Tanshinone IIA Against Cerebral Ischemic Stroke and Ischemia-Reperfusion Injury: A Review of the Current Documents.

Stroke is a well-known neurological disorder that carries significant morbidity and mortality rates worldwide. Cerebral Ischemic Stroke (CIS), the most common subtype of stroke, occurs when thrombosis or emboli form elsewhere in the body and travel to the brain, leading to reduced blood perfusion. Cerebral Ischemia/Reperfusion Injury (CIRI) is a common complication of CIS and arises when blood flow is rapidly restored to the brain tissue after a period of ischemia. The therapeutic approaches currently recognized for CIS, such as thrombolysis and thrombectomy, have notable side effects that limit their clinical application. Recently, there has been growing interest among researchers in exploring the potential of herbal agents for treating various disorders and malignancies. One such herbal agent with medicinal applications is tanshinone IIA, an active diterpene quinone extracted from Salvia miltiorrhiza Bunge. Tanshinone IIA has shown several pharmacological benefits, including anti-inflammatory, antioxidant, anti-apoptotic, and neuroprotective properties. Multiple studies have indicated the protective role of tanshinone IIA in CIS and CIRI. This literature review aims to summarize the current findings regarding the molecular mechanisms through which this herbal compound improves CIS and CIRI.

Cellular junction dynamics and Alzheimer's disease: a comprehensive review.

Alzheimer's disease (AD) is a prevalent neurodegenerative disorder characterized by progressive neuronal damage and cognitive decline. Recent studies have shed light on the involvement of not only the blood-brain barrier (BBB) dysfunction but also significant alterations in cellular junctions in AD pathogenesis. In this review article, we explore the role of the BBB and cellular junctions in AD pathology, with a specific focus on the hippocampus. The BBB acts as a crucial protective barrier between the bloodstream and the brain, maintaining brain homeostasis and regulating molecular transport. Preservation of BBB integrity relies on various junctions, including gap junctions formed by connexins, tight junctions composed of proteins such as claudins, occludin, and ZO-1, as well as adherence junctions involving molecules like vascular endothelial (VE) cadherin, Nectins, and Nectin-like molecules (Necls). Abnormalities in these junctions and junctional components contribute to impaired neuronal signaling and increased cerebrovascular permeability, which are closely associated with AD advancement. By elucidating the underlying molecular mechanisms governing BBB and cellular junction dysfunctions within the context of AD, this review offers valuable insights into the pathogenesis of AD and identifies potential therapeutic targets for intervention.

Cell-mediated barriers in cancer immunosurveillance.

The immune cells within the tumor microenvironment (TME) exert multifaceted functions ranging from tumor-antagonizing or tumor-promoting activities. During the initial phases of tumor development, the tumor-antagonizing immune cells in the TME combat cancer cells in an immune surveillance process. However, with time, cancer cells can evade detection and impede the immune cells' effectiveness through diverse mechanisms, such as decreasing immunogenic antigen presentation on their surfaces and/or secreting anti-immune factors that cause tolerance in TME. Moreover, some immune cells cause immunosuppressive situations and inhibit antitumoral immune responses. Physical and cellular-mediated barriers in the TME, such as cancer-associated fibroblasts, tumor endothelium, the altered lipid composition of tumor cells, and exosomes secreted from cancer cells, also mediate immunosuppression and prevent extravasation of immune cells. Due to successful clinical outcomes of cancer treatment strategies the potential barriers must be identified and addressed. We need to figure out how to optimize cancer immunotherapy strategies, and how to combine therapeutic approaches for maximum clinical benefit. This review provides a detailed overview of various cells and molecules in the TME, their association with escaping from immune surveillance, therapeutic targets, and future perspectives for improving cancer immunotherapy.

The beneficial effects of simultaneous supplementation of Lactobacillus reuteri and calcium fluoride nanoparticles on ovariectomy-induced osteoporosis.

