Angiotensin II Type 1 receptor blockade attenuates the neuropathological changes in the spinal cords of diabetic rats with modulation of nuclear factor erythroid 2-related factor 2/ heme oxygenase 1 system

Peripheral and central neuropathies frequently complicate worldwide diabetes. Compared to peripheral neuropathy, central neuropathy didn`t gain a major research interest. Angiotensin II is reported to be involved in diabetic neuropathic pain but its role in the central pathological changes in the spinal cord is not clear. Here, we study the role of Losartan; an Angiotensin II receptor 1 (AT1) antagonist in suppression of the diabetes-induced changes in the spinal cord. Three groups of rats were applied; a negative control group, a streptozotocin (STZ) diabetic group, and a group receiving STZ and Losartan. After two months, the pathological alteration in the spinal cord was investigated, and an immunohistochemical study was performed for neuronal, astrocytic, and microglial markers; nuclear protein (NeuN), Glial fibrillary acidic protein (GFAP), and Ionized calcium-binding adaptor molecule 1 (Iba1), respectively, and for an apoptosis marker; caspase-3, and the inflammatory marker; nuclear factor kappa B (NF-kB) signaling, heme oxygenase-1 (HO-1) and nuclear factor erythroid 2-related factor 2 (Nrf2); physiological antioxidant system. The results showed that Losartan caused recovery of spinal cord changes, by inhibiting the microglial and astrocytic activation, suppressing neuronal apoptosis and NF-kB expression with activation of Nrf2/HO-1 (P<0.0005). It is suggested, herein, that Losartan can suppress diabetes-induced glial activation, inflammation, neuronal apoptosis, and oxidative stress in the spinal cord; the mechanisms that may underlie the role of AT1 antagonism in suppressing diabetic neuropathic pain.

The role of stinging nettle (Urtica dioica L.) in the management of rotenone-induced Parkinson's disease in rats

Parkinson's disease (PD) is one of the most common neurodegenerative conditions. Alpha-synuclein deposition, Lewy bodies (LBs) formation, disruption of the autophagic machinery, apoptosis of substantia nigra dopaminergic neurons, oxidative stress, and neuroinflammation are all pathologic hallmarks of PD. The leaves of the stinging Nettle (Urtica dioica L.) have a long history as an herbal cure with antioxidant, anti-inflammatory, anti-cancer, immunomodulatory, and neuroprotective properties. The current study aims for the first time to investigate the role of Nettle supplementation on Rotenone-induced PD. Rats were divided into five groups; a Saline control, Nettle control (100 mg/kg/day), Rotenone control (2 mg/kg/day), Rotenone + Nettle (50 mg /kg/day), and Rotenone + Nettle (100 mg/kg). After four weeks, the rats were examined for behavioral tests. The midbrains were investigated for histopathological alteration and immunohistochemical reaction for Tyrosine hydroxylase in the dopaminergic neurons, α-synuclein for Lewy bodies, caspase 3 for apoptotic neurons, LC3 and P62 for autophagic activity. Midbrain homogenates were examined for oxidative stress markers. mRNA expression of TNFα and Il6; inflammatory markers, Bcl-2, BAX and Caspase 3; apoptosis markers, were detected in midbrains. The results showed that Nettle caused recovery of midbrain dopaminergic neurons, by inhibiting apoptosis, inflammation, and oxidative stress and by restoring the autophagic machinery with clearance of α-synuclein deposits. We can conclude that Nettle is a potentially effective adjuvant in the treatment of Parkinson's disease.

Suppression of neuronal apoptosis and glial activation with modulation of Nrf2/HO-1 and NF-kB signaling by curcumin in streptozotocin-induced diabetic spinal cord central neuropathy

Introduction

Diabetes is a global disease, commonly complicated by neuropathy. The spinal cord reacts to diabetes by neuronal apoptosis, microglial activation, and astrocytosis, with a disturbance in neuronal and glial Nuclear factor erythroid 2-related factor/Heme oxygenase-1 (Nrf2/HO-1) and Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) signaling. Curcumin, a bioactive natural substance, showed neuroprotective role in many diseases. However, its role in the treatment of the diabetic central neuropathy of spinal cord and the underlying mechanisms still need clarification. The present study tried to evaluate the role of curcumin in diabetes-induced central neuropathy of the spinal cord in rats.

