c-Jun N-terminal kinase 3 deficiency protects axotomized retinal ganglion cells via affecting mitochondria involved apoptosis pathway.

AIM: To illustrate the isoform-specific role and mechanism of c-Jun N-terminal kinases (JNKs) in mouse optic nerve axotomy induced neurotrauma. METHODS: We firstly investigated the expression of JNK1, JNK2, and JNK3 in the retinal ganglion cells (RGCs) by double-immunofluorescent staining. Then we created optic nerve axotomy model in wild type as well as JNK1, JNK2, JNK3, isoform specific gene deficiency mice. With that, we checked the protein expression profile of JNKs and its active form, and quantified the survival RGCs number by immunofluorescence staining. We further explored the molecules underlying isoform specific protective effect by real-time polymerase chain reaction (PCR) and Western blotting assay. RESULTS: We found that all the three isoforms of JNKs were expressed in the RGCs. Deficiency of JNK3, but not JNK1 or JNK2, significantly alleviated optic nerve axotomy induced RGCs apoptosis. We further established that expression of Noxa, a pro-apoptotic member of BH3 family, was significantly suppressed only in JNK3 gene deficiency mice. But tumor necrosis factor receptor 1 (TNFR1) and Fas, two key modulators of death receptor mediated apoptosis pathway, did not display obvious change in the expression. CONCLUSION: It is suggested that mitochondria mediated apoptosis, but not death receptor mediated apoptosis got involved in the JNK3 gene deficiency induced RGCs protection. Our study provides a novel insight into the isoform-specific role of JNKs in neurotrauma and indicates some cues for its therapeutics.

NMR assignments and single-crystal X-ray diffraction analysis of deoxyloganic acid.

7-Deoxyloganic acid (1), citrusin C (2), 3,4-dihydroxyl benzoic acid (3) and (E)-caffeic acid (4) were isolated from the water-soluble fraction of ethanol extracts of Morina nepalensis var. alba Hand.-Mazz. and their structures were determined on the basis of spectroscopic evidence. The total assignments of 1H and 13C NMR spectra of 1 in solvents CD3OD, D2O and CDCl3 were reported, in addition to the single-crystal X-ray diffraction analysis of its tetraacetate 1a. All compounds were obtained from Morina genus for the first time.

Four new oleanane type saponins from Morina nepalensis var. alba.

Four new oleanane type saponins, monepalosides G-J (1-4), were isolated from the water-soluble part of the whole plant of Morina nepalensis var. alba Hand-Mazz. On the basis of chemical and spectroscopic evidence, their structures were determined as 3-O-alpha-L-arabinopyranosyl-(1 --> 3)-alpha-L-arabinopyranosyl oleanolic acid 28-O-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranoside (monepaloside G, 1), 3-O-alpha-L-arabinopyranosyl-(1 --> 3)-beta-D-xylopyranosyl oleanolic acid 28-O-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranoside (monepaloside H, 2), 3-O-alpha-L-arabinopyranosyl-(1 --> 3)-[beta-D-glucopyranosyl-(1 --> 2)]-alpha-L-arabinopyranosyl oleanolic acid 28-O-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranoside (monepaloside I, 3), 3-O-beta-D-glucopyranosyl-(1 --> 4)-beta-D-glucopyranosyl-(1 --> 3)]-alpha-L-arabinopyranosyl oleanolic acid 28-O-beta-D-glucopyranosyl-(1 --> 6)-beta-D-glucopyranoside (monepaloside J, 4), respectively. Two-dimensional NMR spectra, including H-H COSY, HMQC, 2D HMQC-TOCSY, HMBC and ROESY were utilized in the structure elucidation and complete assignments of 1H and 13C NMR spectra.