BACKGROUND: The development of new strategies to inhibit and/or treat osteoporosis as a chronic systemic disease is one of the most crucial topics. The present study aimed to investigate the simultaneous effects of calcium fluoride nanoparticles (CaF2 NPs) and lactobacillus reuteri ATCC PTA 6475 (L. reuteri) against osteoporosis in an ovariectomized rat model (OVX). METHODS: In this study, 18 matured Wistar female rats were randomly assigned into 6 groups, including control, OVX, sham, OVX + L. reuteri, OVX + CaF2 NPs, and OVX + L. reuteri + CaF2 NPs. We used OVX rats to simulate post-menopausal osteoporosis, and the treatments were begun two weeks before OVX and continued for four weeks. All groups' blood samples were collected, and serum biomarkers (estrogen, calcium, vitamin D3, and alkaline phosphatase (ALP)) were measured. The tibia and Femur lengths of all groups were measured. Histopathological slides of tibia, kidney, and liver tissues were analyzed using the Hematoxylin and Eosin staining method. RESULTS: Our results revealed that dietary supplementation of L. reuteri and CaF2 NPs in low doses for 6 weeks did not show adverse effects in kidney and liver tissues. The tibial and femoral lengths of OVX rats as well as the population of osteoblasts and osteocytes and newly generated osteoid in the tibia remarkably increased in the combination therapy group. Moreover, there was a significant increase in serum estrogen levels and a significant decrease in serum calcium and alkaline phosphatase levels in combination treatment groups compared to the OVX groups not receiving the diet. CONCLUSIONS: Our results suggest the favorable effects of the simultaneous supplementation of L. reuteri and CaF2 NP to reduce post-menopausal bone loss.

Therapeutic Potential of Oral-Derived Mesenchymal Stem Cells in Retinal Repair.

The retina has restricted regeneration ability to recover injured cell layer because of reduced production of neurotrophic factors and increased inhibitory molecules against axon regrowth. A diseased retina could be regenerated by repopulating the damaged tissue with functional cell sources like mesenchymal stem cells (MSCs). The cells are able to release neurotrophic factors (NFs) to boost axonal regeneration and cell maintenance. In the current study, we comprehensively explore the potential of various types of stem cells (SCs) from oral cavity as promising therapeutic options in retinal regeneration. The oral MSCs derived from cranial neural crest cells (CNCCs) which explains their broad neural differentiation potential and secret rich NFs. They are comprised of dental pulp SCs (DPSCs), SCs from exfoliated deciduous teeth (SHED), SCs from apical papilla (SCAP), periodontal ligament-derived SCs (PDLSCs), gingival MSCs (GMSCs), and dental follicle SCs (DFSCs). The Oral MSCs are becoming a promising source of cells for cell-free or cell-based therapeutic approach to recover degenerated retinal. These cells have various mechanisms of action in retinal regeneration including cell replacement and the paracrine effect. It was demonstrated that they have more neuroprotective and neurotrophic effects on retinal cells than immediate replacement of injured cells in retina. This could be the reason that their therapeutic effects would be weakened over time. It can be concluded that neuronal and retinal regeneration through these cells is most likely due to their NFs that dramatically suppress oxidative stress, inflammation, and apoptosis. Although, oral MSCs are attractive therapeutic options for retinal injuries, more preclinical and clinical investigations are required.

Safety and Effectiveness of Cinnomer® on Disease Characteristics, Depression, and Quality of Life of Patients with Multiple Sclerosis: A Phase IV, Post-marketing, Prospective, Multicenter Study.

BACKGROUND: Every patient diagnosed with definite multiple sclerosis (MS) should begin disease modifying therapies. Cinnomer® contains 40 mg glatiramer acetate (GA) and is available in prefilled syringes and autoinjector devices. METHODS: A phase IV multicenter study was conducted to explore the safety and effectiveness of Cinnomer® in the treatment of MS. Study-related data were collected for 14 months. RESULTS: Totally, 368 Iranian relapsing-remitting MS patients in nine cities were enrolled. The patients were either treatment naïve (n=191) or switchers (n=177). Cinnomer® treatment was associated with a significant reduction in annual relapse rate (ARR) (RR: 0.65, 95% CI: 0.43, 0.98). Final mean Expanded Disability Status Scale (EDSS) scores showed improvement from baseline (difference: -0.21, 95% confidence interval (CI): -0.34, -0.08). There was a significant decrease in gad-enhancing lesions during treatment (difference: -0.38, 95% CI: -0.64, -0.12). The mean score for the depression measure (21-item BDI-II questionnaire) significantly improved (difference: -2.39, 95% CI: -3.74, -1.03). There was a significant change in the "psychological well-being" dimension (P=0.02) (in line with BDI-II scores) and "rejection" MusiQoL dimensions (P=0.04). The adverse events documented throughout the study were not unexpected for GA and were principally not serious. CONCLUSION: Safety measures were in line with the known profiles of GA. The results suggest that Cinnomer® is effective with respect to clinical outcomes and from the patient's perspective and in reducing MRI-measured MS activity.

