Piperlongumine regulates genes involved in the skin barrier in epidermal keratinocyte HaCaT cells.

Given that the skin is the largest tissue in the human body, performing external barrier functions with innate and adaptive immunity and undergoing substantial changes during aging, it is under investigation as a major target of various bioactive molecules. In the present study, we examined the biological activity of the senolytic piperlongumine by analyzing alterations in mRNA expression of notable skin genes using transformed aneuploid immortal epidermal keratinocytes, HaCaT cells. We observed that piperlongumine increased the mRNA expression of genes playing critical roles in skin barrier function. In addition, piperlongumine increased expression enzymes involved in the synthesis of ceramide, a major component of intercellular lipids. Furthermore, we measured the protein levels of various cytokines secreted by epidermal keratinocytes and found changes in the release of GRO-αßγ, CCL5, and MCP1. Additionally, we observed that piperlongumine treatment modulated the expression of keratinocyte-specific aging markers and influenced telomerase activity. Based on these findings, piperlongumine could regulate the physiological activity of epidermal keratinocytes to induce beneficial effects in human skin by regulating important skin-related genes.

Colon cancer: the 2023 Korean clinical practice guidelines for diagnosis and treatment.

Colorectal cancer is the third most common cancer in Korea and the third leading cause of death from cancer. Treatment outcomes for colon cancer are steadily improving due to national health screening programs with advances in diagnostic methods, surgical techniques, and therapeutic agents.. The Korea Colon Cancer Multidisciplinary (KCCM) Committee intends to provide professionals who treat colon cancer with the most up-to-date, evidence-based practice guidelines to improve outcomes and help them make decisions that reflect their patients' values and preferences. These guidelines have been established by consensus reached by the KCCM Guideline Committee based on a systematic literature review and evidence synthesis and by considering the national health insurance system in real clinical practice settings. Each recommendation is presented with a recommendation strength and level of evidence based on the consensus of the committee.

Mimicking chronic alcohol effects through a controlled and sustained ethanol release device.

Alcohol consumption, a pervasive societal issue, poses considerable health risks and socioeconomic consequences. Alcohol-induced hepatic disorders, such as fatty liver disease, alcoholic hepatitis, chronic hepatitis, liver fibrosis, and cirrhosis, underscore the need for comprehensive research. Existing challenges in mimicking chronic alcohol exposure in cellular systems, attributed to ethanol evaporation, necessitate innovative approaches. In this study, we developed a simple, reusable, and controllable device for examining the physiological reactions of hepatocytes to long-term alcohol exposure. Our approach involved a novel device designed to continuously release ethanol into the culture medium, maintaining a consistent ethanol concentration over several days. We evaluated device performance by examining gene expression patterns and cytokine secretion alterations during long-term exposure to ethanol. These patterns were correlated with those observed in patients with alcoholic hepatitis. Our results suggest that our ethanol-releasing device can be used as a valuable tool to study the mechanisms of chronic alcohol-mediated hepatic diseases at the cellular level. Our device offers a practical solution for studying chronic alcohol exposure, providing a reliable platform for cellular research. This innovative tool holds promise for advancing our understanding of the molecular processes involved in chronic alcohol-mediated hepatic diseases. Future research avenues should explore broader applications and potential implications for predicting and treating alcohol-related illnesses.

Ca2+ homeostasis and male fertility: a target for a new male contraceptive system.

Ca2+ is a key secondary messenger that determines sperm motility patterns. Mammalian sperm undergo capacitation, a process to acquire fertilizing ability, in the female reproductive tract. Capacitated sperm change their flagellar waveform to develop hyperactivated motility, which is crucial for successful sperm navigation to the eggs and fertilization. The sperm-specific channel, CATSPER, and an ATPase transporter, PMCA4, serve as major paths for Ca2+ influx and efflux, respectively, in sperm. The ionic paths coordinate Ca2+ homeostasis in the sperm, and their loss-of-function impairs sperm motility, to cause male infertility. In this review, we summarize the physiological significance of these two Ca2+ gates and suggest their potential applications in novel male contraceptives.

mFOLFIRINOX versus mFOLFOX 6 as adjuvant treatment for high-risk stage III colon cancer - the FROST trial: study protocol for a multicenter, randomized controlled, phase II trial.