Methods

Twenty rats were divided into three groups; group 1: a negative control group; group 2: received streptozotocin (STZ) to induce type I diabetes, and group 3: received STZ + Curcumin (150 mg/kg/day) for eight weeks. The spinal cords were examined for histopathological changes, and immunohistochemical staining for Glia fibrillary acidic protein (GFAP); an astrocyte marker, Ionized calcium-binding adaptor molecule 1 (Iba1), a microglial marker, neuronal nuclear protein (NeuN); a neuronal marker, caspase-3; an apoptosis marker, Nrf2/HO-1, NF-kB, and oxidative stress markers were assessed.

Results

Curcumin could improve spinal cord changes, suppress the expression of Iba1, GFAP, caspase-3, and NF-kB, and could increase the expression of NeuN and restore the Nrf2/HO-1 signaling.

Discussion

Curcumin could suppress diabetic spinal cord central neuropathy, glial activation, and neuronal apoptosis with the regulation of Nrf2/HO-1 and NF-kB signaling.

Methotrexate-Induced Alteration of Renal Aquaporins 1 and 2, Oxidative Stress and Tubular Apoptosis Can Be Attenuated by Omega-3 Fatty Acids Supplementation

Methotrexate (MTX) is a potent anti-cancer drug, commonly associated with nephrotoxicity via the induction of oxidative stress and apoptosis with alteration of renal water channel proteins, namely aquaporins (AQPs). Omega-3 long-chain polyunsaturated fatty acids (LC-PUFA) have shown cytoprotective effects through their anti-oxidant and antiapoptotic activities. The present study aims for the first time to explore the role of LC-PUFA against MTX-induced nephrotoxicity. Rats were divided into the following groups: saline control, LC-PUFA control, MTX, MTX + LC-PUFA (150 mg/kg), or MTX + LC-PUFA (300 mg/kg). Then, H&E staining and immunohistochemical staining for the anti-apoptosis marker B-cell lymphoma 2 (BCL-2), the apoptosis marker BCL2-Associated X Protein (BAX), the proinflammatory marker Nuclear factor kappa B (NF-kB), AQPs 1 and 2 were performed in kidney sections with an assessment of renal oxidative stress. The MTX caused a renal histopathological alteration, upregulated renal BAX and NF-kB, downregulated Bcl-2 and AQP1, altered the distribution of AQP2, and caused oxidative stress. The LC-PUFA attenuated the pathological changes and decreased renal BAX and NF-kB, increased BCL-2 and AQP1, restored the normal distribution of AQP2, and decreased the oxidative stress. Therefore, LC-PUFA is a good adjuvant to MTX to prevent its adverse effects on kidneys through its antiapoptotic, antioxidant, and anti-inflammatory effect and its role in the restoration of the expression of AQPs 1 and 2.

Targeting Hydrogen Sulfide Modulates Dexamethasone-Induced Muscle Atrophy and Microvascular Rarefaction, through Inhibition of NOX4 and Induction of MGF, M2 Macrophages and Endothelial Progenitors

Long-term use of Glucocorticoids produces skeletal muscle atrophy and microvascular rarefaction. Hydrogen sulfide (H2S) has a potential role in skeletal muscle regeneration. However, the mechanisms still need to be elucidated. This is the first study to explore the effect of Sodium hydrosulfide (NaHS) H2S donor, against Dexamethasone (Dex)-induced soleus muscle atrophy and microvascular rarefaction and on muscle endothelial progenitors and M2 macrophages. Rats received either; saline, Dex (0.6 mg/Kg/day), Dex + NaHS (5 mg/Kg/day), or Dex + Aminooxyacetic acid (AOAA), a blocker of H2S (10 mg/Kg/day) for two weeks. The soleus muscle was examined for contractile properties. mRNA expression for Myostatin, Mechano-growth factor (MGF) and NADPH oxidase (NOX4), HE staining, and immunohistochemical staining for caspase-3, CD34 (Endothelial progenitor marker), vascular endothelial growth factor (VEGF), CD31 (endothelial marker), and CD163 (M2 macrophage marker) was performed. NaHS could improve the contractile properties and decrease oxidative stress, muscle atrophy, and the expression of NOX4, caspase-3, Myostatin, VEGF, and CD31 and could increase the capillary density and expression of MGF with a significant increase in expression of CD34 and CD163 as compared to Dex group. However, AOAA worsened the studied parameters. Therefore, H2S can be a promising target to attenuate muscle atrophy and microvascular rarefaction.

