Hypoxic-conditioned medium from adipose tissue mesenchymal stem cells improved neuroinflammation through alternation of toll like receptor (TLR) 2 and TLR4 expression in model of Alzheimer's disease rats

Exploring the impact of acetylsalicylic acid and conditioned medium obtained from mesenchymal cells, individually and in combination, on cognitive function, histological changes, and oxidant-antioxidant balance in male rats with hippocampal injury

BACKGROUND

The hippocampus is susceptible to damage, leading to negative impacts on cognition. Conditioned medium (CM) obtained from adipose tissue-derived mesenchymal stem cells (MSCs) and acetylsalicylic acid (ASA) have shown neuroprotective effects independently. This study explored the synergistic potential of ASA and CM from adipose-derived MSCs against hippocampal injury.

METHODS

Adult male Wistar rats received bilateral hippocampal ethidium bromide (EB) injections to induce hippocampal damage. Rats were treated with ASA and/or CM derived from adipose tissue MSCs every 48 h for 16 days. Behavioral tests (open field test, Morris water maze, novel object recognition, and passive avoidance), oxidative stress, Western blot analysis of brain-derived neurotrophic factor (BDNF) and cerebral dopamine neurotrophic factor (CDNF) expression, and hippocampal histological investigation were conducted.

RESULTS

Administration of EB caused impairments in spatial, recognition, and passive avoidance memory, as well as heightened oxidative stress, reduced BDNF/CDNF expression, and pyramidal cell loss in the hippocampal CA1 region. Administration of ASA, CM, or a combination of both mitigated these hippocampal damages and cognitive deficits, elevated BDNF and CDNF levels, and alleviated the CA1 necrosis caused by EB. Moreover, co-administering ASA and CM resulted in greater improvements in spatial memory compared to administering ASA alone, suggesting possible synergistic interactions.

CONCLUSIONS

The ability of ASA, CM obtained from adipose tissue-derived MSCs, and their combination therapy to alleviate hippocampal injuries highlights their promising therapeutic potential as a neuroprotection strategy against brain damage. Our findings provide preliminary evidence of the potential synergistic effects of ASA and CM, which warrants further investigations.

Restoring Synaptic Function: How Intranasal Delivery of 3D-Cultured hUSSC Exosomes Improve Learning and Memory Deficits in Alzheimer's Disease

Memory problems are often the first signs of cognitive impairment related to Alzheimer's disease (AD), and stem cells and stem cell-derived exosomes (EXOs) have been studied for their therapeutic potential to improve the disease signs. While many studies have shown the anti-inflammatory and immunomodulatory effects of stem cells and exosomes on improving memory in different AD models, there is still insufficient data to determine how they modulate neural plasticity to enhance spatial memory and learning ability. Therefore, we conducted a study to investigate the effects of exosomes derived from 3D-cultured human Unrestricted Somatic Stem Cells (hUSSCs) on spatial memory and neuroplasticity markers in a sporadic rat model of AD. Using male Wistar rats induced by intracerebral ventricle injection of streptozotocin, we demonstrated that intranasal administration of hUSSC-derived exosomes could decrease Aβ accumulation and improve learning and memory in the Morris water maze test. We also observed an increase in the expression of pre-synaptic and post-synaptic molecules involved in neuronal plasticity, including NMDAR1, integrin β1, synaptophysin, pPKCα, and GAP-43, in the hippocampus. Our findings suggest that intranasal administration of exosomes can ameliorate spatial learning and memory deficits in rats, at least in part, by increasing the expression of neuroplasticity proteins. These results may encourage researchers to further investigate the molecular pathways involved in memory improvement after stem cell and exosome therapy, with the goal of increasing the efficacy and safety of exosome-based treatments for AD.

Comparison of the efficacy of human umbilical cord mesenchymal stem cells conditioned medium and platelet-rich plasma on the hippocampus of STZ-induced rat model of Alzheimer's disease: A behavioral and stereological study

Introduction

Alzheimer's disease (AD) is accompanied by progressive cognitive disorders and memory loss. This study aims to determine the combined effects of conditioned medium of human umbilical cord mesenchymal stem cells (CM) and platelet-rich plasma (PRP) on AD model rats.

