Sulforaphane Prevents Neuronal Apoptosis and Memory Impairment in Diabetic Rats.

BACKGROUND/AIMS: To explore the effects of sulforaphane (SFN) on neuronal apoptosis in hippocampus and memory impairment in diabetic rats. METHODS: Thirty male rats were randomly divided into normal control, diabetic model and SFN treatment groups (N = 10 in each group). Streptozotocin (STZ) was applied to establish diabetic model. Water Morris maze task was applied to test learning and memory. Tunel assaying was used to detect apoptosis in hippocampus. The expressions of Caspase-3 and myeloid cell leukemia 1(MCL-1) were detected by western blotting. Neurotrophic factor levels and AKT/GSK3ß pathway were also detected. RESULTS: Compared with normal control, learning and memory were apparently impaired, with up-regulation of Caspase-3 and down-regulation of MCL-1 in diabetic rats. Apoptotic neurons were also found in CA1 region after diabetic modeling. By contrast, SFN treatment prevented the memory impairment, decreased the apoptosis of hippocampal neurons. SFN also attenuated the abnormal expression of Caspase-3 and MCL-1 in diabetic model. Mechanically, SFN treatment reversed diabetic modeling-induced decrease of p-Akt, p-GSK3ß, NGF and BDNF expressions. CONCLUSION: SFN could prevent the memory impairment and apoptosis of hippocampal neurons in diabetic rat. The possible mechanism was related to the regulation of neurotropic factors and Akt/GSK3ß pathway.

Human umbilical cord mesenchymal stem cells promote carcinoma growth and lymph node metastasis when co-injected with esophageal carcinoma cells in nude mice.

BACKGROUND: Human umbilical cord blood derived-mesenchymal stem cells (hUCMSCs) offer an attractive alternative to bone marrow-derived MSCs (BMMSCs) for cell-based therapy as it is a less invasive source of biological material. However, limited studies have been conducted with hUCMSCs as compared to BMMSCs. The present study was conducted to evaluate the effects of hUCMSCs in esophageal carcinoma (EC). METHODS: hUCMSCs together with EC cells were transplanted subcutaneously into BALB/c nude mice to observe the effects of hUCMSCs on tumor establishment. hUCMSCs injected through the caudal vein to the mice with pre-established EC to observe the effects of hUCMSCs on tumor outgrowth. In order to elucidate the underlying mechanisms, we also performed in vitro experiments including directly co-culture, transwell assay, proliferation assay and western blotting analysis. RESULTS: hUCMSCs promoted EC formation in nude mice. In the in vivo model of pre-established EC, intravenously injected hUCMSCs potently promoted tumor growth. When in vitro co-cultured with hUCMSCs, EC cells proliferation increased. After co-cultured with hUCMSCs through transwell system, EC cells showed increased proliferation. Through transwell assay, we also observed that EC cells recruited MSCs, and MSCs promoted EC cells migration and invasion. Western blotting data showed that the expressions of proliferation related proteins Bcl-2, survivin and metastasis related proteins MMP-2 and MMP-9 were up-regulated in the EC cells transwell co-cultured with hUCMSCs. CONCLUSIONS: Our results indicated that hUCMSCs could favor tumor growth in vivo and in vitro. Thus, the exploitation of hUCMSCs in new therapeutic strategies should be cautious under the malignant conditions.

Sex differences in diabetes­induced hepatic and renal damage.

Diabetes mellitus (DM) is a disease that affects millions of individuals worldwide and is characterized by abnormal glucose metabolism that can induce severe damage to numerous organs throughout the body. Sex differences have been demonstrated in a number of factors associated with diabetes and its complications, such as diabetic kidney disease and diabetic liver disease. To investigate the sex differences in DM further, the changes in the weight, food and water intake, and blood sugar of mice were recorded for 8 weeks in the present study. Hematoxylin and eosin staining, Masson's trichrome staining and transmission electron microscopy were used to observe the pathological changes of liver and kidney tissues. There is no significant difference in the water intake and blood glucose concentration between db/db female and male mice was observed. However, sex differences in liver and kidney damage including glomerular injury and hepatic fibrosis were found. In conclusion, the present study characterized the features of liver and kidney damage in db/db mice and indicated that sex differences should be taken into account in experiments using female and male experimental animals. Furthermore, sex differences should be taken into account in the selection of drug interventions in experiments and in clinical drug therapy.

Exenatide exerts a neuroprotective effect against diabetic cognitive impairment in rats by inhibiting apoptosis: Role of the JNK/c­JUN signaling pathway.

