C–H benzylation of quinoxalin-2(1H)-ones via visible-light riboflavin photocatalysis

An efficient visible light promoted riboflavin-catalyzed direct benzylation of substituted quinoxalin-2(1H)-ones for the synthesis of various C3-benzylated quinoxalin-2(1H)-one derivatives has been developed under mild conditions.

Periodicities in the Daily Proton Fluxes from 2011 to 2019 Measured by the Alpha Magnetic Spectrometer on the International Space Station from 1 to 100 GV

We present the precision measurement of the daily proton fluxes in cosmic rays from May 20, 2011 to October 29, 2019 (a total of 2824 days or 114 Bartels rotations) in the rigidity interval from 1 to 100 GV based on 5.5×10^{9} protons collected with the Alpha Magnetic Spectrometer aboard the International Space Station. The proton fluxes exhibit variations on multiple timescales. From 2014 to 2018, we observed recurrent flux variations with a period of 27 days. Shorter periods of 9 days and 13.5 days are observed in 2016. The strength of all three periodicities changes with time and rigidity. The rigidity dependence of the 27-day periodicity is different from the rigidity dependences of 9-day and 13.5-day periods. Unexpectedly, the strength of 9-day and 13.5-day periodicities increases with increasing rigidities up to ∼10  GV and ∼20  GV, respectively. Then the strength of the periodicities decreases with increasing rigidity up to 100 GV.

Erratum: Properties of a New Group of Cosmic Nuclei: Results from the Alpha Magnetic Spectrometer on Sodium, Aluminum, and Nitrogen [Phys. Rev. Lett. 127, 021101 (2021)]

This corrects the article DOI: 10.1103/PhysRevLett.127.021101.

[Mesenchymal Stem Cells Cultured in 3D System Inhibit Non-small Cell Lung Cancer Cells Through p38 MAPK and CXCR4/AKT Pathways by IL-24 Regulating]

Non-small cell lung cancer (NSCLC) is prevalent worldwide and has a high mortality rate. Even if mesenchymal stem cells (MSCs) are suggested as cancer treatment, the studies of their effects on NSCLC cells contradict each other, mainly due to utilization of two-dimensional (2D) culture system. Three-dimensional (3D) culture systems resemble tissue organization in vivo. Here we comprehensively explore the inhibitory effects of MSCs on NSCLC cells in a 3D culture system. We confirmed that the inhibitory effects of 3D-cultured MSCs (3D-MSCs) on the proliferation and migration of NSCLC cells are greater than that of the 2D-cultured MSCs. 3D-MSCs overexpress IL-24, which serve as the key factor enhancing antitumor effects of MSCs. In these cells, IL-24 affects p38 MAPK and CXCR4/AKT pathways. Overall, this study provides the support for use of MSCs in tumor.

Properties of a New Group of Cosmic Nuclei: Results from the Alpha Magnetic Spectrometer on Sodium, Aluminum, and Nitrogen

We report the properties of sodium (Na) and aluminum (Al) cosmic rays in the rigidity range 2.15 GV to 3.0 TV based on 0.46 million sodium and 0.51 million aluminum nuclei collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. We found that Na and Al, together with nitrogen (N), belong to a distinct cosmic ray group. In this group, we observe that, similar to the N flux, both the Na flux and Al flux are well described by the sums of a primary cosmic ray component (proportional to the silicon flux) and a secondary cosmic ray component (proportional to the fluorine flux). The fraction of the primary component increases with rigidity for the N, Na, and Al fluxes and becomes dominant at the highest rigidities. The Na/Si and Al/Si abundance ratios at the source, 0.036±0.003 for Na/Si and 0.103±0.004 for Al/Si, are determined independent of cosmic ray propagation.

