Clinical Characteristics and Risk Factors for Mortality in Critical Coronavirus Disease 2019 Patients 50 Years of Age or Younger During the Delta Wave: Comparison With Patients > 50 Years in Korea.

BACKGROUND: Numerous patients around the globe are dying from coronavirus disease 2019 (COVID-19). While age is a known risk factor, risk analysis in the young generation is lacking. The present study aimed to evaluate the clinical features and mortality risk factors in younger patients (≤ 50 years) with a critical case of COVID-19 in comparison with those among older patients (> 50 years) in Korea. METHODS: We analyzed the data of adult patients only in critical condition (requiring high flow nasal cannula oxygen therapy or higher respiratory support) hospitalized with PCR-confirmed COVID-19 at 11 hospitals in Korea from July 1, 2021 to November 30, 2021 when the delta variant was a dominant strain. Patients' electronic medical records were reviewed to identify clinical characteristics. RESULTS: During the study period, 448 patients were enrolled. One hundred and forty-two were aged 50 years or younger (the younger group), while 306 were above 50 years of age (the older group). The most common pre-existing conditions in the younger group were diabetes mellitus and hypertension, and 69.7% of the patients had a body mass index (BMI) > 25 kg/m². Of 142 younger patients, 31 of 142 patients (21.8%, 19 women) did not have these pre-existing conditions. The overall case fatality rate among severity cases was 21.0%, and it differed according to age: 5.6% (n = 8/142) in the younger group, 28.1% in the older group, and 38% in the ≥ 65 years group. Age (odds ratio [OR], 7.902; 95% confidence interval [CI], 2.754-18.181), mechanical ventilation therapy (OR, 17.233; 95% CI, 8.439-35.192), highest creatinine > 1.5 mg/dL (OR, 17.631; 95% CI, 8.321-37.357), and combined blood stream infection (OR, 7.092; 95% CI, 1.061-18.181) were identified as independent predictors of mortality in total patients. Similar patterns were observed in age-specific analyses, but most results were statistically insignificant in multivariate analysis due to the low number of deaths in the younger group. The full vaccination rate was very low among study population (13.6%), and only three patients were fully vaccinated, with none of the patients who died having been fully vaccinated in the younger group. Seven of eight patients who died had a pre-existing condition or were obese (BMI > 25 kg/m²), and the one remaining patient died from a secondary infection. CONCLUSION: About 22% of the patients in the young critical group did not have an underlying disease or obesity, but the rate of obesity (BMI > 25 kg/m²) was high, with a fatality rate of 5.6%. The full vaccination rate was extremely low compared to the general population of the same age group, showing that non-vaccination has a grave impact on the progression of COVID-19 to a critical condition. The findings of this study highlight the need for measures to prevent critical progression of COVID-19, such as vaccinations and targeting young adults especially having risk factors.

Maternal and Neonatal Outcomes in Pregnant Women With Coronavirus Disease 2019 in Korea.

BACKGROUND: This study aimed to describe the maternal, obstetrical, and neonatal outcomes in pregnant women with coronavirus disease 2019 (COVID-19) and identify the predictors associated with the severity of COVID-19. METHODS: This multicenter observational study included consecutive pregnant women admitted because of COVID-19 confirmed using reverse transcriptase-polymerase chain reaction (RT-PCR) test at 15 hospitals in the Republic of Korea between January 2020 and December 2021. RESULTS: A total of 257 women with COVID-19 and 62 newborns were included in this study. Most of the patients developed this disease during the third trimester. Nine patients (7.4%) developed pregnancy-related complications. All pregnant women received inpatient treatment, of whom 9 (3.5%) required intensive care, but none of them died. The gestational age at COVID-19 diagnosis (odds ratio [OR], 1.096, 95% confidence interval [CI], 1.04-1.15) and parity (OR, 1.703, 95% CI, 1.13-2.57) were identified as significant risk factors of severe diseases. Among women who delivered, 78.5% underwent cesarean section. Preterm birth (38.5%), premature rupture of membranes (7.7%), and miscarriage (4.6%) occurred, but there was no stillbirth or neonatal death. The RT-PCR test of newborns' amniotic fluid and umbilical cord blood samples was negative for severe acute respiratory syndrome coronavirus 2. CONCLUSION: At the time of COVID-19 diagnosis, gestational age and parity of pregnant women were the risk factors of disease severity. Vertical transmission of COVID-19 was not observed, and maternal severity did not significantly affect the neonatal prognosis.

