Neuroregenerative Properties Research Articles

A tacrolimus-eluting nerve guidance conduit enhances regeneration in acritical-sized peripheral nerve injury rat model.

Critical-sized peripheral nerve injuries pose a significant clinical challenge and lead to functional loss and disability. Current regeneration strategies, including autografts, synthetic nerve conduits, and biologic treatments, encounter challenges such as limited availability, donor site morbidity, suboptimal recovery, potential immune responses, and sustained stability and bioactivity. An obstacle in peripheral nerve regeneration is the immune response that can lead to inflammation and scarring that impede the regenerative process. Addressing both the immunological and regenerative needs is crucial for successful nerve recovery. Here, we introduce a novel biodegradable tacrolimus-eluting nerve guidance conduit engineered from a blend of poly (L-lactide-co-caprolactone) to facilitate peripheral nerve regeneration and report the testing of this conduit in 15-mm critical-sized gaps in the sciatic nerve of rats. The conduit's diffusion holes enable the local release of tacrolimus, a potent immunosuppressant with neuro-regenerative properties, directly into the injury site. A series of in vitro experiments were conducted to assess the ability of the conduit to maintain a controlled tacrolimus release profile that could promote neurite outgrowth. Subsequent in vivo assessments in rat models of sciatic nerve injury revealed significant enhancements in nerve regeneration, as evidenced by improved axonal growth and functional recovery compared to controls using placebo conduits. These findings indicate the synergistic effects of combining a biodegradable conduit with localized, sustained delivery of tacrolimus, suggesting a promising approach for treating peripheral nerve injuries. Further optimization of the design and long-term efficacy studies and clinical trials are needed before the potential for clinical translation in humans can be considered.

Neurosteroids and translocator protein 18kDa (TSPO) ligands as novel treatment options in depression.

Recently, the gamma-aminobutyric acid (GABA) system has come into focus for the treatment of anxiety, postpartum depression, and major depressive disorder. Endogenous 3α-reduced steroids such as allopregnanolone are potent positive allosteric modulators of GABAA receptors and have been known for decades. Current industry developments and first approvals by the U.S. food and drug administration (FDA) for the treatment of postpartum depression with exogenous analogues of these steroids represent a major step forward in the field. 3α-reduced steroids target both synaptic and extrasynaptic GABAA receptors, unlike benzodiazepines, which bind to synaptic receptors. The first FDA-approved 3α-reduced steroid for postpartum depression is brexanolone, an intravenous formulation of allopregnanolone. It has been shown to provide rapid relief of depressive symptoms. An orally available 3α-reduced steroid is zuranolone, which also received FDA approval in 2023 for the treatment of postpartum depression. Although a number of studies have been conducted, the efficacy data were not sufficient to achieve approval of zuranolone in major depressive disorder by the FDA in 2023. The most prominent side effects of these 3α-reduced steroids are somnolence, dizziness and headache. In addition to the issue of efficacy, it should be noted that current data limit the use of these compounds to two weeks. An alternative to exogenous 3α-reduced steroids may be the use of substances that induce endogenous neurosteroidogenesis, such as the translocator protein 18kDa (TSPO) ligand etifoxine. TSPO has been extensively studied for its role in steroidogenesis, in addition to other functions such as anti-inflammatory and neuroregenerative properties. Currently, etifoxine is the only clinically available TSPO ligand in France for the treatment of anxiety disorders. Studies are underway to evaluate its antidepressant potential. Hopefully, neurosteroid research will lead to the development of fast-acting antidepressants.

Pharmacological Treatment of Acute Spinal Cord Injuries In The Light Of Recent Developments

Spinal injuries represent a significant public health issue with both individual and societal implications due to its potential to result in long-term or permanent disability and death. Today, notwithstanding the comprehensive elucidation of the mechanism of injury in its all aspects and breakthroughs in early diagnosis techniques and treatment, spinal injuries still retain their devastating nature. Although many agents hypothesized to possess neuroprotective and neuroregenerative properties have been demonstrated to be effective in the experiments, research involving human subjects is still in progress, offering promising developments. Methylprednisolone at a high dose is the most extensively investigated therapeutic for acute spinal injuries. Despite significant controversy, it remains a viable treatment option. It is anticipated that combining stem cell transplantation with multiple pharmacological agents will yield more favorable outcomes.

