A novel mechanism of PHB2-mediated mitophagy participating in the development of Parkinson's disease

JOURNAL/nrgr/04.03/01300535-202408000-00037/figure1/v/2023-12-16T180322Z/r/image-tiff Endoplasmic reticulum stress and mitochondrial dysfunction play important roles in Parkinson's disease, but the regulatory mechanism remains elusive. Prohibitin-2 (PHB2) is a newly discovered autophagy receptor in the mitochondrial inner membrane, and its role in Parkinson's disease remains unclear. Protein kinase R (PKR)-like endoplasmic reticulum kinase (PERK) is a factor that regulates cell fate during endoplasmic reticulum stress. Parkin is regulated by PERK and is a target of the unfolded protein response. It is unclear whether PERK regulates PHB2-mediated mitophagy through Parkin. In this study, we established a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of Parkinson's disease. We used adeno-associated virus to knockdown PHB2 expression. Our results showed that loss of dopaminergic neurons and motor deficits were aggravated in the MPTP-induced mouse model of Parkinson's disease. Overexpression of PHB2 inhibited these abnormalities. We also established a 1-methyl-4-phenylpyridine (MPP+)-induced SH-SY5Y cell model of Parkinson's disease. We found that overexpression of Parkin increased co-localization of PHB2 and microtubule-associated protein 1 light chain 3, and promoted mitophagy. In addition, MPP+ regulated Parkin involvement in PHB2-mediated mitophagy through phosphorylation of PERK. These findings suggest that PHB2 participates in the development of Parkinson's disease by interacting with endoplasmic reticulum stress and Parkin.

Gene replacement therapy in Bietti crystalline corneoretinal dystrophy: an open-label, single-arm, exploratory trial

Bietti crystalline corneoretinal dystrophy is an inherited retinal disease caused by mutations in CYP4V2, which results in blindness in the working-age population, and there is currently no available treatment. Here, we report the results of the first-in-human clinical trial (NCT04722107) of gene therapy for Bietti crystalline corneoretinal dystrophy, including 12 participants who were followed up for 180-365 days. This open-label, single-arm exploratory trial aimed to assess the safety and efficacy of a recombinant adeno-associated-virus-serotype-2/8 vector encoding the human CYP4V2 protein (rAAV2/8-hCYP4V2). Participants received a single unilateral subretinal injection of 7.5 × 1010 vector genomes of rAAV2/8-hCYP4V2. Overall, 73 treatment-emergent adverse events were reported, with the majority (98.6%) being of mild or moderate intensity and considered to be procedure- or corticosteroid-related; no treatment-related serious adverse events or local/systemic immune toxicities were observed. Compared with that measured at baseline, 77.8% of the treated eyes showed improvement in best-corrected visual acuity (BCVA) on day 180, with a mean ± standard deviation increase of 9.0 ± 10.8 letters in the 9 eyes analyzed (p = 0.021). By day 365, 80% of the treated eyes showed an increase in BCVA, with a mean increase of 11.0 ± 10.6 letters in the 5 eyes assessed (p = 0.125). Importantly, the patients' improvement observed using multifocal electroretinogram, microperimetry, and Visual Function Questionnaire-25 further supported the beneficial effects of the treatment. We conclude that the favorable safety profile and visual improvements identified in this trial encourage the continued development of rAAV2/8-hCYP4V2 (named ZVS101e).

Nur77 increases mitophagy and decreases aggregation of α-synuclein by modulating the p-c-Abl/p-PHB2 Y121 in α-synuclein PFF SH-SY5Y cells and mice

Parkinson's disease (PD) is characterized by the progressive death of dopamine (DA) neurons and the pathological accumulation of α-synuclein (α-syn) fibrils. In our previous study, simulated PHB2 phosphorylation was utilized to clarify the regulatory role of c-Abl in PHB2-mediated mitophagy in PD models. In this investigation, we employed an independently patented PHB2Y121 phosphorylated antibody in the PD model to further verify that the c-Abl inhibitor STI571 can impede PHB2Y121 phosphorylation, decrease the formation of α-Syn polymers, and improve autophagic levels. The specific involvement of Nur77 in PD pathology has remained elusive. We also investigate the contribution of Nur77, a nuclear transcription factor, to α-syn and mitophagy in PD. Our findings demonstrate that under α-syn, Nur77 translocates from the cytoplasm to the mitochondria, improving PHB-mediated mitophagy by regulating c-Abl phosphorylation. Moreover, Nur77 overexpression alleviates the expression level of pS129-α-syn and the loss of DA neurons in α-syn PFF mice, potentially associated with the p-c-Abl/p-PHB2 Y121 axis. This study provides initial in vivo and in vitro evidence that Nur77 protects PD DA neurons by modulating the p-c-Abl/p-PHB2 Y121 axis, and STI571 holds promise as a treatment for PD.

Is polyethylene glycol loxenatide 100 μg the preferred glucagon-like peptide-1 receptor agonist for type 2 diabetes mellitus? A meta-analysis and trial sequential analysis

OBJECTIVE

This study aimed to systematically evaluate the efficacy, safety and optimal dose of polyethylene glycol loxenatide (PEX168) for treating type 2 diabetes mellitus (T2DM).

MATERIALS AND METHODS

Clinical trials of PEX168 for T2DM were identified in 8 databases, with a build time limit of January 2023. Included studies were subjected to meta-analysis and trial sequential analysis (TSA).

RESULTS

On the efficacy endpoint, the meta-analysis showed that PEX168 100 μg significantly reduced 0.86% glycated hemoglobin type A1c (HbA1c) (MD -0.86, 95% CI -1.02 - -0.70,  p<0.00001), 1.11 mmol/L fasting plasma glucose (FPG) (MD -1.11, 95% CI -1.49 - -0.74, p<0.00001) and 1.91 mmol/L 2h postprandial glucose (PPG) (MD -1.91, 95% CI -3.35 - -0.46, p=0.01) compared with placebo. The TSA showed that all these benefits were conclusive. On safety endpoints, total adverse events (AEs), gastrointestinal (GI) AEs, serious AEs, and hypoglycemia were comparable to placebo for PEX168 100 μg (p>0.05). In the dose comparison, the HbA1c, FPG, and 2h PPG of PEX168 200 μg were comparable to 100 μg (p>0.05), while GI AEs were significantly higher than 100 μg (RR=2.84, 95% CI 1.64-4.93,  p=0.0002).

CONCLUSIONS

PEX168 100 μg can significantly lower blood glucose and does not increase the risk of total AEs, GI AEs, and hypoglycemia, which may be a preferred glucagon-like peptide-1 receptor agonist for type 2 diabetes mellitus.

[Play the "combo fist" in the diagnosis and treatment of advanced gastric cancer]

The incidence of gastric cancer ranks fifth among malignant tumors worldwide, with the fourth highest mortality rate. A noteworthy characteristic of our country is the high prevalence of advanced-stage patients of approximately 40%. Advanced-stage gastric cancer carries an unfavorable prognosis with median survival of around one year. Diagnosis methods for advanced-stage gastric cancer (such as laparoscopic exploration, molecular profiling, and artificial intelligence) are still being continuously improved, while chemotherapy remains the primary treatment. With the rapid development of medical science, the role of surgical intervention in advanced-stage gastric cancer is becoming increasingly prominent. Therefore, as gastric tumor surgeons, we should consider how to use a combination of treatments, including surgery, chemotherapy, targeted therapy, immunotherapy, and interventional therapy, based on different pathological stages and the heterogeneity of tumors. With a multidisciplinary approach involving experts from various fields, we can collectively improve the survival rate and quality of life for advanced-stage patients. This article provides a brief overview of the current advances in the diagnosis and treatment of advanced-stage gastric cancer, and discusses therapeutic decision primarily from the perspective of surgeons.