[Analysis of fusion gene expression in acute myeloid leukemia]

Objective: To analyze the genetic landscape of multiple fusion genes in patients with de novo acute myeloid leukemia (AML) and investigate the characteristics of immunophenotypes and mutations. Methods: The results of multiple fusion genes from 4192 patients with de novo AML were retrospectively analyzed from 2016 to 2020. In addition, the immunophenotypical data and the mutational results from high-through put method were statistically investigated and correlated as well. Results: ①Among the 52 targets, 29 different types of fusion genes were detected in 1948 patients (46.47%) with AML, which demonstrated an "exponential distribution" . ② As the age increased, the number of patients with fusion gene increased first and then decreased gradually. The total incidence rate of fusion genes and MLL rearrangment in children were significantly higher than those in adults (69.18% vs 44.76%, 15.35% vs 8.36%) . ③The mutations involving FLT3 and RAS signaling pathway contributed most in patients with MLL rearrangment. ④No specific immunophenotypic characteristics were found in AML patients with MLL or NUP98 rearrangements. Conclusion: Nearly half of AML patients were accompanied by specific fusion gene expression, the proportions of different fusion genes in pediatric and adults patients were different by multiple PCR. The gene mutations and immunophenotype of these AML patients have certain rules.

POS0885 HIGH INCIDENCE AND MORTALITY OF PNEUMOCYSTIS JIROVECI INFECTION IN ANTI-MDA5-ANTIBODY POSITIVE DERMATOMYOSITIS: EXPERIENCE FROM A SINGLE CENTER

Background:

Idiopathic inflammatory myopathies (IIM) was associated with a significantly higher risk of opportunistic infections that including Pneumocystis jiroveci pneumonia(PJP) which is potentially fatal opportunistic infection. However, no prior studies have evaluated the PJP infection in subtypes of IIM.

Objectives:

To investigate the incidence rate and mortality rate of PJP infection in subgroups of IIM patients according to myopathy specific antibodies.

Methods:

In the first part, we reviewed 463 consecutive patients with IIM retrospectively to analyze incidence of PJP infection. In the next part, we enrolled 30 consecutive PJP infection patients with any rheumatic disease was to identify the mortality rate and risk factors. Kaplan-Meier curve with log rank test was used to access differences in survival. Univariate and multivariate analyses were performed to identify prognostic factors using Cox regression.

Results:

We found that 12(7.5%) PJP cases occurred in 160 anti-MDA5-ab-positive DM patients, while only two (0.7%) PJP cases were found in 303 anti-MDA5-ab-negtive DM/PM patients(P < 0.05). PJP infection typically happened in the first two months of the treatment for anti-MDA5-ab-positive DM patients who have a significant decrease in the CD4+ T cell counts and Lymphocyte counts (P < 0.05). Only two (16.7%) anti-MDA5-ab-positive DM patients recover from PJP, with lethally higher mortality than those PJP infection with other rheumatic diseases (83.3% vs. 38.9%, P < 0.05). We found no association between the time to anti-PJP treatment and treatment outcomes in anti-MDA5-ab-positive DM; yet we confirmed in PJP infection with other rheumatic diseases that anti-PJP treatment within 6 days crucially increased the survival (P < 0.05).

Conclusion:

PJP infection has alarming high incidence and mortality in anti-MDA5-ab-positive DM patients. Unlike PJP infection with other rheumatic diseases, timely treatment for PJP doesn’t improve the prognosis of this particular subtype. Therefore, the necessity of further study of PJP prophylaxis treatment in anti-MDA5-ab-positive DM patients is verified.

References:

[1]Hsu CY, et al. Comparing the burdens of opportunistic infections among patients with systemic rheumatic diseases: a nationally representative cohort study. ARTHRITIS RES THER 2019, 21(1):211.

