Ultra-structural changes and apoptotic activity in cerebellum of post-menopausal-diabetic rats: a histochemical and ultra-structural study

Protective effects of gallic acid against nickel-induced kidney injury: impact of antioxidants and transcription factor on the incidence of nephrotoxicity

Nickel (Ni) is a common metal with a nephrotoxic effect, damaging the kidneys. This study investigated the mechanism by which gallic acid (GA) protects mice kidneys against renal damage induced by Nickel oxide nanoparticles (NiO-NPs). Forty male Swiss albino mice were randomly assigned into four groups, each consisting of ten mice (n = 10/group): Group I the control group, received no treatment; Group II, the GA group, was administrated GA at a dosage of 110 mg/kg/day body weight; Group III, the NiO-NPs group, received injection of NiO-NPs at a concentration of 20 mg/kg body weight for 10 consecutive days; Group IV, the GA + NiO-NPs group, underwent treatment with both GA and NiO-NPs. The results showed a significant increase in serum biochemical markers and a reduction in antioxidant activities. Moreover, levels of 8-hydroxy-2'-deoxyguanosine (8-OH-dG), phosphorylated nuclear factor kappa B (p65), and protein carbonyl (PC) were significantly elevated in group III compared with group I. Furthermore, the western blot analysis revealed significant high NF-κB p65 expression, immunohistochemistry of the NF-κB and caspase-1 expression levels were significantly increased in group III compared to group I. Additionally, the histopathological inspection of the kidney in group III exhibited a substantial increase in extensive necrosis features compared with group I. In contrast, the concomitant coadministration of GA and NiO-NPs in group IV showed significant biochemical, antioxidant activities, immunohistochemical and histopathological improvements compared with group III. Gallic acid has a protective role against kidney dysfunction and renal damage in Ni-nanoparticle toxicity.

Analysis of white matter tract integrity using diffusion kurtosis imaging reveals the correlation of white matter microstructural abnormalities with cognitive impairment in type 2 diabetes mellitus

Background

This study aimed to identify disruptions in white matter integrity in type 2 diabetes mellitus (T2DM) patients by utilizing the white matter tract integrity (WMTI) model, which describes compartment-specific diffusivities in the intra- and extra-axonal spaces, and to investigate the relationship between WMTI metrics and clinical and cognitive measurements.

Methods

A total of 73 patients with T2DM and 57 healthy controls (HCs) matched for age, sex, and education level were enrolled and underwent diffusional kurtosis imaging and cognitive assessments. Tract-based spatial statistics (TBSS) and atlas-based region of interest (ROI) analysis were performed to compare group differences in diffusional metrics, including fractional anisotropy (FA), mean diffusivity (MD), axonal water fraction (AWF), intra-axonal diffusivity (Daxon), axial extra-axonal space diffusivity (De,//), and radial extra-axonal space diffusivity (De,⊥) in multiple white matter (WM) regions. Relationships between diffusional metrics and clinical and cognitive functions were characterized.

Results

In the TBSS analysis, the T2DM group exhibited decreased FA and AWF and increased MD, De,∥, and De,⊥ in widespread WM regions in comparison with the HC group, which involved 56.28%, 32.07%, 73.77%, 50.47%, and 75.96% of the mean WM skeleton, respectively (P < 0.05, TFCE-corrected). De,⊥ detected most of the WM changes, which were mainly located in the corpus callosum, internal capsule, external capsule, corona radiata, posterior thalamic radiations, sagittal stratum, cingulum (cingulate gyrus), fornix (stria terminalis), superior longitudinal fasciculus, and uniform fasciculus. Additionally, De,⊥ in the genu of the corpus callosum was significantly correlated with worse performance in TMT-A (β = 0.433, P < 0.001) and a longer disease duration (β = 0.438, P < 0.001).

Conclusions

WMTI is more sensitive than diffusion tensor imaging in detecting T2DM-related WM microstructure abnormalities and can provide novel insights into the possible pathological changes underlying WM degeneration in T2DM. De,⊥ could be a potential imaging marker in monitoring disease progression in the brain and early intervention treatment for the cognitive impairment in T2DM.

GABA Administration Ameliorates the Toxicity of Doxorubicin on CSF and the Brain of Albino Rats

Background

Gamma-aminobutyric acid (GABA) is the main inhibitory neurotransmitter in the mammalian brain and is a non-proteinogenic amino acid. Doxorubcin (DOX) or adriamycin is one of the most potent chemotherapy drugs for breast cancer.

Purpose

This study focused on diminishing the brain injury and neurotoxicity of doxorubicin (DOX) by GABA administration.

Methods

Rats were randomly divided into four groups (8 rats each), which were the control group, DOX group (3 mg/kg for 4 weeks, then 2 mg/kg for 2 weeks), GABA group (2 mg/kg for 21 days), and DOX + GABA group (treated as the second and third groups). Neurotoxicity and brain injury were assessed by determining CSF biomarkers, serum inflammatory markers, and histopathological evaluation of the cerebral cortex.