Methods

Forty-eight male Sprague Dawley rats were classified into 6 groups: Control, Sham, AD, and three treatment groups. AD was induced by streptozotocin(STZ; 3 mg/kg, intracerebroventricular (ICV)) and the treatment groups received injections of CM [(200 µl, intraperitoneally (i.p.), and/or PRP (100 µl, intravenously(i.v)] for 8 days. Behavioral tests (Morris water maze and novel objective recognition) were used to assess learning ability and memory. At the end of the behavioral tests, the rats were sacrificed and their brain was entirely removed, sectioned, and stained with cresyl violet. The hippocampus volume and number of neurons were evaluated by stereological techniques.

Results

In the AD group, the discrimination ratio, time spent in the target zone, volume of Cornu Ammonis1 (CA1) and Dentate Gyrus (DG), and the number of pyramidal and granular cells decreased significantly compared to the Sham group. The mentioned parameters increased in the CM and CM+PRP groups compared to the AD group (p < 0.01). PRP did not have any noticeable effect on the examined parameters.

Conclusions

CM may be beneficial in the treatment of AD as it led to better improvement in STZ-induced learning and memory impairments as well as the structure of the hippocampus.

Stem cell-conditioned medium is a promising treatment for Alzheimer's disease

BACKGROUND AND AIM

Alzheimer's disease (AD), a prevalent progressive neurodegenerative disease, is mainly characterized by dementia, memory loss, and cognitive disorder. Rising research was performed to develop pharmacological or non-pharmacological approaches to treat or improve AD complications. Mesenchymal stem cells (MSCs) are stromal cells that can self-renew and exhibit multilineage differentiation. Recent evidence suggested that some of the therapeutic effects of MSCs are mediated by the secreted paracrine factors. These paracrine factors, called MSC- conditioned medium (MSC-CM), may stimulate endogenous repair, promote angio- and artery genesis, and reduce apoptosis through paracrine mechanisms. The current study aims to systematically review the advantages of MSC-CM to the development of research and therapeutic concepts for AD management.

MATERIAL AND METHODS

The present systematic review was performed using PubMed, Web of Science, and Scopus from April 2020 to May 2022 following the "Preferred Reporting Items for Systematic Reviews" (PRISMA) guidelines. The keywords, including "Conditioned medium OR Conditioned media OR Stem cell therapy" AND "Alzheimer's," was searched, and finally, 13 papers were extracted.

RESULTS

The obtained data revealed that MSC-CMs might positively affect neurodegenerative diseases prognosis, especially AD, through various mechanisms, including a decrease in neuro-inflammation, reduction of oxidative stress and Aβ formation, modulation of Microglia function and count, reduction of apoptosis, induction of synaptogenesis and neurogenesis. Also, the results showed that MSC-CM administration could significantly improve cognitive and memory function, increase the expression of neurotrophic factors, decrease the production of pro-inflammatory cytokines, improve mitochondrial function, reduce cytotoxicity, and increase neurotransmitter levels.

CONCLUSION

While inhibiting the induction of neuroinflammation could be considered the first therapeutic effect of CMs, the prevention of apoptosis could be regarded as the most crucial effect of CMs on AD improvement.

The Immunomodulatory Role of Cell-Free Approaches in SARS-CoV-2-Induced Cytokine Storm-A Powerful Therapeutic Tool for COVID-19 Patients

Currently, there is still no effective and definitive cure for the coronavirus disease 2019 (COVID-19) caused by the infection of the novel highly contagious severe acute respiratory syndrome virus (SARS-CoV-2), whose sudden outbreak was recorded for the first time in China in late December 2019. Soon after, COVID-19 affected not only the vast majority of China's population but the whole world and caused a global health public crisis as a new pandemic. It is well known that viral infection can cause acute respiratory distress syndrome (ARDS) and, in severe cases, can even be lethal. Behind the inflammatory process lies the so-called cytokine storm (CS), which activates various inflammatory cytokines that damage numerous organ tissues. Since the first outbreak of SARS-CoV-2, various research groups have been intensively trying to investigate the best treatment options; however, only limited outcomes have been achieved. One of the most promising strategies represents using either stem cells, such as mesenchymal stem cells (MSCs)/induced pluripotent stem cells (iPSCs), or, more recently, using cell-free approaches involving conditioned media (CMs) and their content, such as extracellular vesicles (EVs) (e.g., exosomes or miRNAs) derived from stem cells. As key mediators of intracellular communication, exosomes carry a cocktail of different molecules with anti-inflammatory effects and immunomodulatory capacity. Our comprehensive review outlines the complex inflammatory process responsible for the CS, summarizes the present results of cell-free-based pre-clinical and clinical studies for COVID-19 treatment, and discusses their future perspectives for therapeutic applications.

