Mild Oxidative Stress Induced by Sodium Arsenite Reduces Lipocalin-2 Expression Levels in Cortical Glial Cells.

Astrocytes and microglia, the most abundant glial cells in the central nervous system, are involved in maintaining homeostasis in the brain microenvironment and in the progression of various neurological disorders. Lipocalin-2 (LCN2) is a small secretory protein that can be transcriptionally upregulated via nuclear factor kappa B (NF-κB) signaling. It is synthesized and secreted by glial cells, resulting in either the restoration of damaged neural tissues or the induction of neuronal apoptosis in a context-dependent manner. It has recently been reported that when glial cells are under lipopolysaccharide-induced inflammatory stress, either reduced production or accelerated degradation of LCN2 can alleviate neurotoxicity. However, the regulatory mechanisms of LCN2 in glial cells are not yet fully understood. In this study, we used primary astroglial-enriched cells which produce LCN2 and found that the production of LCN2 could be reduced by sodium arsenite treatment. Surprisingly, the reduced LCN2 production was not due to the suppression of NF-κB signaling. Mild oxidative stress induced by sodium arsenite treatment activated antioxidant responses and downregulated Lcn2 expression without reducing the viability of astroglial-enriched cells. Intriguingly, reduced LCN2 production could not be achieved by simple activation of the nuclear factor erythroid-2-related factor 2 (Nrf2)-Kelch-like ECH-associated protein 1 (Keap1) pathway in astroglial-enriched cells. Thus, it appears that mild oxidative stress, occurring in an Nrf2-independent manner, is required for the downregulation of Lcn2 expression. Taken together, our findings provide new insights into the regulatory mechanisms of LCN2 and suggest that mild oxidative stress may alter LCN2 homeostasis, even under neuroinflammatory conditions.

Synergistic Renoprotective Effect of Melatonin and Zileuton by Inhibition of Ferroptosis via the AKT/mTOR/NRF2 Signaling in Kidney Injury and Fibrosis.

According to recent evidence, ferroptosis is a major cell death mechanism in the pathogenesis of kidney injury and fibrosis. Despite the renoprotective effects of classical ferroptosis inhibitors, therapeutic approaches targeting kidney ferroptosis remain limited. In this study, we assessed the renoprotective effects of melatonin and zileuton as a novel therapeutic strategy against ferroptosis-mediated kidney injury and fibrosis. First, we identified RSL3-induced ferroptosis in renal tubular epithelial HK-2 and HKC-8 cells. Lipid peroxidation and cell death induced by RSL3 were synergistically mitigated by the combination of melatonin and zileuton. Combination treatment significantly downregulated the expression of ferroptosis-associated proteins, 4-HNE and HO-1, and upregulated the expression of GPX4. The expression levels of p-AKT and p-mTOR also increased, in addition to that of NRF2 in renal tubular epithelial cells. When melatonin (20 mg/kg) and zileuton (20 mg/kg) were administered to a unilateral ureteral obstruction (UUO) mouse model, the combination significantly reduced tubular injury and fibrosis by decreasing the expression of profibrotic markers, such as α-SMA and fibronectin. More importantly, the combination ameliorated the increase in 4-HNE levels and decreased GPX4 expression in UUO mice. Overall, the combination of melatonin and zileuton was found to effectively ameliorate ferroptosis-related kidney injury by upregulating the AKT/mTOR/ NRF2 signaling pathway, suggesting a promising therapeutic strategy for protection against ferroptosis-mediated kidney injury and fibrosis.

Vactosertib, TGF-ß receptor I inhibitor, augments the sensitization of the anti-cancer activity of gemcitabine in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) exhibits a pronounced extracellular matrix (ECM)-rich response, which is produced by an excessive amount of transforming growth factor ß (TGF-ß), resulting in tumor progression and metastasis. In addition, TGF-ß signaling contributes to rapidly acquired resistance and incomplete response to gemcitabine. Recently, selective inhibitors of the TGF-ß signaling pathway have shown promise in PDAC treatment, particularly as an option for augmenting responses to chemotherapy. Here, we investigated the synergistic anticancer effects of a small-molecule TGF-ß receptor I kinase inhibitor (vactosertib/EW-7197) in the presence of gemcitabine, and its mechanism of action in pancreatic cancer. Vactosertib sensitized pancreatic cancer cells to gemcitabine by synergistically inhibiting their viability. Importantly, the combination of vactosertib and gemcitabine significantly attenuated the expression of major ECM components, including collagens, fibronectin, and α-SMA, in pancreatic cancer compared with gemcitabine alone. This resulted in potent induction of mitochondrial-mediated apoptosis, gemcitabine-mediated cytotoxicity, and inhibition of tumor ECM by vactosertib. Additionally, the combination decreased metastasis through inhibition of migration and invasion, and exhibited synergistic anti-cancer activity by inhibiting the TGF-ß/Smad2 pathway in pancreatic cancer cells. Furthermore, co-treatment significantly suppressed tumor growth in orthotopic models. Therefore, our findings demonstrate that vactosertib synergistically increased the antitumor activity of gemcitabine via inhibition of ECM component production by inhibiting the TGF-ß/Smad2 signaling pathway. This suggests that the combination of vactosertib and gemcitabine may be a potential treatment option for patients with pancreatic cancer.

