Spectral Analysis of Interaction between Human Telomeric G-Quadruplex and Liliflorin A, the First Lignan Derivative Interacted with G-Quadruplex DNA.

Human telomeric G-quadruplex is a four-stranded structure folded by guanines (G) via Hoogsteen hydrogen bonding. The ligands which stabilize the G-quadruplex are often telomerase inhibitors and may become antitumor agents. Here, the interaction between a lignan derivative liliflorin A and human telomeric sequence dGGG (TTAGGG)3G-quadruplex HTG21 were examined by CD, FRET, and NMR spectroscopic methods. In addition, Molecular Docking was used to study the binding of liliflorin A to dTAGGG (TTAGGG)3 G-quadruplex HTG23. The CD data showed that liliflorin A enhanced HTG21 T(m). The T(m) value of G-quadruplex was enhanced 3.2 degrees C by 4.0 µmol x L(-1) liliflorin A in FRET. The NMR spectra of HTG21 showed vivid alteration after reacting with liliflorin A in 3 hours. Molecular Docking suggested liliflorin A bound to the wide groove of HTG23 at G9, G10, G16 and G17. Liliflorin A was the first lignan derivative that could stabilize HTG21 selectively and provided a new candidate for antitumor drug design targeting on human telomeric G-quadruplex.

[Correlation study between lupus nephritis patients of rheumatism syndrome and SLEDAI--a clinical study].

OBJECTIVE: To explore lupus nephritis (LN) patients' monocyte chemotactic protein 1 (MCP-1) and urinary IP-10 (ulP-10) levels, the correlation between each clinical activity index and rheumatism syndrome, thereby proving objective evidence for microscopic typing of rheumatism syndrome. METHODS: Totally 60 LN patients were assigned to the rheumatism group (31 cases) and the non-rheumatism group (29 cases). Besides, 20 healthy volunteers were recruited as the normal control group. Clinical data and renal pathology were collected, and urinary levels of MCP-1 and IP-10 detected by ELISA. The correlation between rheumatism syndrome and each activity index as well as manifestations of clinical activities was comprehensively analyzed. Results (1) Patients in the rheumatism group were more liable to occur fever, serositis, edema, and hypertension (P<0.05). (2) Compared with the non-rheumatism group, patients in the rheumatism group exhibited much higher levels of 24 h protein quantification and blood urea nitrogen, higher levels of uMCP-1 and ulP-10. Microscopic hematuria, anti-ds-DNA, anti-Sm, the positive rate of AnuA, scores of SLEDAI and BILAG were higher in the rheumatism group than in the non-rheumatism group (P<0.05). Levels of plasma albumin and complement C3 were lower in the rheumatism group than in the non-rheumatism group (P<0.05). (3) The average activity index (AI) of the renal pathology was higher in the rheumatism group than in the non-rheumatism group. The most frequent pathological type of rheumatism group was type IV of LN. CONCLUSIONS: More severe renal damage and immune abnormality occurred in LN patients of rheumatism syndrome. Rheumatism syndrome is closely correlated to clinical activity indices.