BACKGROUND: High-risk stage III colon cancer has a considerably poorer prognosis than stage II and low-risk stage III colon cancers. Nevertheless, most guidelines recommend similar adjuvant treatment approaches for all these stages despite the dearth of research focusing on high-risk stage III colon cancer and the potential for improved prognosis with intensive adjuvant treatment. Given the the proven efficacy of triplet chemotherapy in metastatic colorectal cancer treatment, the goal of this study is to evaluate the oncologic efficacy and safety of mFOLFIRINOX in comparison to those of the current standard of care, mFOLFOX 6, as an adjuvant treatment for patients diagnosed with high-risk stage III colon cancer after radical resection. METHODS: This multicenter, randomized (1:1), open-label, phase II trial will assess and compare the effectiveness and toxicity of mFOLFIRINOX and mFOLFOX 6 in patients with high-risk stage III colon cancer after radical resection. The goal of the trial is to enroll 312 eligible patients, from 11 institutes, aged between 20 and 70 years, with an Eastern Cooperative Oncology Group (ECOG) performance status of 0-2, or between 70 and 75 with an ECOG performance status of 0. Patients will be randomized into two arms - Arm A, the experimental arm, and Arm B, the reference arm - and will receive 12 cycles of mFOLFIRINOX and mFOLFOX 6 every 2 weeks, respectively. The primary endpoint of this study is the 3-year disease-free survival, and secondary endpoints include the 3-year overall survival and treatment toxicity. DISCUSSION: The Frost trial would help determine the oncologic efficacy and safety of adjuvant triplet chemotherapy for high-risk stage III colon cancers and ultimately improve prognoses. TRIAL REGISTRATION: ClinicalTrials.gov NCT05179889, registered on 17 December 2021.

Prolonged stress response induced by chronic stress and corticosterone exposure causes adult neurogenesis inhibition and astrocyte loss in mouse hippocampus.

Chronic stress is a pervasive and complex issue that contributes significantly to various mental and physical health disorders. Using the previously established chronic unpredictable stress (CUS) model, which simulates human stress situations, it has been shown that chronic stress induces major depressive disorder (MDD) and memory deficiency. However, this established model is associated with several drawbacks, such as limited research reproducibility and the inability to sustain stress response. To resolve these issues, we developed a new CUS model (CUS+C) that included exogenous corticosterone exposure to induce continuous stress response. Thereafter, we evaluated the effect of this new model on brain health. Thus, we observed that the use of the CUS+C model decreased body and brain weight gain and induced an uncontrolled coat state as well as depressive-like behavior in adult mice. It also impaired learning memory function and cognitive abilities, reduced adult hippocampal neurogenesis as well as the number of hippocampal astrocytes, and downregulated glial fibrillary acidic protein expression in the brains of adult mice. These findings can promote the utilization and validity of the animal stress model and provide new information for the treatment of chronic stress-induced depressive and memory disorders.

Efficacy of a 1 day Rifaximin and Metronidazole Regimen and Mechanical Bowel Preparation for Preventing Surgical Site Infection in Minimally Invasive Colorectal Cancer Surgery: A Prospective Observational Study.

