The effects of short-term hypoxia on human mesenchymal stem cell proliferation, viability and p16(INK4A) mRNA expression: Investigation using a simple hypoxic culture system with a deoxidizing agent

A hypoxic environment is thought to be important for the maintenance of stemness and suppressing cell senescence, in stem cells. Therefore, a hypoxic condition is induced during cell expansion and/or induction of intended differentiation. However, the induction of these conditions requires a specially equipped hypoxia chamber and expensive gas mixtures, which are expensive and space-consuming. Owing to these restrictions, appropriate hypoxic conditions cannot be provided during cell transportation, which is increasingly required for regenerative medicine. Hence, a simple and economical culture system is required. The purpose of this study was to investigate the effects of short-term hypoxic conditions on human mesenchymal stem cell (MSC) proliferation, viability, and senescence, utilizing the CulturePal system (CulturePal-Zero and CulturePal-Five), a novel and simple hypoxic culture system with a built-in deoxidizing agent. The O₂ concentration in the CulturePal-Zero was observed to reduce to <0.1% within 1 h, and to 5% within 24 h in the CulturePal-Five system. Cell proliferation under these hypoxic conditions showed a sharp increase at 5% O₂ concentration, and no noticeable cell death was observed even at severe hypoxic conditions (<0.1% O₂) up to 72h. The p16INK4A (cell senescence marker) mRNA expression was retained under hypoxic conditions up to 72h, but it was up-regulated under normoxic conditions. Interestingly, the p16INK4A expression altered proportionately to the O₂ concentration. These results indicated that the short-term hypoxic condition, at an approximate O₂ concentration of 5%, would be suitable for promoting cell proliferation and repressing cell senescence, without aggravating the MSC viability. Therefore, the CulturePal systems may be suitable for providing an appropriate hypoxic condition in stem cell research and transportation

The BH3-Only SNARE BNip1 Mediates Photoreceptor Apoptosis in Response to Vesicular Fusion Defects

SummaryIntracellular vesicular transport is important for photoreceptor function and maintenance. However, the mechanism underlying photoreceptor degeneration in response to vesicular transport defects is unknown. Here, we report that photoreceptors undergo apoptosis in a zebrafish β-soluble N-ethylmaleimide-sensitive factor attachment protein (β-SNAP) mutant. β-SNAP cooperates with N-ethylmaleimide-sensitive factor to recycle the SNAP receptor (SNARE), a key component of the membrane fusion machinery, by disassembling the cis-SNARE complex generated in the vesicular fusion process. We found that photoreceptor apoptosis in the β-SNAP mutant was dependent on the BH3-only protein BNip1. BNip1 functions as a component of the syntaxin-18 SNARE complex and regulates retrograde transport from the Golgi to the endoplasmic reticulum. Failure to disassemble the syntaxin-18 cis-SNARE complex caused BNip1-dependent apoptosis. These data suggest that the syntaxin-18 cis-SNARE complex functions as an alarm factor that monitors vesicular fusion competence and that BNip1 transforms vesicular fusion defects into photoreceptor apoptosis

Group 2 innate lymphoid cells support hematopoietic recovery under stress conditions

The cell-cycle status of hematopoietic stem and progenitor cells (HSPCs) becomes activated following chemotherapy-induced stress, promoting bone marrow (BM) regeneration; however, the underlying molecular mechanism remains elusive. Here we show that BM-resident group 2 innate lymphoid cells (ILC2s) support the recovery of HSPCs from 5-fluorouracil (5-FU)-induced stress by secreting granulocyte-macrophage colony-stimulating factor (GM-CSF). Mechanistically, IL-33 released from chemosensitive B cell progenitors activates MyD88-mediated secretion of GM-CSF in ILC2, suggesting the existence of a B cell-ILC2 axis for maintaining hematopoietic homeostasis. GM-CSF knockout mice treated with 5-FU showed severe loss of myeloid lineage cells, causing lethality, which was rescued by transferring BM ILC2s from wild-type mice. Further, the adoptive transfer of ILC2s to 5-FU-treated mice accelerates hematopoietic recovery, while the reduction of ILC2s results in the opposite effect. Thus, ILC2s may function by "sensing" the damaged BM spaces and subsequently support hematopoietic recovery under stress conditions.Sudo T., Motomura Y., Okuzaki D., et al. Group 2 innate lymphoid cells support hematopoietic recovery under stress conditions. Journal of Experimental Medicine 218, e20200817 (2021); https://doi.org/10.1084/jem.20200817

