Research progress on the development of human neutrophil elastase inhibitors / 药学学报

Human neutrophil elastase (hNE) is a serine proteolytic enzyme mainly distributed in neutrophils. When the balance between anti-hNE protein and hNE is broken, excessive release of hNE can cause the occurrence of various diseases. Therefore, inhibition of hNE is a promising therapeutic strategy. In this paper, the structure, action mechanism, physiological function of hNE and the development of hNE inhibitors were briefly summarized, in order to provide information for the related research.

Research progress of KRAS inhibitors / 药学学报

The RAS (rat sarcoma) gene is one of the important oncogenes, and its mutation is present in about 30% human tumors. KRAS (kirsten rat sarcoma viral oncogene) is one of the three RAS subtypes, and KRAS mutations are more common than the mutations in other two RAS subtypes. In recent years, with the continuous research, new ideas have been provided for the treatment of cancers via targeting-KRAS. Efforts have been made to develop various KRAS inhibitors. Here, based on the mechanism of action, we classified KRAS inhibitors into two categories: inhibitors that directly target KRAS and inhibitors that indirectly act on KRAS. The representative KRAS inhibitors were summarized and introduced in this paper.

Research progress on indoleamine 2,3-dioxygenase 1 (IDO1) inhibitors / 药学学报

Indoleamine 2,3-dioxygenase 1 (IDO1) is the rate-limiting enzyme in the degradation of tryptophan to kynurenine. IDO1 is highly expressed in some tumor tissues. IDO1 can deplete tryptophan in tumor microenvironment, inhibit T cell function, and mediate the immune escape of tumor cells. Thus, IDO1 is considered a potential target of tumor immunotherapy. Currently, there are several IDO1 inhibitors in clinical research studies. The mechanism of IDO1-mediated tumor immune escape and the structure of IDO1 inhibitors are summarized in this review.

Synthesis of benzimidazole and benzothiazole derivatives as a sirtuins 2 inhibitor / 药学学报

A series of novel benzimidazole and benzothiazole derivatives were designed and synthesized as inhibitors of SIRT1-SIRT3. The target compounds were synthesized from potassium O-ethyldithiocarbonate through a three-step route. The structures of the obtained compounds were elucidated by 1H NMR and HR-MS. Of all compounds, six showed potent SIRT2-inhibitory activities with IC50 values ranging from 2.8 to 21.2 μmol·L-1. Among them, compound 10c displayed the most potent SIRT2-inhibitory activities (IC50 = 2.8 μmol·L-1), with more than 35-fold selectivity over SIRT1 and SIRT3 (IC50>100 μmol·L-1).

Facilitating the measurement of circulatory hydrogen sulfide with fluorescence probe-coated microplates / 北京大学学报(医学版)

Objective:The hydrogen sulfide (H2 S) role in pathogenesis of various diseases were wildly addressed in recent decade.The circulatory (plasma or serum) and biological fluid H2S measurement is still an enormous issues due to the technical limitation.This paper aimed to develop a novel measurement method based on fluorescence probe.Methods:Firstly,20 μL ethanol was used to dissolve 100 pmol fluorescence probe,then added in a 96-well plate.An equal volume of ethanol was also added to the blank well of the plate.The plate was placed in a dark room for about 1 h until the fluorescence probe was evenly coated in the 96-well microplate and dried.The plate was frozen at-20 ℃ for later use.Secondly,the plasma or serum sample was added with saturated ammonium sulfate buffer (pH 7.8) and then centrifuged to remove the proteins.The equal volume supernatant liquid was added to the probecoated well and the probe-uncoated well.The plate was incubated in a dark environment at 37 ℃ for 2 h.Finally,after incubation,the fluorescence density was acquired at λEx/λEm 340/445 nm in a microplate reader.The differences of the fluorescence density values between the probe-coated well and probeuncoated well were counted and H2S concentration of plasma/serum was calculated by standard curve with NaHiS.Results:The method had high sensitivity (from 0.3 to 100 μmol/L) and specificity for measuring H2S as compared with other biologically relevant reactive sulfur species and sulfur-containing amino acid.Serum H2S concentrations were assayed in 188 health volunteers using this method [(12.1 ±3.5) μmol/L,95％ CI:4.6-19.8 μmol/L],and the frequency distribution showed a normal tendency(one-sample Kolmogorov-Smirnov test,P ＞ 0.1).The serum H2S concentrations in 30 hypertension patients were decreased compared with 22 age-and gender-matched health individuals (paired-samples t test,t =9.937,P ＜ 0.001).There were no differences of H2S concentration in serum [(19.66 ±2.32) μmol/L] or plasma [(18.67 ±2.07) μmol/L],between the samples acquired from artery [(19.34 ±0.51) μmol/L] or vein [(18.99 ±0.50) μ mol/L] of male Wistar rats (repeated measurement of ANOVA,P =0.38).One week frozen samples did not affect the detection.The values of the repeated measurement did not differ (two-way ANOVA,P ＞ 0.05).Conclusion:The present method is easily performed with high sensitivity,specificity and repeatability for circulatory H2S.It is also quick and may apply for large samples.

Progress in single-domain antibody derived from heavy-chain antibody / 生物工程学报

Functional heavy-chain antibodies (HCAbs) lacking light chains occur naturally in camels. The variable domain of heavy chain of heavy-chain antibody is referred to VHH. The VHH gene family is homologous to human VH subgroup III. The single-domain VHH antibodies are constructed by cloning the variable domains of HCAbs. Compared to human VHs, VHH germ-line sequences contain some hallmark substitutions in framework region 2, including V37F(Y), G44 E, L45 R, W47G. The substitutions at positions 44, 45, 47 are often used to camelise the human VHs. Being a small binders, VHH antibodies are well expressed, extremely stable and very soluble. Camelised human VHs are proved to exhibit the same qualities as those of VHH antibodies. The single-domain VHH antibodies will be useful in the drug development and basic research.