Acknowledgements:

The authors thank Dr. An Sun,

Disclosure of Interests:

None declared

The analysis of the effects of Liuwei Dihuang decoction on aging-related metabolites and metabolic pathways in naturally aging mice by ultra-performance liquid chromatography quadruple time-of-light mass spectrometry

Liuwei Dihuang decoction (LWDH) has been used to treat age-related diseases in Asia for thousands of years. Its effect is significant, but the mechanism is not entirely understood. The development and maturity of metabonomics technology have created a new way to understand its effects. In this study, 20-month-old naturally aging mice were used as the research subjects. Mice were randomly divided into the young group, elderly group, vitamin E group, and LWDH group, with 10 mice in each group. The UPLC-Q-TOF-MS technique analyzed the changes in plasma metabolism of these mice. Principal component analysis (PCA) and orthogonal partial least-squares discriminant analysis (OPLS-DA) were used to study metabolic markers and metabolic pathways. Compared with the elderly group, the organ index and weightbearing swimming time of the LWDH and vitamin E groups increased (P ≤ 0.01). The results show that LWDH can benignly regulate the expression level of 11 aging-associated metabolites in aged mice and alleviate the aging state of mice. These metabolites mainly affect the metabolism of glutathione, unsaturated fatty acid biosynthesis, pyrimidine, selenium, pentose phosphate, arginine, and proline.

Risk factors for delayed radiographic resolution in children with refractory Mycoplasma pneumoniae pneumonia

OBJECTIVE

To determine the risk factors for delayed radiographic resolution in children with refractory Mycoplasma pneumoniae pneumonia (RMPP) and explore the most suitable time for interventional bronchoscopy.

METHODS

This retrospective study involved 142 children with RMPP who were admitted to our hospital from 1 January 2015 to 31 December 2017. They were divided into a common resolution group and a delayed resolution group based on their chest radiograph series.

RESULTS

Among the 142 patients, 67 showed common resolution on chest radiographs and 75 showed delayed resolution. Independent risk factors for delayed resolution were a clinical course of ≥11.5 days before the performance of interventional bronchoscopy, mucus plug formation, corticosteroid resistance, and atelectasis. When bronchoscopy was performed before the disease had been present for <11.5 days, the length of hospitalization, total fever duration, and duration of time until disappearance of coughing were shorter than those in children who underwent bronchoscopy after the disease had been present for ≥11.5 days.

CONCLUSIONS

Corticosteroid resistance, the time to interventional bronchoscopy, atelectasis, and mucus plug formation were associated with delayed resolution on chest radiographs. Performance of interventional bronchoscopy before the clinical course has reached 11.5 days may help alleviate clinical symptoms and improve radiographic resolution.

Long noncoding RNA SNHG14 promotes malignancy of prostate cancer by regulating with miR-5590-3p/YY1 axis

OBJECTIVE

Studies have demonstrated that long non-coding RNAs (lncRNAs) are important in the development and prognosis of prostate cancer. The aim of this study was to investigate the functions and mechanism of lnc-SNHG14 in prostate cancer.

PATIENTS AND METHODS

Quantitative Real Time-Polymerase Chain Reaction (qRT-PCR) or Western blot (WB) were performed to detect mRNA expressions of SNHG14 and miR-5590-3p, and the protein levels of Yin Yang-1 (YY1) in prostate cancer tissues, adjacent tissues, and cancer cell lines. The correlation analysis was used to analyze the correlations between SNHG14, miR-5590-3p, and YY1. Kaplan-Meier survival analysis was used to analyze the overall survival for prostate cancer patients. Cell Counting Kit-8 (CCK-8) assay was performed to measure cell proliferation ability and flow cytometry assay was used to detect cell apoptotic rate. Besides, transwell assay was used to measure cell invasion ability. In addition, WB was performed to measure protein expressions in prostate cancer cell lines. Finally, Luciferase reporter assay was performed to verify the binding sites between SNHG14 and miR-5590-3p, miR-5590-3p, and YY1.