Exenatide could reduce blood glucose and alleviate cognitive dysfunction induced by diabetes mellitus (DM). In the present study, a diabetic model was established in Sprague­Dawley rats to further explore the mechanism of exenatide on diabetes­induced cognitive impairment. Notably, the model rats performed poorly in the Morris water maze test and had more apoptotic neurons compared with the control rats. By contrast, exenatide attenuated cognitive impairment and inhibited neuronal apoptosis in the DM rat model. To explore the neuroprotective mechanisms of exenatide, western blotting was performed to detect the expression levels of markers of endoplasmic reticulum stress, including cytochrome c (Cyt­c), Caspase­3, JNK and c­JUN, in hippocampal tissue. Reverse transcription­quantitative PCR was also performed to measure the mRNA expression levels of Cyt­c and Caspase­3. After 16 weeks of treatment, exenatide treatment downregulated Cyt­c, Caspase­3, phosphorylated (p)­JNK and p­c­JUN expression in the hippocampal tissue of diabetic rats. Moreover, Cyt­c, Caspase­3, JNK and JUN expression levels were detected following treatment with a specific inhibitor of JNK (SP600125). The results revealed that SP600125 had similar inhibitory effects on the JNK pathway and ERS­related protein expression (Cyt­t, Caspase­3, p­JNK and p­c­JUN). These results suggested that exenatide improved cognitive dysfunction in DM rats and that the underlying mechanism may be associated with inhibiting apoptosis by suppressing the activation of JNK/c­JUN.

Fish oil supplementation attenuates cognitive impairment by inhibiting neuroinflammation in STZ-induced diabetic rats.

Type 2 diabetes mellitus (T2DM) markedly impairs human health. During T2DM development, some patients experience cognitive dysfunction and behavioral deficits, which are characterized by neuronal injury and memory loss. It has been reported that the incidence of dementia in middle-aged and elderly patients with diabetes is significantly higher than that in normal elderly patients. Currently, the pathogenesis of cognitive dysfunction in diabetes remains unknown, and there is no standard or specific method to diagnose the disease in clinical practice. Evidence has shown that fish oil (FO) can alleviate depressive-like behaviors by attenuating neuroinflammation in a rat model, and improve cognitive dysfunction by inhibiting apoptosis. Therefore, it is reasonable to speculate that FO may reduce cognitive impairment by attenuating neuroinflammation in diabetic rats. In the present study, we investigated the effects of FO supplementation on cognitive dysfunction in a streptozotocin-induced diabetic rat model. FO administration for 10 weeks improved spatial learning and memory as evaluated by performance in the Morris water maze (MWM). Besides, FO significantly improved the morphology of neurons in the hippocampus and cortex of diabetic rats and reduced the neuronal nuclear condensation. Moreover, FO decreased the mRNA expression of IL-1ß, IL -6, and TNF-α and increased the mRNA expression of IL-4 and IL-10 in the cortex and hippocampus. FO also attenuated the brain inflammatory cascade and simultaneously reduced diabetes-induced oxidative stress. In addition, FO increased the protein expression of Nrf2 and HO-1 in cortex and hippocampus of diabetic rats. These results provide a novel horizon for the study of neuroprotective effect of FO and further clarify the connections among inflammation, oxidative stress and diabetes-induced cognitive impairment.

Effects of resveratrol on learning and memory in rats with vascular dementia.

The purpose of the present study was to study the effects of resveratrol on cognitive function in rats with vascular dementia and to investigate the molecular mechanisms of its neuroprotective effects. Forty­five SD rats were randomly divided into 3 groups: The control group (Con group, n=15), the model group (VD group, n=15) and the resveratrol­treated VD group (Res group, n=15). The VD rats (the VD group and the Res group) were generated by bilateral common carotid artery occlusion. The rats in the Res group received daily resveratrol treatment intraperitoneally for 4 weeks. Cognitive function was tested using the Morris water maze test. The levels of SOD and MDA (oxidative stress indicators) were detected by ELISA kits. The protein expression of Bax, Bcl­2 and caspase­3 was detected by western blotting. Compared with the rats in the Con group, the rats in the VD group exhibited decreased cognitive function, significantly increased hippocampal content of MDA, Bax and caspase­3 (P<0.05), and significantly reduced hippocampal expression of SOD and Bcl­2 (P<0.05). Compared with the rats in the VD group, the rats in the Res group exhibited increased cognitive ability, reduced hippocampal content of MDA, Bax and caspase­3 (P<0.05), and increased hippocampal expression of SOD and Bcl­2 (P<0.05). Resveratrol treatment significantly improved the spatial learning and memory of the VD rats. The mechanism associated with the neuroprotective effects of resveratrol may be closely related to the inhibition of the apoptosis pathway and oxidative stress injury.

