Direct Synthesis of α- and β-2'-Deoxynucleosides with Stereodirecting Phosphine Oxide via Remote Participation

2'-Deoxynucleosides and analogues play a vital role in drug development, but their preparation remains a significant challenge. Previous studies have focused on β-2'-deoxynucleosides with the natural β-configuration. In fact, their isomeric α-2'-deoxynucleosides also exhibit diverse bioactivities and even better metabolic stability. Herein, we report that both α- and β-2'-deoxynucleosides can be prepared with high yields and stereoselectivity using a remote directing diphenylphosphinoyl (DPP) group. It is particularly efficient to prepare α-2'-deoxynucleosides with an easily accessible 3,5-di-ODPP donor. Instead of acting as a H-bond acceptor on a 2-(diphenylphosphinoyl)acetyl (DPPA) group in our previous studies for syn-facial O-glycosylation, the phosphine oxide moiety here acts as a remote participating group to enable highly antifacial N-glycosylation. This proposed remote participation mechanism is supported by our first characterization of an important 1,5-briged P-heterobicyclic intermediate via variable-temperature NMR spectroscopy. Interestingly, antiproliferative assays led to a α-2'-deoxynucleoside with IC50 values in the low micromole range against central nervous system tumor cell lines SH-SY5Y and LN229, whereas its β-anomer exhibited no inhibition at 100 μM. Furthermore, the DPP group significantly enhanced the antitumor activities by 10 times.

POS0558 A INFLAMMATORY FACTOR-BASED NOMOGRAM PREDICTS FIRST REMISSION TIME OF RHEUMATOID ARTHRITIS PATIENTS WITH BASELINE GALECTIN-9

Background

Rheumatoid arthritis (RA) is an autoimmune disease. The core treatment principle of RA is to achieve remission or low disease activity as soon as possible to ensure optimal outcomes. Predicting the first remission time according to the patient’s risk factors is very important for the choice of treatment scheme.

Objectives

We aimed to verify the prognostic value of inflammatory factors in RA and establish a nomogram based on Human Interleukin-6(IL-6), Galectin-9(Gal-9)and disease activity to predict the first remission time after conventional synthetic DMARDstreatment.

Methods

184 RA active patients(DAS28-ESR> 3.2, ACR 1987 criteria or EULAR 2010 criteria) were enrolled in the rheumatology department of Qilu Hospital of Shandong University from June 2014 to June 2020.129 patients were assigned to the development cohort and 55 patients were assigned to the validation cohort randomly. Baseline clinical data and plasma were collected. The expressions of Tumour Necrosis Factor α (TNF-α), Vascular Endothelial Growth Factor (VEGF), IL-6 and Gal-9 in plasma of RA patients were detected by ELISA. All patients were treated with csDMARDs and we recorded activity of each follow-up visit until 36 months. Lasso regression and Cox regression analysis were used to screen the 14 variables (including activity indices and cytokines) at baseline, and the prediction model was established to draw the nomogram.

Results

Patient age, CRP, IL-6, Gal-9, HAQ and DAS28-ESR were the significant prognostic factors in the lasso and Cox regression analyses, especially Gal-9. The multivariate analysis revealed that IL-6≤ 9.04 pg/ml(HR =0.54, 95% CI:0.31–0.95), Gal-9≤ 4490 pg/ml(HR =0.43, 95% CI:0.21–0.89) were independent protective factors (Table 1). Above-mentioned six factors were included in our model as predictors (Figure 1). The resulting model containing six factors had good discrimination ability in both the development cohort (C-index, 0.729) and the validation cohort (C-index, 0.710). Time-dependent ROC curve (Figure 2), calibration analysis (Figure 3) and decision curve analysis (DCA) show that the nomogram has significant discriminant power, stability and clinical practicability in predicting the first remission time.

Conclusion

We constructed and validated a nomogram with baseline activity indices and cytokines that can predict first remission time in RA patients after csDMARDs treatment. Using this simple-to-use model with plasma Gal-9 at baseline, the remission rate can be determined for an individual patient and could be useful for the early identification of high-risk patients.

References

[1]SUN J, SUI Y, WANG Y, et al. Galectin-9 expression correlates with therapeutic effect in rheumatoid arthritis [J]. Scientific reports, 2021, 11(1): 5562.

[2]ZHANG L, CHEN F, GENG S, et al. Methotrexate (MTX) Plus Hydroxychloroquine versus MTX Plus Leflunomide in Patients with MTX-Resistant Active Rheumatoid Arthritis: A 2-Year Cohort Study in Real World [J]. Journal of inflammation research, 2020, 13: 1141-50.

[3]FORNARO M, CACCIAPAGLIA F, LOPALCO G, et al. Predictors of long-term clinical remission in rheumatoid arthritis [J]. European journal of clinical investigation, 2021, 51(2): e13363.

Acknowledgements

Funded by ECCM Program of Clinical Research Center of Shandong University (No. 2021SDUCRCB010)

Disclosure of Interests

None declared.