A novel DDR1 inhibitor enhances the anticancer activity of gemcitabine in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is an extracellular matrix (ECM)-rich carcinoma, which promotes chemoresistance by inhibiting drug diffusion into the tumor. Discoidin domain receptor 1 (DDR1) increases tumor progression and drug resistance by binding to collagen, a major component of tumor ECM. Therefore, DDR1 inhibition may be helpful in cancer therapeutics by increasing drug delivery efficiency and improving drug sensitivity. In this study, we developed a novel DDR1 inhibitor, KI-301690 and investigated whether it could improve the anticancer activity of gemcitabine, a cytotoxic agent widely used for the treatment of pancreatic cancer. KI-301690 synergized with gemcitabine to suppress the growth of pancreatic cancer cells. Importantly, its combination significantly attenuated the expression of major tumor ECM components including collagen, fibronectin, and vimentin compared to gemcitabine alone. Additionally, this combination effectively decreased mitochondrial membrane potential (MMP), thereby inducing apoptosis. Further, the combination synergistically inhibited cell migration and invasion. The enhanced anticancer efficacy of the co-treatment could be explained by the inhibition of DDR1/PYK2/FAK signaling, which significantly reduced tumor growth in a pancreatic xenograft model. Our results demonstrate that KI-301690 can inhibit aberrant ECM expression by DDR1/PYK2/FAK signaling pathway blockade and attenuation of ECM-induced chemoresistance observed in desmoplastic pancreatic tumors, resulting in enhanced antitumor effect through effective induction of gemcitabine apoptosis.

Lidocaine enhances the efficacy of palbociclib in triple-negative breast cancer.

The use of anesthetics in the surgical resection of tumors may influence the prognosis of cancer patients. Lidocaine, a local anesthetic, is known to act as a chemosensitizer and relieve pain in some cancers. In addition, palbociclib, a potent cyclin-dependent kinase (CDK) 4/6 inhibitor, has been approved for chemotherapy of advanced breast cancer. However, recent studies have revealed the acquired resistance of breast cancer cells to palbociclib. Therefore, the development of combination therapies that can extend the efficacy of palbociclib or delay resistance is crucial. This study investigated whether lidocaine would enhance the efficacy of palbociclib in breast cancer. Lidocaine synergistically suppressed the growth and proliferation of breast cancer cells by palbociclib. The combination treatment showed an increased cell cycle arrest in the G0/G1 phase by decreasing retinoblastoma protein (Rb) and E2F1 expression. In addition, it increased apoptosis by loss of mitochondrial membrane potential as observed by increases in cytochrome c release and inhibition of mitochondria-mediated protein expression. Additionally, it significantly reduced epithelial-mesenchymal transition and PI3K/AKT/GSK3ß signaling. In orthotopic breast cancer models, this combination treatment significantly inhibited tumor growth and increased tumor cell apoptosis compared to those treated with a single drug. Taken together, this study demonstrates that the combination of palbociclib and lidocaine has a synergistic anti-cancer effect on breast cancer cells by the inhibition of the PI3K/AKT/GSK3ß pathway, suggesting that this combination could potentially be an effective therapy for breast cancer.

Effectiveness of maturity of Rubus occidentalis on hyperalgesia induced by acidic saline injection in rats.