Dietary Astaxanthin: A Promising Antioxidant and Anti-Inflammatory Agent for Brain Aging and Adult Neurogenesis.

Decreased adult neurogenesis, or the gradual depletion of neural stem cells in adult neurogenic niches, is considered a hallmark of brain aging. This review provides a comprehensive overview of the intricate relationship between aging, adult neurogenesis, and the potential neuroregenerative properties of astaxanthin, a carotenoid principally extracted from the microalga Haematococcus pluvialis. The unique chemical structure of astaxanthin enables it to cross the blood-brain barrier and easily reach the brain, where it may positively influence adult neurogenesis. Astaxanthin can affect molecular pathways involved in the homeostasis, through the activation of FOXO3-related genetic pathways, growth, and regeneration of adult brain neurons, enhancing cell proliferation and the potency of stem cells in neural progenitor cells. Furthermore, astaxanthin appears to modulate neuroinflammation by suppressing the NF-κB pathway, reducing the production of pro-inflammatory cytokines, and limiting neuroinflammation associated with aging and chronic microglial activation. By modulating these pathways, along with its potent antioxidant properties, astaxanthin may contribute to the restoration of a healthy neurogenic microenvironment, thereby preserving the activity of neurogenic niches during both normal and pathological aging.

THE NOOTROPIC EFFECT OF A DIPEPTIDE MIMETIC OF NGF IN AN EXPERIMENTAL MODEL OF ALZHEIMER'S DISEASE

Relevance. The role of nerve growth factor (NGF) deficiency in the pathogenesis of Alzheimer's disease (AD) is well-known. The clinical application of full-size neurotrophin is limited due to its low bioavailability and the risk of adverse effects. At the V.V. Zakusov Institute of Pharmacology, a dimeric di-peptide mimetic of the 4th loop of NGF, compound GK-2 (hexamethylenediamide bis-(N-monosuccinyl-L-glutamyl-L-lysine), was created. It selectively activates specific TrkA receptors and possesses neuroprotective and neuroregenerative properties. Additionally, GK-2 lacks the main side effects of NGF, namely hyperalgesia and weight loss. The aim of the current study was to investigate the influence of GK-2 on rat memory under the conditions of the scopolamine-induced model of AD. Material and Methods. Scopolamine was administered intraperitoneally to rats at a dose of 2 mg/kg for 32 days. Simultaneously with scopolamine, animals were intraperitoneally injected with GK-2 at doses of 0.5 and 1 mg/kg. Following the administration of the compounds, a novel object recogni-tion test was conducted to assess both short-term and long-term memory. Results. Rats receiving scopolamine exhibited a statistically significant decline in long-term memory. The dipeptide GK-2 at a dose of 1 mg/kg com-pletely counteracted the development of this impairment. Conclusion. The dipeptide mimetic of nerve growth factor, GK-2, shows promise for further investigation as a potential therapeutic agent for the treatment of AD.

Development of ibuprofen-loaded electrospun materials suitable for surgical implantation in peripheral nerve injury

The development of nerve wraps for use in the repair of peripheral nerves has shown promise over recent years. A pharmacological effect to improve regeneration may be achieved by loading such materials with therapeutic agents, for example ibuprofen, a non-steroidal anti-inflammatory drug with neuroregenerative properties. In this study, four commercially available polymers (polylactic acid (PLA), polycaprolactone (PCL) and two co-polymers containing different ratios of PLA to PCL) were used to fabricate ibuprofen-loaded nerve wraps using blend electrospinning. In vitro surgical handling experiments identified a formulation containing a PLA/PCL 70/30 molar ratio co-polymer as the most suitable for in vivo implantation. In a rat model, ibuprofen released from electrospun materials significantly improved the rate of axonal growth and sensory recovery over a 21-day recovery period following a sciatic nerve crush. Furthermore, RT-qPCR analysis of nerve segments revealed that the anti-inflammatory and neurotrophic effects of ibuprofen may still be observed 21 days after implantation. This suggests that the formulation developed in this work could have potential to improve nerve regeneration in vivo.

