A variety of mechanisms help tumor escape from the recognition and killing by the body immune system. In recent years, the adenosine pathway has been found to play an important role in tumor immune evasion. Adenosine is produced from extracellular adenosine triphosphate (ATP) in the presence of two ectonucleotidases (CD39 and CD73), and exerts specific functions through binding to its receptors [mainly adenosine A2A receptor (A2AR)]. Studies have suggested that the adenosine pathway can be over-activated in the tumor micro-environment, and thus promoting tumor development and progression by generating the immuno-suppressive signals. This review talked about the role of the adenosine pathway in regulating tumor immunity and its potential clinical application value. At the same time, the latest research evidence of adenosine-pathway-related targeted drugs is evaluated and summarized to provide a comprehensive reference for understanding the significance of the adenosine pathway in cancer management.

Periodontitis is a typical osteoimmune disorder characterized by inflammatory absorption of alveolar bone, and is the main cause for loose and fall off teeth in adults. Bacterial antigens stimulate the osteoclasts and aggravate periodontal inflammation, so it is of great significance for treatment of periodontitis to control inflammation and block the resorption of alveolar bone. Milk fat globule epidermal growth factor 8 (MFG-E8), as a lipophilic glycoprotein on the cell membrane, is expressed in multiple organs and histiocytes and participates in the bone immune response. MFG-E8 is involved in the development of osteoinflammatory diseases including periodontitis, so can be used as a new marker for the diagnosis of periodontal disease, and also has the potential of targeted therapy for periodontitis with the aggravation of osteoinflammatory diseases, the decreased expression of MFG-E8, reduction of osteoclasts formation and inhibition of alveolar bone resorption. MFG-E8 may be committed to early diagnosis and intervention to control the disease in order to reduce the economic burden of patients and improve the quality of life, and may become a hot spot for the treatment of periodontitis and other osteoinflammatory diseases in the future. Therefore, the research progress of MFG-E8-mediated osteoimmunology in periodontitis has reviewed in present paper to provide new ideas for clinical diagnosis and treatment of periodontitis.

By April 19, 2021, the ongoing coronavirus disease 2019 (COVID-2019), which is caused by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) has infected more than one hundred and fourty million individuals across more than 200 countries or territories and killed more than three million twenty-six thousand individuals worldwide. There are currently no specific drugs available for patients with COVID-19 infection, but a number of potential drug targets have been identified with the further understanding of the virological characteristics and pathogenesis of SARS-CoV-2. Some candidate drugs have shown good antiviral activity against SARS-CoV-2 in preclinical or clinical trials. This paper summarizes the current status of potential therapeutic drugs for COVID-19 in order to provide references for future COVID-19 therapy.

Objective To investigate the photodynamic effect of IR-820 and perfluoropentane (PFP) loaded phase-transition multifunctional molecular imaging probe (IR-820/PFP@PLGA NPs) on ultrasound/photoacoustic dual-mode imaging and fibroblast-like synoviocytes (FLSs) of rheumatoid arthritis (RA) in vitro. Methods The IR-820/PFP@PLGA nanoparticles were prepared by double emulsification method. The basic characteristics, thermal phase transition and photothermal effect of IR-820/PFP@PLGA nanoparticles were determined, the ultrasound/photoacoustic dual-mode imaging ability in vitro of the IR-820/PFP@PLGA nanoparticles were observed, and the generation of reactive oxygen species in vitro were evaluated. The photodynamic therapy effect of the nanoparticles on fibroblast-like synoviocytes was observed by CCK-8 method and flow cytometry. Results The prepared IR-820/PFP@PLGA nanoparticles were dark green, with a particle size of (261.8±3.2) nm and a potential of (–27.4±0.7) mV. The size of the IR-820/PFP@PLGA nanoparticles were uniform and the morphology were regular. The size of nanoparticles and the temperature of nanoparticle solution increased obviously by laser irradiation, it was positively correlated with the concentration of nanoparticles, and enhanced ultrasound imaging was observed. The photoacoustic imaging effect of nanoparticle was linearly correlated with the concentration of IR-820/PFP@PLGA nanoparticles; The singlet oxygen sensor green(SOSG) assay revealed that the nanoparticles produced a large amount of reactive oxygen species after laser irradiation with time-dependent manner; it was found by in vitro cell experiments that the nanoparticles had good biological safety, while the cytotoxicity increased along with the advanced nanoparticle concentration after laser irradiation, and also the apoptosis increased significantly. Conclusion IR-820/PFP@PLGA nanoparticles have a good dual-mode imaging and photodynamic effect on FLSs, which can provide a new idea for the integration of diagnosis and treatment for RA.

