Regulatory role of PDK1 via integrated gene analysis of mitochondria-immune response in periodontitis.

AIMS: To investigate the association between mitochondrial events and immune response in periodontitis and related regulatory genes. MAIN METHODS: Gene expression profiles in gingival tissues were retrieved from the Gene Expression Omnibus. Mitochondria-immune response-related differentially expressed genes (MIR-DEGs) between the healthy and periodontitis samples were determined. WGCNA, GO, and KEGG were used to investigate the function and the enriched pathways of MIR-DEGs. The correlation between MIR-DEGs expression and clinical probing pocket depth was analyzed. The MIR-DEGs were further identified and verified in animal samples. A periodontitis model was established in C57BL/6 mice with silk ligation. Micro-computed tomography was used to assess alveolar bone loss. Western blot, quantitative real-time polymerase chain reaction, and immunohistochemical analyses further validated the differential expression of the MIR-DEGs. KEY FINDINGS: A total of ten MIR-DEGs (CYP24A1, PRDX4, GLDC, PDK1, BCL2A1, CBR3, ARMCX3, BNIP3, IFI27, and UNG) were identified, the expression of which could effectively distinguish patients with periodontitis from the healthy controls. Enhanced immune response was detected in the periodontitis group with that in the healthy controls, especially in B cells. PDK1 was a critical MIR-DEG correlated with B cell immune response and clinical periodontal probing pocket depth. Both animal and clinical periodontal samples presented higher gene and protein expression of PDK1 than the control samples. Additionally, PDK1 colocalized with B cells in both animal and clinical periodontal tissues. SIGNIFICANCE: Mitochondria participate in the regulation of the immune response in periodontitis. PDK1 may be the key mitochondria-related gene regulating B-cell immune response in periodontitis.

OTUD6A in tubular epithelial cells mediates angiotensin II-induced kidney injury by targeting STAT3.

Kidney fibrosis is a prominent pathological feature of hypertensive kidney diseases (HKD). Recent studies have highlighted the role of ubiquitinating/deubiquitinating protein modification in kidney pathophysiology. Ovarian tumor domain-containing protein 6 A (OTUD6A) is a deubiquitinating enzyme involved in tumor progression. However, its role in kidney pathophysiology remains elusive. We aimed to investigate the role and underlying mechanism of OTUD6A during kidney fibrosis in HKD. The results revealed higher OTUD6A expression in kidney tissues of nephropathy patients and mice with chronic angiotensin II (Ang II) administration than that from the control ones. OTUD6A was mainly located in tubular epithelial cells. Moreover, OTUD6A deficiency significantly protected mice against Ang II-induced kidney dysfunction and fibrosis. Also, knocking OTUD6A down suppressed Ang II-induced fibrosis in cultured tubular epithelial cells, whereas overexpression of OTUD6A enhanced fibrogenic responses. Mechanistically, OTUD6A bounded to signal transducer and activator of transcription 3 (STAT3) and removed K63-linked-ubiquitin chains to promote STAT3 phosphorylation at tyrosine 705 position and nuclear translocation, which then induced profibrotic gene transcription in epithelial cells. These studies identified STAT3 as a direct substrate of OTUD6A and highlighted the pivotal role of OTUD6A in Ang II-induced kidney injury, indicating OTUD6A as a potential therapeutic target for HKD.NEW & NOTEWORTHY Ovarian tumor domain-containing protein 6 A (OTUD6A) knockout mice are protected against angiotensin II-induced kidney dysfunction and fibrosis. OTUD6A promotes pathological kidney remodeling and dysfunction by deubiquitinating signal transducer and activator of transcription 3 (STAT3). OTUD6A binds to and removes K63-linked-ubiquitin chains of STAT3 to promote its phosphorylation and activation, and subsequently enhances kidney fibrosis.

Mitochondrial impairment and downregulation of Drp1 phosphorylation underlie the antiproliferative and proapoptotic effects of alantolactone on oral squamous cell carcinoma cells.

BACKGROUND: Oral squamous cell carcinoma (OSCC) is one of the most prevalent and fatal oral cancers. Mitochondria-targeting therapies represent promising strategies against various cancers, but their applications in treating OSCC are limited. Alantolactone (ALT) possesses anticancer properties and also regulates mitochondrial events. In this study, we explored the effects of ALT on OSCC and the related mechanisms. METHODS: The OSCC cells were treated with varying concentrations and duration of ALT and N-Acetyl-L-cysteine (NAC). The cell viability and colony formation were assessed. The apoptotic rate was evaluated by flow cytometry with Annexin V-FITC/PI double staining. We used DCFH-DA and flow cytometry to detect reactive oxygen species (ROS) production and DAF-FM DA to investigate reactive nitrogen species (RNS) level. Mitochondrial function was reflected by mitochondrial reactive oxygen species (ROS), mitochondrial membrane potential (MMP), and ATP levels. KEGG enrichment analyses determined the mitochondrial-related hub genes involved in OSCC progression. Dynamin-related protein 1 (Drp1) overexpression plasmids were further transfected into the cells to analyze the role of Drp1 in OSCC progression. Immunohistochemistry staining and western blot verified the expression of the protein. RESULTS: ALT exerted anti-proliferative and pro-apoptosis effects on OSCC cells. Mechanistically, ALT elicited cell injury by promoting ROS production, mitochondrial membrane depolarization, and ATP depletion, which were reversed by NAC. Bioinformatics analysis showed that Drp1 played a crucial role in OSCC progression. OSCC patients with low Drp1 expression had a higher survival rate. The OSCC cancer tissues presented higher phosphorylated-Drp1 and Drp1 levels than the normal tissues. The results further showed that ALT suppressed Drp1 phosphorylation in OSCC cells. Moreover, Drp1 overexpression abolished the reduced Drp1 phosphorylation by ALT and promoted the cell viability of ALT-treated cells. Drp1 overexpression also reversed the mitochondrial dysfunction induced by ALT, with decreased ROS production, and increased mitochondrial membrane potential and ATP level. CONCLUSIONS: ALT inhibited proliferation and promoted apoptosis of oral squamous cell carcinoma cells via impairment of mitochondrial homeostasis and regulation of Drp1. The results provide a solid basis for ALT as a therapeutic candidate for treating OSCC, with Drp1 being a novel therapeutic target in treating OSCC.

Continuous Flow-Enabled Synthesis of Bench-Stable Bicyclo[1.1.1]pentane Trifluoroborate Salts and Their Utilization in Metallaphotoredox Cross-Couplings.

Bicyclo[1.1.1]pentane motifs have gained increasing popularity in medicinal chemistry as bioisosteres because of their ability to impact key physicochemical properties. However, reports of direct C(sp2)-C(sp3) cross-coupling of these fragments to afford biaryl isosteres have been scarce. Herein we describe the development of continuous flow-enabled synthesis of bench-stable bicyclo[1.1.1]pentane trifluoroborate salts. Furthermore, we demonstrate the use of metallaphotoredox conditions to enable cross-coupling of these building blocks with complex aryl halide substrates.

Improving resolution of superlens lithography by phase-shifting mask.

We propose to apply phase-shifting mask (PSM) to superlens lithography to improve its resolution. The PSM comprises of chromium slits alternatively filled by Ag and PMMA. The pi-phase shift is induced whereas their transmittance of electric intensity is almost equal for two neighboring slits. The destructive interference between two slits has greatly improved the spatial resolution and image fidelity. For representative configurations of superlens lithography, FDTD numerical simulations demonstrate that two slits with center-to-center distance d = 35 nm (~λ/10) can be resolved in PSM design, compared to 60 nm (~λ/6) without the PSM.