Lactiplantibacillus plantarum and faecal microbiota transplantation can improve colitis in mice by affecting gut microbiota and metabolomics

Gut microbiota may have therapeutic effects on inflammatory bowel disease (IBD). Regulating intestinal microbiota through Lactiplantibacillus plantarum (L. plantarum) and faecal microbiota transplantation (FMT) is a novel approach to treating IBD. This study aimed to explore the effect of L. plantarum and FMT pretreatment in alleviating colitis in mice. Five groups of mice (n = 6 per group) were included: CON group, DSS group (dextran sodium sulphate-induced colitis mice), LP-DSS pretreatment group (colitis mice were given strain L. plantarum and 5% DSS), DSS-FMT group (mice pretreated with faecal microbiota transplantation were given 5% DSS), and LP-FMT pretreatment group (mice pretreated with faecal microbiota transplantation and L. plantarum were given 5% DSS). Serum metabolites and intestinal microbiota were analysed by 16S rRNA sequencing liquid chromatography-mass spectrometry (LC-MS). The results demonstrated that L. plantarum and FMT improved gut microbiota in mice by increasing Firmicutes and decreasing the Bacteroidetes. In the serum metabolomics analysis, there were 11 differential metabolites in the DSS-FMT and LP-FMT pretreatment groups, and these differential metabolites were mainly glycerophospholipids and sphingolipids. It is worth noting that Lachnospira and Lactobacillus were positively associated with 8 differential metabolites. These results suggest that L. plantarum and FMT can regulate intestinal microorganisms and serum metabolomics to alleviate inflammation.

Impacts of Combining Pulsed Low Dose Rate Radiotherapy (PLDR) and Anti-PD-1 Antibody on Tumor Growth and Its Mechanism for Lung Cancer in Mice

PURPOSE/OBJECTIVE(S)

As an emerging anti-tumor strategy, Immunotherapies has been approved for the treatment of a variety of tumors. Recent data suggest that the efficacy of radiotherapy in various cancers can be augmented when combined with immune checkpoint blockade. Then, pulsed low dose rate radiotherapy (PLDR) is a new radiotherapy segmentation method. Therefore, this study investigated the inhibitory effect of PLDR combined with anti-PD-1 antibody on lung cancer in mice and its impact on tumor immune microenvironment.

MATERIALS/METHODS

By transplanting murine LLC cells into the right leg of C57BL/6 mice with immune activity, a transplanted subcutaneous tumor model was established. The mice were randomly divided into five groups: control, conventional radiotherapy (RT)±anti-PD-1 antibody (mAb),PLDR±anti-PD-1 antibody (mAb). RT was delivered as a dose of 5 × 2 Gy whereas PLDR involved delivering a dose of 2 Gy as 10 pulses of 0.2 Gy, each 3 minutes apart and lasting for 5 days. Anti-PD-1 antibody and isotype control were administered intraperitoneally once every three days at a dose of 5mg/kg, three times in total. The tumor, blood and tumor-draining lymph nodes (TDLNs) were harvested after treatment, and a single cell suspension was prepared for flow cytometry to analyze the changes in the immune microenvironment of the tumor tissue, the expression of PD-L1. PD-1 and the activated systemic immune response; Finally, this study explored a mechanism able to explain the observed synergy of combined therapy.

RESULTS

PLDR combined with anti-PD-1 antibody can better inhibit the growth of tumor than RT,PLDR and RT combined group. Survival analysis demonstrated a statistically significant advantage for PLDR+anti-PD-1 than other groups. Median survival with PLDR+anti-PD-1mAb was 63d compared with 54d with RT+anti-PD-1mAb,41d with RT and 40d with PLDR and 33 with control. Meanwhile both RT and PLDR induced up-regulation of PD-L1 expression on tumor surface and PD-1 expression on lymphocytes. Then, the frequency of CD4+,CD8+T cells were higher in the PLDR combined treatment group in tumor blood and draining lymph nodes, and synergistically reduce the local accumulation of tumor-infiltrating myeloid-derived suppressor cells (MDSCs) than others. Finally, the main reason for the better tumor inhibition effect of PLDR combined group is that it upgrades the number and activity of CD8+T cells in tumor.

CONCLUSION

PLDR combined with anti-PD-1 antibody can result in better tumor growth inhibition and significantly delay the survival time of mice, which was mainly through the cytotoxic T cell-dependent mechanism, meanwhile increasing the infiltration of CD4 + and CD8 +T-cells in tissues.

Design and testing of a humanized porcine donor for xenotransplantation

Recent human decedent model studies1,2 and compassionate xenograft use3 have explored the promise of porcine organs for human transplantation. To proceed to human studies, a clinically ready porcine donor must be engineered and its xenograft successfully tested in nonhuman primates. Here we describe the design, creation and long-term life-supporting function of kidney grafts from a genetically engineered porcine donor transplanted into a cynomolgus monkey model. The porcine donor was engineered to carry 69 genomic edits, eliminating glycan antigens, overexpressing human transgenes and inactivating porcine endogenous retroviruses. In vitro functional analyses showed that the edited kidney endothelial cells modulated inflammation to an extent that was indistinguishable from that of human endothelial cells, suggesting that these edited cells acquired a high level of human immune compatibility. When transplanted into cynomolgus monkeys, the kidneys with three glycan antigen knockouts alone experienced poor graft survival, whereas those with glycan antigen knockouts and human transgene expression demonstrated significantly longer survival time, suggesting the benefit of human transgene expression in vivo. These results show that preclinical studies of renal xenotransplantation could be successfully conducted in nonhuman primates and bring us closer to clinical trials of genetically engineered porcine renal grafts.

Analysis of prognostic factors for vocal fold leukoplakia based on 344 cases at a two-year follow up

OBJECTIVE

To evaluate risk factors for poor prognosis in vocal fold leukoplakia.

METHODS

Clinical data were collected for 344 patients with vocal fold leukoplakia who received surgical treatment in our otolaryngology department from October 2010 to June 2019. Univariate and multivariate logistic regression analyses of the relevant factors were conducted.

RESULTS

Among the 344 patients, 98 exhibited recurrence and 30 underwent a malignant change. Multivariate logistic regression analysis showed that size of the lesion (p = 0.03, odds ratio = 2.14), form of the lesion under white light (p < 0.001), surgical method (p < 0.001, odds ratio = 0.28) and pathological type (p < 0.001) were independent factors that affected the recurrence of vocal fold leukoplakia. In both univariate and multivariate analyses, the sole independent risk factor for malignant transformation of vocal fold leukoplakia was pathological type (p < 0.001).

CONCLUSION

The outlook for vocal fold leukoplakia depends on several clinical factors, especially pathological type. The more severe the pathological type, the more likely it is to recur or become cancerous.

