Manganese (Mn) is an essential trace element required for the development of human body and acts as an enzyme co-factor or activator for various reactions of metabolism. While essential in trace ...amounts, excessive Mn exposure can result in toxic accumulations in human brain tissue and resulting extrapyramidal symptoms called manganism similar to idiopathic Parkinson's disease (PD). Quercetin (QCT) has been demonstrated to play an important role in altering the progression of neurodegenerative diseases by protecting against oxidative stress. This study aimed to investigate the protective effect of QCT on Mn-induced neurotoxicity and the underlying mechanism in SK-N-MC human neuroblastoma cell line and Sprague-Dawley (SD) male rat brain. The results showed that Mn treatment significantly decreased the cell viability of SK-N-MC cell and increased the release of lactate dehydrogenase (LDH), which was attenuated by QCT pretreatment at 10 and 20 µg/mL. Compared to the Mn alone group, QCT pretreatment significantly attenuated Mn-induced oxidative stress, mitochondrial dysfunction and apoptosis. Meanwhile, QCT pretreatment markedly downregulated the NF-κB but upregulated the heme oxygenase-1 (HO-1) and Nrf2 proteins, compared to the Mn alone group. Our result showed the beneficial effect of QCT on hematological parameters against Mn in rat brain. QCT decrease reactive oxygen species (ROS) and protein carbonyl levels and increased Cu/Zn-superoxide dismutase (SOD) activity induced in Mn-treated rats. QCT administration caused a significant reduction in the Mn-induced neuroinflammation by inhibiting the expression of inflammatory markers such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6) cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). QCT lowered the Mn elevated levels of various downstream apoptotic markers, including Bax, cytochrome
, cleaved caspase-3 and polymerase-1 (PARP-1), while QCT treatment upregulated anti-apoptotic Bcl-2 proteins and prevented Mn-induced neurodegeneration. Furthermore, administration of QCT (25 and 50 mg/kg) to Mn-exposed rats showed improvement of histopathological alteration in comparison to Mn-treated rats. Moreover, administration of QCT to Mn-exposed rats showed significant reduction of 8-hydroxy-2'-deoxyguanosine (8-OHdG), Bax, activated caspase-3 and PARP-1 immunoreactivity. These results indicate that QCT could effectively inhibit Mn induced apoptosis and inflammatory response in SK-N-MC cells and SD rats, which may involve the activation of HO-1/Nrf2 and inhibition of NF-κB pathway.
Cancers cells have the ability to develop chemotherapy resistance, which is a persistent problem during cancer treatment. Chemotherapy resistance develops through different molecular mechanisms, ...which lead to modification of the cancer cells signals needed for cellular proliferation or for stimulating an immune response. The endoplasmic reticulum (ER) is an important organelle involved in protein quality control, by promoting the correct folding of protein and ER-mediated degradation of unfolded or misfolded protein, namely, ER-associated degradation. Disturbances of the normal ER functions causes an accumulation of unfolded or misfolded proteins in the ER lumen, resulting in a condition called "ER stress (ERS)." ERS triggers the unfolded protein response (UPR)-also called the ERS response (ERSR)-to restore homeostasis or activate cell death. Although the ERSR is one emerging potential target for chemotherapeutics to treat cancer, it is also critical for chemotherapeutics resistance, as well. However, the detailed molecular mechanism of the relationship between the ERSR and tumor survival or drug resistance remains to be fully understood. In this review, we aim to describe the most vital molecular mechanism of the relationship between the ERSR and chemotherapy resistance. Moreover, the review also discusses the molecular mechanism of ER stress-mediated apoptosis on cancer treatments.
An attention guided convolutional neural network (CNN) for the classification of breast cancer histopathology images is proposed. Neural networks are generally applied as black box models and often ...the network's decisions are difficult to interpret. Making the decision process transparent, and hence reliable is important for a computer-assisted diagnosis (CAD) system. Moreover, it is crucial that the network's decision be based on histopathological features that are in agreement with a human expert. To this end, we propose to use additional region-level supervision for the classification of breast cancer histopathology images using CNN, where the regions of interest (RoI) are localized and used to guide the attention of the classification network simultaneously. The proposed supervised attention mechanism specifically activates neurons in diagnostically relevant regions while suppressing activations in irrelevant and noisy areas. The class activation maps generated by the proposed method correlate well with the expectations of an expert pathologist. Moreover, the proposed method surpasses the state-of-the-art on the BACH microscopy test dataset (part A) with a significant margin.