Results

DOX treatment significantly increased the levels of all CSF biomarkers (S100B, IL-1β, ubiquitin carboxy-terminal hydrolase L1 (UCH-L1), glial fibrillary acidic protein (GFAP), spectrin breakdown products (SBDP145), and C-C motif chemokine ligand 2 (CCL2) and all inflammatory markers (IL-6, TNF-α, and IFN-γ), causing extensive neutrophilic infiltration and great alteration in the cerebral cortex architecture as evidence of neurotoxicity. The oral administration of GABA significantly reduced the levels of all CSF biomarkers and inflammatory markers and restored the normal architecture of the cerebral cortex, with observed ameliorations in neutrophilic infiltration.

Conclusion

GABA administration can ameliorate neurotoxicity and protect the brain against the negative effects of DOX treatment.

Electric field-directed migration of mesenchymal stem cells enhances their therapeutic potential on cisplatin-induced acute nephrotoxicity in rats

Cisplatin is widely used as an anti-neoplastic agent but is limited by its nephrotoxicity. The use of mesenchymal stem cells (MSCs) for the management of acute kidney injury (AKI) represents a new era in treatment but effective homing of administered cells is needed. This study aimed to investigate the effect of bone marrow-derived mesenchymal stem cells (BM-MSCs) on cisplatin-induced AKI in rats after directed migration by electric field (EF). Forty-eight adult male albino rats were equally classified into four groups: control, cisplatin-treated, cisplatin plus BM-MSCs, and cisplatin plus BM-MSCs exposed to EF. Serum levels of IL-10 and TNF-α were measured by ELISA. Quantitative real-time PCR analysis for gene expression of Bcl2, Bax, caspase-3, and caspase-8 was measured. Hematoxylin and eosin (H&E) staining, periodic acid Schiff staining, and immunohistochemical analysis were also done. MSC-treated groups showed improvement of kidney function; increased serum levels of IL-10 and decreased levels of TNF-α; and increased mRNA expression of Bcl2 and decreased expression of Bax, caspase-3, and caspase-8 proteins comparable to the cisplatin-injured group. EF application increased MSCs homing with significant decrease in serum urea level and caspase-3 gene expression together with significant increase in Bcl2 expression than occurred in the MSCs group. Restoration of normal kidney histomorphology with significant decrease in immunohistochemical expression of caspase-3 protein was observed in the BM-MSCs plus EF group compared to the BM-MSCs group. EF stimulation enhanced the MSCs homing and improved their therapeutic potential on acute cisplatin nephrotoxicity.

Cortical gray matter microstructural alterations in patients with type 2 diabetes mellitus

BACKGROUND AND PURPOSE

Neurodegenerative processes are widespread in the brains of type 2 diabetes mellitus (T2DM) patients; gaps remain to exist in the current knowledge of the associated gray matter (GM) microstructural alterations.

METHODS

A cross-sectional study was conducted to investigate alterations in GM microarchitecture in T2DM patients by diffusion tensor imaging and neurite orientation dispersion and density imaging (NODDI). Seventy-eight T2DM patients and seventy-four age-, sex-, and education level-matched healthy controls (HCs) without cognitive impairment were recruited. Cortical macrostructure and GM microstructure were assessed by surface-based analysis and GM-based spatial statistics (GBSS), respectively. Machine learning models were trained to evaluate the diagnostic values of cortical intracellular volume fraction (ICVF) for the classification of T2DM versus HCs.

RESULTS

There were no differences in cortical thickness or area between the groups. GBSS analysis revealed similar GM microstructural patterns of significantly decreased fractional anisotropy, increased mean diffusivity and radial diffusivity in T2DM patients involving the frontal and parietal lobes, and significantly lower ICVF values were observed in nearly all brain regions of T2DM patients. A support vector machine model with a linear kernel was trained to realize the T2DM versus HC classification and exhibited the highest performance among the trained models, achieving an accuracy of 74% and an area under the curve of 83%.

CONCLUSIONS

NODDI may help to probe the widespread GM neuritic density loss in T2DM patients occurs before measurable macrostructural alterations. The cortical ICVF values may provide valuable diagnostic information regarding the early GM microstructural alterations in T2DM.

Non-alcoholic fatty liver disease through the female lifespan: the role of sex hormones

The prevalence of non-alcoholic fatty liver disease (NAFLD) differs between various stages of the female lifespan. The aim of this review is to summarize current evidence on the association of NAFLD and circulating sex hormones and to explore the pathogenesis of NAFLD within the context of (1) sex hormone changes during the reproductive, post-reproductive female life and beyond and (2) the in vitro and in vivo evidence on pharmacological modulation in women on menopausal hormone treatment (MHT) or endocrine therapy after breast cancer. The fluctuation in estrogen concentrations, the relative androgen excess, and the age-related reduction in sex hormone-binding globulin are related to increased NAFLD risk. Moreover, the peri-menopausal changes in body composition and insulin resistance might contribute to the increased NAFLD risk. Whether MHT prevents or improves NAFLD in this population remains an open question. Studies in women with breast cancer treated with tamoxifen or non-steroidal aromatase inhibitors point to their adverse effects on NAFLD development, although a more pronounced effect of tamoxifen is reported. Future studies focusing on the underlying pathogenesis should identify subgroups with the highest risk of NAFLD development and progression into more aggressive forms, as well as elucidate the role of hormone therapies, such as MHT.