Bibliometric analysis of intestinal microbiota in diabetic nephropathy

OBJECTIVE

The purpose of this study is to use bibliometrics to explore the research overview and research hotspots.

MATERIALS AND METHODS

The relevant literature on intestinal flora and diabetic nephropathy in the Web of Science Core Collection was sorted out, and VOSviewer, CiteSpace, Scimago Graphica and other software were used to conduct data visualization analysis on the number of publications, countries, institutions, journals, authors, keywords and citations.

RESULTS

A total of 124 relevant literatures were included. From 2015 to 2022, the number of published papers increased every year. The countries, institutions and journals that published the most articles in this field are China, Isfahan University Medical Science and Frontiers in Pharmacology. Liu Bicheng and Mirlohi Maryam are the authors with the most published articles in this field. The main keywords of research in this field are obesity, inflammation, oxidative stress, indoxyl sulfate, short-chain fatty acids (SCFAs) and Chinese herbal medicine.

CONCLUSIONS

This is the first bibliometric analysis of diabetic nephropathy and gut microbiota, reporting hot spots and emerging trends. Obesity, inflammation, oxidative stress, indoxyl sulfate, SCFAs and Chinese herbal medicine are the main keywords of current research, and SCFAs and Chinese herbal medicine may be the hotspots of future research.

Efficacy and safety of iguratimod combined with methylprednisolone for primary Sjögren's syndrome: a meta-analysis and trial sequential analysis

OBJECTIVE

The purpose of this study is to evaluate the combination of iguratimod (IGU) and methylprednisolone (MP) for the efficacy and safety of primary Sjögren's syndrome (pSS) by a meta-analysis and a trial sequential analysis (TSA).

MATERIALS AND METHODS

Clinical studies of IGU combined with MP for pSS were searched through eight databases. Revman 5.3 and TSA 0.9.5.10 Beta were used for the meta-analysis and TSA.

RESULTS

In terms of efficacy endpoints, compared with "HCQ+MP" group, "IGU+MP" group decreased erythrocyte sedimentation rate (ESR) [mean difference (MD)=-5.15, 95% confidence interval (CI)=(-7.37, -2.93), p<0.0001], immunoglobulin G (IgG) [MD=-3.38, 95% CI=(-4.13, -2.64), p<0.00001], immunoglobulin M (IgM) [MD=-0.64, 95% CI=(-1.19, -0.09), p=0.02], Immunoglobulin A (IgA) [MD=-1.16, 95% CI=(-1.92, -0.39), p=0.003], EULAR Sjögren's Syndrome Disease Activity Index (ESSDAI) [MD=-1.62, 95% CI=(-2.07, -1.17), p<0.0001], EULAR Sjögren's Syndrome Patient Reported Index (ESSPRI) [MD=-2.07, 95% CI=(-2.54, -1.59), p<0.0001], increase platelet (PLT) [MD=13.21, 95% CI=(9.77,16.65), p<0.00001], and improve Schirmer I test (SIT) [MD=1.86, 95% CI=(1.40, 2.32), p<0.0001]. TSA presented that these benefits observed with the current information volume were all conclusive, except for IgM. In terms of safety endpoints, the total adverse event rates (AEs), leucopenia, gastrointestinal (GI) AEs, skin diseases, and liver dysfunction of the "IGU+MP" group and the "HCQ+MP" group were comparable. And TSA indicated that the results need to be confirmed by additional studies. Harbord regression showed no publication bias (p=0.986).

CONCLUSIONS

IGU combined with MP effectively attenuates autoimmune responses (IgG, IgM, IgA), reduces clinical symptoms and disease activity (ESR, PLT, ESSPRI, ESSDAI), and improves the exocrine gland functional status (SIT) in patients with pSS. IGU combined with MP does not increase the risk of adverse events, which means that IGU combined with MP may be a safe and effective strategy for the treatment of pSS and has value for further research exploration.

Is tirzepatide 15 mg the preferred treatment strategy for type 2 diabetes? A meta-analysis and trial-sequence-analysis

OBJECTIVE

The study aims to evaluate tirzepatide's efficacy and safety in treating type 2 diabetes by meta-analysis and trial-sequential-analysis (TSA).

MATERIALS AND METHODS

Eight databases were searched for clinical trials on tirzepatide for type 2 diabetes with a time limit of November 2022. Revman5.3 and TSA 0.9.5.10 Beta were selected for meta-analysis and TSA.

RESULTS

Compared with placebo, the meta-analysis demonstrated that tirzepatide 15 mg reduced hemoglobin-type-A1C (HbA1c) (p<0.00001), fasting-serum-glucose (FSG) (p<0.00001), and weight (p<0.00001). Compared with insulin, tirzepatide 15 mg reduced HbA1c (p<0.00001), FSG (p<0.00007), and weight (p<0.00001). Compared with glucagon-like-peptide-1 receptor-agonist (GLP-1 RA), tirzepatide 15 mg reduced HbA1c (p=0.00004), FSG (p=0.001), and weight (p<0.00001). In safety endpoints, the meta-analysis revealed that adverse events (AEs) of placebo, insulin and GLP-1 RA were comparable to tirzepatide 15 mg. The total AEs (p=0.02) and gastrointestinal (GI) AEs (p=0.03) were higher in tirzepatide 15 mg than in the placebo, while hypoglycemia (<54 mg/dl) was comparable. The major adverse cardiovascular events-4 (MACE-4) (p=0.03) and hypoglycemia (<54 mg/dl) (p<0.00001) of tirzepatide 15 mg were lower when compared to insulin, while total AEs (p=0.03) were increased. Compared with GLP-1 RA, tirzepatide 15 mg was comparable in safety endpoints in total AEs and GI AEs, while hypoglycemia (<54 mg/dl) (p=0.04) was higher. TSA indicated that HgA1c, FSG, and weight benefits were conclusive. In safety endpoints, only MACE-4 and hypoglycemia (<54 mg/dl) of Tirzepatide 15 mg vs. Insulin were conclusive. Harbord regression of AEs suggested no evident publication bias (p=0.618).

CONCLUSIONS

Tirzepatide 15 mg reduced HbA1c and weight more effectively than placebo, insulin, and GLP-1 RA. Total AEs were higher than placebo and insulin but comparable to GLP-1 RA. Tirzepatide 15 mg is a kind of optimal strategy to treat type 2 diabetes. However, there is a need to focus on GI AEs.