Cuscuta epithymum Murr. crude extract pre-conditioning protects C6 cells from L-glutamate-induced neurotoxicity.

BACKGROUND: Cuscuta epithymum Murr. (C. epithymum), as an herbal medicine, has played an anti-cancerous role in various studies; however, its possible neuroprotective effects have been neglected. Here, we aimed to investigate the protective effects of C. epithymum seeds crude extract and different fractions on rat glioblastoma cells (C6) in L-glutamate oxidative condition. METHODS: Initially, the total phenolic content of C. epithymum crude extract and the fractions (all produced by maceration method) was determined. Subsequently, C6 cells were pre-treated with the various concentrations of crude extract and fractions 24 h before L-glutamate exposure. Likewise, C6 cells were treated with the same concentrations of crude extract and fractions 24 h after exposure to L-glutamate. The cell viability and morphology were compared in crude extract and fractions groups, then superoxide dismutase (SODs) activity, reactive oxygen species (ROS), and malondialdehyde (MDA) levels were measured. The flow cytometry test was used to study C. epithymum crude extract's effects on the cell cycle and also to quantify the apoptosis, necrosis, and live cells population in different groups. RESULTS: C. epithymum crude extract and fractions (hexanoic, dichloromethanolic, and methanolic) had concentration-dependent cytotoxicity (IC50:126.47, 2101.96, 140.97, and 218.96 µg/ml, respectively). The crude extract and methanolic fraction contained phenolic compounds (55.99 ± 2.795 and 50.80 ± 2.969 mg gallic acid/g extract), while in hexanoic and dichloromethanolic fractions, the phenolic content was undetectable. In the cell viability assay, in comparison to fractions, the crude extract showed a more protective effect against glutamate-induced oxidative condition (P < 0.0001). The crude extract increased the SODs activity (P < 0.001) and decreased MDA and ROS levels (P < 0.0001) in comparison to the glutamate group. The crude extract significantly increased the population of cells in G1 (from 63.04 to 76.29) and decreased the percentage of cells in G2 (from 11.56 to 6.7) and S phase (from 25.4 to 17.01). In addition, it decreased the apoptotic and necrotic cell populations (from 34 to 17.1) and also increased the percentage of live cells (from 66.8 to 83.4 percent) in the flow cytometry test. CONCLUSION: C. epithymum crude extract plays a neuroprotective role by activating the defense mechanisms in cell against the oxidative condition.

Periodontal ligament stem cells as a promising therapeutic target for neural damage.

BACKGROUND: The damaged neuronal cells of adult mammalian lack the regenerative ability to replace the neuronal connections. Periodontal ligament stem cells (PDLSCs) are the promising source for neuroregenerative applications that can improve the injured microenvironment of the damaged neural system. They provide neuronal progenitors and neurotrophic, anti-apoptotic and anti-inflammatory factors. In this study, we aimed to comprehensively explore the various neuronal differentiation potentials of PDLSCs for application in neural regeneration therapy. MAIN TEXT: PDLSCs have superior potential to differentiate into various neural-like cells through a dedifferentiation stage followed by differentiation process without need for cell division. Diverse combination of nutritional factors can be used to induce the PDLSCs toward neural lineage. PDLSCs when coupled with biomaterials could have significant implications for neural tissue repair. PDLSCs can be a new clinical research target for Alzheimer's disease treatment, multiple sclerosis and cerebral ischemia. Moreover, PDLSCs have beneficial effects on retinal ganglion cell regeneration and photoreceptor survival. PDLSCs can be a great source for the repair of injured peripheral nerve through the expression of several neural growth factors and differentiation into Schwann cells. CONCLUSION: In conclusion, these cells are an appealing source for utilizing in clinical treatment of the neuropathological disorders. Although significant in vitro and in vivo investigations were carried out in order for neural differentiation evaluation of these cells into diverse types of neurons, more preclinical and clinical studies are needed to elucidate their therapeutic potential for neural diseases.