Enhanced Autophagic Flux, Suppressed Apoptosis and Reduced Macrophage Infiltration by Dasatinib in Kidneys of Obese Mice

Obesity causes renal changes (ORC), characterized by defective renal autophagy, lipogenesis, enhanced macrophage infiltration and apoptosis. We hypothesize that Dasatinib, a tyrosine kinase inhibitor, may ameliorate changes associated with obesity. We the mice with either Obesogenic diet (OD) or a standard basal diet. After 12 weeks, the mice received either vehicle or Dasatinib 4 mg/kg/d for an additional four weeks. We examined serum creatinine, urea, lipid profile and renal cortical mRNA expression for lipogenesis marker SREBP1, inflammatory macrophage marker iNOS and fibrosis markers; TGFβ and PDGFA genes; immunohistochemical (IHC) staining for CD68; inflammatory macrophage marker and ASMA; fibrosis marker, LC3 and SQSTM1/P62; autophagy markers and western blotting (WB) for caspase-3; and, as an apoptosis marker, LC3II/I and SQSTM1/P62 in addition to staining for H&E, PAS, Sirius red and histopathological scoring. Dasatinib attenuated renal cortical mRNA expression for SREBP1, iNOS, PDGFA and TGFβ and IHC staining for CD68, ASMA and SQSTM1/P62 and WB for caspase-3 and SQSTM1/P62, while elevating LC3 expression. Moreover, Dasatinib ameliorated ORC; glomerulosclerosis, glomerular expansion, tubular dilatation, vacuolation and casts; inflammatory cellular infiltration; and fibrosis. Dasatinib is a promising therapy for ORC by correcting autophagy impairment, attenuating lipogenesis, apoptosis and macrophage infiltration by inducing antifibrotic activity.

Modulation of COX-2 and NADPH oxidase-4 by alpha-lipoic acid ameliorates busulfan-induced pulmonary injury in rats

Aims

This study aimed to explore the potential protective effect of α-lipoic acid on busulfan-induced pulmonary fibrosis in rats.

Main methods

Eighteen adult male rats were divided into 3 groups; control, busulfan, and busulfan plus α-lipoic acid groups. Lung index ratio, serum level of proinflammatory cytokine were assessed. The activities of antioxidant enzymes and lipid peroxidation products were estimated in the lung tissues in addition to the histopathological analyses. The deposition of the collagen in the lung tissues was evaluated by Sirius red staining. The expressions of α-smooth muscle actin (α-SMA), TNF-α, and Caspase 3 were determined immunohistochemically. The pulmonary expression of COX-2 and NOX-4 mRNA was assessed using qRT-PCR.

Key findings

Administration of ALA significantly protect the lung against BUS-induced pulmonary fibrosis, besides the upregulation of antioxidants, and downregulation of pro-inflammatory cytokines. Also, it reduced collagen deposition that associated with a decreased expression of α-SMA, TNF-α, and Caspase 3 in the lung tissues. Moreover, ALA significantly upregulated the expression of COX-2 concomitant with the downregulation of elevated NOX-4.

Significance

ALA attenuates the lung cytotoxicity of busulfan through its anti-inflammatory, anti-apoptotic, and antifibrotic effects that may be mediated by upregulation of COX-2 and downregulation of NOX-4.

Efficacy of biocompatible trilayers nanofibrous scaffold with/without allogeneic adipose-derived stem cells on class II furcation defects of dogs' model

OBJECTIVE

This study aimed to evaluate the regenerative capacity of a newly-developed polycaprolactone (PCL)-based nanofibrous composite scaffold either alone or in combination with adipose-derived mesenchymal stem cells (ADSCs) as a treatment modality for class II furcation defects.