The establishment of a rheumatoid arthritis primate model in Macaca fascicularis.

BACKGROUND: Rheumatoid arthritis (RA) is a long-term autoimmune disorder that mostly affects the joints and leads to the destruction of cartilage. An RA model in non-human primates is especially useful because of their close phylogenetic relationship to humans in terms of cross-reactivity to compounds developed using modern drug technologies. METHODS: We used a collagen-induced arthritis (CIA) model in Macaca fascicularis. CIA was induced by the immunization of chicken type II collagen. Swelling was measured as the longitudinal and transverse axes of 16 proximal interphalangeal joints. RESULTS: A new system for visual evaluation was created, with a perfect score of 16. Individual behavioral analysis was also conducted. Serum was collected once a week after the first immunization. Blood chemistry and inflammatory cytokine parameters were higher in the CIA group than in the wild type group. CONCLUSION: In conclusion, we established CIA in M. fascicularis, and the results can be used for drug evaluation models.

Lecithin nano-liposomal particle as a CRISPR/Cas9 complex delivery system for treating type 2 diabetes.

BACKGROUND: Protein-based Cas9 in vivo gene editing therapeutics have practical limitations owing to their instability and low efficacy. To overcome these obstacles and improve stability, we designed a nanocarrier primarily consisting of lecithin that can efficiently target liver disease and encapsulate complexes of Cas9 with a single-stranded guide RNA (sgRNA) ribonucleoprotein (Cas9-RNP) through polymer fusion self-assembly. RESULTS: In this study, we optimized an sgRNA sequence specifically for dipeptidyl peptidase-4 gene (DPP-4) to modulate the function of glucagon-like peptide 1. We then injected our nanocarrier Cas9-RNP complexes directly into type 2 diabetes mellitus (T2DM) db/db mice, which disrupted the expression of DPP-4 gene in T2DM mice with remarkable efficacy. The decline in DPP-4 enzyme activity was also accompanied by normalized blood glucose levels, insulin response, and reduced liver and kidney damage. These outcomes were found to be similar to those of sitagliptin, the current chemical DPP-4 inhibition therapy drug which requires recurrent doses. CONCLUSIONS: Our results demonstrate that a nano-liposomal carrier system with therapeutic Cas9-RNP has great potential as a platform to improve genomic editing therapies for human liver diseases.

Serum aminoacyl-tRNA synthetase-interacting multifunctional protein-1 (AIMP1), a novel disease activity predictive biomarker of systemic lupus erythematosus.

OBJECTIVES: Secreted aminoacyl-tRNA synthetase-interacting multifunctional protein-1 (AIMP1) has been reported to have pro-inflammatory properties. The aim of this study was to evaluate the clinical significance of serum AIMP1 in patients with systemic lupus erythematosus (SLE). METHODS: Serum levels of AIMP1 were measured in 160 patients with SLE using a human AIMP1 ELISA kit. Eighty patients were classified as active SLE (SLEDAI-2K ≥ 5), and 80 patients were classified as stable SLE. Correlation between serum AIMP1, SLE disease activity index-2000 (SLEDAI-2K), and laboratory variables related to disease activity or inflammatory burdens were assessed using Pearson's correlation analysis. The optimal cut-off value for serum AIMP1 to predict active SLE was estimated by using a receiver operator characteristic curve, and logistic regression analysis was used to compare the odds ratios (ORs) of laboratory variables in predicting active SLE. RESULTS: The median serum AIMP1 was higher in patients with active SLE than those with stable SLE (8.0 vs. 6.5 ng/ml, p<0.001). Serum AIMP1 demonstrated correlation with SLEDAI-2K and laboratory variables related to disease activity or inflammatory burdens. The optimal cut-off AIMP1 to predict active SLE was 10.09. Multivariate logistic regression analysis including conventional laboratory variables demonstrated that serum AIMP1 ≥10.09 ng/ml (OR 3.919, 95% confidence interval 1.223-12.564, p=0.022) was useful in predicting active SLE. CONCLUSIONS: Serum levels of AIMP1 were associated with disease activity of SLE and could predict active SLE based on SLEDAI-2K.