Recent advances and challenges in graphene-based nanocomposite scaffolds for tissue engineering application.

Graphene-based nanocomposites have recently attracted increasing attention in tissue engineering because of their extraordinary features. These biocompatible substances, in the presence of an apt microenvironment, can stimulate and sustain the growth and differentiation of stem cells into different lineages. This review discusses the characteristics of graphene and its derivatives, such as their excellent electrical signal transduction, carrier mobility, outstanding mechanical strength with improving surface characteristics, self-lubrication, antiwear properties, enormous specific surface area, and ease of functional group modification. Moreover, safety issues in the application of graphene and its derivatives in terms of biocompatibility, toxicity, and interaction with immune cells are discussed. We also describe the applicability of graphene-based nanocomposites in tissue healing and organ regeneration, particularly in the bone, cartilage, teeth, neurons, heart, skeletal muscle, and skin. The impacts of special textural and structural characteristics of graphene-based nanomaterials on the regeneration of various tissues are highlighted. Finally, the present review gives some hints on future research for the transformation of these exciting materials in clinical studies.

In Vitro Human Cancer Models for Biomedical Applications.

Cancer is one of the leading causes of death worldwide, and its incidence is steadily increasing. Although years of research have been conducted on cancer treatment, clinical treatment options for cancers are still limited. Animal cancer models have been widely used for studies of cancer therapeutics, but these models have been associated with many concerns, including inaccuracy in the representation of human cancers, high cost and ethical issues. Therefore, in vitro human cancer models are being developed quickly to fulfill the increasing demand for more relevant models in order to get a better knowledge of human cancers and to find novel treatments. This review summarizes the development of in vitro human cancer models for biomedical applications. We first review the latest development in the field by detailing various types of in vitro human cancer models, including transwell-based models, tumor spheroids, microfluidic tumor-microvascular systems and scaffold-based models. The advantages and limitations of each model, as well as their biomedical applications, are summarized, including therapeutic development, assessment of tumor cell migration, metastasis and invasion and discovery of key cancer markers. Finally, the existing challenges and future perspectives are briefly discussed.

Mesenchymal Stem Cells in the Treatment of New Coronavirus Pandemic: A Novel Promising Therapeutic Approach.

After severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) outbreaks, coronavirus disease 2019 (COVID-19) is the third coronavirus epidemic that soon turned into a pandemic. This virus causes acute respiratory syndrome in infected people. The mortality rate of SARS-CoV-2 infection will probably rise unless efficient treatments or vaccines are developed. The global funding and medical communities have started performing more than five hundred clinical examinations on a broad spectrum of repurposed drugs to acquire effective treatments. Besides, other novel treatment approaches have also recently emerged, including cellular host-directed therapies. They counteract the unwanted responses of the host immune system that led to the severe pathogenesis of SARS-CoV-2. This brief review focuses on mesenchymal stem cell (MSC) principles in treating the COVID-19. The US clinical trials database and the world health organization database for clinical trials have reported 82 clinical trials (altogether) exploring the effects of MSCs in COVID-19 treatment. MSCs also had better be tried for treating other pathogens worldwide. MSC treatment may have the potential to end the high mortality rate of COVID-19. Besides, it also limits the long-term inability of survivors.

IGF-I combined with exercise improve diabetes-induced vascular dysfunction in heart of male Wistar rats.