POS0555 THE NON-APOPTOTIC PROGRAMMED-CELL-DEATH-RELATED SIGNATURE PREDICTS ANTI-TNF THERAPY NONRESPONSE IN PATIENTS WITH RHEUMATOID ARTHRITIS

Background

EULAR guideline in rheumatoid arthritis (RA) recommended the primary failure of the first-line conventional synthetic modifying anti-rheumatic drugs (csDMARDs) patients switching to tumor necrosis factor alpha inhibitors (TNFi) [1]. Nevertheless, approximately 30-40% csDMARDs-IR patients also experience inefficacy of TNFi [2]. There is still no index to predict whether TNFi would be responded or not. Moreover, only few studies had focused on the relationship between TNFi nonresponse and other cell programmed deaths except apoptosis.

Objectives

To predict the possibility of TNFi response prior to prescript in RA patients with the biomarkers of non-apoptotic programmed cell death in synovial cells.

Methods

The datasets of 22 TNFi treated RA synovial samples were enrolled from the Gene Expression Omnibus (GEO) database (GSE140036 and GSE15602). And the differentially expressed genes (DEGs) and modules related to TNFi treatment through weight gene correlation network analysis (WGCNA) were identified with the R packages “limma” and “WGCNA”. Then the enrichment analysis among the shared genes was performed through the R.4.1.2, Metascape website, and WebGestalt website. Following with the confirmation of the non-apoptotic programmed cell death (NAPCD) genes in the shared genes with Student’s T-Test. Furthermore, the TNFi treatment cohort was clustered based on the hub genes, making the receiver operating characteristic (ROC) curve analysis. Moreover, the least absolute shrinkage and selection operator (LASSO) model was constructed to identify the predictive genes.

Results

2624 DEGs were identified significantly, including 161 upregulated genes and 2463 downregulated genes. One module with TNFi treatment was constructed in WGCNA, significant in both response and nonresponse. Then the gene signatures for TNFi nonresponse were collected from overlaps 2260 genes in above. And we found 38 NAPCD genes might play role in TNFi nonresponse, but reserved 33 genes which statistically significant with T-Test. 22 TNFi treated synovial samples in GEO database could be classified into response or nonresponse subgroups. The ROC curve showed that the AUC for 32 genes in these samples ranged from 0.7 to 0.9, expected for CD46. At last, the LASSO model indicated that CASP5, CAPN10, ITGB4, NLRP2, and SLC2A8 could predict the TNFi nonresponse, as the risk score = CASP5 × 0.028 + CAPN10 × 0.064 + ITGB4× 0.080+ NLRP2 × 0.317+ SLC2A8 × 0.090 (Figure 1).

Figure 1.

Predictive model of TNFi nonresponse based on NAPCD genes. (A) Volcano map of differential expressed genes; (B) Correlation heat map of gene modules and phenotypes, the red is positively correlated with the phenotype, blue is negatively correlated with the phenotype; (C) The shared 38 genes of TNFi response & nonresponse DEGs, among the WGCNA turquoise module and cell programmed death genes; (D) Consensus clustering matrix for k = 2; (E) The ROC curve of 33 genes; (F) LASSO regression of the 32 genes,except for CD46; (G) Nomogram for predicting TNFi nonresponse in TNFi treatment RA cohort, indicated five possible indicators (CASP5, CAPN10, ITGB4, NLRP2, and SLC2A8) were closely related to TNFi nonresponse.

Conclusion

Our study firstly screened out the 38 NAPCD candidate genes signatures in RA synovial tissues which took part in TNFi nonresponse through WGCNA and DEGs. Further analysis confirmed that five possible indicators (CASP5, CAPN10, ITGB4, NLRP2, and SLC2A8) were closely related to TNFi nonresponse.

References

[1]van Delft MAM, Huizinga TWJ: An overview of autoantibodies in rheumatoid arthritis. Journal of autoimmunity 2020, 110:102392.

[2]Aletaha D: Precision medicine and management of rheumatoid arthritis. Journal of autoimmunity 2020, 110:102405.

Acknowledgements

Funded by ECCM Program of Clinical Research Center of Shandong University.

Disclosure of Interests

None declared.

Tyrosine kinase involvement in renal arteriolar constrictor responses to angiotensin II