BACKGROUND: Rubus occidentalis, also known as black raspberry, contains several bioactive components that vary depending on the maturity of the fruit. The goal of this study was to evaluate the efficacy of immature Rubus occidentalis extract(iROE) on acid-induced hyperalgesia, investigate the mechanism involved, and compare the antihyperalgesic effect of immature and mature ROEs. METHODS: In adult male Sprague-Dawley rats, chronic muscle pain was induced via two injections of acidic saline into one gastrocnemius muscle. To evaluate the dose response, the rats were injected intraperitoneally with 0.9% saline or iROE (10, 30, 100, or 300 mg/kg) following hyperalgesia development. To evaluate the mechanism underlying iROE-induced analgesia, the rats were injected intraperitoneally with saline, yohimbine 2 mg/kg, dexmedetomidine 50 µg/kg, prazosin 1 mg/kg, atropine 5 mg/kg, mecamylamine 1 mg/kg, or naloxone 5 mg/kg 24 h after hyperalgesia development, followed by iROE 300 mg/kg administration. To compare immature versus mature ROE, the rats were injected with mature ROE 300 mg/kg and immature ROE 300 mg/kg after hyperalgesia development. For all experiments, the mechanical withdrawal threshold(MWT) was evaluated using von Frey filaments before the first acidic saline injection, 24 h after the second injection, and at various time points after drug administration. Data were analysed using multivariate analysis of variance(MANOVA) and the linear mixed-effects model(LMEM). We compared the MWT at each time point using analysis of variance with the Bonferroni correction. RESULTS: The iROE 300 mg/kg injection resulted in a significant increase in MWT compared with the control, iROE 30 mg/kg, and iROE 100 mg/kg injections at ipsilateral and contralateral sites. The iROE injection together with yohimbine, mecamylamine, or naloxone significantly decreased the MWT compared with iROE alone, whereas ROE together with dexmedetomidine significantly increased the MWT. According to MANOVA, the effects of immature and mature ROEs were not significantly different; however, the LMEM presented a significant difference between the two groups. CONCLUSIONS: Immature R. occidentalis showed antihyperalgesic activity against acid-induced chronic muscle pain, which may be mediated by the α2-adrenergic, nicotinic cholinergic, and opioid receptors. The iROE displayed superior tendency regarding analgesic effect compared to mature ROE.

Evaluation of the skin phototoxicity of systemically administered pharmaceuticals in Sprague-Dawley rats.

In vivo phototoxicity testing is important for predicting drug-induced phototoxicity in humans. Currently, there is no internationally validated in vivo test method for the photosafety evaluation of pharmaceuticals. In this study, we evaluated the phototoxicity of systemically administered drugs using SD rats. We first determined the appropriate ultraviolet A (UVA) dose using 8-methoxypsoralen, a well-known phototoxic drug. Compared to lower and higher UVA doses, we found that a UVA dose of 10 J/cm2 allowed for the detection of phototoxic responses in both a dose- and time-dependent manner. We next performed a phototoxicity study using seven pharmaceutical drugs which included known phototoxic and non-phototoxic drugs using a UVA dose of 10 J/cm2. In order to improve the accuracy of our assessment, we evaluated both gross skin findings as well as histopathological findings. Using gross skin findings alone resulted in an accuracy of 85.7% which could be increased to 100% accuracy when the gross skin findings were combined with histopathological findings. This study suggests that the inclusion of histopathological findings increases the accuracy of the phototoxicity evaluation of systemically administered drugs in SD rats. In conclusion, we found that for studying drug-induced phytotoxicity, a 10 J/cm2 UVA dose serves as the optimal radiation dose, and that the inclusion of histopathological findings increases the accuracy of the phototoxicity evaluation of the drugs.

Self-Injurious Thoughts and Behaviors Interview-Korean Version: Psychometric Properties.

OBJECTIVE: There is currently no structured interview tool developed that comprehensively evaluates self-injurious thoughts and behaviors (SITB) in Korea. The Self-injurious Thoughts and Behaviors Interview (SITBI) collectively measures suicidal ideation, plans, gestures, attempts, and non-suicidal self-injuries (NSSI). The SITBI's reliability and validity have been established with it being widely used in English speaking countries. This study evaluated the psychometric validity of the Korean version of the SITBI (SITBI-K). METHODS: The SITBI's validity as a diagnostic assessment tool for NSSI and suicidal behavior disorder (SBD), as defined by the Diagnostic and Statistical Manual of Mental Disorders-5th edition, was examined. Analyses were performed on 108 university students reporting experiences of suicidal thoughts and behaviors (female 84.26%, mean age=22.10, ±SD 3.33). RESULTS: The SITBI-K displayed excellent interrater reliability, with a credible test-retest reliability at two months. Construct validity examined the correlation between the SITBI-K's modules and approved the self-report results. Appropriate convergent and discriminant validities were obtained for suicidal ideation, plans, gestures, attempts, and NSSI. CONCLUSION: The SITBI-K showed excellent psychometric validity at a level comparable to the original. Its clinical utility for both NSSI and SBD diagnoses was confirmed.