Introduction: This research investigates the impact of insulin-like growth factor-I (IGF -I)and exercise on mediators associated with angiogenesis (VEGF-A, TSP-1, and NF-кß) and capillarization status of the diabetic rats' hearts. Methods: Splitting of forty Wistar male rats into five groups occurred as following: control,diabetes, diabetes+IGF-I, diabetes+exercise, and diabetes+exercise+IGF-I.Through intraperitoneal administration of 60 mg/kg streptozotocin, the condition of Type 1diabetes was escalated. After four weeks of treatment with IGF-I (2 mg/kg/day) or treadmill exercise (17 m/min, zero degrees slope, 30 min/day), in the heart, microvascular density and protein levels of VEGF-A, TSP-1, and NF-Ðºß were determined by H&E staining and ELISA,respectively. Results: Within the diabetic group, observations present a significant decrease in VEGF-A and MVD levels, whereas an increase in the TSP-1 and NF-Κb levels. While these impacts were reversed by either IGF-I or exercise treatments, simultaneous treatment had synergistic effects. Moreover, among diabetic rats, undesirable histologic alterations of the heart were demonstrated, including myonecrosis, interstitial edema, hemorrhage, and mononuclear immune cell infiltration, whereas treatments improved these changes. Conclusion: These data manifest that IGF-I and exercise can increase the cardiac angiogenesis of diabetic rats through increasing expression of VEGF-A, and decreasing TSP-1 and NF-кßproteins level, also can improve myocardial tissue damages.

Osteogenic Differentiation Potential of Adipose-Derived Mesenchymal Stem Cells Cultured on Magnesium Oxide/Polycaprolactone Nanofibrous Scaffolds for Improving Bone Tissue Reconstruction.

Purpose: Recently, bone tissue engineering as a new strategy is used to repair and replace bone defects due to limitations in allograft and autograft methods. In this regard, we prepared nanofibrous scaffolds composed of polycaprolactone (PCL) and magnesium oxide (MgO) nanoparticles using the electrospinning technique for possible bone tissue engineering applications. Methods: The fabricated composites were characterized via scanning electron microscopy (SEM) imaging of scaffolds and seeded cells, water contact angle, DAPI staining, and MTT assay. Then osteogenic differentiation of adipose-derived mesenchymal stem cells cultured on this composite scaffold was determined by standard osteogenic marker tests, including alkaline phosphatase (ALP) activity, calcium deposition, and expression of osteogenic differentiation genes in the laboratory conditions. Results: The SEM analysis demonstrated that the diameter of nanofibers significantly decreased from 1029.25±209.349 µm to 537.83+0.140 nm, with the increase of MgO concentration to 2% (P < 0.05). Initial adhesion and proliferation of the adipose-derived mesenchymal stem cells on MgO/PCL scaffolds were significantly enhanced with the increasing of MgO concentration (P < 0.05). The 2% MgO/PCL nanofibrous scaffold showed significant increase in ALP activity (P < 0.05) and osteogenic-related gene expressions (Col1a1 and OPN) (P < 0.05) in compared to pure PCL and (0, 0.5 and 1%) MgO/PCL scaffolds. Conclusion: According to the results, it was demonstrated that MgO/PCL composite nanofibers have considerable osteoinductive potential, and taking together adipose-derived mesenchymal stem cells-MgO/PCL composite nanofibers can be a proper bio-implant to usage for bone regenerative medicine applications. Future in vivo studies are needed to determine this composite therapeutic potential.

Anisotropic behavior of random lasing in a highly concentrated dye solution.

Angular dependence of the diffusive random laser (DRL) emission is assessed due to excitation of a highly concentrated solution of Rhodamine 6G (Rd6G) comprising monomers and dimers. Dimerization at extremely high concentrations leads to the random fluctuation of the dielectric constant in gain medium. As a result, aggregated dye molecules provide multiple scattering events for propagating photons which is confirmed by enhanced backscattering (EBS) test. This scattering feedback besides Försters resonance energy transfer (FRET) from monomers to dimers provide RL spikes over low quantum yield dimeric fluorescence spectra. The unique spectral feature of RL emission is strong dependence on the angle of detection that results from anisotropic inner filter effect (IFE) within the gain volume due to local excitation of the medium by a pencil-like beam of laser. The results have a merit of importance in optical characterization of the media in which the fluorophores can aggregate significantly.

Current advances and challenges in COVID-19 vaccine development: from conventional vaccines to next-generation vaccine platforms.

The world is grappling with an unprecedented public health crisis COVID-19 pandemic caused by the novel coronavirus SARS-CoV-2. Due to the high transmission/mortality rates and socioeconomic impacts of the COVID-19, its control is crucial. In the absence of specific treatment, vaccines represent the most efficient way to control and stop the pandemic. Many companies around the world are currently making efforts to develop the vaccine to combat COVID-19. This review outlines key strategies for generating SARS-CoV-2 vaccine candidates, along with the mechanism of action, advantages, and potential limitations of each vaccine. The use of nanomaterials and nanotechnology for COVID-19 vaccines development will also be discussed.