Mesenchymal stromal cell-derived secretome-based therapy for neurodegenerative diseases: overview of clinical trials

BACKGROUND

Over the past few years, mesenchymal stromal cells (MSCs) have attracted a great deal of scientific attention owing to their promising results in the treatment of incurable diseases. However, there are several concerns about their possible side effects after direct cell transplantation, including host immune response, time-consuming cell culture procedures, and the dependence of cell quality on the donor, which limit the application of MSCs in clinical trials. On the other hand, it is well accepted that the beneficial effects of MSCs are mediated by secretome rather than cell replacement. MSC secretome refers to a variety of bioactive molecules involved in different biological processes, specifically neuro-regeneration.

MAIN BODY

Due to the limited ability of the central nervous system to compensate for neuronal loss and relieve disease progress, mesenchymal stem cell products may be used as a potential cure for central nervous system disorders. In the present study, the therapeutic effects of MSC secretome were reviewed and discussed the possible mechanisms in the three most prevalent central nervous system disorders, namely Alzheimer's disease, multiple sclerosis, and Parkinson's disease. The current work aimed to help discover new medicine for the mentioned complications.

CONCLUSION

The use of MSC-derived secretomes in the treatment of the mentioned diseases has encouraging results, so it can be considered as a treatment option for which no treatment has been introduced so far.

Exosomal microRNA-342-5p secreted from adipose-derived mesenchymal stem cells mitigates acute kidney injury in sepsis mice by inhibiting TLR9

BACKGROUND

Sepsis-related acute kidney injury (AKI) is an inflammatory disease associated with extremely high mortality and health burden. This study explored the possibility of exosomes secreted by adipose-derived mesenchymal stem cells (AMSCs) serving as a carrier for microRNA (miR)-342-5p to alleviate sepsis-related AKI and investigated the possible mechanism.

METHODS

Serum was obtained from 30 patients with sepsis-associated AKI and 30 healthy volunteers for the measurement of miR-342-5p, blood urea nitrogen (BUN), and serum creatinine (SCr) levels. For in vitro experiments, AMSCs were transfected with LV-miR-342-5p or LV-miR-67 to acquire miR-342-5p-modified AMSCs and miR-67-modified AMSCs, from which the exosomes (AMSC-Exo-342 and AMSC-Exo-67) were isolated. The human renal proximal tubular epithelial cell line HK-2 was induced by lipopolysaccharide (LPS) to construct a cellular model of sepsis. The expression of Toll-like receptor 9 (TLR9) was also detected in AKI cells and mouse models. The interaction between miR-342-5p and TLR9 was predicted by dual luciferase reporter gene assay.

RESULTS

Detection on clinical serum samples showed that BUN, SCr, and TLR9 were elevated and miR-342-5p level was suppressed in the serum of patients with sepsis-associated AKI. Transfection with LV-miR-342-5p reinforced miR-342-5p expression in AMSCs and AMSC-secreted exosomes. miR-342-5p negatively targeted TLR9. LPS treatment enhanced TLR9 expression, reduced miR-342-5p levels, suppressed autophagy, and increased inflammation in HK-2 cells, while the opposite trends were observed in LPS-induced HK-2 cells exposed to AMSC-Exo-342, Rapa, miR-342-5p mimic, or si-TLR9. Additionally, the effects of AMSC-Exo-342 on autophagy and inflammation in LPS-induced cells could be weakened by 3-MA or pcDNA3.1-TLR9 treatment. Injection of AMSC-Exo-342 enhanced autophagy, mitigated kidney injury, suppressed inflammation, and reduced BUN and SCr levels in sepsis-related AKI mouse models.

CONCLUSION

miR-342-5p transferred by exosomes from miR-342-5p-modified AMSCs ameliorated AKI by inhibiting TLR9 to accelerate autophagy.

Early activation of Toll-like receptor-3 reduces the pathological progression of Alzheimer's disease in APP/PS1 mouse

BACKGROUND

Toll-like receptor 3 (TLR3) plays an important role in the immune/inflammatory response in the nervous system and is a main pathological feature of Alzheimer's disease (AD). This study investigates the role of early activation of TLR3 in the pathophysiological process of AD.