Experiments were performed to test the hypothesis that tyrosine kinase activity contributes to renal arteriolar contractile responses to angiotensin (Ang) II. Rats were subjected to short-term enalaprilat treatment to decrease endogenous Ang II formation before tissue was harvested for experiments with the in vitro blood-perfused juxtamedullary nephron technique. Acute surgical papillectomy was used to avoid the indirect afferent arteriolar effect of Ang II that arises through increased tubuloglomerular feedback sensitivity. Arteriolar lumen diameter responses to 1 and 10 nmol/L Ang II were monitored by videomicroscopic methods before and during treatment with various tyrphostin compounds: 100 micromol/L AG18 (broad-spectrum tyrosine kinase inhibitor), 100 nmol/L AG1478 (selective epidermal growth factor receptor tyrosine kinase inhibitor), or 100 micromol/L AG9 (inactive analog). Baseline afferent arteriolar lumen diameter averaged 23.5+/-1.2 micrometer and was not influenced by any tyrphostin. Ang II (10 nmol/L) decreased afferent diameter by 11.1+/-1.0 micrometer under untreated conditions, a response that was not altered by AG9 but significantly blunted by AG18 (34+/-9% inhibition) or AG1478 (52+/-8% inhibition). AG18 did not suppress afferent arteriolar contractile responses to membrane depolarization (20 to 55 mmol/L K(+ )bath). Efferent arteriolar baseline diameter averaged 24.1+/-0.8 micrometer and was unaltered by AG18 or AG1478; however, efferent diameter responses to 10 nmol/L Ang II were diminished 52+/-10% by AG18 and 51+/-13% by AG1478. These observations indicate that Ang II signaling in renal afferent and efferent arteriolar vascular smooth muscle is either mediated or modulated by tyrosine kinase activity, including that of the epidermal growth factor receptor tyrosine kinase.

[A study on chemical constituents in seeds of Crataegus pinnatifida Bge. var. major N. E. Br]

OBJECTIVE

To study the chemical constituents in the seed of Crataegus pinnatifida var. major.

METHOD

Four compounds were isolated and identified by column chromatography and 1H, 13C-NMR data.

RESULTS

The compounds obtained were identified as protocatechuic acid, gallic acid, catechol and p-hydroxybenzoic acid.

CONCLUSION

All the compounds were isolated from this plant for the first time.

Changes in lactate dehydrogenase and 3-hydroxyacetyl-CoA dehydrogenase activities in rat skeletal muscle by the administration of Eucommia ulmoides OLIVER leaf with spontaneous running-training

We examined the effect of Eucommia ulmoides OLIVER leaf on rat skeletal muscles together with spontaneous running-training in terms of the isozyme profile and specific activity of lactate dehydrogenase (LDH; EC 1.1.1.27) and 3-hydroxyacetyl-CoA dehydrogenase (HAD; EC 1.1.1.35). On the twenty-ninth day of the experimental period, a mandatory endurance running exercise (treadmill, 7 degrees grade) was conducted. Twenty-four hours later, the rats were sacrificed and the skeletal muscles and other organs were dissected. Due to the training, the HAD specific activity in the skeletal muscles had increased and a more oxidative metabolism had developed, which was further enhanced by the administration of the leaf. In soleus (SOL) muscle in the Eucommia leaf treated running-training group (ET), the LDH specific activity in the skeletal muscle was significantly higher than in the sedentary control group (SC). The isozyme profile of the group ET was significantly different when compared with the group SC. The changes in the LDH isozyme profile were larger in the SOL than that in extensor digitorum longus (EDL) muscle. The results show that mechanical training and the use of the leaf cooperatively increase the ability to avoid lactate accumulation in skeletal muscle. This effect is supported by the group where 67% of rats accomplished the endurance running exercise. Theses results suggest that the administration of Eucommia ulmoides OLIVER leaf along with light intensity training enhances the ability of a muscle to resist fatigue.

[Preliminary evaluation on bone mass of tibia by ultrasonic measurement]

The speed of ultrasound (SOS) in right middle tibia and bone mineral density (BMD) of left radius at the distal one-third were measured by ultrasonic measurement and single photoabsorptionmetry in 260 healthy individuals simultaneously. SOS of tibia was positively correlated with BMD of radius (r = 0.64). The peak bone mass of both measurements was at 33 to 36 years of age. Height was positively correlated with the SOS of tibia, while weight was positively correlated with SOS of female tibia, period of menopause negatively correlated with female's SOS of tibia. The concordance of SOS of tibia and BMD of radius in diagnosis of osteoporosis was 36.8%. The results suggest that ultrasonic measurement of tibia is an effective method of bone mass measurement.

[Studies on chemical components of Carthamus tinctorius petals]

The flower petals of Carthamus tinctorius L. (Compositae) provide one of the most important drugs in traditional Chinese medicine[1] used for the treatment of gynecological diseases, heart diseases and inflammation[2]. Carthamin, safflor yellows A and B, safflomin A, and C, isocarthamin, isocarthamidin, hydroxysafflor yellow A, and tinctormine have been reported from these petals, as well as several new flavonoids and phenolic compounds[3]. A continuation of these studies has led to the isolation of four compounds including a new flavonoid glucoside. The dried petals of C. tinctorius, cultivated in Sichuan, China, were extracted with 95% ethanol, and the extract was partitioned between H2O and organic solvents (petroleum ether and EtOAc). The water fraction was subjected to Diaion D101 and Sephadex LH-20 column chromatography with elution by a gradient of EtOH in water to yield compounds 1-4. Compound I is 6-hydroxykaempferol 3-O-glucoside, compound II is a new compound named 6-hydroxykaempferol 7-O-glucoside, compound 3 is kaempferol 3-O-rutinoside and compound 4 is quercetin 3-O-glucoside.