Rutin Attenuates Oxidative Stress Via PHB2-Mediated Mitophagy in MPP+-Induced SH-SY5Y Cells

Oxidative stress plays a crucial role in the occurrence and development of Parkinson's disease (PD). Rutin, a natural botanical ingredient, has been shown to have antioxidant properties. Therefore, the aim of this study was to investigate the neuroprotective effects of rutin on PD and the underlying mechanisms. MPP⁺(1-methyl-4-phenylpyridinium ions)-treated SH-SY5Y cells were used as an in vitro model of PD. Human PHB2-shRNA lentiviral particles were transfected into SH-SY5Y cells to interfere with the expression of Prohibitin2 (PHB2). The oxidative damage of cells was analyzed by detecting intracellular reactive oxygen species (ROS), malondialdehyde (MDA), and mitochondrial membrane potential (MMP). Western blotting was used to detect the protein expression of antioxidant factors such as nuclear factor E2-related factor 2 (Nrf2), heme oxygenase-1 (HO-1), NADPH quinone oxidoreductase-1 (NQO-1), and mitophagy factors PHB2, translocase of outer mitochondrial membrane 20 (TOM20), and LC3II/LC3I (microtubule-associated protein II light chain 3 (LC3II) to microtubule-associated protein I light chain 3 (LC3I)). In addition, we also examined the expression of PHB2 and LC3II/LC3I by immunofluorescence staining. MPP⁺ treatment significantly increased the generation of ROS and MDA and the level of MMP depolarization and decreased the protein expression of Nrf2, HO-1, NQO1, TOM20, PHB2, and LC3II/LC3I. In MPP⁺-treated SH-SY5Y cells, rutin significantly decreased the generation of ROS and MDA and the level of MMP depolarization and increased the protein expression of Nrf2, HO-1, NQO-1, TOM20, PHB2, and LC3II/LC3I. However, the protective role of rutin was inhibited in PHB2-silenced cells. Rutin attenuates oxidative damage which may be associated with PHB2-mediated mitophagy in MPP⁺-induced SH-SY5Y cells. Rutin might be used as a potential drug for the prevention and treatment of PD.

Pregnancy rate and reproductive hormones in humpback whale blubber: Dominant form of progesterone differs during pregnancy

To better understand reproductive physiology of humpback whales Megaptera novaeangliae that reside in Hawai'i and Alaska, enzyme immunoassays were validated for both progesterone and testosterone in free-ranging and stranded animals (n = 185 biopsies). Concentrations were analyzed between different depths of large segments of blubber taken from skin to muscle layers of stranded female (n = 2, 1 pregnant, 1 non-pregnant) and male (n = 1) whales. Additionally, progesterone metabolites were identified between pregnant (n = 1) and non-pregnant (n = 3) females using high pressure liquid chromatography (HPLC). Progesterone concentrations were compared between juvenile (i.e., sexually immature), lactating, and pregnant females, and male whales, and pregnancy rates of sexually mature females were calculated. Based on replicate samples from ship struck animals collected at 7 depth locations, blubber containing the highest concentration of progesterone was located 1 cm below the skin for females, and the highest concentration of testosterone was in the skin layer of one male whale. HPLC of blubber samples of pregnant and non-pregnant females contain different immunoreactive progesterone metabolites, with the non-pregnant female eluate comprised of a more polar, and possibly conjugated, form of progesterone than the pregnant female. In females, concentrations of progesterone were highest in the blubber of pregnant (n = 28, 28.6 ± 6.9 ng/g), followed by lactating (n = 16, 0.9 ± 0.1 ng/g), and female juvenile (n = 5, 1.0 ± 0.2 ng/g) whales. Progesterone concentrations in male (n = 24, 0.6 ng/g ± 0.1 ng/g) tissues were the lowest all groups, and not different from lactating or juvenile females. Estimated summer season pregnancy rate among sexually mature females from the Hawai'i stock of humpback whales was 0.562 (95 % confidence interval 0.528-0.605). For lactating females, the year-round pregnancy rate was 0.243 (0.09-0.59), and varies depending on the threshold of progesterone assumed for pregnancy in the range between 3.1 and 28.5 ng/g. Our results demonstrate the synergistic value added when combining immunoreactive assays, HPLC, and long-term sighting histories to further knowledge of humpback whale reproductive physiology.

Inertial imitation method of MMC with hybrid topology for VSC-HVDC

A new virtual synchronous generator (VSG) control strategy was researched and proposed for a VSC-HVDC (High Voltage Direct Current Based on Voltage Source Converter) transmission system. It can be applied to half-bridge or full-half-bridge hybrid topology modular multi-level converter (MMC) to improve the stability and reliability of the system. First, it is proposed that the energy stored in the equivalent capacitor of MMC power module was used to imitate the rotor inertial of synchronous generator. It can buffer transient power fluctuations and synchronize autonomously with the grid. Then the impedance characteristics of the proposed control method have been deduced and analyzed. The results show that the VSG control loop mainly improves the low frequency characteristics of the converter. Secondly, the ability to suppress transient fault current is weak. So, a method, that the given values of inner current loop are calculated by grid impedance matrix, was used. A double closed loop control structure composed by a power outer loop based on VSG control and a current inner loop is obtained. The simulation results show that it can effectively improve the current control capability during the transient process for systems with a 1:2 ratio of converter capacity to grid capacity (The grid short-circuit capacity is 60MW and the MMC is 30 MW). Finally, a hybrid MMC simulation model was built based on PSCAD and the steady-state and transient fault ride-through simulations were performed. The power adjustment time of MMC under the proposed VSG control is about 1s, while the adjustment time under the conventional control strategy is greater than 4s.

Intelligent cataract surgery supervision and evaluation via deep learning

PURPOSE

To assess the performance of a deep learning (DL) algorithm for evaluating and supervising cataract extraction using phacoemulsification with intraocular lens (IOL) implantation based on cataract surgery (CS) videos.

MATERIALS AND METHODS

DeepSurgery was trained using 186 standard CS videos to recognize 12 CS steps and was validated in two datasets that contained 50 and 21 CS videos, respectively. A supervision test including 50 CS videos was used to assess the DeepSurgery guidance and alert function. In addition, a real-time test containing 54 CSs was used to compare the DeepSurgery grading performance to an expert panel and residents.

RESULTS

DeepSurgery achieved stable performance for all 12 recognition steps, including the duration between two pairs of adjacent steps in internal validation with an ACC of 95.06% and external validations with ACCs of 88.77% and 88.34%. DeepSurgery also recognized the chronology of surgical steps and alerted surgeons to order of incorrect steps. Six main steps are automatically and simultaneously quantified during the evaluation process (centesimal system). In a real-time comparative test, the DeepSurgery step recognition performance was robust (ACC of 90.30%). In addition, DeepSurgery and an expert panel achieved comparable performance when assessing the surgical steps (kappa ranged from 0.58 to 0.77).

CONCLUSIONS

DeepSurgery represents a potential approach to provide a real-time supervision and an objective surgical evaluation system for routine CS and to improve surgical outcomes.

A proteomic atlas of atherosclerosis: regional proteomic signatures for plaque inflammation and calcification

Funding Acknowledgements

Type of funding sources: Foundation. Main funding source(s): This study was mainly supported from the British Heart Foundation (BHF) supporting Prof. Manuel Mayr as a Chair Holder (CH/16/3/32406) with BHF programme grant support (RG/16/14/32397) and Dr. Theofilatos with BHF programm grant support (G/20/10387).

Background

Using proteomics, we strove to reveal novel molecular subtypes of human atherosclerotic lesions, study their associations with histology and imaging and relate them to long-term cardiovascular outcomes.

Methods

219 samples were obtained from 120 patients undergoing carotid endarterectomy. Sequential protein extraction was combined with multiplexed, discovery proteomics. Parallel reaction monitoring for 135 proteins was deployed for targeted validation. A combination of statistical, bioinformatics and machine learning methods was used to perform differential expression, network, pathway enrichment analysis and train and evaluate prognostic models.

