[Effect and mechanism of cardiac adipose triglyceride lipase overexpression on burn-induced cardiac injury]

Objective: To explore the effect and potential mechanism of cardiac adipose triglyceride lipase (ATGL) overexpression on burn-induced cardiac injury. Methods: Eight-week-old C57BL/6J mice with cardiac ATGL overexpression driven by the myosin heavy chain (MHC) promoter (MHC-ATGL burn group) and wild-type (wild-type burn group) mice were randomly chose to the following experiments with burn injury after 24 h (n=8/group), MHC-ATGL mice and wild-type mice with corresponded age and sex were included as control. Cardiac ATGL protein expression, serum levels of cardiac troponin T and cardiac kinase-MB (CK-MB), cardiac free fatty acid and reactive oxygen species were detected. The wild-type and MHC-ATGL burn groups were not only compared with their corresponded control groups, but also compared between each other. Results: The hair color and development were shown little difference between each group. ATGL protein expression is elevated in wild-type burn group (1.00±0.68 vs 3.09±0.93, P=0.023) and decreased in MHC-ATGL burn group (17.84±2.41 vs 10.36±2.22, P<0.001), while ATGL protein expression is still increased in MHC-ATGL burn group compared with wild-type burn group (P<0.001). Serum levels of cardiac troponin T and CK-MB were both elevated in wild-type burn group and MHC-ATGL burn group [(0.456±0.131) vs (0.076±0.019) μg/L and (0.219±0.089) vs (0.060±0.019) μg/L, (1 421±162) vs (221±67) U/L and (761±142) vs (221±41) U/L] (all P<0.001), while serum levels of cardiac troponin T and CK-MB was still decreased in MHC-ATGL burn group compared with wild-type burn group (P<0.001). In addition, cardiac free fatty acid was increased in wild-type burn group and little difference was found in MHC-ATGL burn group [(2.54±0.51) vs (0.46±0.27) mmol/L, P<0.001, and (0.81±0.38) vs (0.59±0.25) mmol/L, P=0.251], while cardiac free fatty acid was significant reduction in MHC-ATGL burn group compared with wild-type burn group (P<0.001). Levels of cardiac reactive oxygen species was both elevated in wild-type burn group and MHC-ATGL burn group [(1.89±0.23) vs (1.00±0.18) and (1.38±0.17) vs (0.95±0.13)] (both P<0.001), while levels of cardiac reactive oxygen was reduction in MHC-ATGL burn group compared with wild-type burn group (P<0.001). Conclusion: Cardiac ATGL overexpression may protect against burn-induced cardiac injury through reducing free fatty acid and reactive oxygen species production.

[CD38 dictates cardiac damage through mitochondrial apoptotic pathway under hypoxic-ischemic conditions]