Objective To investigate the effect of simulated high altitude and cold conditions on the model of severe abdominal infection in rabbits. Methods 60 New Zealand rabbits were randomly divided into plain group (altitude 100 m, temperature 5℃, n=20), sub-plateau group (altitude 1000 m, temperature –5℃, n=20) and plateau group (altitude 5000 m, temperature –25℃, n=20). Each group was kept in the corresponding animal feeding cabin for 14 days, then induced severe abdominal model by cecal ligation and puncture (CLP). The basic data were measured before operation, and the peripheral vein blood was extracted 24 and 72 hours after operation. The levels of C-reactive protein (CRP), procalcitonin (PCT), tumor necrosis factor-α (TNF-α), albumin (ALB), prealbumin (PAB) were measured by ELISA, and the white blood cell count (WBC) was performed. The rabbits were killed 72 hours after operation, the ascites were collected from the abdominal fluid, and collected liver, kidney and small intestine, and the pathological changes were observed by HE staining. Pearson correlation was used to analyze the correlation between the infection indexes and the high cold factors at high altitude. Results Seventy-two hours after operation, the survival rate of CLP model rabbits in plain group, sub-plateau group and plateau group was 65.0%(13/20), 35.0%(7/20), 10.0%(2/20), respectively. With the increase of altitude and the decrease of temperature, the survival rate of CLP model rabbits decreased gradually (P<0.01). All CLP rabbits began to show signs of less movement, curling, mental burnout, shortness of breath, coarse breath tone, diarrhea and eye corner exudates. In the plain group, the anal temperature increased continuously and then decreased slowly, with the highest value of 39.2℃ and the lowest value of 36.5℃; in the sub-plateau group, the anal temperature increased sharply and then decreased gradually, with the highest value of 40.6℃ and the lowest value of 34.9℃; in the plateau group, the anal temperature decreased rapidly, with the highest value of 41.2℃ and the lowest value of 34.0℃. At 24 and 72 hours after operation, the levels of PCT and TNF-α in venous blood of CLP model rabbits in plateau group and sub-plateau group were higher than those in plain group, and those in plateau group were higher than those in sub-plateau group (P<0.05); at 72 hours after operation, the levels of ALB and PAB in venous blood of CLP model rabbits in plateau group and sub-plateau group were lower than those in plain group, and those in plateau group were lower than those in sub-plateau group (P<0.05). Pearson correlation analysis showed that PCT, TNF-α were positively correlated with high altitude cold factors (r=0.288, r=0.368, P<0.05), WBC and CRP had no significant correlation with them (r=0.462, r=0.397, P>0.05). The results of ascite culture showed that 51, 69 and 107 pathogens were isolated from plain group, sub-plateau group and plateau group respectively, among which gram-negative bacteria accounted for 52.94%(27/51), 49.27%(34/69), 42.06%(45/107), and gram-positive bacteria accounted for 29.41%(15/51), 34.78%(24/69), 43.93%(47/107). Conclusion The high cold condition at high altitude is an important factor in the infection degree and death of CLP model rabbits. It can aggravate the infection of abdominal cavity and damage the important organ function, affect the nutrition absorption and metabolism of the body. The difference between the pathogenic bacteria and the plain area under this condition may affect the process and treatment of abdominal infection diseases, which is worth further study.