Pharmacological strategies to prevent postoperative delirium: a systematic review and network meta-analysis.

BACKGROUND: Postoperative delirium (POD) is a condition of cerebral dysfunction and a common complication after surgery. This study aimed to compare and determine the relative efficacy of pharmacological interventions for preventing POD using a network meta-analysis. METHODS: We performed a systematic and comprehensive search to identify and analyze all randomized controlled trials until June 29, 2020, comparing two or more pharmacological interventions, including placebo, to prevent or reduce POD. The primary outcome was the incidence of POD. We performed a network meta-analysis and used the surface under the cumulative ranking curve (SUCRA) values and rankograms to present the hierarchy of the pharmacological interventions evaluated. RESULTS: According to the SUCRA value, the incidence of POD decreased in the following order: the combination of propofol and acetaminophen (86.1%), combination of ketamine and dexmedetomidine (86.0%), combination of diazepam, flunitrazepam, and pethidine (84.8%), and olanzapine (75.6%) after all types of anesthesia; combination of propofol and acetaminophen (85.9%), combination of ketamine and dexmedetomidine (83.2%), gabapentin (82.2%), and combination of diazepam, flunitrazepam, and pethidine (79.7%) after general anesthesia; and ketamine (87.1%), combination of propofol and acetaminophen (86.0%), and combination of dexmedetomidine and acetaminophen (66.3%) after cardiac surgery. However, only the dexmedetomidine group showed a lower incidence of POD than the control group after all types of anesthesia and after general anesthesia. CONCLUSIONS: Dexmedetomidine reduced POD compared with the control group. The combination of propofol and acetaminophen and the combination of ketamine and dexmedetomidine seemed to be effective in preventing POD. However, further studies are needed to determine the optimal pharmacological intervention to prevent POD.

Pharmacologic interventions for postoperative nausea and vomiting after thyroidectomy: A systematic review and network meta-analysis.

OBJECTIVE: To determine the effectiveness of pharmacologic interventions for preventing postoperative nausea and vomiting (PONV) in patients undergoing thyroidectomy. DESIGN: Systematic review and network meta-analysis (NMA). DATA SOURCES: MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Google Scholar. ELIGIBILITY CRITERIA, PARTICIPANTS, AND INTERVENTIONS: Randomized clinical trials that investigated the efficacy of pharmacologic interventions in preventing PONV in patients undergoing thyroidectomy were included. The primary endpoints were the incidences of postoperative nausea and vomiting (PONV), postoperative nausea (PON), postoperative vomiting (POV), use of rescue antiemetics, and incidence of complete response in the overall postoperative phases. The secondary endpoints were the same parameters assessed in the early, middle, and late postoperative phases. The surface under the cumulative ranking curve (SUCRA) values and rankograms were used to present the hierarchy of pharmacologic interventions. RESULTS: Twenty-six studies (n = 3,467 patients) that investigated 17 different pharmacologic interventions were included. According to the SUCRA values, the incidence of PONV among the overall postoperative phases was lowest with propofol alone (16.1%), followed by palonosetron (27.5%), and with tropisetron (28.7%). The incidence of PON among the overall postoperative phases was lowest with propofol alone (11.8%), followed by tropisetron and propofol combination (14%), and ramosetron and dexamethasone combination (18.0%). The incidence of POV among the overall postoperative phases was lowest with tropisetron and propofol combination (2.2%), followed by ramosetron and dexamethasone combination (23.2%), and tropisetron alone (37.3%). The least usage of rescue antiemetics among the overall postoperative phases and the highest complete response was observed with tropisetron and propofol combination (3.9% and 96.6%, respectively). CONCLUSION: Propofol and tropisetron alone and in combination, and the ramosetron and dexamethasone combination effectively prevented PONV, PON, POV in patients undergoing thyroidectomy, with some heterogeneity observed in this NMA of full-text reports. Their use minimized the need for rescue antiemetics and enhanced the complete response. TRIAL REGISTRATION NUMBER: CRD42018100002.

Evaluation of skin phototoxicity of transdermally administered pharmaceuticals in Sprague-Dawley rats.