METHODS

In the experiment, the agonist of TLR3, Poly(I:C), was intraperitoneally injected into the APP/PS1 mouse model of AD and wild-type control mice starting from the age of 4 to 9 months. At the age of 14 months, behavioral tests were conducted. Western blot and immunohistochemistry staining were used to evaluate the level of amyloid β-protein (Aβ), the activation of inflammatory cells, and neuron loss. In addition, the levels of inflammatory cytokines were measured using a quantitative polymerase chain reaction.

RESULTS

The results demonstrated that the early activation of TLR3 attenuated neuronal loss and neurobehavioral dysfunction. Moreover, the early activation of TLR3 reduced Aβ deposition, inhibited the activation of microglia and astrocytes, and decreased the transcription of pro-inflammatory factors in the hippocampus.

CONCLUSIONS

The results indicated that the activation of TLR3 by Poly (I:C) in the early stage of development of AD in a mouse model attenuated neuron loss and improved neurobehavioral functions. The underlying mechanisms could be attributed to its role in Aβ clearance, the inhibition of glial cells, and the regulation of neuroinflammation in the hippocampus.

Stem Cell Therapy for Alzheimer's Disease: A Scoping Review for 2017-2022

Alzheimer's disease (AD) has been a major causal factor for mortality among elders around the world. The treatments for AD, however, are still in the stage of development. Stem cell therapy, compared to drug therapies and many other therapeutic options, has many advantages and is very promising in the future. There are four major types of stem cells used in AD therapy: neural stem cells, mesenchymal stem cells, embryonic stem cells, and induced pluripotent stem cells. All of them have applications in the treatments, either at the (1) cellular level, in an (2) animal model, or at the (3) clinical level. In general, many more types of stem cells were studied on the cellular level and animal model, than the clinical level. We suggest for future studies to increase research on various types of stem cells and include cross-disciplinary research with other diseases. In the future, there could also be improvements in the timeliness of research and individualization for stem cell therapies for AD.

Systems Medicine as a Strategy to Deal with Alzheimer's Disease

The traits of Alzheimer's disease (AD) include amyloid plaques made of Aβ1-40 and Aβ1-42, and neurofibrillary tangles by the hyperphosphorylation of tau protein. AD is a complex disorder that is heterogenous in genetical, neuropathological, and clinical contexts. Current available therapeutics are unable to cure AD. Systems medicine is a strategy by viewing the body as a whole system, taking into account each individual's unique health profile, provide treatment and associated nursing care clinically for the patient, aiming for precision. Since the onset of AD can lead towards cognitive impairment, it is vital to intervene and diagnose early and prevent further progressive loss of neurons. Moreover, as the individual's brain functions are impaired due to neurodegeneration in AD, it is essential to reconstruct the neurons or brain cells to enable normal brain functions. Although there are different subtypes of AD due to varied pathological lesions, in the majority cases of AD, neurodegeneration and severe brain atrophy develop at the chronic stage. Novel approaches including RNA based gene therapy, stem cell based technology, bioprinting technology, synthetic biology for brain tissue reconstruction are researched in recent decades in the hope to decrease neuroinflammation and restore normal brain function in individuals of AD. Systems medicine include the prevention of disease, diagnosis and treatment by viewing the individual's body as a whole system, along with systems medicine based nursing as a strategy against AD that should be researched further.

Mesenchymal stromal cells for the treatment of Alzheimer’s disease: Strategies and limitations

Alzheimer’s disease (AD) is a major cause of age-related dementia and is characterized by progressive brain damage that gradually destroys memory and the ability to learn, which ultimately leads to the decline of a patient’s ability to perform daily activities. Although some of the pharmacological treatments of AD are available for symptomatic relief, they are not able to limit the progression of AD and have several side effects. Mesenchymal stem/stromal cells (MSCs) could be a potential therapeutic option for treating AD due to their immunomodulatory, anti-inflammatory, regenerative, antioxidant, anti-apoptotic, and neuroprotective effects. MSCs not only secret neuroprotective and anti-inflammatory factors to promote the survival of neurons, but they also transfer functional mitochondria and miRNAs to boost their bioenergetic profile as well as improve microglial clearance of accumulated protein aggregates. This review focuses on different clinical and preclinical studies using MSC as a therapy for treating AD, their outcomes, limitations and the strategies to potentiate their clinical translation.