Tauroursodeoxycholic acid improves viability of artificial RBCs.

Tauroursodeoxycholic acid (TUDCA) is known to prevent apoptosis through the Bax pathway and to promote neovascularization by enhancing the mobilization of stem cells, their differentiation. This study was performed to investigate the effect of TUDCA on erythropoiesis in hematopoietic stem cells (HSCs). Since erythropoiesis of CD34(+) HSCs is divided into four phases, the total cell number, viable cell number, cell viability, cell morphology, and expressed erythroid markers in each phase were examined. The number of viable control cells and their viability did not differ from those of the TUDCA-treated cells in phase I and II. However, TUDCA increased cell viability compared to the control in phases III and IV. Cell distribution differed that the immature erythroid cell number was higher for the TUDCA-treated cells than for the control cells until phase III, but all developed into RBCs in the last. The final RBC number and viability was significantly higher in TUDCA-treated cells compared to the control cells. Taken together, we suggest that TUDCA addition to cell cultures for artificial RBC production could be used as a new protocol for improving the viability of RBCs.

Tauroursodeoxycholic acid, a bile acid, promotes blood vessel repair by recruiting vasculogenic progenitor cells.

Although serum bile acid concentrations are approximately 10 µM in healthy subjects, the crosstalk between the biliary system and vascular repair has never been investigated. In this study, tauroursodeoxycholic acid (TUDCA) induced dissociation of CD34(+) hematopoietic stem cells (HSCs) from stromal cells by reducing adhesion molecule expression. TUDCA increased CD34(+) /Sca1(+) progenitors in mice peripheral blood (PB), and CD34(+) , CD31(+) , and c-kit(+) progenitors in human PB. In addition, TUDCA increased differentiation of CD34(+) HSCs into EPC lineage cells via Akt activation. EPC invasion was increased by TUDCA, which was mediated by fibroblast activating protein via Akt activation. Interestingly, TUDCA induced integration of EPCs into human aortic endothelial cells (HAECs) by increasing adhesion molecule expression. In the mouse hind limb ischemia model, TUDCA promoted blood perfusion by enhancing angiogenesis through recruitment of Flk-1(+) /CD34(+) and Sca-1(+) /c-kit(+) progenitors into damaged tissue. In GFP(+) bone marrow-transplanted hind limb ischemia, TUDCA induced recruitment of GFP(+) /c-kit(+) progenitors to the ischemic area, resulting in an increased blood perfusion ratio. Histological analysis suggested that GFP(+) progenitors mobilized from bone marrow, integrated into blood vessels, and differentiated into VEGFR(+) cells. In addition, TUDCA decreased cellular senescence by reducing levels of p53, p21, and reactive oxygen species and increased nitric oxide. Transplantation of TUDCA-primed senescent EPCs in hind limb ischemia significantly improved blood vessel regeneration, as compared with senescent EPCs. Our results suggested that TUDCA promoted neovascularization by enhancing the mobilization of stem/progenitor cells from bone marrow, their differentiation into EPCs, and their integration with preexisting endothelial cells.

Clinical Characteristics and Pregnancy-Related Outcomes of Pregnant Women Hospitalized with COVID-19 During the Delta Wave: A Single-Center Observational Study.