Our aim is to explore differences in Hector Battifora mesothelial‐1 (HBME‐1), cytokeratin‐19 (CK19), Galectin‐3 (Gal‐3), and CD56 expression in infiltrative follicular variants of papillary carcinoma ...(IFVPTC) and encapsulated follicular variants of papillary carcinoma (EFVPTC) and to provide clues for distinguishing the two subtypes preoperatively. Tissue microarrays from 100 EFVPTC (45 non‐invasive follicular thyroid neoplasms with papillary‐like nuclear features (NIFTP) and 55 invasive EFVPTCs), 43 IFVPTCs, and 64 follicular neoplasms (FN) were immunostained with HBME‐1, CK19, Gal‐3, and CD56. Each case was scored 1 point for every positive result. Immunohistochemical expression was not significantly different in invasive EFVPTC and NIFTP, except for that of HBME‐1. HBME‐1, CK19, Gal‐3, and CD56 expression were significantly higher in IFVPTC than in EFVPTC. At the cutoff of 3 points, the score method had special diagnostic value for differentiating IFVPTC from EFVPTC and FN and for predicting lymph node metastasis. Scoring of immunohistochemistry results may be applied to core biopsy or cell blocks to assist ultrasonographic, cytologic and molecular tests in differentiating IFVPTC and EFVPTC preoperatively, possibly appropriately guiding EFVPTC preoperatively for limited operation or active surveillance.
Abstract
Despite highly promising characteristics of three-dimensionally (3D) nanostructured catalysts for the oxygen evolution reaction (OER) in polymer electrolyte membrane water electrolyzers ...(PEMWEs), universal design rules for maximizing their performance have not been explored. Here we show that woodpile (WP)-structured Ir, consisting of 3D-printed, highly-ordered Ir nanowire building blocks, improve OER mass activity markedly. The WP structure secures the electrochemically active surface area (ECSA) through enhanced utilization efficiency of the extended surface area of 3D WP catalysts. Moreover, systematic control of the 3D geometry combined with theoretical calculations and various electrochemical analyses reveals that facile transport of evolved O
2
gas bubbles is an important contributor to the improved ECSA-specific activity. The 3D nanostructuring-based improvement of ECSA and ECSA-specific activity enables our well-controlled geometry to afford a 30-fold higher mass activity of the OER catalyst when used in a single-cell PEMWE than conventional nanoparticle-based catalysts.
Ovarian cancer (OC) is the most lethal of the gynecologic cancers, and platinum-based treatment is a part of the standard first-line chemotherapy regimen. However, rapid development of acquired ...cisplatin resistance remains the main cause of treatment failure, and the underlying mechanism of resistance in OC treatment remains poorly understood. Faced with this problem, our aim in this study was to generate cisplatin-resistant (CisR) OC cell models in vitro and investigate the role of epithelial-mesenchymal transition (EMT) transcription factor Twist on acquired cisplatin resistance in OC cell models. To achieve this aim, OC cell lines OV-90 and SKOV-3 were exposed to cisplatin using pulse dosing and stepwise dose escalation methods for a duration of eight months, and a total of four CisR sublines were generated, two for each cell line. The acquired cisplatin resistance was confirmed by determination of 50% inhibitory concentration (IC
) and clonogenic survival assay. Furthermore, the CisR cells were studied to assess their respective characteristics of metastasis, EMT phenotype, DNA repair and endoplasmic reticulum stress-mediated cell death. We found the IC
of CisR cells to cisplatin was 3-5 times higher than parental cells. The expression of Twist and metastatic ability of CisR cells were significantly greater than those of sensitive cells. The CisR cells displayed an EMT phenotype with decreased epithelial cell marker E-cadherin and increased mesenchymal proteins N-cadherin and vimentin. We observed that CisR cells showed significantly higher expression of DNA repair proteins, X-ray repair cross-complementing protein 1 (XRCC1) and poly (ADP-ribose) polymerases 1 (PARP1), with significantly reduced endoplasmic reticulum (ER) stress-mediated cell death. Moreover, Twist knockdown reduced metastatic ability of CisR cells by suppressing EMT, DNA repair and inducing ER stress-induced cell death. In conclusion, we highlighted the utilization of an acquired cisplatin resistance model to identify the potential role of Twist as a therapeutic target to reverse acquired cisplatin resistance in OC.
Incidental thyroid nodules are commonly detected on ultrasonography (US). This has contributed to the rapidly rising incidence of low-risk papillary thyroid carcinoma over the last 20 years. The ...appropriate diagnosis and management of these patients is based on the risk factors related to the patients as well as the thyroid nodules. The Korean Society of Thyroid Radiology (KSThR) published consensus recommendations for US-based management of thyroid nodules in 2011 and revised them in 2016. These guidelines have been used as the standard guidelines in Korea. However, recent advances in the diagnosis and management of thyroid nodules have necessitated the revision of the original recommendations. The task force of the KSThR has revised the Korean Thyroid Imaging Reporting and Data System and recommendations for US lexicon, biopsy criteria, US criteria of extrathyroidal extension, optimal thyroid computed tomography protocol, and US follow-up of thyroid nodules before and after biopsy. The biopsy criteria were revised to reduce unnecessary biopsies for benign nodules while maintaining an appropriate sensitivity for the detection of malignant tumors in small (1-2 cm) thyroid nodules. The goal of these recommendations is to provide the optimal scientific evidence and expert opinion consensus regarding US-based diagnosis and management of thyroid nodules.