Histomorphological changes and molecular mechanisms underlying the ameliorative effect of resveratrol on the liver of silver nanoparticles-exposed rats

Exposure to the deleterious effects of silver nanoparticles (AgNPs) is inevitable due to their wide use in medicine and daily life. The current study aimed to delineate the histomorphological changes and the molecular mechanisms underlying the ameliorative effect of Resveratrol (RSV) on rats' livers exposed to AgNPs. Fifty healthy adult male Wistar albino rats were divided into four groups: control, AgNPs-exposed, RSV-treated after AgNPs exposure, and recovery groups. Liver sections were examined by light and electron microscopes, and immunohistochemistry was performed for detection of activated caspase3 and TNFα. Serum ALT and AST, plasma levels of TNFα, IL-6, GSH and SOD were measured. mRNA expression of SIRT1, ADORA3, PAI, CDK1, Nrf2 and NFκB genes in liver tissue homogenate was performed using qRT-PCR. AgNPs-exposure for 28 days caused marked liver tissue damage with trapping in hepatocytes and Kupffer cells, while RSV treatment ameliorated liver ultrastructure and function. Our results clarified the molecular basis of RSV ameliorative effect on liver tissue by significant upregulation of SIRT1-NrF2 signaling pathway with increased levels of the antioxidant GSH and SOD, which represent the antioxidant effect of RSV. Significant upregulation of the protective ADORA3 with downregulation of the proinflammatory PAI-1 and NFκB mRNA expression levels besides decreased plasma levels of TNFα, IL-6 and decreased immunoexpression of TNFα in liver tissue, represent the anti-inflammatory effect of RSV. In addition, decreased immunoexpression of caspase3 and downregulation of CDK1 expression, represent its antiapoptotic effect. In conclusion: RSV ameliorates AgNPs-induced liver damage by antioxidant, anti-inflammatory and antiapoptotic effects.Abbreviations: AgNPs: Silver nanoparticles, RSV: Resveratrol, ROS: Reactive oxygen species, ESR: Electron spin resonance, DMPO: 5,5-Dimethyl-1-pyrroline-N-oxide, H₂O₂: Hydrogen peroxide, SOD: Superoxide dismutase, CAT: Catalase, GPx: Glutathione peroxidase, MPTP: Methyl-4-phenyl-1.2.3.6-tetrahydropyridine, MDA: Malondialdehyde, TNF: Tumor necrosis factor, GSH: Glutathione, Nrf2: Nuclear factor-erythroid 2-related factor 2, ARE: Antioxidant response elements, KEAP1: Kelch-1ike ECH-associated protein l, AMPK: AMP-activated protein kinase, HO-1: Heme oxygenase-1, NF-κB: Nuclear factor-kappa B, SIRT1: Sirtuins, FOXO: Forkhead box, UCP2: Uncoupling protein 2, STZ: Streptozotocin nicotinamide, HSC: hepatic stellate cells, ECM: extracellular matrix.

White Matter Microstructural Abnormalities of the Visual Pathway in Type 2 Diabetes Mellitus: A Generalized Q-sampling Imaging Study

RATIONALE AND OBJECTIVES

Neurodegeneration is an early event in the pathogenesis of diabetic retinopathy (DR). We assessed the white matter microstructural integrity of the visual pathway in diabetes patients vs. healthy subjects, and investigated the advantages of generalized Q-sampling imaging (GQI) in the assessment of the visual pathway.

MATERIALS AND METHODS

T1-weighted, T2-weighted fluid-attenuated inversion recovery, and simultaneous multislice- diffusion sequences were acquired from 21 DR patients, 29 diabetes patients without DR (NDR group), and 28 age- and gender-matched healthy controls. Diffusion source images were reconstructed to GQI. Region of interest (ROI)-based analysis was utilized to evaluate microstructural alterations in the visual pathway. Multivariate linear regression analysis (forward stepwise method) was performed to investigate associations between clinical data and mean GQI parameters.

RESULTS

ROI-based analyses indicated that the GQI parameters generalized fractional anisotropy, quantitative anisotropy (QA), and normalized QA (NQA) were significantly lower in the NDR group than in the healthy controls, and even lower in the DR group than in the NDR group. Disease duration was significantly and negatively correlated with mean generalized fractional anisotropy and mean NQA.

CONCLUSION

GQI could sensitively and non-invasively evaluate the visual pathway in diabetes patients. The nerve fibers of the visual pathway were damaged before the onset of retinopathy, and this damage was aggravated after retinopathy onset, as a consequence of long exposure to hyperglycemia.

Effects of Quercetin and Coenzyme Q10 on Biochemical, Molecular, and Morphological Parameters of Skeletal Muscle in Trained Diabetic Rats

BACKGROUND

Diabetes mellitus (DM) affects the musculoskeletal system through its metabolic perturbations. Exercise modulates blood sugar levels and increases the body's sensitivity to insulin in patients with DM.