MATERIALS AND METHODS

After ADSCs isolation and scaffold characterization, the mandibular premolars of adult male mongrel dogs were selected and randomly assigned into three equal groups. In group I, class II furcation defects were surgically induced to the inter-radicular bone. While class II furcation defects of group II were induced as in group I. In addition, the defects were filled with the prefabricated scaffold. Moreover, class II furcation defects of group III were induced as in group II and instead the defects were filled with the prefabricated scaffold seeded with ADSCs. The dogs were sacrificed at 30 days or at 60 days. Periodontal wound healing/regeneration was evaluated by radiological examination using cone beam computed tomography and histologically using ordinary, histochemical, and immunohistochemical staining.

RESULTS

In the two examination periods, group II defects compared to group I, and group III compared to the other groups showed a decrease in defect dimensions radiographically. Histologically, histochemically, and immunohistochemically, they significantly demonstrated better periodontal wound healing/regeneration, predominant collagen type I of newly formed bone and periodontal ligament with a significant increase in the immunoreactivity of vascular endothelial growth factor and osteopontin.

CONCLUSIONS

The newly fabricated nanofibrous scaffold has enhanced periodontal wound healing/regeneration of class II furcation defects with further enhancement achieved when ADSCs seeded onto the scaffold before implantation.

CLINICAL RELEVANCE

The implementation of our newly-developed PCL-based nanofibrous composite scaffolds in class II furcation defect either alone or in conjunction with ADSCs can be considered as a suitable treatment modality to allow periodontal tissues regeneration.

Eicosapentaenoic and docosahexaenoic acids attenuate methotrexate-induced apoptosis and suppression of splenic T, B-Lymphocytes and macrophages with modulation of expression of CD3, CD20 and CD68

Methotrexate (MTX) is a chemotherapeutic agent used for cancer and autoimmune disorders. MTX may cause multi-organ affections. However, few studies examined MTX-induced splenic suppression and therapeutic modalities against it. This is the first study to explore the efficacy of omega-3 fatty acids; Eicosapentaenoic (EPA) and Docosahexaenoic (DHA) against MTX-induced splenic suppression and its effect on splenic macrophages and lymphocytes. Five groups of Sprague Dawley rats were used. Group 1 received saline; group 2: omega-3 only; group 3: a single dose of MTX (20 mg/kg); groups 4 and 5: MTX (20 mg/kg) + either omega-3 (150) or (300 mg/kg) once daily, respectively, given for two days before MTX and three days after it. Splenic tissues were then removed, evaluated for oxidative stress markers; GSH, MDA, and for mRNA expression of the apoptotic marker caspase-3, the anti-apoptotic marker Bcl-2 and the inflammatory cytokine TNFα. Moreover, H&E stain, Prussian blue stain for iron, and immunohistochemical staining for TNFα, T lymphocyte marker; CD3, B lymphocyte marker; CD20, and macrophage marker; CD68, were performed with morphometric analysis. EPA and DHA could decrease the MTX-induced increase in the histopathological injury score, splenic hemosiderin, splenic MDA, mRNA expression of TNFα, caspase-3 and could increase the MTX-induced decrease in Splenic GSH and mRNA expression for Bcl-2. It also decreased the MTX-induced elevation in the immunopositive area of TNFα, and increased the area percentage of CD3+, CD20+ and CD68+ cells. Therefore, omega-3 can be a promising adjuvant to help MTX action with prevention of its deleterious effects on spleen.

Independent of Calorie Intake, Short-term Alternate-day Fasting Alleviates NASH, With Modulation of Markers of Lipogenesis, Autophagy, Apoptosis, and Inflammation in Rats