Results

Our extensive proteomics analysis from the core and periphery of plaques doubled the coverage of the plaque proteome compared to the largest proteomics study on atherosclerosis thus far. Plaque inflammation and calcification signatures were inversely correlated and validated with targeted proteomics. The inflammation signature was enriched with neutrophil-derived proteins, including calprotectin (S100A8/9) and myeloperoxidase. The calcification signature contained fetuin-A, osteopontin, and gamma-carboxylated proteins. Sex differences in the proteome of atherosclerosis were explained by a higher proportion of calcified plaques in women. Single-cell RNA sequencing data attributed the inflammation signature predominantly to neutrophils and macrophages and the calcification signature to smooth muscle cells, except for certain plasma proteins that were not expressed but retained in the plaque, i.e., fetuin-A. Echogenic lesions reflect the collagen content and calcification of plaque but carotid Duplex ultrasound fails to capture the extent of inflammatory protein changes in symptomatic plaques. Applying dimensionality reduction and machine learning on the proteomics data defined 4 distinct plaque phenotypes and revealed key protein signatures linked to smooth muscle cell content, plaque calcification and structural extracellular matrix, which improved the 9-year prognostic AUC by 25% compared to ultrasound and histology. A biosignature of four proteins (CNN1, PROC, SERPH, and CSPG2) independently predicted the progression of atherosclerosis and cardiovascular mortality with an AUC of 75%

Conclusion

We combined discovery and targeted proteomics with network reconstruction and clustering techniques to provide molecular insights into protein changes in atherosclerotic plaques. The application of proteomics and machine learning techniques revealed distinct clusters of plaques that inform on disease progression and future adverse cardiovascular events.

Cold Spray: Over 30 Years of Development Toward a Hot Future

Cold Spray (CS) is a deposition process, part of the thermal spray family. In this method, powder particles are accelerated at supersonic speed within a nozzle; impacts against a substrate material triggers a complex process, ultimately leading to consolidation and bonding. CS, in its modern form, has been around for approximately 30 years and has undergone through exciting and unprecedented developmental steps. In this article, we have summarized the key inventions and sub-inventions which pioneered the innovation aspect to the process that is known today, and the key breakthroughs related to the processing of materials CS is currently mastering. CS has not followed a liner path since its invention, but an evolution more similar to a hype cycle: high initial growth of expectations, followed by a decrease in interest and a renewed thrust pushed by a number of demonstrated industrial applications. The process interest is expected to continue (gently) to grow, alongside with further development of equipment and feedstock materials specific for CS processing. A number of current applications have been identified the areas that the process is likely to be the most disruptive in the medium-long term future have been laid down.

Cross-talk between enhancers, structural elements and activating transcription factors maintains the 3D architecture and expression of the CFTR gene

Robust protocols to examine 3D chromatin structure have greatly advanced knowledge of gene regulatory mechanisms. Here we focus on the cystic fibrosis transmembrane conductance regulator (CFTR) gene, which provides a paradigm for validating models of gene regulation built upon genome-wide analysis. We examine the mechanisms by which multiple cis-regulatory elements (CREs) at the CFTR gene coordinate its expression in intestinal epithelial cells. Using CRISPR/Cas9 to remove CREs, individually and in tandem, followed by assays of gene expression and higher-order chromatin structure (4C-seq), we reveal the cross-talk and dependency of two cell-specific intronic enhancers. The results suggest a mechanism whereby the locus responds when CREs are lost, which may involve activating transcription factors such as FOXA2. Also, by removing the 5' topologically-associating domain (TAD) boundary, we illustrate its impact on CFTR gene expression and architecture. These data suggest a multi-layered regulatory hierarchy that is highly sensitive to perturbations.

Clinical effect of unilateral balloon infusion of low dose bone cement in PKP for osteoporotic thoracolumbar compression fractures in the elderly

OBJECTIVE

The study was undertaken to determine the clinical effectiveness of percutaneous kyphoplasty (PKP) with unilateral balloon infusion of low dose of bone cement for treatment of osteoporotic vertebral compression fractures (OVCFs) in the elderly.

PATIENTS AND METHODS

A retrospective study was carried out. A total of 36 patients with OVCFs treated by PKP from August 2019 and August 2020 were included. Patients were divided into two groups according to the amount of bone cement infused into the vertebral body. The amount of cement in conventional-dose group was 3.5-6.0 mL and the amount of cement in small-dose group was 1.8-3.0 mL. Pain relief before and after the operation were evaluated, and the leakage of bone cement in the two groups was also observed.

RESULTS

Two groups of patients have obtained a good clinical efficacy. Pain has significant differences before and after the operation (p < 0.05). More importantly, compared with conventional-dose group, small-dose group has lower bone cement leakage rate (p < 0.05).

CONCLUSIONS

PKP with small-dose bone cement infusion can obtain the same clinical effects of conventional-dose, but the incidence of bone cement leakage is lower and safe.

Mechanical and Fatigue Properties of Diamond-Reinforced Cu and Al Metal Matrix Composites Prepared by Cold Spray

Diamond-reinforced metal matrix composites (DMMC) prepared by cold spray are emerging materials simultaneously featuring outstanding thermal conductivity and wear resistance. In our paper, their mechanical and fatigue properties relevant to perspective engineering applications were investigated using miniature bending specimens. Two different diamond mass concentrations (20 and 50%) embedded in two metal matrices (Al-lighter than diamond, Cu-heavier than diamond) were compared with the respective cold-sprayed pure metals, as well as bulk Al and Cu references. The pure Al, Cu coatings showed properties typical for cold spray deposits, i.e., decreased elastic moduli (50 GPa for Al, 80 GPa for Cu), limited ductility (< 1 × 10-3) and low fracture toughness (3.8 MPa·m0.5 for Al, 5.6 MPa·m0.5 for Cu) when compared to the bulks. Significantly improved properties (strain at fracture, ultimate strength, fatigue crack growth resistance, fracture toughness) were then observed for the produced DMMC. The improvement can be explained by a combination of two factors: changes in the properties of the metallic matrix triggered by the reinforcement particles peening effect and stress redistribution due to the particles presence.

[Microcontact printing and its application prospect in bone tissue engineering]

The application of bone tissue engineering regeneration technology is expected to repair maxillofacial bone tissue defects caused by tumors, trauma, etc. Surface patterning occupies an important position in bone tissue engineering. Microcontact printing is an emerging technology through which the elastic stamp contacts with the substance and materials used as ink can be transferred from stamp to substance to form patterns. The biggest characteristic of the technology is to fabricate high-throughput and high-accuracy patterned surface, making it widely applied. This review summarized the application and optimization of microcontact printing, and prospected its application in bone tissue engineering.

POS0320 POOR PROGNOSIS PREDICTION IN ANTI-MDA5 POSITIVE DERMATOMYOSITIS ASSOCIATED WITH INTERSTITIAL LUNG DISEASE: THE CROSS-CAR DECISION TREE MODEL

Background:

The prognosis of anti-melanoma differentiation-associated gene 5 positive dermatomyositis (anti-MDA5+ DM) – associated interstitial lung disease (ILD) is poor and heterogeneity.