RESULTS

The results showed that SNHG14 was significantly increased in prostate cancer tissues and prostate cancer cell lines, which were related with advanced stage and poor diagnosis for prostate cancer patients. MiR-5590-3p was reduced in prostate cancer tissues and cell lines, which were negatively correlated with SNHG14. YY1 was found to be increased in prostate cancer tissues, which was negatively correlated with miR-5590-3p and positively correlated with SNHG14. Furthermore, SNHG14 knockdown inhibited cell proliferation, invasion, and promoted cell apoptosis in DU145 cells. In addition, protein expressions of Cyclin D1, Bcl-2, and N-cadherin were repressed, and the levels of Bax, Cleaved Caspase-3, and E-cadherin were increased. Besides, miR-5590-3p inhibition promoted cell proliferation and invasion, and inhibited apoptosis in DU145 cells. Importantly, Luciferase reporter assay proved that SNHG14 could directly sponge with miR-5590-3p, which could bind with YY1 and regulate the functions of cancer cell. Finally, we proved that SNHG14 regulated cell proliferation, cell apoptosis, and invasion via miR-5590-3p/ YY1 axis in prostate cancer.

CONCLUSIONS

Above all, we found that SNHG14 was increased in prostate cancer patients, which was related with future diagnosis for prostate cancer patients. Of note, we discovered that SNHG14 could promote cell proliferation, invasion, and repress cell apoptosis via miR-5590-3p/YY1 axis in prostate cancer, which might provide a new target for treating prostate cancer.

Properties of Heavy Secondary Fluorine Cosmic Rays: Results from the Alpha Magnetic Spectrometer

Precise knowledge of the charge and rigidity dependence of the secondary cosmic ray fluxes and the secondary-to-primary flux ratios is essential in the understanding of cosmic ray propagation. We report the properties of heavy secondary cosmic ray fluorine F in the rigidity R range 2.15 GV to 2.9 TV based on 0.29 million events collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. The fluorine spectrum deviates from a single power law above 200 GV. The heavier secondary-to-primary F/Si flux ratio rigidity dependence is distinctly different from the lighter B/O (or B/C) rigidity dependence. In particular, above 10 GV, the F/Si/B/O ratio can be described by a power law R^{δ} with δ=0.052±0.007. This shows that the propagation properties of heavy cosmic rays, from F to Si, are different from those of light cosmic rays, from He to O, and that the secondary cosmic rays have two classes.

Properties of Iron Primary Cosmic Rays: Results from the Alpha Magnetic Spectrometer

We report the observation of new properties of primary iron (Fe) cosmic rays in the rigidity range 2.65 GV to 3.0 TV with 0.62×10^{6} iron nuclei collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. Above 80.5 GV the rigidity dependence of the cosmic ray Fe flux is identical to the rigidity dependence of the primary cosmic ray He, C, and O fluxes, with the Fe/O flux ratio being constant at 0.155±0.006. This shows that unexpectedly Fe and He, C, and O belong to the same class of primary cosmic rays which is different from the primary cosmic rays Ne, Mg, and Si class.

Astragalus membranaceus root supplementation improves average daily gain, rumen fermentation, serum immunity and antioxidant indices of Tibetan sheep

The use of antibiotics as supplements in animal feed is restricted due to possible health hazards associated with them. Consequently, there is increasing interest in exploiting natural products to improve health and production of livestock with no detrimental side effects. In this study, we examined the effect of Astragalus membranaceus root (AMT) supplementation on DM intake, growth performance, rumen fermentation and immunity of Tibetan sheep. Twenty-four male Tibetan sheep (31 ± 1.4 kg; 9 months old) were assigned randomly to one of four dietary treatments with different levels of AMT: 0, 20, 50 and 80 g/kg DM (A₀, A₂, A₅ and A₈, respectively) in addition to their basal diets. A₀ acted as a control group, and measurements were recorded over a 56-d feeding period. Sheep fed with AMT had a higher average daily gain and a lower feed:gain ratio than controls (P < 0.001). Rumen concentrations of NH₃-N (P < 0.001), total volatile fatty acids (P = 0.028), acetate (P = 0.017) and propionate (P = 0.031) in A₅ and A₈ were higher than those in A₀. The addition of AMT in the feed significantly increased serum antioxidant and immunity factors of the sheep and increased the concentrations of serum interleukin, immunoglobulin and tumour necrosis factor-α (P = 0.010). We concluded that AMT can be used as a feed additive to improve growth performance and rumen fermentation and enhance the immunity of Tibetan sheep. Some responses exhibited a dose-dependent response, whereas other did not exhibit a pattern, with an increase in AMT. The addition of 50 and 80 g/kg AMT of total DM intake showed the most promising results.