OBJECTIVE

This study aimed to investigate the potential effects of combined quercetin and coenzyme Q10 (CoQ10) supplements with or without exercise on the histological, biochemical and molecular structures of diabetic rat's skeletal muscle.

METHOD

A total of 64 adult male albino rats were divided into six groups: control, trained nondiabetic, non-trained diabetic, diabetic rats treated with combined CoQ10 and quercetin, diabetic rats with treadmill training, and diabetic rats treated with treadmill training and CoQ10 and quercetin. Blood and skeletal muscle samples were obtained from all groups for routine histological examination and biochemical determination of cytokine levels and protein activities. Quantitative real-time polymerase chain reaction (qRT-PCR) and morphometric analysis of PAS and Bax expressions were also performed.

RESULTS

Biochemical analysis revealed improvement in all studied parameters with combined CoQ10 and quercetin than exercise training alone. Combined treatment and exercise showed significant improvement in all parameters especially interleukin 6 and malondialdehyde. Fibronectin type III domain-containing protein 5 (FNDC5) expression and irisin levels increased in all trained groups but combined treatment with exercise significantly increased their levels than exercise alone. Histological analysis revealed improvement after exercise or combined treatment; however, when exercise was combined with CoQ10 and quercetin, marked improvement was observed.

CONCLUSION

the combination of CoQ10 and quercetin could be promising in preserving musculoskeletal function in patients with DM concomitantly with physical exercise.

Histological and Biochemical Changes in Adult Male Rat Liver after Spinal Cord Injury with Evaluation of the Role of Granulocyte-Colony Stimulating Factor

Spinal cord injury (SCI) is a devastating disease leading to motor disability. Metabolic dysfunction is another complication of SCI. Thus, we aimed to study the effect of SCI on the histological and biochemical structure of the liver in adult male rats and to delineate the role of post-injury administration of G-CSF. Thirty adult male Sprague-Dawley rats were assigned into three groups: Group I; control (18 rats subdivided equally into three subgroups), and 12 rats underwent SCI and were divided into an SCI group II and G-SCF-treated group III. Twenty-one days post-injury, liver sections were processed for light and electron microscopic examinations and immunohistochemical staining for PCNA and CD68 antibodies. The biochemical assay was carried out for detection of serum levels of ALT, AST, total proteins, albumin, total cholesterol, triglycerides, HDL-c, GSH and MDA. Liver tissue levels of GPx and MDA as well as semiquantitative RT-PCR analysis of hepatic cytokine expression were also conducted. In the SCI group, results showed liver tissue damage in the form of lipid infiltration, blood vessel congestion, vacuolated cells with apoptotic nuclei and increased collagen deposition. Increased CD68-positive macrophages and a decreased number of PCNA-positive cells was detected. Moreover, liver enzymes, total cholesterol and triglycerides were increased while serum albumin, total proteins and HDL-c were decreased in the SCI group. Oxidative stress and increased expression of inflammatory cytokines were detected. Administration of G-CSF induced significant liver improvement with retained liver function by anti-inflammatory, immune-modulatory and antioxidant mechanisms.

Moderate intensity intermittent exercise upregulates neurotrophic and neuroprotective genes expression and inhibits Purkinje cell loss in the cerebellum of ovariectomized rats

Decreases in estrogen levels due to menopause or ovariectomy may disrupt cerebellar motor functions. This study aimed at investigating the effects of Moderate Intensity Intermittent Exercise (MIEx) on the cerebellum of ovariectomized rats by analyzing neurotrophic and neuroprotective markers, as well as cerebellar motor functions. Thirty-two female Sprague Dawley rats were divided into four groups, i.e. Sham and ovariectomy (Ovx) of non-MIEx (NMIEx) groups, and Sham and Ovx with MIEx groups. MIEx was performed 5 days a week on treadmill for 6 weeks. Motor functions were assessed using rotarod, footprint, open field, and wire hanging tests. Real-time polymerase chain reaction was performed to determine messenger RNA (mRNA) expressions of Pgc-1α, BDNF, synaptophysin, Bcl-2, and Bax. Unbiased stereology was used to estimate the total number of cerebellar Purkinje cells. The Ovx MIEx group had higher Pgc-1α and Bcl-2 mRNA expressions, and number of Purkinje cells, but lower Bax mRNA expression than the Ovx NMIEx group. All motor functions of MIEx groups were better than the Sham and Ovx groups without MIEx. Motor functions on rotarod task, OFT, and FPT correlated significantly with the mRNAs expression of Bcl-2, Bax, BDNF, synaptophysin, Pgc-1α, and the number of cerebellar Purkinje cells in ovariectomized rats. MIEx improves cerebellar neurotrophic and neuroprotective markers, as well as motor functions of ovariectomized rats.