High Expression of Dihydropyrimidine Dehydrogenase in Lung Adenocarcinoma is Associated With Mutations in Epidermal Growth Factor Receptor: Implications for the Treatment of Non?Small-Cell Lung Cancer Using 5-Fluorouracil

BackgroundIt has been shown that 5-fluorouracil (5-FU) sensitivity in patients with non?small-cell lung cancer (NSCLC) is associated with epidermal growth factor receptor (EGFR) mutation status. However, the relationship between dihydropyrimidine dehydrogenase (DPD), a 5-FU degrading enzyme, and EGFR mutation status is unknown. Here, we focus on clinicopathologic factors and in vitro correlations between DPD expression and EGFR mutation status.Patients and MethodsEGFR mutations and messenger RNA (mRNA) levels of DPD and thymidylate synthase (TS) were analyzed in 47 resected NSCLC tumors by laser-capture microdissection. In addition, relationships between EGFR mutation status and the immunohistochemical expression of DPD and TS in 49 patients with primary NSCLC who were treated with a 5-FU derivative of S-1 postoperatively were examined. Correlations among clinicopathologic factors were evaluated. The effect of epidermal growth factor on DPD expression was also investigated in vitro in various cell lines.ResultsAdenocarcinoma in situ showed significantly higher DPD mRNA levels and more EGFR mutation frequency than other histological types (P < .05). DPD immunopositive cases were more frequently observed in adenocarcinoma, in females, and in nonsmokers. DPD immunopositive cases were correlated with EGFR mutation status (P < .003). The prognoses of wild-type EGFR and mutated EGFR populations were similarly favorable with postoperative S-1 treatment, which overcomes the problem of 5-FU degradation in mutated EGFR. In vitro, EGFR-mutated cell lines showed high DPD mRNA and protein expression.ConclusionHigh DPD expression was shown to be correlated with EGFR mutation in adenocarcinoma cells and tissues. Clinicians should take this finding into consideration when using 5-FU to treat patients with NSCLC

Solitary metastasis to a superior mediastinal lymph node after distal gastrectomy for gastric cancer: a case report

Abstract Background Mediastinal lymph node metastases occasionally occur in patients of advanced gastric cancer of the cardia with esophageal invasion, but they rarely occur in patients with gastric cancer of other sites. This report describes a case of a solitary metastasis to t a superior mediastinal lymph node after distal gastrectomy for gastric cancer of the antrum. Case presentation A 70-year-old man underwent curative distal gastrectomy for advanced gastric cancer of the antrum (pT2pN2M0, stage IIB). Postoperatively, he underwent adjuvant chemotherapy with S-1 (100 mg/day). Although the serum levels of his tumor markers increased after surgery, computed tomography scans did not detect evidence of early recurrence in the superior mediastinum. However, a 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) scan showed accumulation of fluorodeoxyglucose in the upper mediastinum with no evidence of recurrence elsewhere. Therefore, a solitary superior mediastinal lymph node was suspected to have a metastatic lesion derived from the gastric cancer. The patient underwent tumor resection right mini-thoracotomy two years and three months following gastrectomy. A pathological examination demonstrated moderately differentiated adenocarcinoma, confirming that it was a metastatic adenocarcinoma from the gastric cancer. The patient developed recurrences in the superior mediastinum and several right costa six months following the second surgery. He was treated with chemotherapy, but he died 18 months after the second operation. Conclusion We present a rare case of a solitary metastasis to a superior mediastinal lymph node after distal gastrectomy for gastric cancer. An FDG-PET scan is useful for the diagnosis of mediastinal lymph node metastasis in gastric cancer. Metastasis to the superior mediastinal lymph nodes from gastric cancer in sites other than the cardia suggests systemic expansion of gastric cancer, and therefore, even a solitary metastasis may be related to a poor prognosis