Bidirectional communication between brain and visceral white adipose tissue: Its potential impact on Alzheimer's disease

A variety of axes between brain and abdominal organs have been reported, but the interaction between brain and visceral white adipose tissue (vWAT) remains unclear. In this review, we summarized human studies on the association between brain and vWAT, and generalized their interaction and the underlying mechanisms according to animal and cell experiments. On that basis, we come up with the concept of the brain-vWAT axis (BVA). Furthermore, we analyzed the potential mechanisms of involvement of BVA in the pathogenesis of Alzheimer's disease (AD), including vWAT-derived fatty acids, immunological properties of vWAT, vWAT-derived retinoic acid and vWAT-regulated insulin resistance. The proposal of BVA may expand our understanding to some extent of how the vWAT impacts on brain health and diseases, and provide a novel approach to study the pathogenesis and treatment strategies of neurodegenerative disorders.

Adipose tissue-derived stem cells as a potential candidate in treatment of Alzheimer's disease: A systematic review on preclinical studies

In recent years, numerous investigations have evaluated the efficacy of adipose tissue-derived stem cells (ADSCs) and their exosome transplantation in managing Alzheimer's disease (AD) in different animal models. However, there are still many contradictions among the studies that hinder reaching a reliable conclusion. Therefore, we aimed to systematically review the existing evidence regarding the efficacy of ADSCs administration in treatment of AD. The systematic search was conducted in the databases of Medline (via PubMed), Embase, Scopus, and Web of Science, in addition to the manual search in Google and Google scholar, to find articles published until March 13, 2021. Preclinical studies were included and two independent reviewers summarized the eligible papers. Ten articles were included in our review. The treatment strategies varied between isolated ADSC, ADSCs exosomes, ADSCs conditioned medium, and combination therapy (ADSCs plus conditioned medium in one study, and ADSCs plus melatonin in another study). Overview of the included articles showed promising results of ADSCs and its conditioned medium/exosome administration in animal models of AD. These studies showed significant learning and memory improvements through ADSCs and their conditioned medium/exosome administration in animal models of AD. In addition, the application of ADSCs reduced the amyloid-beta plaque deposits in the hippocampus and neocortex of these animals. Based on the aforementioned evidence, studies have suggested potential beneficial effects of ADSCs in the treatment of AD, particularly through decreasing the size of Aβ plaques and improvement of cognitive deficits. Further investigations regarding the subject are encouraged to achieve more accurate conclusions.

Switching Roles: Beneficial Effects of Adipose Tissue-Derived Mesenchymal Stem Cells on Microglia and Their Implication in Neurodegenerative Diseases

Neurological disorders, including neurodegenerative diseases, are often characterized by neuroinflammation, which is largely driven by microglia, the resident immune cells of the central nervous system (CNS). Under these conditions, microglia are able to secrete neurotoxic substances, provoking neuronal cell death. However, microglia in the healthy brain carry out CNS-supporting functions. This is due to the ability of microglia to acquire different phenotypes that can play a neuroprotective role under physiological conditions or a pro-inflammatory, damaging one during disease. Therefore, therapeutic strategies focus on the downregulation of these neuroinflammatory processes and try to re-activate the neuroprotective features of microglia. Mesenchymal stem cells (MSC) of different origins have been shown to exert such effects, due to their immunomodulatory properties. In recent years, MSC derived from adipose tissue have been made the center of attention because of their easy availability and extraction methods. These cells induce a neuroprotective phenotype in microglia and downregulate neuroinflammation, resulting in an improvement of clinical symptoms in a variety of animal models for neurological pathologies, e.g., Alzheimer’s disease, traumatic brain injury and ischemic stroke. In this review, we will discuss the application of adipose tissue-derived MSC and their conditioned medium, including extracellular vesicles, in neurological disorders, their beneficial effect on microglia and the signaling pathways involved.

Naproxen as a potential candidate for promoting rivastigmine anti-Alzheimer activity against aluminum chloride-prompted Alzheimer's-like disease in rats; neurogenesis and apoptosis modulation as a possible underlying mechanism

BACKGROUND AND AIM

Alzheimer's disease (AD) is one of the leading causes of dependence and disability among the elderly worldwide. The traditional anti-Alzheimer medication, rivastigmine, one of the cholinesterase inhibitors (ChEIs), fails to achieve a definitive cure. We tested the hypothesis that naproxen administration to the rivastigmine-treated aluminum chloride (AlCl3) Alzheimer's rat model could provide an additive neuroprotective effect compared to rivastigmine alone.

MATERIALS AND METHODS

The studied groups were control (Cont), AlCl3 treated (Al), rivastigmine treated (RIVA), naproxen treated (Napro), and combined rivastigmine and naproxen treated (RIVA + Napro). Rats' memory, spatial learning, and cognitive behavior were assessed followed by evaluation of hippocampal acetylcholinesterase (AChE) activity. Hippocampal and cerebellar histopathology were thoroughly examined. Activated caspase-3 and the neuroepithelial stem cells marker; nestin expressions were immunohistochemically assayed.