[Effectiveness and safety of sofosbuvir/velpatasvir combination ± ribavirin in the treatment of Chinese adults with chronic hepatitis C virus infection]

Objective: To understand the effectiveness and safety sofosbuvir/velpatasvir (SOF/VEL) combination ±ribavirin in the treatment of chronic hepatitis C virus (HCV) infection in China. Methods: A total of 96 Chinese adults with chronic HCV infection who were treated with SOF/VEL combination ± ribavirin for 12 weeks between July 2018 and February 2020 were selected. HCV RNA, routine blood test, liver, kidney and coagulation function, abdominal Color Doppler ultrasound or CT and liver stiffness were detected at baseline, 4 weeks of treatment, end of treatment and 12 weeks of follow-up. Adverse events and laboratory abnormalities during the treatment were recorded. A t-test was used to compare the measurement data between the two groups, and the analysis of variance was used for multiple group comparison. Results: A total of 93 cases (96.9%) achieved sustained virological response (SVR12), of which 3 cases had relapsed. 88 cases (91.7%, 88/96) had achieved rapid virological response (RVR). 96 cases (100%) had achieved virological response by the end of treatment (EOT). In patients with decompensated liver cirrhosis, the average baseline Child-Pugh score and Model for End-Stage Liver Disease score was 7.4±1.0, and 11.4±1.7, respectively. Among them, 12 cases of the SOF/VEL combined with RBV treatment had achieved SVR12 (100%) at 12 weeks, while only 3 of the 5 cases of single-tablet regimen of SOF/VEL had achieved SVR12 (60%). There was no significant difference between creatinine levels and baseline during or 12 weeks after treatment. The incidence of adverse events in patients with chronic hepatitis C and compensated cirrhosis was 6.3% (5/79), while that in patients with decompensated cirrhosis was 35.3% (6/17). The most common adverse events were hyperbilirubinemia, fatigue and anemia. There were no serious adverse events, deaths or discontinuation of treatment due to adverse events. Conclusion: SOF/VEL combination ± ribavirin in the treatment of various common genotypes of chronic hepatitis C, compensated cirrhosis, decompensated cirrhosis and hepatocellular carcinoma has higher SVR12 in China, and the tolerance and safety are good.

[Surgical treatment strategies for Siewert type II adenocarcinoma of the esophagogastric junction]

The incidence of adenocarcinoma of the esophagogastric junction (AEG) continues to rise. While many treatment modalities are available, surgery is still the basis of comprehensive treatment of AEG. Siewert type II AEG, is more controversial than the other two types in terms of lymph node metastasis, surgical approach, extent of resection, and digestive tract reconstruction. When the distance of the superior tumor margin is more than 3 cm proximal to the EGJ line is more than 3 cm, thorough mediastinal lymph node dissection should be performed through thoracic approach. Total gastrectomy is the treatment of choice for Siewert type II tumors. When the tumor stage is in an early stage, the length of the tumor is ≤4 cm, and esophageal involvement is less than 3 cm, transthoracic esophagectomy plus proximal gastrectomy is feasible. The digestive tract reconstruction can be based on the experience of the operator and patient's choice of conditions.

