Role of vasoactive intestinal peptide in Aspergillus fumigatus-infected cornea

AIM： To investigate the anti-inflammatory role of vasoactive intestinal peptide（VIP） in Aspergillus fumigatus（A. fumigatus） ketatitis.METHODS： Expression of VIP was tested by polymerase chain reaction（PCR） in C57BL/6 and BALB/c normal and A. fumigatus infected corneas. C57BL/6 mice were pretreated with recombinant（r） VIP, while BALB/c mice were pretreated with VIP antagonist, and then infected with A. fumigatus. Clinical score was recorded. Expression of pro-and anti-inflammatory cytokines, toll-like receptor 4（TLR4）, lectin-like oxidized low-density lipoprotein receptor 1（LOX-1）, and neutrophil infiltration were tested by PCR, enzyme-linked immunosorbent assay（ELISA）, and myeloperoxidase（MPO） assay.RESULTS： VIP mR NA expression in BALB/c cornea was higher than C57BL/6 cornea at 1 and 3 d post infection（p.i.）. rV IP treatment of C57BL/6 mice showed alleviated disease and down-regulated expression of interleukin-1β（IL-1β） and tumor necrosis factor-α（TNF-α）, while IL-10 expression was up-regulated. Neutrophil infiltration and TLR4, IL-17 expression were decreased after rVIP treatment, while LOX-1 expression was up-regulated in C57BL/6. VIP antagonist pretreatment showed increased disease and higher IL-1β, TNF-α, TLR4, IL-17 and MPO levels, while IL-10 and LOX-1 levels were down-regulated in BALB/c mice.CONCLUSION： rVIP alleviate disease response of C57BL/6 mice. VIP antagonist resulted in worsened disease of BALB/c mice. VIP proposed anti-inflammatory role in A. fumigatus keratitis.

Expression of CTB-human Insulin(BA) Fusion Protein in Gynostemma Pentapyhllum Makino Callus Cells and Its Hypoglycemic Effect in Mice

The plant expression vector of choleratoxin B subunit（CTB）-human insulin（BA） fusion protein pBI121/（CTB-BA） was constructed first and then the Gynostemma Pentapyhllum Makino callus cell line that could express CTB-human insulin fusion protein was constructed and its hypoglycemic effect was evaluated in mice. The plant expression vector pBl 121/（CTB-BA） was digested with both BamI and SacI. Agrobacterium tumerfaciens strain LBA4404 was transformed with previously constructed recombinant plasmid pBI121/（CTB-BA） via the freeze thawing method, then CTB-BA gene was integrated to G Pentapyhllum Makino callus cells by co-culturing the cells with the transformed LBA4404 strain. The transformed G Pentapyhllum Makino callus cells were identified by DNA sequence assey and RT-PCR. The expressed product was identified by western-blot and its amount was tested by ELISA kit and its blood sugar decreasing effect was tested in mice. The sequences of synthetic CTB and human insulin genes（BA） were completely identical to those designed. Restriction map proved that the length of gene fragment in- serted into expression vector pBI121 was consistent with that expected. The sequence of genomic DNA of expressed product was completely identical to that designed. The result of RT-PCR was consistent with that expected. The expressed product showed a specific band with a relative molecular mass of 17000 by Western-blot. The human insulin expression amount was 6.03 μIU/mL according to the ELISA result. The animal test showed that only the G Pentapyhllum Makino callus cell line itself showed activity in decreasing the blood sugar of mice, however, the activity of the transformed G Pentapyhllum Makino callus cells was much higher, The plant expression vector pBI121/（CTB-BA） was constructed and expressed in the G Pentapyhllum Makino callus cells successfully for the first time. The trans- formed G Pentapyhllum Makino callus cells showed high activity in decreasing the blood sugar of mice. This study developed a new way for the development of oral administration insulin.

Insulin Sensitivity of Term Newborns Exposed in Utero to HIV and Antiretrovirals in Yaoundé

Introduction: Antiretrovirals (ARVs) and the human immunodeficiency virus (HIV) are implicated in the onset of insulin resistance. They cross the placental barrier thereby inducing early modifications of the fetal environment. The aim of our study was to assess insulin sensitivity in full-term newborns exposed in utero to HIV and ARVs in Yaoundé. Materials and Methods: We conducted an analytical cross-sectional study in 2 maternities in the city of Yaoundé from November 2021 to June 2022. We generated two groups of newborns (NBs): one group born to HIV positive mothers on ARVs and the other control group born to HIV negative mothers. Clinical data from mothers and NBs were collected. A homeostatic model assessment of insulin resistance (HOMA-IR) like index with C peptide served to assess insulin sensitivity. We used the Spearman correlation to measure the strength of association between insulin sensitivity and the different variables. A p-value Results: Of 70 neonates included, 35 were born to HIV positive mothers on ARVs and 35 to HIV negative mothers. The median age of HIV positive and negative mothers was 30 (27 - 32) and 34 (24 - 47) years, respectively (p = 0.791). The body mass index before pregnancy as well as the average newborn weights were comparable in both groups. The ARV protocol associating Tenofovir, Lamivudine, Efavirenz was used by 97.1% of HIV positive mothers. In the exposed NBs group, C peptide was significantly lower (p < 0.001) and blood glucose significantly higher (p < 0.001). The median values of HOMA-IR were 1.4 (0.8 - 1.9) and 2 (1.4 - 2.6) (p = 0.001) for exposed and unexposed NBs, respectively. Conclusion: Newborns exposed to HIV and ARVs had lower C peptide levels and were more sensitive to insulin. Close metabolic monitoring of these newborns would allow early diagnosis and management of any glucose regulation disorder.

Urotensin Ⅱ level is elevated in inflammatory bowel disease patients

It was reported that the urotensin Ⅱ(U-Ⅱ) level in inflammatory bowel disease(IBD) patients are significantly higher than in controls. To provide future guidance for the management of cardiovascular risk factors in IBD patients, the sample size of the current study appears to be limited, and more clinical samples to compare U-Ⅱ levels in IBD patients and controls are needed. This will clarify the possible roles of inflammation factors and related signaling pathways(like EPK1/2, NF-κB and Rho/ROCK) in the pathophysiology of IBD. Therefore, large multicenter studies should be done to confirm the findings and underlying mechanisms in the future.

CHEMICAL MODIFICATION OF SULFHYDRYL GROUPS OF E.coli LEUCYL-tRNA SYNTHE-TASE AND SEQUENCING OF [^(14)C]NEM-LABELED PEPTIDES

The chemical modification of the sulfhydryl groups of E. coli Leucyl--tRNA synthetase(LeuRS) by DTNB, NEM and IAA resulted in a time-dependent loss of both amino-acid acti-vation and aminoacylation activities in parallel. The second-order reaction constants of DTNB,NEM and IAA were 1700, 150 and 0.46 mol/L^(-1) min^(-1) respectively. Chemical stoichiometryshowed that only one sulfhydryl group of LeuRS was essential for both activities. Substratesleucine and Leu-AMP protected the active sulfhydryl group from modification, suggestingthat the modified sulfhydryl group is located in or near the active site region responsiblefor amino-acid activation. [^(14)C]NEM--labeled LeuRS was subjected to tryptic digestion, andpeptides were separated and sequenced. 179 Cys~*-Asp-Thr-Leu182 was identified as the major[^(14)C]NEM-labeled site in LeuRS. This result is consistent with the previous observationthat the region for Leu--AMP formation was located at the N--terminal part of LeuRS.