RESULTS

AD rats displayed significantly impaired memory and cognitive function, augmented hippocampal AChE activity; massive neurodegeneration associated with enhanced astrogliosis, apoptosis, and impaired neurogenesis. Except for the enhancement of neurogenesis and suppression of apoptosis, the combination therapy had no additional neuroprotective benefit over rivastigmine-only therapy.

CONCLUSION

Naproxen's efficacy was established by its ability to function at the cellular level, improved neurogenesis, and decreased, apoptosis without having an additional mitigating impact on cognitive impairment in rivastigmine-treated AD rats.

Engrafted stem cell therapy for Alzheimer's disease: A promising treatment strategy with clinical outcome

To date, although the microscopic alterations present in Alzheimer's disease (AD) have been well known for over a century only a handful of symptomatic treatments have been developed which are a far cry from a full cure providing volatile benefits. In this context, the intervention of stem cell therapy (SCT) has been proposed as an auxiliary treatment for AD as suggested by the rising number of pre-clinical studies that stem cell engraftment could provide an exciting future treatment regimen against neurodegeneration. Although, most of the primary enthusiasm about this approach was based on replacing deteriorating neurons, the latest studies have implied that the positive modulations fostered by stem cells are fuelled by bystander effects. Present review provides a detailed update on stem cell therapy for AD along with meticulous discussion regarding challenges in developing different stem cells from an aspect of experiment to clinical research and their potential in the milieu of AD hallmarks. Specifically, we focus and provide in depth view on recent advancements in the discipline of SCT aiming to repopulate or regenerate the degenerating neuronal circuitry in AD using stem-cell-on-a-chip and 3D bioprinting techniques. The focus is specifically on the successful restoration of cognitive functions upon engraftment of stem cells on in vivo models for the benefit of the current researchers and their understanding about the status of SCT in AD and finally summarizing on what future holds for SCT in the treatment of AD.

Mesenchymal stem cells as a potential therapeutic tool to cure cognitive impairment caused by neuroinflammation

An established contribution of neuroinflammation to multiple brain pathologies has raised the requirement for therapeutic strategies to overcome it in order to prevent age- and disease-dependent cognitive decline. Mesenchymal stem cells (MSCs) produce multiple growth and neurotrophic factors and seem to evade immune rejection due to low expression of major histocompatibility complex class I molecules. Therefore, MSCs are widely used in experiments and clinical trials of regenerative medicine. This review summarizes recent data concerning the optimization of MSC use for therapeutic purposes with the emphasis on the achievements of the last 2 years. Specific attention is paid to extracellular vesicles secreted by MSCs and to the role of α7 nicotinic acetylcholine receptors. The reviewed data demonstrate that MSCs have a significant therapeutic potential in treating neuroinflammation-related cognitive disfunctions including age-related neurodegenerative diseases. The novel data demonstrate that maximal therapeutic effect is being achieved when MSCs penetrate the brain and produce their stimulating factors in situ. Consequently, therapeutic application using MSCs should include measures to facilitate their homing to the brain, support the survival in the brain microenvironment, and stimulate the production of neurotrophic and anti-inflammatory factors. These measures include but are not limited to genetic modification of MSCs and pre-conditioning before transplantation.

Alzheimer's disease neuropathology is exacerbated following traumatic brain injury. Neuroprotection by co-administration of nanowired mesenchymal stem cells and cerebrolysin with monoclonal antibodies to amyloid beta peptide

Military personnel are prone to traumatic brain injury (TBI) that is one of the risk factors in developing Alzheimer's disease (AD) at a later stage. TBI induces breakdown of the blood-brain barrier (BBB) to serum proteins into the brain and leads to extravasation of plasma amyloid beta peptide (ΑβP) into the brain fluid compartments causing AD brain pathology. Thus, there is a need to expand our knowledge on the role of TBI in AD. In addition, exploration of the novel roles of nanomedicine in AD and TBI for neuroprotection is the need of the hour. Since stem cells and neurotrophic factors play important roles in TBI and in AD, it is likely that nanodelivery of these agents exert superior neuroprotection in TBI induced exacerbation of AD brain pathology. In this review, these aspects are examined in details based on our own investigations in the light of current scientific literature in the field. Our observations show that TBI exacerbates AD brain pathology and TiO₂ nanowired delivery of mesenchymal stem cells together with cerebrolysin-a balanced composition of several neurotrophic factors and active peptide fragments, and monoclonal antibodies to amyloid beta protein thwarted the development of neuropathology following TBI in AD, not reported earlier.