BACKGROUND: A combination of oral antibiotics and mechanical bowel preparation is recommended for patients scheduled to undergo elective colorectal surgery on the basis of recent large trials that have reported the superiority of this approach in preventing surgical site infections (SSIs). However, there are no standard recommendations for this approach. Therefore, in this study, we evaluated the efficacy of rifaximin and metronidazole and mechanical bowel preparation for preventing SSIs in cases of minimally invasive surgery for colorectal cancer. METHODS: This single-arm prospective observational study included 256 individuals. The primary end point was the rate of SSI. Rifaximin 400 mg and metronidazole 500 mg were administered twice daily (10 am and 10 pm), and mechanical bowel preparation was administered the day before the operation. RESULTS: After excluding 15 patients, 241 were enrolled. No adverse event occurred following the administration of oral antibiotics and mechanical bowel preparation; there was 100% compliance. The total SSI rate was 2.9%; the rates of incisional and organ/space SSIs were 1.2% and 1.7%, respectively. All patients were treated conservatively. Univariate analyses revealed preoperative anemia, hypoalbuminemia, and transfusion and postoperative transfusion were significantly associated with SSIs. DISCUSSION: A 1 day rifaximin and metronidazole regimen with mechanical bowel preparation for elective minimally invasive surgery for colorectal cancer was associated with a favorable SSI rate of 2.9%, safety, and high compliance. This approach is appropriate for inclusion in the current guidelines for perioperative management of patients scheduled to undergo minimally invasive surgery for colorectal cancer.

Computed tomography-assessed presarcopenia and clinical outcomes after laparoscopic surgery for rectal cancer.

PURPOSE: Previous studies have reported that presarcopenia negatively affects rectal cancer treatment. However, most studies have analyzed patients including majority of open surgery, and the association between presarcopenia and clinical outcomes after laparoscopic rectal cancer surgery remains unclear. This study aimed to evaluate the impact of presarcopenia on the clinical and oncological outcomes after laparoscopic rectal cancer surgery. METHODS: Three hundred and one patients undergoing laparoscopic rectal cancer surgery between December 2009 and May 2016 were enrolled. Body composition was assessed using computed tomography by measuring the muscle and fat areas at the third lumbar (L3) vertebra. The L3 skeletal muscle area was used to calculate the skeletal muscle index and evaluate presarcopenia. RESULTS: Presarcopenia was more common in older ( ≥ 70 years, P = 0.008) or female patients (P = 0.045). Patients with presarcopenia had decreased skeletal muscle area (P < 0.001), lower hemoglobin level (P = 0.034), longer time to first flatus (P < 0.001), and more frequent surgical site infection (P = 0.001). However, survival rates were not significantly different between those with and without presarcopenia. CONCLUSION: Computed tomography-assessed presarcopenia was associated with delayed functional recovery and increased surgical site infection, although it was not revealed as a prognostic factor for oncological outcomes.

Food web structure for high carbon retention in marine plankton communities.

Total annual net primary productions in marine and terrestrial ecosystems are similar. However, a large portion of the newly produced marine phytoplankton biomass is converted to carbon dioxide because of predation. Which food web structure retains high carbon biomass in the plankton community in the global ocean? In 6954 individual samples or locations containing phytoplankton, unicellular protozooplankton, and multicellular metazooplankton in the global ocean, phytoplankton-dominated bottom-heavy pyramids held higher carbon biomass than protozooplankton-dominated middle-heavy diamonds or metazooplankton-dominated top-heavy inverted pyramids. Bottom-heavy pyramids predominated, but the high predation impact by protozooplankton on phytoplankton or the vertical migration of metazooplankton temporarily changed bottom-heavy pyramids to middle-heavy diamonds or top-heavy inverted pyramids but returned to bottom-heavy pyramids shortly. This finding has profound implications for carbon retention by plankton communities in the global ocean.

Comparative detection of syndecan-2 methylation in preoperative and postoperative stool DNA in patients with colorectal cancer.