Evaluation of S100A12 and Apo-A1 plasma level potency in untreated new relapsing-remitting multiple sclerosis patients and their family members.

Multiple sclerosis is an inflammatory disease of the spinal cord and brain. Receptor for advanced glycation end products and Apolipoprotein A1 (Apo-AI) have been recommended to have a pathogenic role in the neuroinflammatory disorder as multiple sclerosis. The purpose of this research was to measure the plasma levels of S100A12 and Apo-A1 in the first-degree family of relapsing-remitting multiple sclerosis (RRMS) patients. Plasma levels of S100A12 & Apo-A1 were evaluated via enzyme-linked immunosorbent assay in the thirty-five new cases of untreated patients with deterministic RRMS according to the McDonald criteria, twenty-four healthy controls, and twenty-six first-degree members of untreated RRMS patients (called them as high-risk group). The main findings of this study were as follows: the plasma level of S100A12 was significantly lower in the new cases of untreated RRMS (P ≤ 0.05; 0.045) and high-risk (P ≤ 0.05; 0.001) groups. Although the plasma protein level of Apo-A1 was reduced significantly in the high-risk group (P < 0.05, P = 0.003) as compared to the healthy control group, there was no significant difference in the untreated RRMS patients (P = 0.379). The plasma level of vitamin D3 in both RRMS patients and high-risk groups displayed significance reduction, although, there was no significant association between vitamin D and S100A12 & Apo-A1 levels. Given the role of S100A12 and Apo-A1 in the inflammatory process performed in the first-degree family members of the RRMS patients, which revealed a significant decrease in this group, we concluded that they can be considered as one of the contributing factors in the pathogenesis of MS, though more research is needed before assuming them as predictive biomarkers.

Potential therapeutic options for COVID-19: an update on current evidence.

SARS-CoV-2, a novel coronavirus, is the agent responsible for the COVID-19 pandemic and is a major public health concern nowadays. The rapid and global spread of this coronavirus leads to an increase in hospitalizations and thousands of deaths in many countries. To date, great efforts have been made worldwide for the efficient management of this crisis, but there is still no effective and specific treatment for COVID-19. The primary therapies to treat the disease are antivirals, anti-inflammatories and respiratory therapy. In addition, antibody therapies currently have been a many active and essential part of SARS-CoV-2 infection treatment. Ongoing trials are proposed different therapeutic options including various drugs, convalescent plasma therapy, monoclonal antibodies, immunoglobulin therapy, and cell therapy. The present study summarized current evidence of these therapeutic approaches to assess their efficacy and safety for COVID-19 treatment. We tried to provide comprehensive information about the available potential therapeutic approaches against COVID-19 to support researchers and physicians in any current and future progress in treating COVID-19 patients.

Molecular pathways involved in COVID-19 and potential pathway-based therapeutic targets.

Deciphering the molecular downstream consequences of severe acute respiratory syndrome coronavirus (SARS-CoV)- 2 infection is important for a greater understanding of the disease and treatment planning. Furthermore, greater understanding of the underlying mechanisms of diagnostic and therapeutic strategies can help in the development of vaccines and drugs against COVID-19. At present, the molecular mechanisms of SARS-CoV-2 in the host cells are not sufficiently comprehended. Some of the mechanisms are proposed considering the existing similarities between SARS-CoV-2 and the other members of the ß-CoVs, and others are explained based on studies advanced in the structure and function of SARS-CoV-2. In this review, we endeavored to map the possible mechanisms of the host response following SARS-CoV-2 infection and surveyed current research conducted by in vitro, in vivo and human observations, as well as existing suggestions. We addressed the specific signaling events that can cause cytokine storm and demonstrated three forms of cell death signaling following virus infection, including apoptosis, pyroptosis, and necroptosis. Given the elicited signaling pathways, we introduced possible pathway-based therapeutic targets; ADAM17 was especially highlighted as one of the most important elements of several signaling pathways involved in the immunopathogenesis of COVID-19. We also provided the possible drug candidates against these targets. Moreover, the cytokine-cytokine receptor interaction pathway was found as one of the important cross-talk pathways through a pathway-pathway interaction analysis for SARS-CoV-2 infection.