Gastric hepatoid adenocarcinoma resulting in a spontaneous gastric perforation: a case report and review of the literature

Abstract Background Gastric hepatoid adenocarcinoma (GHAC) is an atypical form of gastric cancer (GC) that has similar tissue morphology to hepatocellular carcinoma and frequently produces alpha-fetoprotein. We present an exceedingly rare case of GHAC resulting in a spontaneous gastric perforation. Case presentation A 61-year-old man presented at our institution complaining of abdominal and back pain. A computed tomography scan revealed a spontaneous gastric perforation with a solitary liver tumor and lymph node swelling. Following a diagnosis of advanced-stage GC with a gastric perforation, perforative peritonitis, multiple lymph node metastases, and a solitary metastasis of the lateral segment of the liver, the patient underwent distal gastrectomy. Histopathology of the resected specimen revealed that the tumor cells were arranged in a hepatoid pattern. On immunohistochemical staining, the tumor cells were positive for alpha-fetoprotein and Sal-like protein 4. Thus, the patient was diagnosed with GHAC. Hepatic resection of the solitary liver metastasis was performed. However, recurrence occurred and the patient achieved complete response following tegafur/gimeracil/oteracil-based chemotherapy. Conclusions GHAC is a highly malignant histological subtype of GC. We reported on an extremely rare case of GHAC resulting in a spontaneous gastric perforation and reviewed the literature, including epidemiological data, treatment regimens, and the association between GHAC and alpha-fetoprotein-producing GC

Hyperoxia for accidental hypothermia and increased mortality: a post-hoc analysis of a multicenter prospective observational study

Abstract Background Supraphysiologic oxygen administration causes unfavorable clinical outcomes in various diseases, including traumatic brain injury, post–cardiac arrest syndrome, and acute lung injury. Accidental hypothermia is a critical illness that reduces oxygen demands, and excessive oxygen is likely to emerge. This study aimed to determine whether hyperoxia would be associated with increased mortality in patients with accidental hypothermia. Methods A post-hoc analysis of a nationwide multicenter prospective observational study (ICE-CRASH study) on patients with accidental hypothermia admitted in 2019–2022 was conducted. Adult patients without cardiac arrest whose core body temperature was < 32 °C and whose arterial partial pressure of oxygen (PaO2) was measured at the emergency department were included. Hyperoxia was defined as a PaO2 level of 300 mmHg or higher, and 28-day mortality was compared between patients with and without hyperoxia before rewarming. Inverse probability weighting (IPW) analyses with propensity scores were performed to adjust patient demographics, comorbidities, etiology and severity of hypothermia, hemodynamic status and laboratories on arrival, and institution characteristics. Subgroup analyses were conducted according to age, chronic cardiopulmonary diseases, hemodynamic instability, and severity of hypothermia. Results Of the 338 patients who were eligible for the study, 65 had hyperoxia before rewarming. Patients with hyperoxia had a higher 28-day mortality rate than those without (25 (39.1%) vs. 51 (19.5%); odds ratio (OR) 2.65 (95% confidence interval 1.47–4.78); p < 0.001). IPW analyses with propensity scores revealed similar results (adjusted OR 1.65 (1.14–2.38); p = 0.008). Subgroup analyses showed that hyperoxia was harmful in the elderly and those with cardiopulmonary diseases and severe hypothermia below 28 °C, whereas hyperoxia exposure had no effect on mortality in patients with hemodynamic instability on hospital arrival. Conclusions Hyperoxia with PaO2 levels of 300 mmHg or higher before initiating rewarming was associated with increased 28-day mortality in patients with accidental hypothermia. The amount of oxygen to administer to patients with accidental hypothermia should be carefully determined. Trial Registration: The ICE-CRASH study was registered at the University Hospital Medical Information Network Clinical Trial Registry on April 1, 2019 (UMIN-CTR ID, UMIN000036132)