BACKGROUND: Coronavirus disease 2019 (COVID-19) during pregnancy is associated with increased disease severity and an increased risk of perinatal complications. However, few studies of pregnant women with COVID-19 have been conducted in Korea. The purpose of this study was to describe the clinical course and pregnancy outcomes of pregnant women admitted to our hospital with COVID-19 according to the severity. MATERIALS AND METHODS: This retrospective cohort study included women aged 18 years of age or older who were hospitalized in the Gachon University Gil Medical Center with COVID-19 during pregnancy between July 1, 2021 and January 31, 2022. COVID-19 severity was classified according to the "Criteria for severity classification by symptoms of COVID-19" presented by the Korea Disease Control and Prevention Agency. Severe cases were defined as those who required oxygen treatment administered via a high-flow nasal cannula or invasive mechanical ventilation or should be applied extracorporeal membrane oxygenation (ECMO) or continuous renal replacement therapy. RESULTS: A total of 103 pregnant women were hospitalized with COVID-19 during the study period. Their mean age was 33 (± 4.14) years, and 4 (3.9%) had been vaccinated against COVID-19. At the time of diagnosis of COVID-19, 3 (2.9%), 33 (32.0%), and 67 (65.1%) patients were in the first, second, and third trimester, respectively. The most common symptoms were cough (99 patients, 96.1%) and fever (85 patients, 82.5%). There was 1 (1.0%) asymptomatic patient. Forty patients (38.8%) required supplemental oxygen and 19 patients (18.4%) had severe disease. Of the 19 severe cases, 7 were in the 2nd trimester and 12 were in the 3rd trimester. Forty-one (39.8%) patients delivered, including two twin deliveries. Of the 41 cases of delivery, 14 were premature, 4 out of 21 (19.0%) in mild, 4 out of 12 (25.0%) in moderate, and 6 out of 8 (75.0%) in severe. Severe disease was associated with an increased rate of preterm birth (P = 0.012). Four of the 43 neonates (9.1%) received oxygen treatment. CONCLUSION: Pregnant women with COVID-19 had a high rate of severe disease and a high preterm delivery rate, especially among those with severe disease.

Tauroursodeoxycholate (TUDCA), chemical chaperone, enhances function of islets by reducing ER stress.

The exposure to acute or chronic endoplasmic reticulum (ER) stress has been known to induce dysfunction of islets, leading to apoptosis. The reduction of ER stress in islet isolation for transplantation is critical for islet protection. In this study, we investigated whether tauroursodeoxycholate (TUDCA) could inhibit ER stress induced by thapsigargin, and restore the decreased glucose stimulation index of islets. In pig islets, thapsigargin decreased the insulin secretion by high glucose stimulation in a time-dependent manner (1h, 1.35+/-0.16; 2h, 1.21+/-0.13; 4h, 1.17+/-0.16 vs. 0h, 1.81+/-0.15, n=4, p<0.05, respectively). However, the treatment of TUDCA restored the decreased insulin secretion index induced by thapsigargin (thapsigargin, 1.25+/-0.12 vs. thapsigargin+TUDCA, 2.13+/-0.19, n=5, p<0.05). Furthermore, the culture of isolated islets for 24h with TUDCA significantly reduced the rate of islet regression (37.4+/-5.8% vs. 14.5+/-6.4%, n=12, p<0.05). The treatment of TUDCA enhanced ATP contents in islets (27.2+/-3.2pmol/20IEQs vs. 21.7+/-2.8pmol/20IEQs, n=9, p<0.05). The insulin secretion index by high glucose stimulation is also increased by treatment of TUDCA (2.42+/-0.15 vs. 1.92+/-0.12, n=12, p<0.05). Taken together, we suggest that TUDCA could be a useful agent for islet protection in islet isolation for transplantation.

MD001, a Novel Peroxisome Proliferator-activated Receptor α/γ Agonist, Improves Glucose and Lipid Metabolism.

Peroxisome proliferator-activated receptor (PPAR)-α/γ dual agonists have been developed to treat metabolic diseases; however, most of them exhibit side effects such as body weight gain and oedema. Therefore, we developed a novel PPARα/γ dual agonist that modulates glucose and lipid metabolism without adverse effects. We synthesised novel compounds composed of coumarine and chalcone, determined their crystal structures, and then examined their binding affinity toward PPARα/γ. We investigated the expression of PPARα and PPARγ target genes by chemicals in HepG2, differentiated 3T3-L1, and C2C12 cells. We examined the effect of chemicals on glucose and lipid metabolism in db/db mice. Only MD001 functions as a PPARα/γ dual agonist in vitro. MD001 increased the transcriptional activity of PPARα and PPARγ, resulting in enhanced expression of genes related to ß-oxidation and fatty acid and glucose uptake. MD001 significantly improved blood metabolic parameters, including triglycerides, free fatty acids, and glucose, in db/db mice. In addition, MD001 ameliorated hepatic steatosis by stimulating ß-oxidation in vitro and in vivo. Our results demonstrated the beneficial effects of the novel compound MD001 on glucose and lipid metabolism as a PPARα/γ dual agonist. Consequently, MD001 may show potential as a novel drug candidate for the treatment of metabolic disorders.