Objectives:

The aim of this study was to evaluate prognostic factors and to develop a simple and generally applicable bedside decision tree model for predicting outcomes in patients with anti-MDA5+ DM and to guide treatment.

Methods:

We analyzed data for 246 anti-MDA5+ DM patients from Myositis Study Group-Jiangsu, a multicenter cohort across eighteen tertiary hospitals in Jiangsu province, from March 2019 to October 2020. The primary end point was all-cause death, and the secondary end point was occurring of rapidly progressive-ILD (rp-ILD). We used a multivariable Cox proportional hazards model to identify the independent prognostic risk factors of death and rp-ILD respectively. A decision-tree prediction model was developed by using data from 10 hospital of southern region (n=163), with validation by using contemporaneous data from northern region (n=83).

Results:

To assess the risk of rp-ILD, we developed a combined risk score, the CROSS score, that included the following values and scores: C-reactive protein (≤8mg/L, 0; >8mg/L, 3), anti-Ro52 antibody (negative, 0; positive, 4), Sex (Female, 0; Male, 2) and Short course of disease (More than 3 months, 0; Less than 3 months, 2). The mortality risk was identified by the CAR score, including C-reactive protein (≤8mg/L, 0; >8mg/L, 1), Alanine Transaminase (≤50units/L, 0; >50units/L, 1) and rp-ILD (non-rpILD, 0; rp-ILD, 3). We divided patients into three risk groups according to the CROSS score: low, 0 to 3; medium, 4 to 7; and high 8-11. And then Use of a simple decision tree prediction model permitted stratification into three different outcome prediction groups. High-risk patients had significantly higher mortality rates than low- and medium-risk patients in both discovery and validation cohorts (p < 0.0001).

Conclusion:

The CROSS-CAR decision tree model is easy to evaluate the poor prognostic risk in MDA5+ DM patients during any follow-up period. Unnecessary lung examination, such as chest CT scan and arterial blood gas analysis was avoided in low- and medium- rpILD risk patients. The special ambulance, with red cross sign tagged on car in China, may help to screen the high risk patients and to guide further treatment.

Disclosure of Interests:

None declared

OTX2 regulates CFTR expression during endoderm differentiation and occupies 3' cis-regulatory elements

BACKGROUND

Cell-specific and developmental mechanisms contribute to expression of the cystic fibrosis transmembrane conductance regulator (CFTR) gene; however, its developmental regulation is poorly understood. Here we use human induced pluripotent stem cells differentiated into pseudostratified airway epithelial cells to study these mechanisms.

RESULTS

Changes in gene expression and open chromatin profiles were investigated by RNA-seq and ATAC-seq, and revealed that alterations in CFTR expression are associated with differences in stage-specific open chromatin. Additionally, two novel open chromatin regions, at +19.6 kb and +22.6 kb 3' to the CFTR translational stop signal, were observed in definitive endoderm (DE) cells, prior to an increase in CFTR expression in anterior foregut endoderm (AFE) cells. Chromatin studies in DE and AFE cells revealed enrichment of active enhancer marks and occupancy of OTX2 at these sites in DE cells. Loss of OTX2 in DE cells alters histone modifications across the CFTR locus and results in a 2.5-fold to 5-fold increase in CFTR expression. However, deletion of the +22.6 kb site alone does not affect CFTR expression in DE or AFE cells.

CONCLUSIONS

These results suggest that a network of interacting cis-regulatory elements recruit OTX2 to the locus to impact CFTR expression during early endoderm differentiation.

Remote Mesoscopic Signatures of Induced Magnetic Texture in Graphene

Mesoscopic conductance fluctuations are a ubiquitous signature of phase-coherent transport in small conductors, exhibiting universal character independent of system details. In this Letter, however, we demonstrate a pronounced breakdown of this universality, due to the interplay of local and remote phenomena in transport. Our experiments are performed in a graphene-based interaction-detection geometry, in which an artificial magnetic texture is induced in the graphene layer by covering a portion of it with a micromagnet. When probing conduction at some distance from this region, the strong influence of remote factors is manifested through the appearance of giant conductance fluctuations, with amplitude much larger than e^{2}/h. This violation of one of the fundamental tenets of mesoscopic physics dramatically demonstrates how local considerations can be overwhelmed by remote signatures in phase-coherent conductors.

An atlas of human proximal epididymis reveals cell-specific functions and distinct roles for CFTR

Spermatozoa released from the testis are unable to fertilize an egg without a coordinated process of maturation in the lumen of the epididymis. Relatively little is known about the molecular events that integrate this critical progression along the male genital ducts in man. Here, we use single cell RNA-sequencing to construct an atlas of the human proximal epididymis. We find that the CFTR, which is pivotal in normal epididymis fluid transport, is most abundant in surface epithelial cells in the efferent ducts and in rare clear cells in the caput epididymis, suggesting region-specific functional properties. We reveal transcriptional signatures for multiple cell clusters, which identify the individual roles of principal, apical, narrow, basal, clear, halo, and stromal cells in the epididymis. A marked cell type-specific distribution of function is seen along the duct with local specialization of individual cell types integrating processes of sperm maturation.

A functional genomics approach to investigate the differentiation of iPSCs into lung epithelium at air-liquid interface

The availability of robust protocols to differentiate induced pluripotent stem cells (iPSCs) into many human cell lineages has transformed research into the origins of human disease. The efficacy of differentiating iPSCs into specific cellular models is influenced by many factors including both intrinsic and extrinsic features. Among the most challenging models is the generation of human bronchial epithelium at air‐liquid interface (HBE‐ALI), which is the gold standard for many studies of respiratory diseases including cystic fibrosis. Here, we perform open chromatin mapping by ATAC‐seq and transcriptomics by RNA‐seq in parallel, to define the functional genomics of key stages of the iPSC to HBE‐ALI differentiation. Within open chromatin peaks, the overrepresented motifs include the architectural protein CTCF at all stages, while motifs for the FOXA pioneer and GATA factor families are seen more often at early stages, and those regulating key airway epithelial functions, such as EHF, are limited to later stages. The RNA‐seq data illustrate dynamic pathways during the iPSC to HBE‐ALI differentiation, and also the marked functional divergence of different iPSC lines at the ALI stages of differentiation. Moreover, a comparison of iPSC‐derived and lung donor‐derived HBE‐ALI cultures reveals substantial differences between these models.

Antimalarial agent artesunate induces G0/G1 cell cycle arrest and apoptosis via increasing intracellular ROS levels in normal liver cells

Artesunate (ARS) has been shown to be highly effective against chloroquine-resistant malaria. In vitro studies reported that ARS has anticancer effects; however, its detrimental action on cancer cells may also play a role in its toxicity toward normal cells and its potential toxicity has not been sufficiently researched. In this study, we investigated the possible cytotoxic effects using normal BRL-3A and AML12 liver cells. The results showed that ARS dose-dependently inhibited cell proliferation and arrested the G0/G1 phase cell cycle in both BRL-3A and AML12 liver cells. Western blotting demonstrated that ARS induced a significant downregulation of cyclin-dependent kinase-2 (CDK2), CDK4, cyclin D1, and cyclin E1 in various levels and then caused apoptosis when the Bcl-2/Bax ratio decreased. Conversely, the levels of intracellular reactive oxygen species (ROS) were increased. The ROS scavenger N-acetylcysteine can significantly inhibit cell cycle arrest and apoptosis induced by ARS. Thus, the data confirmed that ARS exposure impairs normal liver cell proliferation by inducing G0/G1 cell cycle arrest and apoptosis, and this detrimental action may be associated with intracellular ROS accumulation. Collectively, the possible side effects of ARS on healthy normal cells cannot be neglected when developing therapies.

