only 7 and 8 showed a better P-glycoprotein (P-gp) inhibitory effect at a concentration of 100 nM. These in vitro results were further validated by in silico docking and molecular dynamic (MD) studies, where compounds 7 and 8 exhibited docking scores of -7.089 and -8.196 kcal/mol, respectively, and remained generally stable in 100 ns during MD simulation. Further experiments revealed that peroxides 7 and 8 showed no significant effect on ROS accumulations and caspase-3 activity in A549 cells. Peroxides 7 and 8 were also found to decrease cell membrane potential. In addition, peroxides 7 and 8 were demonstrated to oxidize a flavin cofactor, possibly elucidating its mechanism of action. In conclusion, apoptosis induced by 1,2,4-trioxane was shown to undergo via a ROS- and caspase-3-independent pathway with hyperpolarization of cell membrane potential.

AGEs-Induced Calcification and Apoptosis in Human Vascular Smooth Muscle Cells Is Reversed by Inhibition of Autophagy.

Vascular calcification (VC) in macrovascular and peripheral blood vessels is one of the main factors leading to diabetes mellitus (DM) and death. Apart from the induction of vascular calcification, advanced glycation end products (AGEs) have also been reported to modulate autophagy and apoptosis in DM. Autophagy plays a role in maintaining the stabilization of the external and internal microenvironment. This process is vital for regulating arteriosclerosis. However, the internal mechanisms of this pathogenic process are still unclear. Besides, the relationship among autophagy, apoptosis, and calcification in HASMCs upon AGEs exposure has not been reported in detail. In this study, we established a calcification model of SMC through the intervention of AGEs. It was found that the calcification was upregulated in AGEs treated HASMCs when autophagy and apoptosis were activated. In the country, AGEs-activated calcification and apoptosis were suppressed in Atg7 knockout cells or pretreated with wortmannin (WM), an autophagy inhibitor. These results provide new insights to conduct further investigations on the potential clinical applications for autophagy inhibitors in the treatment of diabetes-related vascular calcification.

Identification of natural compounds as SARS-CoV-2 entry inhibitors by molecular docking-based virtual screening with bio-layer interferometry.

Coronavirus Disease 2019 (COVID-19) is caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), which enter the host cells through the interaction between its receptor binding domain (RBD) of spike glycoprotein with angiotensin-converting enzyme 2 (ACE2) receptor on the plasma membrane of host cell. Neutralizing antibodies and peptide binders of RBD can block viral infection, however, the concern of accessibility and affordability of viral infection inhibitors has been raised. Here, we report the identification of natural compounds as potential SARS-CoV-2 entry inhibitors using the molecular docking-based virtual screening coupled with bilayer interferometry (BLI). From a library of 1871 natural compounds, epigallocatechin gallate (EGCG), 20(R)-ginsenoside Rg3 (RRg3), 20(S)-ginsenoside Rg3 (SRg3), isobavachalcone (Ibvc), isochlorogenic A (IscA) and bakuchiol (Bkc) effectively inhibited pseudovirus entry at concentrations up to 100 µM. Among these compounds, four compounds, EGCG, Ibvc, salvianolic acid A (SalA), and isoliensinine (Isl), were effective in inhibiting SARS-CoV-2-induced cytopathic effect and plaque formation in Vero E6 cells. The EGCG was further validated with no observable animal toxicity and certain antiviral effect against SARS-CoV-2 pseudovirus mutants (D614G, N501Y, N439K & Y453F). Interestingly, EGCG, Bkc and Ibvc bind to ACE2 receptor in BLI assay, suggesting a dual binding to RBD and ACE2. Current findings shed some insight into identifications and validations of SARS-CoV-2 entry inhibitors from natural compounds.

Synthetic Peroxides Promote Apoptosis of Cancer Cells by Inhibiting P-Glycoprotein ABCB5.

This article discloses a new horizon for the application of peroxides in medical chemistry. Stable cyclic peroxides are demonstrated to have cytotoxic activity against cancer cells; in addition a mechanism of cytotoxic action is proposed. Synthetic bridged 1,2,4,5-tetraoxanes and ozonides were effective against HepG2 cancer cells and some ozonides selectively targeted liver cancer cells (the selectivity indexes for compounds 11 b and 12 a are 8 and 5, respectively). In some cases, tetraoxanes and ozonides were more selective than paclitaxel, artemisinin, and artesunic acid. Annexin V flow-cytometry analysis revealed that the active ozonides 22 a and 23 a induced cell death of HepG2 by apoptosis. Further study showed that compounds 22 a and 23 a exhibited a strong inhibitory effect on P-glycoprotein (P-gp/ABCB5)-overexpressing HepG2 cancer cells. ABCB5 is a key player in the multidrug-resistant phenotype of liver cancer. Peroxides failed to demonstrate a direct correlation between oxidative potential and their biological activity. To our knowledge this is the first time that peroxide diastereoisomers have been found to show stereospecific antimalarial action against the chloroquine-sensitive 3D7 strain of Plasmodium falciparum. Stereoisomeric ozonide 12 b is 11 times more active than stereoisomeric ozonide 12 a (IC50 =5.81 vs 65.18 µm). Current findings mean that ozonides merit further investigation as potential therapeutic agents for drug-resistant hepatocellular carcinoma.

Bavachin Protects Human Aortic Smooth Muscle Cells Against ß-Glycerophosphate-Mediated Vascular Calcification and Apoptosis via Activation of mTOR-Dependent Autophagy and Suppression of ß-Catenin Signaling.

Vascular calcification is a major complication of cardiovascular disease and chronic renal failure. Autophagy help to maintain a stable internal and external environment that is important for modulating arteriosclerosis, but its pathogenic mechanism is far from clear. Here, we aimed to identify the bioactive compounds from traditional Chinese medicines (TCM) that exhibit an anti-arteriosclerosis effect. In ß-glycerophosphate (ß-GP)-stimulated human aortic smooth muscle cells (HASMCs), the calcium level was increased and the expression of the calcification-related proteins OPG, OPN, Runx2, and BMP2 were all up-regulated, followed by autophagy induction and apoptosis. Meanwhile, we further revealed that ß-GP induced apoptosis of human osteoblasts and promoted differentiation of osteoblasts through Wnt/ß-catenin signaling. Bavachin, a natural compound from Psoralea corylifolia, dose-dependently reduced the level of intracellular calcium and the expression of calcification-related proteins OPG, OPN, Runx2 and BMP2, thus inhibiting cell apoptosis. In addition, bavachin increased LC3-II and beclin1 expression, along with intracellular LC3-II puncta formation, which autophagy induction is Atg7-dependent and is regulated by suppression of mTOR signaling. Furthermore, addition of autophagy inhibitor, wortmannin (WM) attenuated the inhibitory effect of bavachin on ß-GP-induced calcification and apoptosis in HASMCs. Collectively, the present study revealed that bavachin protects HASMCs against apoptosis and calcification by activation of the Atg7/mTOR-autophagy pathway and suppression of the ß-catenin signaling, our findings provide a potential clinical application for bavachin in the therapy of cardiovascular disease.