Targeting the pyruvate dehydrogenase complex/pyruvate dehydrogenase kinase (PDC/PDK) axis to discover potent PDK inhibitors through structure-based virtual screening and pharmacological evaluation.

Proliferating cancer cells are characterized by the Warburg effect, a metabolic alteration in which ATP is generated from cytoplasmic glycolysis instead of oxidative phosphorylation. The pyruvate dehydrogenase complex/pyruvate dehydrogenase kinase (PDC/PDK) axis plays a crucial role in this effect and has been identified as a potential target for anticancer drug development. Herein, we present the discovery and pharmacological evaluation of potent PDK inhibitors targeting the PDK/PDC axis. We successfully identified 6 compounds from a small molecule library through a structure-based virtual screening campaign and evaluated their enzymatic inhibitory potencies for PDK1-4. Our results indicated that compound 1 exhibited submicromolar inhibitory activities against PDK1-3 (IC50 = 109.3, 135.8, and 458.7 nM, respectively), but is insensitive to PDK4 (IC50 = 8.67 µM). Furthermore, compound 1 inhibited the proliferation of A549 cells with an EC50 value of 10.7 µM. In addition, compound 1 induced cell apoptosis, arrested the cell cycle at the S phase, and reduced cell invasion and migration, while showing low in vivo toxicity at a high dose. Based on these observations, it can be concluded that compound 1 is a promising anti-PDK1-3 lead that merits further investigation.

Exosomal miR-125b-5p derived from adipose-derived mesenchymal stem cells enhance diabetic hindlimb ischemia repair via targeting alkaline ceramidase 2.

INTRODUCTION: Ischemic diseases caused by diabetes continue to pose a major health challenge and effective treatments are in high demand. Mesenchymal stem cells (MSCs) derived exosomes have aroused broad attention as a cell-free treatment for ischemic diseases. However, the efficacy of exosomes from adipose-derived mesenchymal stem cells (ADSC-Exos) in treating diabetic lower limb ischemic injury remains unclear. METHODS: Exosomes were isolated from ADSCs culture supernatants by differential ultracentrifugation and their effect on C2C12 cells and HUVECs was assessed by EdU, Transwell, and in vitro tube formation assays separately. The recovery of limb function after ADSC-Exos treatment was evaluated by Laser-Doppler perfusion imaging, limb function score, and histological analysis. Subsequently, miRNA sequencing and rescue experiments were performed to figure out the responsible miRNA for the protective role of ADSC-Exos on diabetic hindlimb ischemic injury. Finally, the direct target of miRNA in C2C12 cells was confirmed by bioinformatic analysis and dual-luciferase report gene assay. RESULTS: ADSC-Exos have the potential to promote proliferation and migration of C2C12 cells and to promote HUVECs angiogenesis. In vivo experiments have shown that ADSC-Exos can protect ischemic skeletal muscle, promote the repair of muscle injury, and accelerate vascular regeneration. Combined with bioinformatics analysis, miR-125b-5p may be a key molecule in this process. Transfer of miR-125b-5p into C2C12 cells was able to promote cell proliferation and migration by suppressing ACER2 overexpression. CONCLUSION: The findings revealed that miR-125b-5p derived from ADSC-Exos may play a critical role in ischemic muscle reparation by targeting ACER2. In conclusion, our study may provide new insights into the potential of ADSC-Exos as a treatment option for diabetic lower limb ischemia.

Exosomes derived from oral squamous cell carcinoma tissue accelerate diabetic wound healing.

It is a widespread and difficult problem that refractory diabetic wounds have a poor local environment and prolonged inflammatory irritation. Tumor cell-derived exosomes play an important role in the development of tumors, as they can promote tumor cell proliferation, migration, and invasion and enhance tumor cell activity. However, tumor tissue-derived exosomes (Ti-Exos) have been less studied, and it is unclear how they affect wound healing. In this study, we extracted Ti-Exos from human oral squamous carcinoma and paracancerous tissue by ultracentrifugation, size exclusion chromatography, and ultrafiltration and performed exosome characterization. In vitro, the oral squamous cell carcinoma tissue-derived exosomes (OSCC Ti-Exos) promoted the proliferation and migration of endothelial cells, keratinocytes, and fibroblasts. In addition, in vivo experiments showed that the OSCC Ti-Exos accelerated the healing of diabetic wounds and were safe in mice. In contrast, there was no promoting effect of paracancerous tissue-derived exosomes either in vivo or in vitro. In conclusion, OSCC Ti-Exos promoted the healing of diabetic wounds, demonstrated preliminary biosafety in mice, and have promise as therapeutic applications.NEW & NOTEWORTHY Diabetic wound healing has become a public health issue that lacks effective treatment. We collected oral squamous cell carcinoma samples and paracancerous tissue and extracted Ti-Exos for verification. In vitro assays revealed that OSCC Ti-EVs could enhance the proliferation and migration of endothelial cells, keratinocytes, and fibroblasts in diabetic cell model. In vivo assays also verified that OSCC Ti-Exos could promote diabetic wound healing, demonstrated preliminary biosafety in mice, and have promise as therapeutic applications.