Quantitative analysis of functional filtering bleb size using Mask R-CNN

Background

Deep learning has had a large effect on medical fields, including ophthalmology. The goal of this study was to quantitatively analyze the functional filtering bleb size with Mask R-CNN.

Methods

This observational study employed eighty-three images of post-trabeculectomy functional filtering blebs. The images were divided into training and test groups and scored according to the Indiana Bleb Appearance Grading Scale (IBAGS) system. Then, 70 images from the training group were used to train an automatic detection system based on Mask R-CNN and perform a quantitative analysis of the function bleb size. Thirteen images from the test group were used to evaluate the model. During the training process, left and right image-flipping algorithms were used for data augmentation. Finally, the correlation between the functional filtering bleb area and the intraocular pressure (IOP) was analyzed.

Results

The 83 functional filtering blebs have similar morphological features. According to IBAGS, the functional filtering blebs have a high incidence of E1/E2, H1/H2, and V0/V1. Our Mask R-CNN-based model using the selected parameters achieves good results on the training group after a 200-epoch training process. All the Intersection over Union (IoU) scores exceeded 93% on the test group. The Spearman correlation coefficient between the area of functional filtering blebs and the IOP value was −0.757 (P<0.05).

Conclusions

Deep learning is a powerful tool for quantitatively analyzing the functional filtering bleb size. This technique is suitable for use in monitoring post-trabeculectomy filtering blebs in the future.

0559 Association of Rapid Eye Movement Sleep with Insulin Resistance in Han Chinese Patients With Obstructive Sleep Apnea

Introduction

Obstructive sleep apnea (OSA) is increasingly associated with insulin resistance. The underlying pathophysiology remains unclear but rapid eye movement (REM) sleep has been hypothesized to play a key role. To investigate the associations of insulin resistance with respiratory events and sleep duration during REM sleep, 4,062 Han Chinese individuals with suspected OSA were screened and 2,899 were analyzed.

Methods

We screened 4,062 participants with suspected OSA who underwent polysomnography in our sleep center from 2009 to 2016. Polysomnographic variables, biochemical indicators, and physical measurements were collected. Logistic regression analyses were conducted to determine the odds ratios (ORs) and 95% confidence intervals (95% CIs) for insulin resistance as assessed by hyperinsulinemia, the homeostasis model assessment of insulin resistance (HOMA-IR), fasting insulin resistance index (FIRI), and Bennet’s insulin sensitivity index (ISI).

Results

The final analyses included 2,899 participants. After adjusting for age, gender, body mass index, waist circumference, mean arterial pressure, smoking status, alcohol consumption, and the apnea and hypopnea index during non-REM sleep (AHINREM), the results revealed that AHI during REM sleep (AHIREM) was independently associated with insulin resistance; across higher AHIREM quartiles, the ORs (95% CIs) for hyperinsulinemia were 1.340 (1.022, 1.757), 1.210 (0.882, 1.660), and 1.632 (1.103, 2.416); those for abnormal HOMA-IR were 1.287 (0.998, 1.661), 1.263 (0.933, 1.711), and 1.556 (1.056, 2.293); those for abnormal FIRI were 1.386 (1.048, 1.835), 1.317 (0.954, 1.818), and 1.888 (1.269, 2.807); and those for abnormal Bennet’s ISI were 1.297 (1.003, 1.678), 1.287 (0.949, 1.747), and 1.663 (1.127, 2.452) (P &lt; 0.01 for all linear trends). Additionally, the results showed that for every 1-h increase in REM duration, the risk of hyperinsulinemia decreased by 22.3% (P &lt; 0.05).

Conclusion

The present study demonstrated that AHIREM was independently associated with hyperinsulinemia and abnormal HOMA-IR, FIRI, and Bennet’s ISI. Additionally, REM sleep duration was independently associated with hyperinsulinemia.

Support

This study was supported by Grants-in-aid from Shanghai Municipal Commission of Science and Technology (No.18DZ2260200).

0713 Association Between Obesity Indices And Obstructive Sleep Apnea Is Modified By Age In A Sex-specific Manner

Introduction

The beneficial effects of weight loss on obstructive sleep apnea (OSA) are highly variable. Whether the variability is associated with the effects of age and sex remains unclear. This study examined this issue with large cross-sectional data.

Methods

A total of 4600 adult males and 1156 females with suspected OSA were included in the study. Anthropometric measurements, polysomnographic variables, biochemical indicators, and medical history were collected for each subject. Multivariable linear regression with interaction terms was used to estimate the modification effect of age on the associations between OSA severity (assessed by apnea-hypopnea index, AHI) with obesity indices (body mass index, BMI; neck circumference, NC; waist circumference, WC) in a sex-specific manner, and vice versa.

Results

BMI, NC, and WC were all positively correlated with AHI after adjusting for potential confounders in all populations. In males, these associations were much stronger and more significant in younger than older individuals (P for interaction &lt; 0.001). For example, a 10% increase in BMI was independently associated with a 31.6% increase in AHI for males &lt; 40 years old, whereas the corresponding increases were 20.8% and 16.7% for males 40-60 and &gt;60 years old, respectively. By contrast, no modification effect of age was observed in females (P for interaction &gt; 0.05). A 10% increase in BMI was associated with 25.6%, 26.8%, and 23.8% increases in AHI for females &lt; 40, 40-60, and &gt;60 years old, respectively.

Conclusion

Age modifies the associations between obesity indices and OSA severity in a sex-specific manner, and vice versa. These findings may broaden the understanding of age- and sex-related heterogeneities in the pathogenic role of obesity in OSA, and may be beneficial for individualized risk evaluation and treatment management for patients with OSA.

Support

This study was funded by Shanghai Municipal Commission of Science and Technology (grant number.18DZ2260200); the National Key R&D Program of China (grant number: 2017YFC0112500); Multi-Center Clinical Research Project from the School of Medicine, Shanghai Jiao Tong University (grant number: DLY201502); and the Shanghai Shen-Kang Hospital Management Center Project (grant number: SHDC12015101 and 16CR3103B).

0601 Use of The Epworth Sleepiness Scale, the NoSAS, and the STOP-BANG Questionnaire to Identify Patients with Moderate-to-Severe Obstructive Sleep Apnea

Introduction

A variety of scales and questionnaires regarding sleep and sleep-related disorders have been widely used in scientific research and clinical practice, as important tools for differential diagnosis and rapid screening of complex sleep disorders, especially obstructive sleep apnea (OSA). However, the diagnostic efficacy of different scales and questionnaires for patients with different severity of OSA and of different demographic characteristics has not been clearly described. In this study, we evaluated the ability of the most popular scales, including the Epworth Sleepiness Scale (ESS), the NoSAS, and the STOP-BANG questionnaire in predicting moderate-to-severe obstructive sleep apnea (OSA) by gender.