BACKGROUND: Early detection of colorectal cancer (CRC) is essential to reduce cancer-related morbidity and mortality. Stool DNA (sDNA) testing is an emerging method for early CRC detection. Syndecan-2 (SDC2) methylation is a potential biomarker for the sDNA testing. Aberrant DNA methylation is an early epigenetic event during tumorigenesis and can occur in the normal colonic mucosa during aging, which can compromise the sDNA test results. AIM: To determine whether methylated SDC2 in sDNA normalizes after surgical resection of CRC. METHODS: In this prospective study, we enrolled 151 patients with CRC who underwent curative surgical resection between September 2016 and May 2020. Preoperative stool samples were collected from 123 patients and postoperative samples were collected from 122 patients. A total of 104 samples were collected from both preoperative and postoperative patients. Aberrant promoter methylation of SDC2 in sDNA was assessed using linear target enrichment quantitative methylation-specific real-time polymerase chain reaction. Clinicopathological parameters were analyzed using the results of SDC2 methylation. RESULTS: Detection rates of SDC2 methylation in the preoperative and postoperative stool samples were 88.6% and 19.7%, respectively. Large tumor size (3 cm, P = 0.019) and advanced T stage (T3-T4, P = 0.033) were positively associated with the detection rate of SDC2 methylation before surgery. Female sex was associated with false positives after surgery (P = 0.030). Cycle threshold (CT) values were significantly decreased postoperatively compared with preoperative values (P < 0.001). The postoperative negative conversion rate for preoperatively methylated SDC2 was 79.3% (73/92). CONCLUSION: Our results suggested that the SDC2 methylation test for sDNA has acceptable sensitivity and specificity. However, small size and early T stage tumors are associated with a low detection rate of SDC2 methylation. As the cycle threshold values significantly decreased after surgery, SDC2 methylation test for sDNA might have a diagnostic value for CRC.

Safety of early Hartmann reversal during adjuvant chemotherapy in colorectal cancer: a pilot study.

Introduction: Most patients undergoing the Hartmann procedure for complicated colorectal cancer require chemotherapy because of their advanced status. Stoma created during the procedure is typically closed after the completion of postoperative chemotherapy. However, stomas can induce medical or surgical complications and disturb quality of life. This study aimed to evaluate the safety of Hartmann's reversal during postoperative chemotherapy. Methods: We conducted a retrospective review of electronic medical records. Between 2017 and 2021, 96 patients underwent Hartmann reversal for after colorectal cancer surgery. Among them, the number of patients who underwent Hartmann procedure with radical resection of complicated colorectal cancer and Hartmann reversal during adjuvant chemotherapy was 13. The clinical, surgical, and pathological characteristics of the patients were evaluated. Results: Eight and five patients had obstructions and perforations, respectively. Two patients with synchronous liver metastases underwent simultaneous liver resection and reversal simultaneously. Five and eight patients received adjuvant chemotherapy with capecitabine and FOLFOX, respectively. The median interval between the Hartmann procedure and reversal was 3.31 months (2.69-5.59). The median operative time for Hartmann's reversal was 190 min (100-335). The median hospital stay was 10 days (7-21). Four patients (30.8%) developed postoperative complications, and the rate of 3 or higher grade according to the Clavien-Dindo classification within 90 days postoperatively was 0%. Except for 1 patient who refused continuation of chemotherapy, 12 patients completed the planned chemotherapy. Median total duration of adjuvant chemotherapy was 6.78 months (5.98-8.48). There was no mortality. Conclusion: Early Hartmann reversal during adjuvant chemotherapy is tolerable and safe in carefully selected patients. In particular, it can be used as a therapeutic option for patients with complicated colorectal cancer with synchronous resectable metastases.

Short-term outcomes of Early versus conventional adjuvant chemotherapy in stage III colon cancer: randomized clinical trial.