Objective To investigate the possible mechanism of proline/serine rich coil protein 1 and annexin A2 (PSRC1-ANXA2) interaction to attenuate the progression of atherosclerosis. Methods To detect the PSRC1 binding proteins, RAW264.7 macrophages were divided into two groups: control group (Ad-GFP) and PSRC1 overexpression group (Ad-PSRC1), treated with ox-LDL (100 μg/ml) for 24 h after adenovirus transfection, and the PSRC1-binding proteins were detected by non-labeled quantitative macrophages. The above protein spectra were verified by co-immunoprecipitation (Co-IP) and immunofluorescence assay. To detect the effect of PSRC1 overexpression on ANXA2 secretion after ox-LDL stimulation, RAW264.7 macrophages were divided into four groups: control group, ox-LDL group, Ad-GFP+ox-LDL group and Ad-PSRC1+ox-LDL group. The levels of ANXA2 in the cultured supernatant were determined by enzyme-linked immunosorbent assay (ELISA). To detect the knockdown effect of adenovirus Ad-shANXA2 on AXNA2, RAW264.7 macrophages were divided into two groups: Ad-GFP group and Ad-shANXA2 group. The mRNA levels of ANXA2 in RAW264.7 macrophages were detected by real-time fluorescence quantitative PCR (RT-qPCR). To detect the effect of ANXA2 knockdown on the progression of aortic plaque and the secretion of inflammatory factors, 24 ApoE^-/- mice were randomly divided into four groups (6 each): chow diet+Ad-GFP group, chow diet+Ad-shANXA2 group, high fat diet+Ad-GFP group and high fat diet+Ad-shANXA2 group. The atherosclerosis areas (AS) of aorta and aortic root were detected by oil red O staining. The serum levels were determined by ELISA assay of interleukin-1β (IL-1β) and IL-6 in high fat diet+Ad-GFP group and high fat diet+Ad-shANXA2 group. Results The results of proteomics analysis showed that, after stimulation with ox-LDL, the binding of PSRC1 and ANXA2 increased significantly, and the combination was of specificity. Immunofluorescence also showed that the co-localization of PSRC1 and ANXA2 existed in the cells. RT-PCR revealed that, compared with Ad-GFP group, the ANXA2 level decreased significantly in Ad-shANXA2 group (0.198±0.065 vs. 1.002±0.069, P<0.05). ELISA results showed that, compared with the control group, the ANXA2 level increased significantly in the ox-LDL group [(2027.23±93.55) pg/ml vs. (697.01±30.08) pg/ml, P<0.01], and compared with Ad-GFP+ox-LDL group, the ANXA2 level reduced significantly in Ad-PSRC1+ox-LDL group [(1061.65±68.52) pg/ml vs. (2098.67±318.41) pg/ml, P<0.01]. In animal experiments, oil red O staining revealed that no statistical difference existed in the area of aortic gross and aortic root plaques between the two groups of chow diet.Compared with high-fat diet+Ad-GFP group, the percentage of aortic plaque area decreased significantly, and of aortic root section also decreased significantly in high-fat diet+Ad-shANXA2 group (5.29%±1.14% vs. 12.28%±2.48%, P<0.05; 1.31%±0.04%vs. 2.83%±0.22%, P<0.05). ELISA test found that, compared with high-fat diet+Ad-GFP group, the IL-1β level decreased significantly [(122.90±9.80) pg/ml vs. (172.90±21.83) pg/ml, P<0.05], and the IL-6 level decreased also [(3.65±0.12) pg/ml vs.(5.97±0.42) pg/ml, P<0.05] in high-fat diet+Ad-shANXA2 group. Conclusion Over-expression of PSRC1 in macrophages can attenuate the progression of atherosclerosis, where the increased binding of PSRC1 to ANXA2, and the inhibition of ANXA2 release, thereby inhibiting the release of inflammatory factor may be the possible related mechanism.