Cancer chemotherapy resistance is one of the most critical obstacles in cancer therapy. One of the well-known mechanisms of chemotherapy resistance is the change in the mitochondrial death pathways ...which occur when cells are under stressful situations, such as chemotherapy. Mitophagy, or mitochondrial selective autophagy, is critical for cell quality control because it can efficiently break down, remove, and recycle defective or damaged mitochondria. As cancer cells use mitophagy to rapidly sweep away damaged mitochondria in order to mediate their own drug resistance, it influences the efficacy of tumor chemotherapy as well as the degree of drug resistance. Yet despite the importance of mitochondria and mitophagy in chemotherapy resistance, little is known about the precise mechanisms involved. As a consequence, identifying potential therapeutic targets by analyzing the signal pathways that govern mitophagy has become a vital research goal. In this paper, we review recent advances in mitochondrial research, mitophagy control mechanisms, and their implications for our understanding of chemotherapy resistance.
The cornea, with its delicate structure, is vulnerable to damage from physical, chemical, and genetic factors. Corneal transplantation, including penetrating and lamellar keratoplasties, can restore ...the functions of the cornea in cases of severe damage. However, the process of corneal transplantation presents considerable obstacles, including a shortage of available donors, the risk of severe graft rejection, and potentially life-threatening complications. Over the past few decades, mesenchymal stem cell (MSC) therapy has become a novel alternative approach to corneal regeneration. Numerous studies have demonstrated the potential of MSCs to differentiate into different corneal cell types, such as keratocytes, epithelial cells, and endothelial cells. MSCs are considered a suitable candidate for corneal regeneration because of their promising therapeutic perspective and beneficial properties. MSCs compromise unique immunomodulation, anti-angiogenesis, and anti-inflammatory properties and secrete various growth factors, thus promoting corneal reconstruction. These effects in corneal engineering are mediated by MSCs differentiating into different lineages and paracrine action via exosomes. Early studies have proven the roles of MSC-derived exosomes in corneal regeneration by reducing inflammation, inhibiting neovascularization, and angiogenesis, and by promoting cell proliferation. This review highlights the contribution of MSCs and MSC-derived exosomes, their current usage status to overcome corneal disease, and their potential to restore different corneal layers as novel therapeutic agents. It also discusses feasible future possibilities, applications, challenges, and opportunities for future research in this field.
To investigate the prognostic value of the expressions of programmed cell death ligand 1 (PD-L1) and immune checkpoint markers in residual tumors after neoadjuvant chemotherapy (NAC) for advanced ...high-grade serous ovarian cancer (HGSOC).
We collected pre- and post-NAC tumor samples from patients with advanced HGSOC between 2006 and 2017. Post-NAC tumor tissue samples were available for immunostaining from 131 patients. The expressions of PD-L1 and immune checkpoint markers were assessed by immunohistochemical staining and the status of tumor-infiltrating lymphocytes (TILs) was also evaluated. We examined whether there are significant associations between protein expression status and patient outcomes and whether significant changes in protein expression levels occurred in response to NAC.
PD-L1 expression in the tumor cells was evaluated in 113 patients, 12 (10.6%) of whom had high PD-L1 expression (≥25%) in post-NAC tissues. However, these high levels were not associated with progression-free survival (PFS; P = 0.348) or overall survival (OS; P = 0.699). Similarly, high stromal TILs ≥50%; n = 16 (15.0%) among the 107 patients evaluated did not show any significant impact on PFS (P = 0.250) or OS (P = 0.800). Moreover, an abundance of TILs (intraepithelial, CD8+, and Foxp3+) and the expression of immune checkpoint markers (PD-1, ICOS, and LAG-3) in residual tumors did not confer any significant survival benefit. The impact of NAC on PD-L1 expression and stromal TILs varied considerably among individual patients.
Although the expression of PD-L1 and immune checkpoint markers in residual tumors after NAC had no prognostic impact on survival in patients with HGSOC, post-NAC evaluation of these proteins in chemoresistant tumors may help select patients for immunotherapy trials.
•PD-L1 expression and stromal TILs were low in most residual tumors after NAC.•High expression of immune parameters did not show any significant impact on survival.•The impact of NAC on immune parameters varied considerably among individual patients.•This study highlights the importance of evaluating the post-NAC samples to guide adjuvant treatment.
PDF