Allogenic mesenchymal stem cell-conditioned medium does not affect sperm parameters and mitigates early endometrial inflammatory responses in mares

This study aimed to evaluate the effects of mesenchymal stem cell-conditioned medium (MSC-CM) on sperm parameters, intrauterine polymorphonuclear neutrophils (PMN), intrauterine fluid accumulation (IUF), and fertility in mares. In experiment 1, two ejaculates from ten stallions were extended to 50 million sperm/mL using a milk-based extender. Thereafter, 20 mL of extended semen was added of MSC-CM as follows: 0, 5, 10, 15, and 20 mL. Sperm kinetics and plasma membrane integrity were evaluated immediately after dilution (T0) and 2 h post-incubation at 37 °C (T2). In experiment 2, mares characterized as resistant (n = 13) or susceptible (n = 7) to endometritis were inseminated with fresh semen 24 h post-induction of ovulation in two (Control and CM-1) and three (Control, CM-1, and CM-2) cycles in a crossover, as follows: control, no pharmacological interference; CM-1, supplementation of semen insemination dose at 3:4 (v:v, MSC-CM:semen); CM-2, 30 mL of MSC-CM was infused into the uterus 24 h before insemination. Endometrial cytology and uterine fluid were collected 6 and 24 h after insemination to evaluate the number of PMNs and concentrations of interleukins IL6, IL10, and TNFα. IUF was determined by ultrasonography 24 and 48 h after insemination. Pregnancy status was diagnosed 14 days after ovulation. The addition of MSC-CM to semen did not influence sperm parameters at T0 and T2 (P > 0.05) and reduced (CM-1; P < 0.05) the number of PMNs at 6 h post-insemination in resistant mares. In susceptible mares, PMNs at 6 and 24 h post-insemination, as well as IUF were reduced (P < 0.05) in both treated cycles (CM-1 and CM-2). In addition, MSC-CM downregulated IL6 and upregulated IL10 concentrations in the uterus of susceptible mares after insemination. There were no differences in fertility rates among groups both in resistant (Control, 77%, 10/13; CM-1, 62%, 8/13) and susceptible mares (Control, 42.8%, 3/7; CM-1, 57.1%, 4/7; CM-2, 85.7%. 6/7). In conclusion, MSC-CM did not affect sperm parameters when mixed with diluted semen, and reduced post-insemination inflammatory responses in mares.

Role of Militarine in PM2.5-Induced BV-2 Cell Damage

A growing number of studies have shown that air fine particulate matter (PM_2.5) pollution is closely associated with neuroinflammation in humans. Militarine, a glucosyloxybenzyl 2-isobutylmalate compound isolated from Bletilla striata, has been found to exert significant neuroprotective effects. However, the anti-inflammatory, antioxidant and antiapoptotic effects of militarine on PM_2.5-stimulated BV-2 microglial cells have not been reported. This study aimed to investigate the protective effects of militarine against PM_2.5-induced cytotoxicity and its mechanism in BV-2 microglial cells. Our results revealed that pretreatment with 0.31-1.25 μg/mL militarine reversed the morphological changes caused by PM_2.5 and decreased proinflammatory cytokine generation and gene expression in PM_2.5-treated BV-2 cells. In particular, tumor necrosis factor-α and interleukin-6 expression was inhibited in a dose-dependent manner. Notably, militarine markedly inhibited the upregulation of Toll-like receptor 4, Toll-like receptor 2, and cyclo-oxygenase-2 expression at both the mRNA and protein levels and reduced NF-κB pathway-associated protein expression. Immunofluorescence analysis showed that militarine suppressed NF-κB activity through inhibiting p65 nuclear translocation. Our data suggested that militarine alleviated neuroinflammation in BV-2 microglial cells, possibly by inhibiting the expression of neuroinflammatory cytokines through the TLR/NF-κB signaling pathway. Additionally, militarine significantly reduced PM_2.5-mediated reactive oxygen species (ROS) generation and cell apoptosis and restored the mitochondrial membrane potential (MMP; ΔΨm). Collectively, these findings demonstrate that militarine played a protective role against PM_2.5-induced damage in BV-2 cells by exerting anti-inflammatory, antioxidant, and antiapoptotic effects.