Exposure to chronic high glucose induces beta-cell apoptosis through decreased interaction of glucokinase with mitochondria: downregulation of glucokinase in pancreatic beta-cells.

Chronic hyperglycemia is toxic to pancreatic beta-cells, impairing cellular functioning as observed in type 2 diabetes; however, the mechanism underlying beta-cell dysfunction and the resulting apoptosis via glucose toxicity are not fully characterized. Here, using MIN6N8 cells, a mouse pancreatic beta-cell line, we show that chronic exposure to high glucose increases cell death mediated by Bax oligomerization, cytochrome C release, and caspase-3 activation. During apoptosis, glucokinase (GCK) expression decreases in high-glucose-treated cells, concomitant with a decrease in cellular ATP production and insulin secretion. Moreover, exposure to a chronically high dose of glucose decreases interactions between GCK and mitochondria with an increase in Bax binding to mitochondria and cytochrome C release. These events are prevented by GCK overexpression, and phosphorylation of proapoptotic Bad proteins in GCK-overexpressing cells is prolonged compared with Neo-transfected cells. Similar results are obtained using primary islet cells. Collectively, these data demonstrate that beta-cell apoptosis from exposure to chronic high glucose occurs in relation to lowered GCK expression and reduced association with mitochondria. Our results show that this may be one mechanism by which glucose is toxic to beta-cells and suggests a novel approach to prevent and treat diabetes by manipulating Bax- and GCK-controlled signaling to promote apoptosis or proliferation.

The antibody atliximab attenuates collagen-induced arthritis by neutralizing AIMP1, an inflammatory cytokine that enhances osteoclastogenesis.

ARS-interacting multifunctional protein 1 (AIMP1) induces production of inflammatory cytokines from immune cells. Since osteoclastogenesis is promoted by positive regulation of inflammatory cytokines, whether AIMP1 could promote osteoclastogenesis was investigated. AIMP1 induced osteoclastogenesis and acted synergistically with RANKL to promote osteoclastogenesis. Down-regulation of CD23, an AIMP1 receptor, abolished AIMP1-mediated osteoclastogenesis. Enzyme-linked immunosorbent assays showed that the AIMP1 level was significantly higher in the peripheral blood (PB) and synovial fluid of rheumatoid arthritis patients than in normal PB. A monoclonal antibody (clone 15B3AF) that blocked the cytokine activity of AIMP1 inhibited the AIMP1-mediated production of inflammatory cytokines. Clone 15B3AF inhibited the AIMP1-mediated osteoclastogenesis in vitro. We then cloned the complementary determining regions of clone 15B3AF and generated a chimeric antibody (atliximab). In a collagen-induced arthritis mouse model (CIA), atliximab administration significantly attenuated disease severity and improved various histopathological parameters. Three-dimensional micro-computed tomography scanning confirmed that atliximab enhanced the joint structures in CIA mice. Furthermore, atliximab decreased the expression of inflammatory cytokines in the serum and inflamed joints of CIA mice. Taken together, our findings suggest that AIMP1 exacerbates RA by promoting inflammation and osteoclastogenesis and that atliximab could be developed as a therapeutic antibody to target inflammatory diseases, including RA.

Effect of annexin I on insulin secretion through surface binding sites in rat pancreatic islets.

This study investigates the effect of extracellular annexin I (Anx I) on regulating insulin secretion in isolated rat pancreatic islets. Results show that Anx I stimulates insulin release in pancreatic islets regardless of the presence or absence of extracellular Ca2+. In particular, confocal microscopy shows that Anx I binds to the surface of islet cells in the absence of extracellular Ca2+. However, insulin secretion through Anx I significantly decreases in trypsin-treated islets. Likewise, there is minimal binding of Anx I to the surface of trypsin-treated islets. Anti-Anx I polyclonal antibody also inhibits the stimulating effect of Anx I on insulin secretion. These results indicate that Anx I is capable of binding to the cell surface receptor, in order to regulate the stimulation of insulin release in rat pancreatic islets.