Objective To profile transcriptome dynamics in the entecavir resistant hepatitis B virus (ETV-r HBV) stably transfected cell line, and provide fundamental data for future studies to understand mechanisms of infection using this cell line. Methods ETV-r HBV stably transfected cell lines (HepG2.A64) and the corresponding isogenic cell lines (HepG2) were used to profile the transcriptome (n=3). We used DESeq2 software to analyze the sequencing results to identify differentially expressed genes with |log2 Fold Change|>2, padj<0.05. GO and KEGG functional enrichment analysis of differential genes were performed by clusterProfiler software, and then the transcriptional and protein levels of related genes in the DNA repair pathway were detected by RT-qPCR and Western blotting. Results A total of 613 differentially expressed genes were identified in the cell lines before and after stable ETV-r HBV transfection, of which 401 were up-regulated and 212 down-regulated (padj<0.05). GO and KEGG enrichment analysis showed that differentially expressed genes were mainly involved in the inflammatory response, PI3K/Akt signal pathway, PPAR signal pathway, NF-κB signal pathway and immune-related biological processes. Through the analysis of the relevant genes in the DNA repair pathway and the verification by RT-qPCR and Western blotting, it was found that after stable transfection of ETV-r HBV, the mRNA expression of RAD52 and XRCC2 genes in the DNA repair pathway decreased by 68.96%±7.59% and 69.58%±6.32%, respectively, and the protein expression decreased by 69.93%±3.88% and 26.47%±12.7%, respectively, and the differences were statistically significant (P<0.05). Conclusion Compared with the original background cell line HepG2, a lot of genes are differentially expressed at the transcription level in HBV stable cell line, and the DNA repair-related genes in the HepG2.A64 cell line had been decreased significantly.

Objective To investigate the effects of advanced pregnancy on DNA methylation level of hippocampus in the offspring rats. Methods 12- and 3-month-old female SD rats were mated with 3-month-old male SD rats. The offspring(s)from older mother were marked as AMA group, and those from younger mother were marked as control group. The brain and hippocampus samples of the offsprings were taken at the 7th, 14th and 28th day after birth. The mRNA levels of DNA methyltransferase (Dnmt)1, Dnmt3A and Dnmt3B were detected by real-time fluorescent quantitative PCR (RT-PCR). The protein expression levels of Dnmt1, Dnmt3A and Dnmt3B were measured by Western blotting. Immunofluorescence and ELISA were used to detect the localization and expression level of 5-methylcytosine (5-mC) in hippocampus. Results RT-PCR showed the Dnmt1 mRNA level was markedly lower in hippocampus of AMA group than that in control group on day 28 after birth (P<0.05); Western blotting analysis showed the expression level of Dnmt3A protein was obviously higher in hippocampus of the AMA group than that in control group on day 7 after birth (P<0.05), while the expression levels of Dnmt1 and Dnmt3A were lower in AMA group than those in control group on day 28 after birth (P<0.05). Immunofluorescence test showed that the 5-mC level in hippocampus was significantly higher in AMA group than that in control group on day 7 and 14 after birth (P<0.05). ELISA showed that the 5-mC level in hippocampus increased slightly but without statistical significance in AMA group than that in control group on day 7, 14 and 28 after birth (P>0.05). Conclusion Advanced pregnancy may lead to the expression disorder of Dnmts and the increased DNA methylation level in offspring's hippocampus, which may be one of the potential mechanisms of offspring's brain dysfunction.