BACKGROUND: Evidence is lacking regarding the earliest timing of initiating adjuvant chemotherapy to maximize its efficacy safely. A trial was designed and conducted to evaluate the safety and oncological efficacy of early adjuvant chemotherapy compared with conventional adjuvant chemotherapy. The short-term outcomes are reported here. METHODS: A multicentre, randomized (1 : 1), open-label, phase III trial was conducted comparing early adjuvant chemotherapy with conventional adjuvant chemotherapy in patients with stage III colon cancer. Patients who underwent radical surgery who had stage III colon cancer confirmed by histopathological assessment were screened and randomized into the early adjuvant chemotherapy arm or the conventional adjuvant chemotherapy arm. The primary endpoint was 3-year disease-free survival. The adjuvant chemotherapy with FOLFOX was delivered between postoperative day 10 and 14 in the early adjuvant chemotherapy arm, and between postoperative day 24 and 28 in the conventional adjuvant chemotherapy arm. Toxicity and quality of life were evaluated. RESULTS: Between 9 September 2011 and 6 March 2020, 443 patients consented to randomization at eight sites. The intention-to-treat population included 423 patients (209 in the early adjuvant chemotherapy arm and 214 in the conventional adjuvant chemotherapy arm), and the safety population included 380 patients (192 in the early adjuvant chemotherapy arm and 188 in the conventional adjuvant chemotherapy arm). There was no statistically significant difference in overall toxicity (28.1 per cent in the early adjuvant chemotherapy arm and 28.2 per cent in the conventional adjuvant chemotherapy arm, P = 0.244), surgical complications, and quality of life between the two arms. CONCLUSION: Adjuvant chemotherapy can be safely initiated 2 weeks after surgery with toxicity and quality of life comparable to conventional adjuvant chemotherapy for stage III colon cancer.

Anti­tumor properties of FoxO1 in YD­9 oral squamous cell carcinoma cells.

Oral squamous cell carcinoma (OSCC) is a tumor with a poor prognosis and a high recurrence rate. Despite its high annual incidence worldwide, appropriate therapeutic strategies have not yet been developed. Consequently, the 5­year survival rate for OSCC is low when advanced stages or recurrence is diagnosed. Forkhead transcriptional factor O1 (FoxO1) is a key mediator for maintaining cellular homeostasis. FoxO1 can function as a tumor suppressor as well as an oncogene depending on the cancer type. Therefore, the precise molecular functions of FoxO1 need to be validated, considering intracellular factors and the extracellular environment. To the best of our knowledge, however, the roles of FoxO1 in OSCC have not yet been defined. The present study examined FoxO1 levels under pathological conditions (oral lichen planus and oral cancer) and selected an appropriate OSCC cell line (YD­9). Crispr/Cas9 was used to generate FoxO1­deficient YD­9 cells in which the protein levels of phospho ERK and phospho STAT3 were upregulated, promoting cancer proliferation and migration. In addition, FoxO1 reduction increased the levels of the cell proliferation markers phospho H3 (Ser10) and PCNA. FoxO1 loss significantly reduced cellular ROS levels and apoptosis in YD­9 cells. Collectively, the present study demonstrated that FoxO1 exerted an anti­tumor effect by suppressing proliferation and migration/invasion but promoting oxidative stress­linked cell death in YD­9 OSCC cells.

Effects of Continuous Nutrition Care on Nutritional Status and Dietary Habits of Patients With Colorectal Cancer Receiving Adjuvant Chemotherapy After Surgery.

Patients with colorectal cancer may experience symptoms such as diarrhea, nausea, and anorexia, during surgery and chemotherapy, which can increase the risk of malnutrition. In addition, dietary habits play a key role in the onset of colorectal cancer; therefore, it is necessary to improve dietary habits to prevent recurrence during treatment after diagnosis. In this study, a clinical nutritionist conducted 4 interviews for patients diagnosed with colorectal cancer and scheduled for colectomy: before surgery, after surgery, 1st chemotherapy, and 2nd chemotherapy, and provided nutrition care for each treatment course to determine its effects on nutrition status and disease prognosis. Significant weight loss but no decrease in muscle mass was observed during treatment. Body fat mass, although not statistically significant, showed a decreasing tendency. The percentage of people who responded 'yes' to the below items increased after compared to before receiving nutrition education: 'I eat meat or eggs more than 5 times a week,' 'I eat seafood at least three times a week,' 'I eat vegetables at every meal,' 'I eat fruits every day,' and 'I eat milk or dairy products every day.' These results indicate that the patients changed their dietary habit from a monotonous eating pattern to a pattern of consuming various food groups after receiving nutrition education. These results suggest that continuous nutrition care by clinical dietitians, according to the patient's treatment process, can help improve the patient's nutritional status and establish healthy eating habits.