Long noncoding RNA NEAT1 promotes the growth of gastric cancer cells by regulating miR-497-5p/PIK3R1 axis

OBJECTIVE

To investigate the molecular mechanisms of long noncoding RNA (lncRNA) nuclear paraspeckle assembly transcript 1 (NEAT1) in gastric cancer (GC) development progress.

MATERIALS AND METHODS

Relative mRNA and protein expression levels were quantified by quantitative Reverse Transcription-PCR (qRT-PCR) or Western blot analysis. Cell proliferation and cell apoptosis were measured by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay and flow cytometry, respectively. Binding sites of miR-497-5p on NEAT1 or phosphoinositide-3-kinase regulatory subunit 1 (PIK3R1) were determined by RNA pull-down assay or dual-luciferase reporter assay. Finally, the tumorigenic role of NEAT1 in GC was assessed using a xenograft model on nude mice.

RESULTS

NEAT1 was upregulated in GC tissues, promoted proliferation, and inhibited apoptosis of GC cells. NEAT1 could directly bind to and negatively regulate miR-497-5p expression. PIK3R1 was then identified as a downstream target of miR-497-5P. In GC cell models, PIK3R1 was found to be directly negatively regulated by miR-497-5p and indirectly positively regulated by NEAT1. Finally, NEAT1 knockdown inhibited tumor growth, increased miR-497-5p expression, and decreased PIK3R1 expression in xenograft model mice compared with the negative control.

CONCLUSIONS

Functioned as an oncogene, NEAT1 promoted cell growth in GC by regulating miR-497-5p/PIK3R1 axis. These results provided valuable insights into the underlying regulation signaling in gastric cancer development, shedding light on NEAT1 a promising therapeutic target from bench to clinic.

[Safety and feasibility of indocyanine green injection through accessory incision in laparoscopic right hemicolectomy]

Objective: To explore the safety and feasibility of indocyanine green (ICG) injection through accessory incision in laparoscopic right hemicolectomy. Methods: A descriptive case series study was carried out. Clinicopathological data of 29 patients with colon cancer undergoing right hemicolectomy at Department of General Surgery, Guangdong Provincial People's Hospital were retrospectively analyzed. All the patients received ICG injection through accessory incision at the beginning of operation. Results: Among 29 patients, 13 were male and 16 were female with a mean age of (60.8±7.7) years and mean body mass index of (24.3±2.8) kg/m(2); 3 were stage I, 19 were stage II, 7 were stage III. Pericolic, intermediate and main lymph nodes could be detected under near infrared fluorescence imaging (NIRFI) in all the cases. No.6 lymph nodes were observed in 3 cases, while no lymph nodes around superior mesenteric vein (SMV) were found. The average number of fluorescent lymph node was 14.2±6.1. The average developing time of fluorescence was (36.2±3.7) minutes. The average number of harvested lymph nodes was 22.4±8.2. There was no extravasation of imaging agent during the operation, and there were no intraoperative complications such as allergies, massive abdominal bleeding, peripheral organ damage, etc. Operative time was (113.1±10.7) minutes, blood loss during operation was (22.4±3.9) ml, ambulatory time was (1.2±0.4) days, time to the first flatus was (1.7±0.7) days, time to the first fluid diet was (0.7±0.4) days, and postoperative hospital stay was (5.8±1.5) days. No operation-associated complications such as anastomotic bleeding, anastomotic leakage, peritoneal bleeding, peritoneal infection, incision infection occurred after operation. Conclusion: ICG injection through accessory incision in laparoscopic right hemicolectomy is safe and feasible.