A combination of lycopene and human amniotic epithelial cells can ameliorate cognitive deficits and suppress neuroinflammatory signaling by choroid plexus in Alzheimer's disease rat

Neuroinflammation characterized by glial activation and release of proinflammatory mediators is considered to be correlated with cognitive deficits in Alzheimer's disease (AD). Previously, some studies have demonstrated that lycopene (LYCO) or human amniotic epithelial cells (HAECs) could attenuate inflammation in AD. Specifically, the choroid plexus (CP), an epithelial layer that forms the blood-cerebrospinal fluid barrier, is able to modulate the cognitive function, through changes in the neuroinflammatory response and in brain immune surveillance. However, it is unclear if LYCO can interact with HAECs to improve neuroinflammation at the CP. Thus, this study chose the region of interest, considered the feasibility of using a combination of LYCO and HAECs, as a therapeutic agent for immunomodulatory effects at the CP in an acutely induced AD rat model. Results showed that oral administration of LYCO, HAECs transplantation, and their combination significantly improved cognitive deficits in water maze test, decreased the level of proinflammatory mediators (TNF-α and IL-1β), increased the level of anti-inflammatory mediators (IL-10 and TGF-β1) in the cerebro-spinal fluid, and hippocampal tissue. Interestingly, LYCO administration, HAECs transplantation and their combination reversed the Aβ_1-42 induced up-regulation of Toll like receptor 4 and nuclear factor-κB p65 mRNA and protein expressions at the CP. This study provided the novel experimental evidence for the influence of co-treatment with LYCO and HAECs on immunomodulatory capabilities of CP. It could also warrant therapeutic window for the pathophysiology of AD and the associated underlying mechanisms at the CP.

Immunotherapy in progressive supranuclear palsy

PURPOSE OF REVIEW

Progressive supranuclear palsy (PSP) is a progressive adult-onset neurodegenerative disease. Abnormally, phosphorylated forms of the microtubule-associated protein tau containing four repeat domains (4R-tau) aggregate in neurons. Additionally, increasing evidence suggests that secretion and uptake of fragments of abnormal 4R-tau may play a role in disease progression. This extracellular tau is a natural target for immunotherapy.

RECENT FINDINGS

Three monoclonal antibodies targeting extracellular tau are in clinical stages of development. ABBV-8E12 and BIIB092 were safe in Phase 1, but both Phase two studies recently failed futility analyses. UCB0107 recently reported (in abstract form) Phase 1 safety results, and a Phase 2 study is under consideration. Stem cell therapy and the infusion of plasma are also being explored clinically.

SUMMARY

The likely role of extracellular tau in the progression of PSP makes tau a natural target for targeted immunotherapy. Clinical trials are still in early stages, and although tau immunotherapy has largely been shown to be safe, efficacy has yet to be demonstrated.

Assessment of Probiotics Mixture on Memory Function, Inflammation Markers, and Oxidative Stress in an Alzheimer's Disease Model of Rats

Background

The most important cause of neurodegeneration in Alzheimer's disease (AD) is associated with inflammation and oxidative stress. Probiotics are microorganisms that are believed to be beneficial to human and animals. Probiotics reduce oxidative stress and inflammation in some cases. Therefore, this study determined the effects of probiotics mixture on the biomarkers of oxidative stress and inflammation in an AD model of rats.

Methods

In this study, 50 rats were allocated to five groups, namely control, sham, and AD groups with Aβ1-40 intra-hippocampal injection, as well as AD + rivastigmine and AD + probiotics groups with Aβ1-40 intra-hippocampal injection and 2 ml (1010 CFU) of probiotics (Lactobacillus reuteri, Lactobacillus rhamnosus, and Bifidobacterium infantis) orally once a day for 10 weeks. MWM was used to assess memory and learning. To detect Aβ plaque, Congo red staining was used. Oxidative stress was monitored by measuring the MDA level and SOD activity, and to assess inflammation markers (IL-1β and TNF-α) in the hippocampus, ELISA method was employed..

Results

Spatial memory improved significantly in treatment group as measured by MWM. Probiotics administration reduced Aβ plaques in AD rats. MDA decreased and SOD increased in the treatment group. Besides, probiotics reduced IL-1β and TNF-α as inflammation markers in the AD model of rats.

Conclusion

Our data revealed that probiotics are helpful in attenuating inflammation and oxidative stress in AD.