Effect of experimentally induced hypertension on cerebellum of postmenopausal rat

Cerebellum seems to be a specific target for both the decrease of estrogen and hypertension in menopause. The aim of this study was to investigate the hypertension and menopause-induced changes in rat's cerebellar cortex and the possible mechanisms of these changes. Rats were divided into four groups: the sham-operated control (SC-group), the ovariectomized (OVX-group), the hypertensive (H-group), and the ovariectomized-hypertensive (OVX-H-group) group. The mean arterial pressure (MAP), serum nitric oxide (NO), lipid peroxides and antioxidant catalase enzyme levels were assayed. Cerebellar tissue homogenization for analysis of lipid peroxides, antioxidant catalase enzyme, tumor necrosis factor-α (TNF-α), and estradiol was done. Quantification of adrenomedullin (AM) and interleukin-10 (IL-10) mRNA was also done. Cerebella were processed for histological, immunohistochemical and transmission electron microscopic examination. In the OVX-group, insignificant structural and biochemical changes were observed compared with the SC-group apart from the significantly increased lipid peroxides and decreased NO and catalase levels in serum. The H-group showed an elevated lipid peroxides and TNF-α levels, reduced catalase level, numerous degenerated Purkinje cells, vacuolations of the neuropil, some axonal degeneration, and few ghosts in the granular cell layer (GL). However, in OVX-H-group, oxidative stress, inflammation, and cerebellar damage were exacerbated and cerebellar estrogen was reduced associated with reduction in GL thickness and decreased Purkinje cells number. Most axoplasms had degenerated neurofilaments with abnormal myelination. The immunoexpression of glial fibrillary acidic protein were significantly increased in both OVX-group and H-group and significantly decreased in OVX-H group. Gene expression of AM and IL-10 were increased in cerebellar tissues of H-group compared with the SC-group but it was significantly decreased in OVX-H-group compared with H-group. Taken together, postmenopausal rats with hypertension suffered from structural cerebellar changes than rats with only hypertension or estrogen deficiency separately due to augmentation of the increased oxidative stress markers and the proinflammatory cytokines (TNF-α) with down regulation of the anti-inflammatory cytokine (IL-10) and the blood pressure regulator, AM. These suggested that high blood pressure is a critical factor for postmenopausal cerebellum.

Tanshinone IIA ameliorates diabetic cardiomyopathy by inhibiting Grp78 and CHOP expression in STZ-induced diabetes rats

Diabetic cardiomyopathy (DCM), one of the common diabetic complications, causes a high rate of mortality in patients with diabetes. Tanshinone IIA (TSIIA), one of the components of Salvia miltiorrhiza (Danshen), has anti-oxidative stress activity and is widely used to treat diabetes-associated diseases. However, its efficacy on DCM remains unclear. The present study aimed to investigate the potential therapeutic function of TSIIA on DCM in an experimental diabetic rat model. Streptozotocin (STZ)-induced diabetic rats were intraperitoneally injected with TSIIA for 6 weeks. The present results indicated that blood glucose concentration was slightly reduced in the low-dose TSIIA treatment group. TSIIA injection was also noted to improve cardiac function, and restore loss of mitochondrial cristae, swollen mitochondrial matrix and disorganized myofibrils in myocardial cells, which are thought to be characteristics of apoptosis. Furthermore, TSIIA injection could increase the activity of superoxide dismutase in STZ-induced diabetic rats, and suppress the endoplasmic reticulum (ER) stress signaling pathway via reducing the expression of glucose-regulated protein 78 and C/EBP homologous protein. These results provide evidence that TSIIA may ameliorate DCM in diabetic rats, possibly via suppressing oxidative stress and ER stress activation.

Application of neurite orientation dispersion and density imaging to characterize brain microstructural abnormalities in type-2 diabetics with mild cognitive impairment

BACKGROUND

Diffusion-tensor-imaging (DTI) is sensitive in detecting white matter changes in type-2 diabetes mellitus (T2DM). However, DTI indices can be affected by either neurite density or spatial variation. A novel diffusion MRI technique, termed neurite orientation dispersion and density imaging (NODDI), can provide distinct indices of fiber density and dispersion.

PURPOSE

To characterize brain microstructural alterations in T2DM patients with mild cognitive impairment (MCI) using the NODDI model.

STUDY TYPE

Cross-sectional.

SUBJECTS

Twenty T2DM patients with (DM-MCI group), 18 age- and gender-matched T2DM patients with normal cognition (DM-NC group), and 28 euglycemic healthy controls (HC).

FIELD STRENGTH/SEQUENCE

3T/NODDI.

ASSESSMENT

Diffusion data were analyzed using tract-based-spatial-statistics (TBSS) analysis in white matter and voxel-based analysis in both white and gray matter. NODDI indices, including intracellular volume fraction (Vic) and orientation dispersion index (ODI), were estimated from multiple regions and compared among these groups.

STATISTICAL TESTS

Differences between groups were compared by Student's t-test, Pearson chi-square test, or analysis of variance when appropriate. Correlation analyses were performed to investigate the relationship between NODDI variables and clinical measurements.

RESULTS

Whole-brain TBSS revealed that 2.29% and 2.02% of the white matter regions exhibited decreased fractional anisotropy and Vic, respectively, between the DM-NC and HC, while considerably larger white matter areas showed decreased fractional anisotropy (38.38%) and Vic (34.64%) between the DM-MCI and HC (Student's t-test, P < 0.05). However, the angular variation of neurites, characterized by ODI, exhibited very little (0.1%, P < 0.05) or no difference (P > 0.05) between either the DM-MCI or DM-NC groups and HC. Decreased Vic values in the genu of the corpus callosum (R = 0.580, 0.551 and 0.586, P < 0.01) and thalamus (R = 0.570, 0.616, and 0.595, P < 0.05) correlated with glycosylated hemoglobin A1c level, disease duration, and neuropsychological scores, respectively.