Tumor tissue derived extracellular vesicles promote diabetic wound healing.

The diabetic wound nowadays remains a major public health challenge, which is characterized by overproduced reactive oxygen species (ROS). However, the current therapy for diabetic wounds is limited for reliable data in the general application. The growth of tumors has been revealed to share parallels with wound healing. Extracellular vesicles (EVs) derived from breast cancer have been reported to promote cell proliferation, migration and angiogenesis. The tumor tissue-derived EVs (tTi-EVs) of breast cancer performance a feature inheritance from original tissue and might accelerate the diabetic wound healing. We wonder whether the tumor-derived EVs are able to accelerate diabetic wound healing. In this study, tTi-EVs were extracted from breast cancer tissue via ultracentrifugation and size exclusion. Subsequently, tTi-EVs reversed the H2O2-induced inhibition of fibroblast proliferation and migration. Moreover, tTi-EVs significantly accelerated wound closure, collagen deposition and neovascularization, and finally promoted wound healing in diabetic mice. The tTi-EVs also reduced the level of oxidative stress in vitro and in vivo. Besides, the biosafety of tTi-EVs were preliminarily confirmed by blood tests and morphological analysis of major organs. Collectively, the present study proves that tTi-EVs can suppress oxidative stress and facilitate diabetic wound healing, which puts forward a novel function of tTi-EVs and provides potential treatment for diabetic wounds.

Exosomes from Adipose Stem Cells Promote Diabetic Wound Healing through the eHSP90/LRP1/AKT Axis.

Oxidative damage is a critical cause of diabetic wounds. Exosomes from various stem cells could promote wound repair. Here, we investigated the potential mechanism by which exosomes from adipose-derived stem cells (ADSC-EXOs) promote diabetic wound healing through the modulation of oxidative stress. We found that ADSC-EXOs could promote proliferation, migration, and angiogenesis in keratinocytes, fibroblasts, and endothelial cells. Furthermore, ADSC-EXOs reduced the reactive oxygen species (ROS) levels in these cells and protected them against hypoxic and oxidative stress damage. Finally, the local injection of ADSC-EXOs at wound sites significantly increased collagen deposition and neovascularization while reducing ROS levels and cell death; thus, it led to accelerated diabetic wound closure. The mechanism underlying ADSC-EXO functions involved heat-shock protein 90 (HSP90) expressed on the cell surface; these functions could be inhibited by an anti-HSP90 antibody. Exosomal HSP90 could bind to the low-density lipoprotein receptor-related protein 1 (LRP1) receptor on the recipient cell membrane, leading to activation of the downstream AKT signaling pathway. Knockdown of LRP1 and inhibition of the AKT signaling pathway by LY294002 in fibroblasts was sufficient to impair the beneficial effect of ADSC-EXOs. In summary, ADSC-EXOs significantly accelerated diabetic wound closure through an exosomal HSP90/LRP1/AKT signaling pathway.

Design and synthesis of TPP+-Mitomycin C conjugate with reduced toxicity.

Mitomycin C (MMC) is a class of alkylating anticancer drug, which non-specifically interacts with nuclear DNA and cross-links guanine and cytosine of DNA, thereby affecting DNA replication and synthesis. However, toxic effects largely impeded MMC's clinical applications. In this study, triphenylphosphine groups (TPP+) were attached to MMC via the active aziridine amine with the aim to reduce its toxicity. MTT assay suggested that 5 possessed a good anticancer activity (IC50 = 1.09 µM, A549) with negligible effects on human normal cells (IC50 > 20 µM, L02 and HUVEC), while MMC exhibited IC50 values of less than 2.5 µM on the tested human normal cells. Dose range-finding experiments suggested that 5 had little effect on the body weight and tissues in mouse at a dose of 20 mg/kg, indicating significantly reduced toxicity as compared to MMC (LD50 < 2.5 mg/kg). Collectively, these data suggested that TPP+ group could be an effective vector to reduce toxicity of MMC.

A Mitochondria-Targeted Phenylbutyric Acid Prodrug Confers Drastically Improved Anticancer Activities.