The potential of endothelial colony-forming cells to improve early graft loss after intraportal islet transplantation.

Early graft loss in islet transplantation means that a large amount of donor islets is required. Endothelial cells and endothelial colony-forming cells (ECFCs) have been reported to improve instant blood-mediated inflammatory reaction (IBMIR) in vitro. In this study, we examined if ECFC-coated porcine islets would prevent early graft loss in vivo. Human ECFCs were prepared from cord blood and cocultured with islets to make composite grafts. Diabetic nude mice underwent intraportal transplantation. Blood glucose levels were monitored, and morphological examination of the grafts along with analysis of the components of IBMIR and inflammatory reaction were performed with the liver tissues. The ECFC-coated islets significantly decreased blood glucose levels immediately after transplantation compared to the uncoated islets. Composite ECFC islet grafts were observed in the liver sections, associated with a more insulin(+) area compared to that of the uncoated group within 48 h after transplantation. Deposition of CD41a, C5b-9, and CD11b(+) cells was also decreased in the ECFC-coated group. Expression of porcine HMGB1 and mouse TNF-α was increased in the transplantated groups compared to the sham operation group, with a trend of a decreasing trend across the uncoated group, the ECFC-coated group, and the sham group. We demonstrated that the composite ECFC porcine islets transplanted into the portal vein of nude mice improved early graft loss and IBMIR in vivo.

4-Deoxypyridoxine improves the viability of isolated pancreatic islets ex vivo.

The successful islet transplantation, for the treatment of type 1 diabetes, depends on the quantity and the quality of transplanted islets. Previously, it has reported that the significant loss of isolated islet mass could be prevented by sphingolipid metabolite, sphinogosine 1-phophate (S1P). This study was performed to elucidate whether the beneficial effects of S1P maintaining isolated pancreatic islets ex vivo are mimicked by modulation of intracellular S1P. We tested the in vitro effect of various agents that modulate intracellular S1P levels in insulinoma cell lines and isolated islets to compare their anti-apoptotic effects with that of S1P. As results, we discovered that 4-deoxypyridoxine (DOP), which inhibits the degradation of intracellular S1P by inhibiting S1P lyase (SPL) activity, minimized the chemically induced apoptosis of insulinoma cell lines as S1P did. Also, supplementation of DOP in the culture media protected the regression of isolated islets that have been maintained ex vivo at least for 18 h providing the evidence of increasing viability of isolated islets with DOP, which impaired SPL activity. In conclusion, these results suggest that the application of SPL inhibitors could be considered as a supplement for the maintenance of viable islets isolated from donor sources in the process of islet transplantation.

Endothelial progenitor cell cotransplantation enhances islet engraftment by rapid revascularization.

Impaired revascularization of transplanted islets is a critical problem that leads to progressive islet loss. Since endothelial progenitor cells (EPCs) are known to aid neovascularization, we aimed to enhance islet engraftment by cotransplanting EPCs with islets. Porcine islets, with (islet-EPC group) or without (islet-only group) human cord blood-derived EPCs, were transplanted into diabetic nude mice. The islet-EPC group reached euglycemia by ∼11 days posttransplantation, whereas the islet-only group did not. Also, the islet-EPC group had a higher serum porcine insulin level than the islet-only group. Islets from the islet-EPC group were more rapidly revascularized at the early period of transplantation without increment of final capillary density at the fully revascularized graft. Enhanced revascularization rate in the islet-EPC group was mainly attributed to stimulating vascular endothelial growth factor-A production from the graft. The rapid revascularization by EPC cotransplantation led to better graft perfusion and recovery from hypoxia. EPC cotransplantation was also associated with greater ß-cell proliferation, probably by more basement membrane production and hepatocyte growth factor secretion. In conclusion, cotransplantation of EPCs and islets induces better islet engraftment by enhancing the rate of graft revascularization. These findings might provide a directly applicable tool to enhance the efficacy of islet transplantation in clinical practice.