Methods

This cross-sectional study screened 2,031 consecutive subjects referred with suspected OSA from 2012 to 2016. Anthropometric measurements, polysomnographic data, ESS, NoSAS scores and STOP-BANG scores were recorded. Receiver operating characteristic curve analyses were performed, and the final predictive models were verified in a validation cohort.

Results

A total of 1,840 adults were finally included. The STOP-BANG questionnaire afforded a better diagnostic accuracy than did the ESS, with different cutoffs for the two genders: 3 in males and 1 in females. A predictive model based on STOP-BANG yielded an area under the curve (AUC) of 0.918 (0.897-0.935), a sensitivity of 79.89%, and a specificity of 89.19%, in males; and an AUC of 0.951 (0.914-0.975), a sensitivity of 80.52%, and a specificity of 95.92%, in females. In the validation cohort, the sensitivity and specificity were respectively 85.44 and 93.00% in males and respectively 83.02 and 87.60% in females.

Conclusion

The STOP-BANG questionnaire was moderately effective when used to screen for moderate-to-severe OSA. A STOP-BANG-based predictive model afforded excellent diagnostic efficacy, which could be applied in clinical practice. However, gender differences must be considered.

Support

This study was supported by Grants-in-aid from Shanghai Municipal Commission of Science and Technology (Grant No.18DZ2260200).

0565 Obstructive Sleep Apnea, But Not Short Sleep Duration, is Independently Associated with Insulin Resistance: A Large-Scale Cohort Study

Introduction

Both short sleep duration and obstructive sleep apnea (OSA) seem to be associated with insulin resistance. However, the majority of previous studies addressing the relationship between OSA and insulin resistance did not evaluate short sleep duration, and vice versa. In this study, we used a large-scale hospital-based cross-sectional dataset, including 5,447 participants, to examine 1) whether objectively measured short sleep duration and OSA are independently associated with insulin resistance, and 2) whether the presence of OSA modulates the association between sleep duration and insulin resistance.

Methods

Participants were consecutively enrolled from our sleep center during the period from 2007 to 2017. The index of homeostasis model assessment insulin resistance (HOMA-IR) was calculated from insulin and glucose. Sleep duration was determined by standard polysomnography. The associations between sleep duration and insulin resistance were estimated by logistic regression analyses.

Results

A total of 5,447 participants (4507 OSA and 940 primary snorers) were included in the study. In comparison to primary snorers, OSA combined with extremely short sleep duration (&lt; 5 hours) increased the risk of insulin resistance by 34% (OR, 1.34; 95% CI, 1.01-1.77) after adjusting for confounding factors that are frequently associated with insulin resistance and OSA. In subgroup analysis stratified by sleep duration, the risk of insulin resistance in patients with a short sleep duration (5-6 hours or &lt; 5 hours) was increased in those with OSA compared to primary snorers, but not in the other three sleep duration groups (6 - 7, 7 - 8, and &gt; 8 hours).

Conclusion

OSA, but not short sleep duration, was independently associated with insulin resistance. It is worth noting that OSA combined with extremely short sleep duration showed a greater detrimental effect than OSA itself with regard to insulin resistance.

Support

This study was supported by grants-in-aid from Shanghai Municipal Commission of Science and Technology (Grant No.18DZ2260200).

Functional genomics analysis of human colon organoids identifies key transcription factors

Organoids are a valuable three-dimensional (3D) model to study the differentiated functions of the human intestinal epithelium. They are a particularly powerful tool to measure epithelial transport processes in health and disease. Though biological assays such as organoid swelling and intraluminal pH measurements are well established, their underlying functional genomics are not well characterized. Here we combine genome-wide analysis of open chromatin by ATAC-Seq with transcriptome mapping by RNA-Seq to define the genomic signature of human intestinal organoids (HIOs). These data provide an important tool for investigating key physiological and biochemical processes in the intestinal epithelium. We next compared the transcriptome and open chromatin profiles of HIOs with equivalent data sets from the Caco2 colorectal carcinoma line, which is an important two-dimensional (2D) model of the intestinal epithelium. Our results define common features of the intestinal epithelium in HIO and Caco2 and further illustrate the cancer-associated program of the cell line. Generation of Caco2 cysts enabled interrogation of the molecular divergence of the 2D and 3D cultures. Overrepresented motif analysis of open chromatin peaks identified caudal type homeobox 2 (CDX2) as a key activating transcription factor in HIO, but not in monolayer cultures of Caco2. However, the CDX2 motif becomes overrepresented in open chromatin from Caco2 cysts, reinforcing the importance of this factor in intestinal epithelial differentiation and function. Intersection of the HIO and Caco2 transcriptomes further showed functional overlap in pathways of ion transport and tight junction integrity, among others. These data contribute to understanding human intestinal organoid biology.

Highly Efficient Gene Editing of Cystic Fibrosis Patient-Derived Airway Basal Cells Results in Functional CFTR Correction

There is a strong rationale to consider future cell therapeutic approaches for cystic fibrosis (CF) in which autologous proximal airway basal stem cells, corrected for CFTR mutations, are transplanted into the patient's lungs. We assessed the possibility of editing the CFTR locus in these cells using zinc-finger nucleases and have pursued two approaches. The first, mutation-specific correction, is a footprint-free method replacing the CFTR mutation with corrected sequences. We have applied this approach for correction of ΔF508, demonstrating restoration of mature CFTR protein and function in air-liquid interface cultures established from bulk edited basal cells. The second is targeting integration of a partial CFTR cDNA within an intron of the endogenous CFTR gene, providing correction for all CFTR mutations downstream of the integration and exploiting the native CFTR promoter and chromatin architecture for physiologically relevant expression. Without selection, we observed highly efficient, site-specific targeted integration in basal cells carrying various CFTR mutations and demonstrated restored CFTR function at therapeutically relevant levels. Significantly, Omni-ATAC-seq analysis revealed minimal impact on the positions of open chromatin within the native CFTR locus. These results demonstrate efficient functional correction of CFTR and provide a platform for further ex vivo and in vivo editing.

Looping of upstream cis-regulatory elements is required for CFTR expression in human airway epithelial cells

The CFTR gene lies within an invariant topologically associated domain (TAD) demarcated by CTCF and cohesin, but shows cell-type specific control mechanisms utilizing different cis-regulatory elements (CRE) within the TAD. Within the respiratory epithelium, more than one cell type expresses CFTR and the molecular mechanisms controlling its transcription are likely divergent between them. Here, we determine how two extragenic CREs that are prominent in epithelial cells in the lung, regulate expression of the gene. We showed earlier that these CREs, located at -44 and -35 kb upstream of the promoter, have strong cell-type-selective enhancer function. They are also responsive to inflammatory mediators and to oxidative stress, consistent with a key role in CF lung disease. Here, we use CRISPR/Cas9 technology to remove these CREs from the endogenous locus in human bronchial epithelial cells. Loss of either site extinguished CFTR expression and abolished long-range interactions between these sites and the gene promoter, suggesting non-redundant enhancers. The deletions also greatly reduced promoter interactions with the 5' TAD boundary. We show substantial recruitment of RNAPII to the -35 kb element and identify CEBPβ as a key activator of airway expression of CFTR, likely through occupancy at this CRE and the gene promoter.