Brain Homogenate of a Rat Model of Alzheimer's Disease Modifies the Secretome of 3D Cultured Periodontal Ligament Stem Cells: A Potential Neuroregenerative Therapy.

Background: Alzheimer's disease (AD) is a progressive neurodegenerative disease leading to neuronal cell death and manifested by cognitive disorders and behavioral impairment. Mesenchymal stem cells (MSCs) are one of the most promising candidates to stimulate neuroregeneration and prevent disease progression. Optimization of MSC culturing protocols is a key strategy to increase the therapeutic potential of the secretome. Objectives: Here, we investigated the effect of brain homogenate of a rat model of AD (BH-AD) on the enhancement of protein secretion in the secretome of periodontal ligament stem cells (PDLSCs) when cultured in a 3D environment. Moreover, the effect of this modified secretome was examined on neural cells to study the impact of the conditioned medium (CM) on stimulation of regeneration or immunomodulation in AD. Methods: PDLSCs were isolated and characterized. Then, the spheroids of PDLSCs were generated in a modified 3D culture plate. PDLSCs-derived CM was prepared in the presence of BH-AD (PDLSCs-HCM) and the absence of it (PDLSCs-CM). The viability of C6 glioma cells was assessed after exposure to different concentrations of both CMs. Then, a proteomic analysis was performed on the CMs. Results: Differentiation into adipocytes and high expression of MSCs markers verified the precise isolation of PDLSCs. The PDLSC spheroids were formed after 7 days of 3D culturing, and their viability was confirmed. The effect of CMs on C6 glioma cell viability showed that both CMs at low concentrations (> 20 mg/mL) had no cytotoxic effect on C6 neural cells. The results showed that PDLSCs-HCM contains higher concentrations of proteins compared to PDLSCs-CM, including Src-homology 2 domain (SH2)-containing PTPs (SHP-1) and muscle glycogen phosphorylase (PYGM) proteins. SHP-1 has a role in nerve regeneration, and PYGM is involved in glycogen metabolism. Conclusions: The modified secretome derived from 3D cultured spheroids of PDLSCs treated by BH-AD as a reservoir of regenerating neural factors can serve as a potential source for AD treatment.

EGF Receptor Transactivation by Endothelin-1 Increased CHSY-1 Mediated by NADPH Oxidase and Phosphorylation of ERK1/2.

OBJECTIVE: Growth factors [transforming growth factor-ß (TGF-ß), epidermal growth factor (EGF), endothelin-1 (ET1)] stimulate proteoglycan synthesis resulting in retention and accumulation of low density lipoprotein (LDL) in vessel intima and leading to atherosclerosis development. This study investigated the role of ET-1 on the expression of CHSY1, proteoglycan synthesizing enzyme, through both EGF and TGF-ß receptor transactivation in human vascular smooth muscle cells (VSMCs). Also, we explored the involvement of NADPH oxidase (NOX), an important intermediate of redox signaling, in ET-1 transactivated EGF receptor (EGFR) through endothelin receptors. MATERIALS AND METHODS: In this experimental study, phosphorylated ERK1/2 and CHSY1 protein levels in the human VSMCs were measured by Western blot analysis using anti phospho-ERK1/2 (Thr202/Tyr204) and anti CHSY1 antibodies. RESULTS: ET-1 (100 nM) and EGF (100 ng/ml) stimulated ERK1/2 phosphorylation and inhibited in the presence of bosentan (ET receptor inhibitor), AG1478 (EGFR inhibitor), and DPI (NOX antagonist). Also, ET-1 treatment increased CHSY1 enzyme level; this response was suppressed by bosentan, AG1478, DPI, and SB431542, TGF-ß receptor antagonist. This study revealed that ET-1 increases expression of CHSY1 through transactivation of EGF and TGF-ß receptors. CONCLUSION: Transactivation through the EGF receptor mediated by phospho-ERK1/2 leads to expression of CHSY1 protein. EGF receptor transactivation by ET-1 is shown for the first time, to be dependent on NOX enzymes.