[ ABSTRACT] AIM:To observe the change of skin histology in diabetic rats and to investigate the possible me-chanism of c-Jun N-terminal kinase (JNK) protein in the dorsal root ganglion (DRG) during the process.METHODS:Diabetic animal model was established in the male SD rats by intraperitoneal injection of streptozotocin.Plantar skin speci-mens of the rats were collected from control group, DM 2-week group (DM2), DM 4-week group (DM4), and DM 8-week group ( DM8) .Immunohistochemical staining and HE staining were used to observe the change of PGP 9.5 immunoreactive nerve terminals and the structures of the skin tissues.The protein expression of PGP 9.5 in the plantar skin tissues, and JNK and p-JNK protein in the DRG within lumbar 5, 6 (L5, 6), and sacral 1 (S1) spinal cord segments were detected by Western blotting.RESULTS:PGP 9.5 immunoreactive nerve terminals of the plantar skin of the rats mainly distributed in the basal layer of the epidermis and papillary dermis.Compared with control group, PGP 9.5 positive nerve terminals in DM4 group showed reduced density and sparse distribution.PGP 9.5 positive nerve terminals in DM8 group showed signifi-cantly reduced distribution, thinner nerve diameter, shorter length and distorted shape.Histological changes of the thinner epidermal tissue, reduced epidermal cell layers, uneven cell distribution and arrangement in DM4 group, and significantly reduced epidermal cell layers, swollen and blurred cells, increasing cell gap, lack of stratified epidermis arrangement for part of epidermis, atropal and degenerated dermal collagen fiber, significantly decreased subcutaneous fat in DM8 group were observed.The results of Western blotting showed that the protein expression of PGP 9.5 in the plantar skin tissue of DM rats was progressively decreased along with the disease, while the protein level of p-JNK in L5, 6-DRG or S1-DRG showed a gradual increasing trend.PGP 9.5 immunoreactive positive nerve terminal density of plantar skin in DM rats had a negative correlation with the protein level of p-JNK in L5, 6-DRG and S1-DRG (P<0.01), but showed a significant positive correlation with the plantar skin thickness (P<0.01).CONCLUSION:The protein level of p-JNK within L5, 6-DRG or S1-DRG in DM rats shows a progressive enhancement.At the same time, there is a significant change in the skin tissue density and structure.The changes of skin tissue and nerve morphology in DM rat may be related to the activation of JNK/SAPK pathway in L5, 6-DRG or S1-DRG cells.Blocking or inhibiting JNK/SAPK pathway may delay the diabetic pe-ripheral neuropathy and reduce the risk of skin lesions.

OBJECTIVETo examine the expression profile and immunofluorescence localization of the major egg antigen p40 of Schistosoma japonicum (Sjp40) during granuloma formation in the liver of infected New Zealand white rabbits.

METHODSNew Zealand white rabbits were infected with S. japonicum cercariae, and the livers were harvested at 29 and 45 days post-infection (dpi). The total RNA of the liver tissues was extracted for expression profiling of Sjp40 by quantitative reverse transcription-PCR (qRT-PCR) with GAPDH of S. japonicum as the endogenous reference gene. The expression of Sjp40 in the liver were detected by Western blotting using anti-Sjp40 monoclonal antibody (mAb) 9G7 or anti-Toxoplasma gondii tSAG1 mAb Y3A8 (control) as the primary antibody. Paraffin sections of the liver were prepared for observing egg granuloma formation using HE staining and for indirect immunofluorescence assay of Sjp40 location in the trapped eggs and egg granulomas.

RESULTSThe level of Sjp40 mRNA in the eggs trapped in rabbit livers was significantly higher at 45 dpi than that at 29 dpi (P<0.05), and Western blotting confirmed the presence of Sjp40 protein in the rabbit livers at both 29 and 45 dpi. Immunofluorescence assay demonstrated localized expression of Sjp40 in the immature eggs in the rabbit liver at 29 dpi, but at 45 dpi fluorescence was detected in clusters of mature eggs containing miracidium and in the surrounding egg granulomas.

CONCLUSIONSThe transcriptional levels of Sjp40 significantly increased with the maturation of eggs trapped in the rabbit livers. Sjp40 protein spread from the eggs to the surrounding egg granuloma at 45 dpi when acute liver granulomatous lesions occur, suggesting that Sjp40 plays a key role in egg granulomas formation in the livers of infected New Zealand white rabbits.

Animals ; Antibodies, Monoclonal ; Antigens, Helminth ; metabolism ; Fluorescent Antibody Technique ; Gene Expression Profiling ; Granuloma ; parasitology ; Helminth Proteins ; metabolism ; Liver ; parasitology ; RNA, Messenger ; Rabbits ; Schistosoma japonicum ; Schistosomiasis japonica