[Detection and analysis of serum level of anti-Candida enolase IgG antibody in patients with autoimmune diseases].

Objective To detect IgG antibody against Candida enolase in the sera of patients with autoimmune diseases. Methods Using purified recombinant Candida enolase as the coating antigen, an ELISA was established for enolase IgG antibody detection and the reactive conditions were optimized. The enolase IgG antibody in the sera from patients with autoimmune diseases and healthy controls were detected by ELISA. The specificity of the positive sera was confirmed by Western blotting. Results The study collected 70 serum samples from the patients with autoimmune diseases and 44 from the healthy individuals. ELISA showed anti-Candida enolase IgG antibody in 19 cases of the autoimmune disease group and and 3 cases of the healthy control group, the positive rates of which were 27.14% (19/70) and 6.82% (3/44), respectively. In the autoimmune disease group, the positive rate of anti-Candida enolase IgG antibody in the systemic lupus erythematosus patients was 45.8% (11/24), significant higher than that in the rheumatoid arthritis patients (11.8%, 2/17). Western blotting validated the specificity of the positive sera. Conclusion The positive rate of anti-Candida enolase IgG antibody in patients with autoimmune disease is high, which would be an interference factor in the application of IgG antibody detection for the diagnosis of invasive candidiasis.

[Study on differentiation of human umbilical cord-derived mesenchymal stem cells into human sweat gland cells in vitro and the relative signal pathway].

OBJECTIVE: To study the differentiation potential of human umbilical cord-derived mesenchymal stem cells (UCMSC) into human sweat gland cells (hSGC) and the role of extracellular signal-regulated kinase (ERK) pathway. METHODS: UCMSC and hSGC were isolated and cultured in vitro. The former was identified with expression of CD14, CD29, CD34, CD44, CD45, CD105, cytokeratin 7 (CK7), CK19, and carcinoembryonic antigen (CEA), while the latter was identified with expression of CK19 and CEA. UCMSC with density of 5 x 10(4) cells per well placed in lower compartment of Transwell chamber were divided into control group (C, cultured with nutrient solution without any stimulation), thermal injury group (TI, treated with heat-shocked hSGC with density of 1 x 10(4) cells per well inoculated into the upper compartment of Transwell chamber for indirect co-culture), thermal injury + EGF group (TIE, treated with indirect co-culture as used in TI group, with addition of 50 ng/mL EGF), thermal injury + PD98059 group (TIP, treated with indirect co-culture as used in TI group, with addition of 10 nmol/mL ERK specific inhibitor PD98059) according to the random number table. One week after culture, the positive expression rates of CK7 and CK19 in UCMSC were detected by flow cytometry, the expression of CK19 and CEA in UCMSC were examined with immunohistochemical staining and the positive expression rate of CEA was calculated, and the expression level of phosphorylated ERK (pERK) was determined by Western blotting. Data were processed with one-way analysis of variance. RESULTS: (1) CD29, CD44, and CD105 were highly expressed in UCMSC, accompanied by low or negative expression of CD14, CD34, CD45, CK7, CK19, and CEA. The expression of CK19 and CEA were positive in hSGC. The two results showed that UCMSC and hSGC were pure. (2) Compared with those of C group [(2.2 +/- 1.5)%, (2.2 +/- 0.7)%, (3.3 +/- 0.7)%, 0.640 +/- 0.026], the expression levels of CK7, CK19, CEA, and pERK in UCSMC of TI group [(6.4 +/- 0.7)%, (5.7 +/- 0.3)%, (7.4 +/- 1.0)%, 0.790 +/- 0.049] and TIE group [(14.3 +/- 1.0)%, (12.6 +/- 1.1)%, (17.6 +/- 2.3)%, 1.200 +/- 0.032] were significantly increased (with F value respectively 78.49, 139.36, 87.13, and 191.74, P values all below 0.01), and those of TIE group were higher than those of TI group (with F value from 50.14 to 145.47, P values all below 0.01). There were no obvious difference in the 4 indexes between TIP group and C group (with F value from 0.00 to 0.13, P values all above 0.05). CONCLUSIONS: UCMSC co-cultured with heat-shocked hSGC can differentiate into hSGC, and ERK signal pathway participates in the process of differentiation of UCMSC into hSGC.