Phenylbutyric acid (PBA) has been reported as a dual inhibitor of pyruvate dehydrogenase kinases (PDKs) and histone deacetylases (HDACs), exhibiting anticancer effects. However, the low membrane permeability and poor cellular uptake limit its access to the target organelle, resulting in weak potencies against the intended targets. Herein, we report the design and identification of a novel 4-CF3-phenyl triphenylphosphonium-based PBA conjugate (53) with improved in vitro and in vivo anticancer activities. Compound 53 exhibited an IC50 value of 2.22 µM against A375 cells, outperforming the parent drug PBA by about 4000-fold. In the A375 cell-derived xenograft mouse model, 53 reduced the tumor growth by 76% at a dose of 40 mg/kg, while PBA only reduced the tumor growth by 10% at a dose of 80 mg/kg. On the basis of these results, 53 may be considered for further preclinical evaluations for cancer therapy.

The role of lymph node status in cancer-specific survival and decision-making of postoperative radiotherapy in poorly differentiated thyroid cancer: a population-based study.

OBJECTIVE: This study aimed to investigate the prognostic value of lymph node (LN) status for patients with poorly differentiated thyroid cancer (PDTC), and to develop a reliable nomogram to predict the 3-, 5- and 10-year cancer-specific survival (CSS) and assist the decision-making of postoperative radiotherapy (PORT). METHODS: The Surveillance, Epidemiology, and End Results (SEER) database was utilized to screen eligible patients who were diagnosed between 2004 and 2016. The optimal values of age, metastatic lymph node ratio (LNR), and the number of metastatic lymph nodes (MLN) were determined and incorporated into the construction of a nomogram. The performance of the model was evaluated by generating a calibration curve and calculating the consistency index (C-index). Based on the nomogram, patients were classified into three risk cohorts. The prognostic efficacy of PORT was evaluated in each cohort. RESULTS: A total of 522 PDTC patients were included in this study. The LN status-associated parameters (MLN and LNR) were independent risk factors for CSS of PDTC patients. Based on MLN, LNR, and other clinical characteristics (age and T stage), an individualized nomogram was constructed that showed an acceptable predictive performance. Furthermore, we proposed a novel risk-classification system to stratify PDTC patients and to assess the prognostic efficacy of PORT. Only patients in high-risk cohort were found eligible to benefit from PORT. CONCLUSION: LN status is statistically associated with the prognosis of PDTC patients. In addition, the individualized nomogram may be a significant tool to assist the evaluation of patients' long-term prognosis and to guide the decision-making for PORT.

Effects of propofol on intracranial pressure and prognosis in patients with severe brain diseases undergoing endotracheal suctioning.

BACKGROUND: To investigate whether the administration of intravenous propofol before endotracheal suctioning (ES) in patients with severe brain disease can reduce the sputum suction response, improve prognosis, and accelerate recovery. METHODS: A total of 208 severe brain disease patients after craniocerebral surgery were enrolled in the study. The subjects were randomly assigned to the experimental group (n = 104) and the control group (n = 104). The experimental group was given intravenous propofol (10 ml propofol with 1 ml 2% lidocaine), 0.5-1 mg/kg, before ES, while the control group was subjected to ES only. Changes in vital signs, sputum suction effect, the fluctuation range of intracranial pressure (ICP) before and after ES, choking cough response, short-term complications, length of stay, and hospitalization cost were evaluated. Additionally, the Glasgow Outcome Scale (GOS) prognosis score was obtained at 6 months after the operation. RESULTS: At the baseline, the characteristics of the two groups were comparable (P > 0.05). The increase of systolic blood pressure after ES was higher in the control group than in the experimental group (P < 0.05). The average peak value of ICP in the experimental group during the suctioning (15.57 ± 12.31 mmHg) was lower than in the control group (18.24 ± 8.99 mmHg; P < 0.05). The percentage of patients experiencing cough reaction- during suctioning in the experimental group was lower than in the control group (P < 0.05), and the fluctuation range of ICP was increased (P < 0.0001). The effect of ES was achieved in both groups. The incidence of short-term complications in the two groups was comparable (P > 0.05). At 6 months after the surgery, the GOS scores were significantly higher in the experimental than in the control group (4-5 points, 51.54% vs. 32.64%; 1-3 points, 48.46% vs. 67.36%; P < 0.05). There was no significant difference in the length of stay and hospitalization cost between the two groups. CONCLUSIONS: Propofol sedation before ES could reduce choking cough response and intracranial hypertension response. The use of propofol was safe and improved the long-term prognosis. The study was registered in the Chinese Clinical Trial Registry on May 16, 2015 (ChiCTR-IOR-15006441).