Objective: To explore the mechanism of CD38-mediated cardiac damage under hypoxic-ischemic (H/I) conditions. Methods: Twenty CD38(-/-) male mice (8-week-old) and 20 wild-type (WT) male C57BL/6J mice (8-week-old) were randomly selected to construct the model of approximately 25% of the total body surface area (TBSA) burn injury. The cardiomyocytes (CMs) were separated from neonatal mice (1day) to construct the H/I injury model. Ad-CD38 adenovirus was transfected into CD38(-)/- primary CMs to callback CD38 expression. Animal experiments were grouped into WT-control group, CD38(-/-)-control group, WT-burn group, and CD38(-/-)-burn group (10 mice in each group). Primary CMs were divided into 6 groups: WT-normoxia group, CD38(-/-)-normoxia group, CD38(-/-)+Ad-CD38-normoxia group, WT-H/I group, CD38(-/-)-H/I group, CD38(-/-)+Ad-CD38-H/I group. The release of lactic dehydrogenase (LDH) from CMs and the cell viability were measured to estimate the level of myocardial injury. Ultrastructure of cardiomyocytes was examined by electron microscope. CD38 protein level and mitochondrial apoptosis-related proteins were detected by Western blot. Flow cytometry was used to detect mitochondrial reactive oxygen species (MitoSOX) of CMs under H/I condition. Cardiac function of mice was detected by ultrasonic apparatus. Results: (1) Animal experiments: The expression level of cardiac CD38 in WT-burn group was significantly higher than that in sham group (P<0.001). The heart function of CD38(-/-)-burn group was obviously better than WT-burn group [ejection fraction (EF)%: (84.70±2.31)% vs (76.10±2.96)%, shortening fraction (FS)%: (48.90±5.00)% vs (38.10±2.80)%] (both P<0.001). (2) Cell experiments: The expression level of cardiac CD38 in WT CMs under H/I condition was significantly higher than that in WT CMs under normoxia condition (P<0.05). The level of LDH, apoptotic cell and MitoSOX in CD38(-/-)-H/I group were fewer than WT-H/I group and CD38(-/-)+Ad-CD38(-)H/I group [(11.2±3.0)% vs (18.2±3.4)% and (17.6±4.0)%, (13.0±2.8)% vs (23.1±4.9)% and (23.3±6.0)%, (162±11)% vs (228±18)% and (220±18)%] (all P<0.001). The levels of cleaved-caspase3, Cytochrome-C in CD38(-/-)-H/I group were significantly lower than those in WT-H/I group and CD38(-/-)+Ad-CD38-H/I group (P<0.001). The cell viability in CD38(-/-)-H/I group was higher than that in WT-H/I group and CD38(-/-)+Ad-CD38-H/I group (0.355±0.043 vs 0.280±0.051 and 0.291±0.024) (all P<0.05). Electron microscopy results showed that structure of mitochondria in CD38(-/-)-H/I group was better than in WT-H/I group and CD38(-/-)+Ad-CD38-H/I group. Conclusion: Overexpression of CD38 contributes to cardiac damage by stimulating mitochondrial apoptotic pathway.

[Clinical experience and next-generation sequencing analysis of encephalitis caused by pseudorabies virus]

Objective: To detect potential pathogens including pseudorabies virus in patients with encephalitis of unknown etiology in China and describe novel encephalitic entities. Methods: Patients with clinically suspected infectious encephalitis were enrolled in a multicenter study to identify the pathogens in PUMCH Encephalitis Program.Next-generation sequencing(NGS) of cerebrospinal fluid (CSF) was used in patients with encephalitis of unknown etiology enrolled from 2016 to 2017.The patients diagnosed as PRV encephalitis were studied to describe this novel entity. Results: The four patients(3 male, 1 male, 38-54 years old) had occupational exposure to raw park when working in the production or marketing of pork and at least one got injured during pork-cutting.Two of them were confirmed with NGS of CSF, and anti-PRV antibodies were positive in 3 patients whose serum was available for serological analysis.They all presented with an acute onset of fever, convulsion, loss of consciousness and respiratory failure within 1 to 4 days and rapidly deteriorated even on extensive treatment.All the patients needed ICU admission and 3 needed mechanical ventilation.Two patients also had bilateral retinitis.Neuroimaging revealed symmetric gray matter lesions including limbic system, basal ganglia and midbrain without obvious hemorrhage.Lumbar puncture revealed elevated intracranial pressure and lymphocytic pleocytosis [(6-64)×10(6)/L] of CSF.The patients failed to response to the treatment of acyclovir combined with intravenous immunoglobulin and steroids.Modified Rankin Score was 3, 5, 5 and 6 (died) for the 4 patients respectively on last follow-up. Conclusions: PRV could be a cause of severe encephalitis.The patients with suspected pseudorabies encephalitis (PRE) need to be tested for PRV DNA timely.Severe encephalitis with bilateral involvement of limbic system, basal ganglion, thalamus and midbrain in patient with occupational exposure indicate this emerging infectious encephalitis.