[Current practice patterns of preoperative bowel preparation in elective colorectal surgery: a nation-wide survey of Chinese surgeons]

Objective: To understand the current practice of preoperative bowel preparation in elective colorectal surgery in China. Methods: A cross-sectional questionnaire survey was conducted through wechat. The content of the questionnaire survey included professional title of the participants, the hospital class, dietary preparation and protocol, oral laxatives and specific types, oral antibiotics, gastric intubation, and mechanical enema before elective colorectal surgery. A stratified analysis based on hospital class was conducted to understand their current practice of preoperative bowel preparation in elective colorectal surgery. Result: A total of 600 questionnaires were issued, and 516 (86.00%) questionnaires of participants from different hospitals, engaged in colorectal surgery or general surgeons were recovered, of which 366 were from tertiary hospitals (70.93%) and 150 from secondary hospitals (29.07%). For diet preparation, the proportions of right hemicolic, left hemicolic and rectal surgery were 81.59% (421/516), 84.88% (438/516) and 84.88% (438/516) respectively. The average time of preoperative dietary preparation was 2.03 days. The study showed that 85.85% (443/516) of surgeons chose oral laxatives for bowel preparation in all colorectal surgery, while only 4.26% (22/516) of surgeons did not choose oral laxatives. For mechanical enema, the proportions of right hemicolic, left hemicolic and rectal surgery were 19.19% (99/516), 30.04% (155/516) and 32.75% (169/516) respectively. Preoperative oral antibiotics was used by 34.69% (179/516) of the respondents. 94.38% (487/516) of participants were satisfied with bowel preparation, and 55.43% (286/516) of participants believed that preoperative bowel preparation was well tolerated. In terms of preoperative oral laxatives, there was no statistically significant difference between different levels of hospitals [secondary hospitals vs. tertiary hospitals: 90.00% (135/150) vs. 84.15% (308/366), χ(2)=2.995, P=0.084]. Compared with the tertiary hospitals, the surgeons in the secondary hospitals accounted for higher proportions in diet preparation [87.33% (131/150) vs. 76.78% (281/366), χ(2)=7.369, P=0.007], gastric intubation [54.00% (81/150) vs. 36.33% (133/366), χ(2)=13.672, P<0.001], preoperative oral antibiotics [58.67% (88/150) vs. 24.86% (91/366), χ(2)=12.259, P<0.001] and enema [28.67% (43/150) vs. 15.30% (56/366), χ(2)=53.661, P<0.001]. Conclusion: Although the preoperative bowel preparation practice in elective colorectal surgery for most of surgeons in China is basically the same as the current international protocol, the proportions of mechanical enema and gastric intubation before surgery are still relatively high.

SAT0303 SINGLE-CELL DECONVOLUTION OF SKIN FIBROBLAST HETEROGENEITY IN PATIENTS WITH SYSTEMIC SCLEROSIS

Background:

Fibroblast heterogeneity and homeostasis has long been recognized in patients with systemic sclerosis (SSc). However, there is no common consensus on fibroblast subtypes, lineages, biological properties, signaling, and plasticity, which severely hampers our understanding of SSc pathogenesis.

Objectives:

This study is aimed to comprehensively classify skin fibroblast populations from SSc patients.

Methods:

We applied single-cell RNA sequencing on skin fibroblasts from two SSc patients and two health control (HC) with matched age and sex. Cell clustering were mainly determined by UMAP with batch effect correction. Differently expressed genes in each cell cluster was analyzed by Gene Set Enrichment Analysis (GSEA).

Results:

With an unbiased approach, single-cell transcriptome analyses showed classified and defined eight fibroblast types in SSc skin and six in normal skin. The cell types seldom overlapped between the patients and HC. Extracellular interaction and collagen production were remarkably stronger in SSc fibroblasts. A subgroup of dramatic cell proliferation and activation was defined only in SSc fibroblast. Two subtypes responding inflammatory stimuli were only found in SSc patients. Furthermore, delineation of their differentiation trajectory was achieved by a machine learning method.

Conclusion:

This collection of single-cell transcriptomes and the distinct classification of fibroblast subsets provide a new resource for understanding the fibroblast landscape and the roles of fibroblasts in SSc.

References:

N/A

Disclosure of Interests:

None declared