DATA CONCLUSION

T2DM patients with cognitive decline had reduced Vic, which indicated decreased density of axons and dendrites. NODDI might be able to help probe microstructural changes in white and gray matter and provide information on diabetic encephalopathy, including those with cognitive impairment.

LEVEL OF EVIDENCE

1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:889-898.

Resveratrol exerts a protective effect in chronic unpredictable mild stress-induced depressive-like behavior: involvement of the AKT/GSK3β signaling pathway in hippocampus

BACKGROUND

Chronic unpredictable mild stress (CUMS) is an important contributing factor for depression with inflammatory response alteration, neuron apoptosis, and decreased neurogenesis. Previous study reported that the administration of resveratrol alleviated depression by normalizing the increased proinflammatory cytokine levels and inhibiting apoptosis in the hippocampus. However, the upstream signaling pathway that regulates cytokines and apoptosis in the antidepressant effect of resveratrol remains unclear.

OBJECTIVE

The objective of this study is to investigate the possible mechanism of the effect of resveratrol on depression.

METHODS

Male Sprague Dawley rats were exposed to CUMS for four consecutive weeks to elicit depressive-like behavior. The rats in the drug treatment groups were injected with resveratrol (40 or 80 mg/kg/day) and fluoxetine (10 mg/kg/day) intraperitoneally for 4 weeks. Rats in two additional groups were administered LY294002 by bilateral stereotaxic microinjection into the lateral ventricle before resveratrol administration. Behavioral tests, including sucrose preference test, forced swim test, and open field test, were used after 4 weeks of a CUMS procedure to appraise depressive-like behavior. Then, the proinflammatory cytokines (TNF-α, IL-6, and IL-1β) in the hippocampus and prefrontal cortex (PFC) tissues of rats were measured. Apoptosis-related molecules such as Bax and Bcl-2 mRNA levels in the hippocampus were analyzed. Furthermore, p-Akt/Akt and p-GSK3β/GSK3β protein expression in the hippocampus were also measured.

RESULTS

The results show that rats were subjected to CUMS procedure exhibited depressive-like behavior, increased TNF-α, IL-6, and IL-1β levels in hippocampus and PFC, alteration of Bax and Bcl-2 mRNA levels in hippocampus, decreased p-Akt/Akt and p-GSK3β/GSK3β protein expression in hippocampus, and an increased apoptotic cell percentage in the hippocampal CA1 region. However, resveratrol (40 or 80 mg/kg) treatment reversed these behavioral and molecular changes in CUMS rats. The positive control drug fluoxetine showed a similar effect as the resveratrol treatment. When rats were injected with LY294002 before resveratrol treatment, the antidepressant effect of resveratrol was significantly attenuated, TNF-α, IL-6 and IL-1β levels in hippocampus and PFC increased again, Bax mRNA levels increased and Bcl-2 mRNA levels decreased in hippocampus, and Akt/GSK3β protein expression in hippocampus decreased.

CONCLUSIONS

The findings in the present study suggest that the antidepressant effect of resveratrol treatment may act through activation of the Akt/GSK3β signaling pathway and then regulation of proinflammatory cytokine expression and alteration of apoptosis.

Synergistic therapeutic effects of Vitis vinifera extract and Silymarin on experimentally induced cardiorenal injury: The pertinent role of Nrf2

BACKGROUND

Cardiorenal crosstalk has gained growing scientific curiosity recently. Clinical observations have approved that heart and kidney performances are intimately interrelated; acute or chronic dysfunction of either is inevitably mirrored on the other. This coexistence usually has the poor prognosis and worsened outcome.

METHODS

We designed this study to explore therapeutic potentials of combined Vitis vinifera and Silymarin extracts on histopathological alterations of experimentally induced cardiorenal injury model. Moreover, to examine the pertinent role of Nrf2 in their bio-molecular actions. Sixty adult male Wistar albino rats were utilized, further subdivided into control, doxorubicin (DXR), DXR + Silymarin, DXR + Aqueous Vitis, DXR + Ethanolic Vitis, DXR + Ethanolic Vitis + Silymarin. Left ventricle and renal cortex sections from all groups were processed for histopathological examination, biochemical estimation of serum Urea, Creatinine, BUN, lipid profile and hs-CRP and real-time PCR of Nrf2 expression in cardiac and renal tissue homogenate were performed.

RESULTS

Our results proved that combined ethanolic extract of Vitis vinifera and Silymarin restored normal renal and cardiac histomorphology. Significant improvement of Creatinine, BUN, lipid profile and hs-CRP cardiac and renal biochemical indicators confirmed our results. Moreover, significant elevation of mRNA expression levels of Nrf2 proved that combined Vitis vinifera and Silymarin action was directly related to the redox-sensitive regulator pathway.