Non-alcoholic steatohepatitis (NASH) is a worldwide health problem. Alternate-day fasting (ADF), although thought to be aggressive, has proven safety and efficacy. We aimed to evaluate the effect of short-term ADF against already established high-fat-fructose (HFF)-induced NASH, independent of the amount of calorie intake, and to study the effect of ADF on lipogenesis, apoptosis, and hepatic inflammation. Male Sprague Dawley rats were divided into two groups: (1) negative control and (2) NASH group fed on HFF for 9 weeks, and then randomized into two subgroups of either HFF alone or with ADF protocol for 3 weeks. The ADF could improve HFF-related elevation in serum lactate dehydrogenase and could decrease the mRNA expression of lipogenesis genes; acetyl CoA carboxylase, peroxisome proliferator-activated receptor γ, and peroxisome proliferator-activated receptor α; apoptotic genes caspase-3, p53, and inflammatory cyclo-oxygenase 2; and immunohistochemical staining for their proteins in liver with upregulation of LC3 and downregulation of P62 immunoexpression. Moreover, ADF ameliorated HFF-induced steatosis, inflammation, ballooning, and fibrosis through hematoxylin and eosin, Oil Red O, and Sirius Red staining, confirmed by morphometric analysis, without significant weight loss. Significant correlation of morphometric parameters with levels of gene expression was found. These findings suggest ADF to be a safe effective therapeutic agent in the management of NASH.

Can Dasatinib Ameliorate the Hepatic changes, Induced by Long Term Western Diet, in Mice?

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is a worldwide disease that progresses into steatohepatitis (NASH) that has no current effective treatment. This study aimed, for the first time, to investigate the effect of Dasatinib; a tyrosine kinase inhibitor showing anti-PDGFR activity with a macrophage modulating efficacy, on NASH.

METHODS

NASH was induced, in C57BL/6 mice by western diet (WD). Control groups received either DMSO or Dasatinib. After 12 weeks, WD-fed mice received DMSO, Dasatinib (4 mg/kg) or Dasatinib (8 mg/kg) once daily, for four weeks. Serum was examined for ALT and lipid profile. Immunohistochemical staining for SREBP1 (lipogenesis marker), iNOS, arginase-1, CD68, CD163 (macrophage polarization markers), TGF-β (fibrosis marker) and ASMA (a marker for activated hepatic stellate cell), hepatic mRNA expression for SREBP-1, iNOS, arginase-1, TGF-β and PDGFA genes; and western blotting for phosphorylated PDGFR α and β, SREBP1, iNOS, arginase-1, IL1α, COX2, TGF-β and ASMA were performed. Liver sections were stained also for H & E, Oil red O and Sirius red.

RESULTS

Dasatinib could ameliorate the WD-induced disturbance of serum ALT, lipid profile and significantly reduced hepatic expression of PDGFA, phosphorylated PDGFR α and β, IL1α, COX2, SREBP-1, iNOS, CD68, TGF-β and ASMA but increased expression for arginase-1 and CD163 (M2 macrophage markers). Moreover, Dasatinib reduced the steatosis, inflammation, hepatocellular ballooning, hepatic fibrosis and the high NAFLD activity scoring induced by WD.

CONCLUSION

Dasatinib can prevent the progression of WD-induced NASH by attenuating lipogenesis, and inducing M2 macrophage polarization with antifibrotic activity.

Is the hepatocyte ultrastructural zonal heterogeneity changed by overnight (16 h) fasting? Morphometric study

Background and objectives: Hepatocyte ultra-structure is influenced by feeding status, circadian rhythm, and zone location. The goal of the present study was to study the effect of overnight fasting on the hepatocyte ultrastructure and the zonal heterogeneity and to discuss the functional correlation.Methods: A total of 14 male albino rats were divided into two groups: negative control group fed ad libitum and overnight fasting rats for 16 hours. The different subcellular structures of both centrilobular and periportal hepatocytes in both control and fasted groups were compared by transmission electron microscopy. Morphometric analysis of the electron micrographs was also done using imageJ software.Results: The lysosomes surface density, mitochondrial volume and surface densities were significantly higher in periportal hepatocytes however surface density of smooth endoplasmic reticulum (SER) and peroxisomes were significantly higher in centrilobular hepatocytes of the control group. Fasting caused a significant decrease in the surface density of rough endoplasmic reticulum and glycogen volume density but with significant increase in SER surface density with more mitochondrial fusion and stronger mitochondrial ER contacts, isolation membranes, and autophagosomes. The zonal differences were maintained after fasting. The organelles appeared normal with no signs of degeneration.Conclusion: The organelles appeared normal with no signs of degeneration and the zonal differences were maintained after fasting. The change in hepatocyte ultrastructure after fasting may be related to autophagy.