Some drugs cause phototoxicity in humans when exposed to light, thus there is a need for an in vivo phototoxicity test to evaluate them. However, an in vivo phototoxicity test method to evaluate this has not been established. This study aimed to establish an in vivo phototoxicity test method for transdermally administered drugs. For this, we evaluated the phototoxicity using Sprague-Dawley (SD) rats for transdermal administered drugs and we studied the appropriate UVA dose using 8-methoxypsalen, which is a well-known phototoxic drug. We found that a UVA dose of 15 J/cm2 was dose and time dependent response compared to other UVA doses. We performed the Minimum Erythema Dose (MED) test because UVB can cause skin irritation by itself and selected 0.01 J/cm2 as an appropriate dose of UVB. Using the selected UVA and UVB doses, we performed a phototoxicity study of 6 pharmaceutical drugs, which included phototoxic and non-phototoxic drugs. As a result of the phototoxicity test, 100% accuracy was obtained when compared with previous studies. In addition, we performed histopathology to confirm the new findings. We found that histopathology can be used as an additional indicator of phototoxicity test for transdermally administered drugs.

Pharmacologic interventions for postoperative nausea and vomiting after thyroidectomy: A protocol for systematic review and network meta-analysis.

BACKGROUND: We aimed to perform a network meta-analysis (NMA) to quantify and rank the efficacy and safety of the pharmacologic interventions for prophylactic use for postoperative nausea and vomiting (PONV) in patients undergoing thyroidectomies. METHODS: A systematic and comprehensive search will be performed using MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), and Google Scholar, beginning from their inceptions to February 2019. Only randomized clinical trials on the efficacy and safety of pharmacologic interventions for prophylactic use in patients undergoing thyroidectomies will be included.The primary endpoints will be the incidences of postoperative nausea (PON), postoperative vomiting (POV), and PONV in the early, middle, late, and overall phases. The severity of PON, POV, and PONV; the use of rescue antiemetics; the incidence of complete response; and safety issues, such as headache, dizziness, drowsiness, and constipation, will be also assessed.We will conduct both pairwise meta-analysis and NMA. We will use surface under the cumulative ranking curve (SUCRA) values and rankograms to present the hierarchy of pharmacologic interventions. A comparison-adjusted funnel plot will be used to assess the presence of small-study effects. The quality of the studies included will be assessed using the risk of bias tool 2.0. All statistical analyses will be performed using Stata SE version 15.0. RESULTS: The results of this systematic review and NMA will be published in a peer-reviewed journal. CONCLUSION: This systematic review and NMA will provide a comprehensive and convincing evidence summary of prophylactic pharmacologic interventions for PONV after a thyroidectomy. TRIAL REGISTRATION NUMBER: CRD42018100002.

The Mechanism of p53 Rescue by SUSP4.

p53 is an important tumor-suppressor protein deactivation of which by mdm2 results in cancers. A SUMO-specific protease 4 (SUSP4) was shown to rescue p53 from mdm2-mediated deactivation, but the mechanism is unknown. The discovery by NMR spectroscopy of a "p53 rescue motif" in SUSP4 that disrupts p53-mdm2 binding is presented. This 29-residue motif is pre-populated with two transient helices connected by a hydrophobic linker. The helix at the C-terminus binds to the well-known p53-binding pocket in mdm2 whereas the N-terminal helix serves as an affinity enhancer. The hydrophobic linker binds to a previously unidentified hydrophobic crevice in mdm2. Overall, SUSP4 appears to use two synergizing modules, the p53 rescue motif described here and a globular-structured SUMO-binding catalytic domain, to stabilize p53. A p53 rescue motif peptide exhibits an anti-tumor activity in cancer cell lines expressing wild-type p53. A pre-structures motif in the intrinsically disordered proteins is thus important for target recognition.

A pre-structured helix in the intrinsically disordered 4EBP1.

The eIF4E-binding protein 1 (4EBP1) has long been known to be completely unstructured without any secondary structures, which contributed significantly to the proposal of the induced fit mechanism for target binding of intrinsically disordered proteins. We show here that 4EBP1 is not completely unstructured, but contains a pre-structured helix.

Understanding pre-structured motifs (PreSMos) in intrinsically unfolded proteins.

Intrinsically unfolded proteins (IUPs) do not obey the golden rule of structural biology, 3D structure = function, as they manifest their inherent functions without resorting to three-dimensional structures. Absence of a compact globular topology in these proteins strongly implies that their ligand recognition processes should involve factors other than spatially well-defined binding pockets. Heteronuclear multidimensional (HetMulD) NMR spectroscopy assisted with a stable isotope labeling technology is a powerful tool for quantitatively investigating detailed structural features in IUPs. In particular, it allows us to delineate the presence and locations of pre-structured motifs (PreSMos) on a per-residue basis. PreSMos are the transient local structural elements that presage target-bound conformations and act as specificity determinants for IUP recognition by target proteins. Here, we present a brief chronicle of HetMulD NMR studies on IUPs carried out over the past two decades along with a discussion on the functional significance of PreSMos in IUPs.