CONCLUSIONS

We concluded that synergistic therapeutic effect of Vitis vinifera extract and Silymarin on experimental cardiorenal injury model owes principally to promoting activation of the Keap1/Nrf2 signaling pathway.

Preventative effects of resveratrol and estradiol on streptozotocin-induced diabetes in ovariectomized mice and the related mechanisms

Resveratrol, a non-flavonoid polyphenolic compound, is structurally and functionally similar to estrogen and has drawn great attention for its potentially beneficial effects on diabetes. However, it is not known whether it shares the same protective effect against diabetes as estrogen and the underlying mechanisms. The aim of the present study was to investigate the protective effects of phytoestrogen resveratrol and exogenous 17β-estradiol against streptozotocin (STZ)-induced type 1 diabetes. Female mice were ovariectomized (OVX) and chronically injected with different concentrations of resveratrol (0.1, 1 or 10 mg/kg) and 17β-estradiol (0.01, 0.1 or 1 mg/kg) subcutaneously for 4 weeks, and the levels of blood glucose, plasma insulin, plasma antioxidant capacity, the changes of pancreatic islet cells and the expressions of glucose transporter 4 (GLUT4), insulin receptor substrate 1 (IRS-1) and phosphorylation of extracellular signal-regulated kinase (p-ERK) were detected. Resveratrol and 17β-estradiol significantly inhibited the increase of the blood glucose level and the rise of plasma malondialdehyde in STZ-induced diabetic mice, improved the levels of plasma antioxidant capacity and plasma insulin, protected the pancreatic islet cells, and increased the expressions of GLUT4 and IRS-1, but decreased p-ERK expression in skeletal muscle and myocardial tissue. The results suggest that resveratrol or 17β-estradiol shows obvious protection against STZ-induced diabetes in OVX mice, the mechanisms probably involve their ameliorating antioxidant activities and islet function, promoting muscle glucose uptake and inhibiting the expression of p-ERK.

Fluoxetine pretreatment enhances neurogenic, angiogenic and immunomodulatory effects of MSCs on experimentally induced diabetic neuropathy

Being one of the most debilitating complications among diabetic patients, diabetic polyneuropathy (DPN) is a paramount point of continuous research. Stem cell therapies have shown promising results. However, limited cell survival and paracrine activities hinder its transfer from bench to bedside. We designed this study to evaluate fluoxetine-pretreatment technique of mesenchymal stem cells (MSCs) as an approach to enhance their paracrine and immunomodulatory properties in DPN. Effects of fluoxetine treatment of MSCs were tested in vitro. Forty-two adult Wistar male albino rats were utilized, further subdivided into control, diabetic, MSC-treated and fluoxetine-pretreated MSC groups. Sciatic nerve sections were prepared for light and electron microscope examination and immunohistochemical detection of neurofilament (NF) protein. Also, we assessed in vitro survival and paracrine properties of fluoxetine-pretreated MSCs. Real time PCR of BDNF, VEGF, IL-1β, and IL-10 expression in tissue homogenate was performed. Our results showed restoration of normal neuronal histomorphology and ultrastructure, moreover, immunohistochemical expression of anti-neurofilament protein was significantly elevated in MSC-treated groups compared to the diabetic one. Fluoxetine enhanced the MSC survival and their paracrine properties of MSCs in vitro. Furthermore, the fluoxetine-pretreated MSC group revealed a significant elevation of mRNA expression of BDNF (neurotrophic factor) and VEGF (angiogenic factor), denoting ameliorated MSC paracrine properties. Similarly, improved immunomodulatory functions were evident by a significant reduction of interleukin-1β mRNA expression (pro-inflammatory) and a reciprocal significant increase of interleukin-10 (anti-inflammatory). We concluded that fluoxetine-pretreatment of MSCs boosts their survival, paracrine, and immunomodulatory traits and directly influenced neuronal histomorphology. Hence, it presents a promising intervention of diabetic polyneuropathy. Graphical Abstract.

Effect of human umbilical cord blood mesenchymal stem cells administered by intravenous or intravitreal routes on cryo-induced retinal injury

Traumatic optic neuropathy is an important cause of severe vision loss. So, many attempts were performed to transplant stem cells systemically or locally to regenerate the injured retina. In this study, we investigated the effect of human umbilical cord blood mesenchymal stem cells (hUBMSCs) on histological structure, apoptotic, antiapoptotic, oxidant and antioxidant markers in an experimental model of cryo-induced retinal damage in mice. Forty-eight mice were included with 4 major groups; group I contained 18 mice as controls. The others included 30 mice exposed to cryo-induced retinal injury and were subdivided into three equal groups: group II received no treatment after injury. Group III was intravenously injected with hUCBMSCs after injury and group IV received an intravitreal injection with hUCBMSCs into both eyes. Retinal tissues were used for histopathological, immunological and gene expression studies. Real time-PCR was performed to assess B-cell lymphoma 2 (bcl2), Bcl2-associated X protein (bax), heme oxygenase-1 (hmox-1) and thioredoxin-2 (tnx-2) expression and to assess the differentiation of the stem cells into the retinal tissue. Immunohistochemical analysis was performed to assess caspase-3, 3-nitrotyrosine (3-NT) and basic fibroblast growth factor (bFGF). Disturbed retinal structure was seen in cryo-injured mice while hUCBMSCs treated groups showed nearly normal structure. By real time-PCR, significantly reduced mRNA expressions of Bax and notably enhanced mRNA expression of Bcl-2, hmox-1 and txn-2 were demonstrated in retinal injured mice with hUCBMSCs treatment compared to those without. In addition, immunohistochemical analysis confirmed downregulation of 3-NT and caspase-3 and upregulation of bFGF after hUCBMSCs injection in injured retina. Furthermore, there was no differentiation of transplanted stem cells into the retinal tissue. In conclusions, hUCBMSCs could improve the morphological retinal structure in cryo-induced retinal damage model by modulation of the oxidant-apoptotic status and by increased the expression of bFGF. © 2017 IUBMB Life, 69(3):188-201, 2017.