Maintenance therapy with Fluoropyrimidine and cetuximab or bevacizumab after first line FOLFOX-chemotherapy in metastatic colorectal cancer according to RAS or BRAFV600E mutation status.

PURPOSE: Fluoropyrimidine (FP) with oxaliplatin-based chemotherapy is the standard first-line treatment for metastatic colorectal cancer (mCRC); however, oxaliplatin-induced neuropathy critically affects the quality of life of patients. Maintenance strategies with FP plus bevacizumab have been well-established; nonetheless, the real-world outcomes of maintenance therapy with FP and cetuximab are unclear. We investigated the clinical outcomes of patients who underwent maintenance therapy with cetuximab. METHODS: We retrospectively identified and analyzed patients with mCRC who were treated between 2012 and 2021 with first-line oxaliplatin-based induction chemotherapy (IC) plus biologic agents (either cetuximab or bevacizumab), and underwent maintenance therapy (IC regimen without oxaliplatin) after IC. RESULTS: In total, 19 patients who were treated with mFOLFOX6 (FP/leucovorin/oxaliplatin) with cetuximab, and 26 patients who were treated with mFOLFOX6 with bevacizumab were included. In the cetuximab group, all patients were KRAS-, NRAS-, and BRAF-wild type, whereas most patients in the bevacizumab group harbored KRAS or BRAFV600E or NRAS mutants. During the maintenance treatment, seven patients (four [21%] in the cetuximab group and three [11%] in the bevacizumab group) achieved partial response after achieving nadir during induction chemotherapy. The disease control rates of maintenance therapy were 79% and 74% in the cetuximab and bevacizumab groups, respectively. The median progression-free survival of maintenance therapy and overall survival was 5.98 months and 32.4 months in the cetuximab group, and 4.83 months and 25.6 months in the bevacizumab group, respectively. CONCLUSIONS: Maintenance therapy with FP plus biologic agents (either bevacizumab or cetuximab) is a feasible strategy for appropriate mCRC patients according to their RAS/BRAF status. Further large-scale randomized studies are needed to validate the efficacy of anti-epidermal growth factor receptor-based maintenance therapy.

ATG9B Is a Poor Prognostic Marker Associated With Immune Evasion in Colon Adenocarcinoma.

BACKGROUND/AIM: Autophagy-related genes (ATGs) are involved in autophagy activation, which has a pleiotropic role in cancer development. However, the potential value of ATG expression levels in colon adenocarcinoma (COAD) is unclear. This study aimed to examine the modulation of ATG expression levels and their association with clinical and molecular aspects of COAD. MATERIALS AND METHODS: We used the clinical and molecular phenotypes and RNA sequencing datasets of the cancer genome atlas (TCGA)-COAD project using TCGAbiolinks and cBioPortal. Comparisons of ATG expression levels between tumor and normal tissues were performed using DESeq2 within R. Gene expression and immune cell infiltration levels were analyzed by TIMER. RESULTS: ATG9B had the highest expression levels among ATGs in COAD tissues compared to normal tissues and was related to advanced stage and poor prognosis in COAD. In addition, ATG9B expression was positively associated with the consensus molecular subtype 4 and chromosomal instability but negatively correlated with tumor mutation burden. Furthermore, high ATG9B expression levels were associated with low immune cell infiltration and decreased expression of natural killer cell activation genes. CONCLUSION: ATG9B is a poor prognostic biomarker driving immune evasion of COAD through negative correlation with immune cell infiltration.

The role of microRNAs in the molecular link between circadian rhythm and autism spectrum disorder.