Objective To explore the analgesic effect of low-intensity exercise induced by interleukin (IL)-4 on chronic constriction injury of the sciatic nerve (CCI) mice. Methods A total of 48 male C57/BL6 mice were randomized into 6 groups(n=8): sham/sedentary group (SS group), sham/normal saline/exercise group (SNE group), sham/anti-IL-4/exercise group (SAE group), CCI/sedentary group (CS group), CCI/normal saline/exercise group (CNE group), CCI/anti-IL-4/exercise group (CAE group). After inducing CCI, mice were given low-intensity exercise from 1 to 15 days. For the SAE group and the CAE group, mice received 50 μg of IL-4 receptor blocker (IL-4Ra) 30 min before exercise through intraperitoneal injection. Behavioural tests were performed on the 3rd day (T₁), 7th day (T₂), 11th day (T₃) and 15th day (T₄) to analyze the difference of hyperalgesia. On the 15th day after CCI induction, the injured sciatic nerve and lumbar spinal cord (L₁-L₆) of all mice were collected. The levels of IL-4, IL-1Ra, IL-5, TNF-α, IL-1β, brain-derived neurotrophic factor (BDNF) and β-nerve growth factor (β-NGF) were detected by ELISA. Results The paw withdrawal mechanical threshold (PWMT) and paw withdrawal thermal latency (PWTL) values of the CNE group at T₃ and T₄ were higher than those of the CS group and CAE group (P<0.05); the IL-4 levels of the sciatic nerve and lumbar spinal cord in CNE group and CAE group were higher than those of CS group (P<0.05); the IL-1Ra and IL-5 levels of the sciatic nerve and lumbar spinal cord in CNE group were higher than those of CS group and CAE group (P<0.05); the TNF-α, IL-1β, BDNF and β-NGF levels of the sciatic nerve and lumbar spinal cord of CNE group were lower than those of CS group and CAE group (P<0.05). Conclusion Low-intensity exercise exerts the analgesic effect on mice with chronic constriction injury of sciatic nerve through IL-4.

Objective To compare the consistency and accuracy between rapid direct detection method (rapid method)and traditional detection method (traditional method) for bacterial identification and drug sensitivity test of positive blood culture specimens. Methods The bloodstream infection specimens of the outpatients, emergency patients and inpatients of the Chinese PLA General Hospital from 2019 to 2020 were collected and placed in a blood culture apparatus. After the blood culture alarm, positive blood culture specimens were collected. At the same time, the rapid method and the traditional method were used for culture. After culture, bacteria identification and drug susceptibility test were conducted respectively, and the consistency of bacteria identification and drug susceptibility test between the two methods was recorded and compared. Results Among the 149 positive blood specimens from patients with bloodstream infection, 79 strains of Gram-positive cocci and 70 strains of Gram-negative bacilli were identified by traditional method; 75 strains of Gram-positive cocci and 67 strains of Gram-negative bacilli were identified by the rapid method. Compared with the traditional method, the overall coincidence rate of the rapid method in identify bacteria was 95.3%(142/149), among which the coincidence rate of Gram-positive cocci was 94.9%(75/79), and that of Gram-negative bacilli was 95.7%(67/70). In the traditional method, 76 strains (96.2%) of Gram-positive cocci and 66 strains (94.3%) of Gram-negative bacteria can effectively identify their species; 3 strains (3.8%) of Gram-positive cocci and 4 strains (5.7%) of Gram-negative bacilli could effectively identify their genera. In the rapid method, 52 strains (69.3%) of Gram-positive cocci and 63 strains (94.0%) of Gram-negative bacilli could effectively identify their species, 20 strains (26.7%) of Gram-positive cocci and 3 strains (4.5%) of Gram-negative bacilli could effectively identify their genera. According to the criteria of drug sensitivity test results, the coincidence rates between the rapid method and the traditional method for drug sensitivity test of Gram-positive cocci and Gram-negative bacilli were more than or equal to 90.0%, the general error rates were less than 10.0%, the serious error rates were less than 3.0%except compound sulfamethoxazole, and the extremely serious error rates were less than 1.5%. Conclusion The rapid method can effectively shorten the time of identification and drug sensitivity test, and the identification results are accurate. It is helpful for clinicians to make a clear diagnosis and adjust the treatment plan in time, quickly shift from empirical use of broad-spectrum antibiotics to targeted treatment, and provide more effective treatment plan for patients.