AIM To investigate the role of serine/threonine protein phosphatases 1 and 2A (PP1/2A) in regulation of cell signal transduction involved in the tolerance of human umbilical vein endothelial cells (HUVEC) to hypoxia. METHODS HUVEC tolerance was established by hypoxic preconditioning. The tolerance of HUVEC was evaluated by the cell survival rate, lactic dehydrogenase (LDH) releasing and total antagonistic-oxidative capability (T-AOC). Subcellular localization of nuclear factor E2-related factor 2 (Nrf2) was determined by immunocytochemistry combined with Western blot. The expression of stress protein of heme oxygenase-1 (HO-1) was measured by Western blot. RESULTS Hypoxia 90 min decreased the survival rate and T-AOC of HUVEC significantly, increased the release of LDH in cultured HUVEC. Compared with the hypoxic group, hypoxic preconditioning (4, 8 and 24 h after hypoxia 10 min) up-regulated the tolerance against hypoxia in HUVEC, the survival rate of HUVEC and T-AOC increased and the release of LDH down-regulated when insulted with hypoxia (90 min) in HUVEC. Hypoxic preconditioning established the translocation of Nrf2 from cytoplasm to nucleus and up-regulated the expression of downstream protein HO-1. Pretreatment with okadaic acid (40 nmol·L-1), a powerful inhibitor of PP1/2A, for 10 min in hypoxic preconditioning HUVEC partly inhibited the translocation of Nrf2 from cytoplasm to nucleus and the expression of HO-1, abolished the tolerance of HUVEC established by hypoxic preconditioning. CONCLUSION PP1/2A at least partly take part in Regulation of translocation of Nrf2 and expression of HO-1, with is associated with the tolerance of HUVEC established by hypoxic preconditioning.

Objective To compare the detection results and estimate the bias of two hematocyte analyzers of different brands . Methods Sysmex XE‐2100 hematocyte analyzer and Abbott CD‐1700 hematocyte analyzer were chosen to be the reference instru‐ment and comparison instrument ,respectively .40 cases of fresh whole blood samples were collected for the detection of WBC ,RBC , HGB ,HCT ,MCV ,MCH ,MCHC ,and PLT respectively by the two instruments .The correlation coefficient (r) ,regression equa‐tions and bias were calculated and compared to determine the comparability of the two instruments .Results The precisions of two hematocyte analyzers were satisfactory .When fresh whole blood was used as calibrators ,the results of all eight items of the two in‐struments had good correlations (r>0 .975) ,and the relative bias was acceptable .Conclusion The results of two hematocyte ana‐lyzers are comparable .With fresh whole blood using in the comparison test between different hematocyte analyzers ,systematic er‐rors can be discovered in time .

The cytotoxic effect targeting hepatitis B virus (HBV) infected hepatocytes from virus-specific cytotoxic T cells and the neutralizing antibodies secreted by virus-specific B cells play an important role in the immune control and elimination of HBV. In patients with chronic hepatitis B, the liver immune microenvironment usually presents a suppression state, and virus-specific immune cells are mostly exhausted. Studies on the interaction between HBV and host immunity during infection, especially the influence of various viral proteins on immune cell function, will contribute to understanding the mechanism of the chronicity of HBV infection, disease progression, and optimization of immunotherapy against HBV. The review summarized the suppressive effects of HBV viral proteins on the host innate immunity and adaptive immune system, to help us understanding the mechanism(s) relevant to the observation that a CHB patient with HBeAg loss and lower HBsAg level is more likley achieving functionall cure. and expect to provide new sights for accelerate virus clearance and achieve functional cure of chronic hepatitis B, by removing the HBV viral proteins and consequently, liberting host immune from suppression state.

Recently, several phase I and phase II clinical trials of antisense oligodeoxynucleotides (ASOs) targeting to the commonly shared conserved sequences of HBV transcripts brought us some promising results. Particularly in the report of phase IIb clinical trial of Bepirovirsen (GSK3228836), approximately 9-10% patients with low baseline serum HBsAg (> 100 IU/ml & < 3 000 IU/ml) achieved functional cure after 24 weeks’ of Bepirovirsen treatment. After reviewing the results of other clinical trials, one would be impressed to know that ALG-020572 (Aligos), RO7062931 (Roche) and GSK3389404 (GSK) all failed to sufficiently suppress serum HBsAg expression though the hepatocyte-targeted delivery of these ASOs were enhanced via N-acetyl galactosamine conjugation. Bepirovirsen enabled some patients to achieve sustained disappearance of serum HBsAg. The analysis of its distribution in different tissues of patients after drug administration showed that only a few fractions of ASOs entered liver tissues and far fewer eventually entered hepatocytes. Taking into consideration that only a few hepatocytes could be expected positive for HBsAg staining among these participants with low serum HBsAg level. We suspect that the mechanistic contribution of ASOs declining the serum HBsAg is not only via directly acting on the HBV transcripts in hepatocytes, but also via entering non-parenchymal cells such as Kupffer cells and resulting in stimulation and activation of innate immunity. Eventually the serum HBsAg declines in most participants and even disappears in a small fraction of patients with low baseline HBsAg level, via attack the infected hepatocytes evidenced by the aberrant elevation of ALT. Nevertheless, the functional cure of CHB remains a challenging issue and more efforts are needed.

Chronic hepatitis B virus (HBV) infection is one of the major public health issues of ongoing global concern. Due to inadequate understanding of the HBV life cycle, there is a lack of effective drugs to cure chronic hepatitis B. During HBV replication, covalently closed circular DNA (cccDNA) serves as the template for viral replication and can be transcribed to produce five viral RNAs of 3.5, 2.4, 2.1 kb and 0.7 kb in length, which are translated to produce HBeAg, core protein, polymerase (P) protein, HBsAg and HBx proteins, respectively. Among them, the 3.5 kb pregenomic RNA (pgRNA) is also the template for viral reverse transcription. Polymerase protein recognizes and binds to the capsid assembly signal on the pgRNA to initiate capsid assembly and reverse transcription. Recent studies have revealed that the processes of splicing, nuclear export, stability, translation, and pgRNA encapsidation of HBV RNAs are regulated by a post-transcriptional regulatory network within the host cell and depend on unique post-transcriptional regulatory elements in the HBV RNA structure. The aim of this review is to overview the post-transcriptional regulatory mechanisms of HBV RNA and their applications in the study of HBV antiviral therapeutics, with the aim of providing new ideas for the development of new drugs targeting HBV RNA.