Accumulation of α-Synuclein in Cerebellar Purkinje Cells of Diabetic Rats and Its Potential Relationship with Inflammation and Oxidative Stress Markers

Objective. The present study was conducted to evaluate the relationship between plasma oxidative stress markers such as malondialdehyde (MDA) and glutathione (GSH), inflammatory marker pentraxin-3 (PTX3), and cerebellar accumulation of α-synuclein in streptozotocin- (STZ-) induced diabetes model in rats. Methods. Twelve rats were included in the study. Diabetes (n = 6) was induced with a single intraperitoneal injection of streptozotocin (STZ, 60 mg/kg). Diabetes was verified after 48 h by measuring blood glucose levels. Six rats served as controls. Following 8 weeks, rats were sacrificed for biochemical and immunohistochemical evaluation. Results. Plasma MDA levels were significantly higher in diabetic rats when compared with the control rats (p < 0.01), while plasma GSH levels were lower in the diabetic group than in the control group (p < 0.01). Also, plasma pentraxin-3 levels were statistically higher in diabetic rats than in the control rats (p < 0.01). The analysis of cerebellar α-synuclein immunohistochemistry showed a significant increase in α-synuclein immunoexpression in the diabetic group compared to the control group (p < 0.01). Conclusion. Due to increased inflammation and oxidative stress in the chronic period of hyperglycemia linked to diabetes, there may be α-synuclein accumulation in the cerebellum and the plasma PTX3 levels may be assessed as an important biomarker of this situation.

Effect of agomelatine on adult hippocampus apoptosis and neurogenesis using the stress model of rats

Agomelatine (AG) is an agonist of melatonin receptors and an antagonist of the 5-HT2C-receptor subtype. The chronobiotic properties of AG are of significant interest due to the disorganization of internal rhythms, which might play a role in the pathophysiology of depression. The present study was designed to assess the effects of the antidepressant-like activity of AG, a new antidepressant drug, on adult neurogenesis and apoptosis using stress-exposed rat brains. Over the period of 1 week, the rats were exposed to light stress twice a day for 1h. After a period of 1 week, the rats were given AG treatment at a dose of either 10mg/kg or 40mg/kg for 15 days. The animals were then scarified, and the obtained tissue sections were stained with immuno-histochemical anti-BrdU, Caspase-3, and Bcl-2 antibodies. Serum brain-derived neurotrophic factor (BDNF) concentrations were measured biochemically using a BDNF Elisa kit. Biochemical BDNF analysis revealed a high concentration of BDNF in the serum of the stress-exposed group, but the concentrations of BDNF were much lower those of the AG-treated groups. Immuno-histochemical analysis revealed that AG treatment decreased the BrdU-positive and Bcl-2-positive cell densities and increased the Caspase-3-positive cell density in the hippocampus of stress-induced rats as compared to those of the stress group. The results of the study demonstrated that AG treatment ameliorated the hippocampal apoptotic cells and increased hippocampal neurogenesis. These results also strengthen the possible relationship between depression and adult neurogenesis, which must be studied further.

Protective effects of beta glucan in brain tissues of post-menopausal rats: a histochemical and ultra-structural study

Decline of estrogen during menopause has been associated with numerous significant changes that have been linked to many pathophysiological complications. In addition, ovarian hormone deficiency increases the production of reactive oxygen radicals which could result in oxidative stress and cell damage. While estrogen therapy is often considered to overcome the behavioral and physiological shortcomings, antioxidants are gaining popularity for their beneficial property. For this purpose, in the present study, utilizing the antioxidant properties of beta glucan has been examined in treatment of menopause induced oxidative stress in cerebral neurons. Four groups of female Wistar rats were used: control, ovariectomy, ovariectomy + estrogen treated and ovariectomy + beta glucan treated. We observed a significant increase in neural degeneration in ovariectomized rats as compared to controls. Moreover, increased oxidative stress in the brains of the ovariectomized rats has been detected by performing immunohistochemical analysis. A large number of immuno-positive cerebral neurons have been observed in ovariectomy group rat brains. Interestingly, providing beta glucan treatment to ovariectomized rats reduced the number of degenerated neurons. Our study is the first to examine light and electron microscopic examination and immunohistochemical and stereological analysis of estrogen depletion in rats and to test protective role of beta glucan in the experimental study.