Circadian rhythm regulates physiological cycles of awareness and sleepiness. Melatonin production is primarily regulated by circadian regulation of gene expression and is involved in sleep homeostasis. If the circadian rhythm is abnormal, sleep disorders, such as insomnia and several other diseases, can occur. The term 'autism spectrum disorder (ASD)' is used to characterize people who exhibit a certain set of repetitive behaviors, severely constrained interests, social deficits, and/or sensory behaviors that start very early in life. Because many patients with ASD suffer from sleep disorders, sleep disorders and melatonin dysregulation are attracting attention for their potential roles in ASD. ASD is caused by abnormalities during the neurodevelopmental processes owing to various genetic or environmental factors. Recently, the role of microRNAs (miRNAs) in circadian rhythm and ASD have gained attraction. We hypothesized that the relationship between circadian rhythm and ASD could be explained by miRNAs that can regulate or be regulated by either or both. In this study, we introduced a possible molecular link between circadian rhythm and ASD. We performed a thorough literature review to understand their complexity.

Hederacolchiside A1 Suppresses Autophagy by Inhibiting Cathepsin C and Reduces the Growth of Colon Cancer.

While autophagy degrades non-functional or unnecessary cellular components, producing materials for synthesizing cellular components, it can also provide energy for tumor development. Hederacolchiside A1 (HA1) derived from anemone raddeana has anticancer effects on several carcinomas by inducing apoptosis or exhibiting cytotoxicity, but the relationship with autophagy has not been studied. We investigated the association between HA1 and autophagy and evaluated its anticancer effect on colon cancer. HA1 induced accumulation of the autophagy-related markers LC3B and SQSTM1, with distinct vacuolar formation, unlike other autophagy inhibitors; the effects were similar to those of chloroquine. In addition, HA1 decreased the expression and proteolytic activity of lysosomal protein cathepsin C, reduced the growth of colon cancer cells in vitro, and inhibited tumor growth in vivo. It also reduced the expression of Ki-67 and cathepsin C in mouse tissues and reduced the growth of spheroids and organoids composed of cancer cells. Taken together, these results imply that HA1 regulates cell growth and autophagy and has potential as a promising therapeutic agent in colon cancer.

Internal ribosomal entry site-mediated translational activity of nitric oxide synthase 2.

The internal ribosome entry site (IRES) is a unique structure found in the 5' untranslated region (5'-UTR) of specific messenger RNAs (mRNAs) that allows ribosomes to bind and initiate translation without the need for a cap structure. In this study, we investigated the presence and functional properties of the IRES activity of nitric oxide synthase 2 (NOS2) mRNA, which encodes an enzyme that produces nitric oxide in response to various stimuli such as inflammation. Nitric oxide is a signaling molecule that plays a crucial role in various physiological processes, including immune responses and neuronal signaling. Our results showed the existence of IRES activity in the 5'-UTR of Nos2 mRNA in various cell types. IRES-mediated translation of NOS2 mRNA was higher in neuronal cells and its activity increased in response to lipopolysaccharide (LPS). Despite inhibition of cap-dependent translation, nitrite production was partially maintained. These results demonstrate the presence of IRES activity in the 5'-UTR of NOS2 mRNA and suggest that IRES-mediated translation plays a key role in controlling nitric oxide production in response to LPS, an inflammatory stimulus.

c-Abl Regulates the Pathological Deposition of TDP-43 via Tyrosine 43 Phosphorylation.

Non-receptor tyrosine kinase, c-Abl plays a role in the pathogenesis of several neurodegenerative disorders such as Alzheimer's disease and Parkinson's disease. Here, we found that TDP-43, which was one of the main proteins comprising pathological deposits in amyotrophic lateral sclerosis (ALS), is a novel substrate for c-Abl. The phosphorylation of tyrosine 43 of TDP-43 by c-Abl led to increased TDP-43 levels in the cytoplasm and increased the formation of G3BP1-positive stress granules in SH-SY5Y cells. The kinase-dead mutant of c-Abl had no effect on the cytoplasmic localization of TDP-43. The expression of phosphor-mimetic mutant Y43E of TDP-43 in primary cortical neurons accumulated the neurite granule. Furthermore, the phosphorylation of TDP-43 at tyrosine 43 by c-Abl promoted the aggregation of TDP-43 and increased neuronal cell death in primary cortical neurons, but not in c-Abl-deficient primary cortical neurons. Identification of c-Abl as the kinase of TDP43 provides new insight into the pathogenesis of ALS.