Abstract 6 Combined Umbilical Cord Mesenchymal Stromal/Stem Cell Application For Primary Torsion Dystonia Treatment (Case Report)

Abstract Introduction Primary torsion dystonia (PTD) is a neurological disorder characterized by sustained or intermittent muscle contractions causing abnormal movements and/or postures with severe disability of young patients. Traditional therapies for PTD include oral anti-parkinsonism drugs, botulinum neurotoxin, pallidotomy and deep brain stimulation. Stem cell therapy is another promising treatment option, due to its neuroregenerative properties. Objectives The objective of the study was to investigate the effect of combined (intrathecal and intravenous) administration of umbilical cord derive stromal/stem cells (UC-MCS) on PTD reduction. Methods Patient M, born on 25.06.2004, fell ill gradually, 8 years ago developed signs of muscle dystonia, especially in right hand. Genetic tests were carried out, which revealed mutations in the DYT-1 gene. The diagnosis of primary torsion dystonia was established. Conservative treatment was not effective. The patient was offered treatment in the frame of research scientific program "To investigate the effectiveness of regenerative cell technologies in the neurosurgical treatment of patients with demyelinating diseases of the CNS and cerebral palsy. № 0119U000112" UC-MSCs for this study were isolated from healthy human umbilical cord and prepared due to the minimal criteria established by the Mesenchymal and Tissue Stem Cell Committee of the International Society for Cellular Therapy. 3 injections of UC-MSC were performed with time interval of 6 month (intravenously and intrathecally in a dose of 6 × 107at each injection). Intrathecal administration was performed according to the typical method of performing lumbar puncture in compliance with the rules of asepsis and antiseptics in the operation room using local anesthesia. Results Prior to stem cells injection, the patient's Unified Dystonia Rating Scale (UDRS) dystonia movement score was 15, which progressively decreased after procedure to 13, 10, 7 and 4 after 6, 12, 18 and 24 months respectively. There was a significant improvement in the patient's quality of life. Discussion UC-MSC significantly reduce dystonia in patient. This result is probably achieved due to the neuroregenerative and neurotrophic effects of UC-MSCs. Study results suggest the need to provide larger multicenter randomized studies with more sophisticated methods of investigations.

Advancing Nerve Regeneration: Translational Perspectives of Tacrolimus (FK506).

Peripheral nerve injuries have far-reaching implications for individuals and society, leading to functional impairments, prolonged rehabilitation, and substantial socioeconomic burdens. Tacrolimus, a potent immunosuppressive drug known for its neuroregenerative properties, has emerged in experimental studies as a promising candidate to accelerate nerve fiber regeneration. This review investigates the therapeutic potential of tacrolimus by exploring the postulated mechanisms of action in relation to biological barriers to nerve injury recovery. By mapping both the preclinical and clinical evidence, the benefits and drawbacks of systemic tacrolimus administration and novel delivery systems for localized tacrolimus delivery after nerve injury are elucidated. Through synthesizing the current evidence, identifying practical barriers for clinical translation, and discussing potential strategies to overcome the translational gap, this review provides insights into the translational perspectives of tacrolimus as an adjunct therapy for nerve regeneration.

Protocol for Safety and Efficacy of MLC901 (NeuroAiD II) in Patients With Moderate Traumatic Brain Injury: A Randomized Double-Blind Placebo-Controlled Trial (ANDROMEDA).

Traumatic brain injury (TBI) remains a leading cause of death and disability, affecting approximately 69 million individuals each year worldwide. A significant portion of TBI research has focused on treatments for neuroprotection and/or neurorecovery, with most failing to transition to successful clinical applications despite promising animal/in vitro study results. MLC901 (NeuroAiD II), with origins from a traditional Chinese medicine, has been shown to exhibit both neuroprotective and neuroregenerative properties in in vitro and animal studies for stroke and TBI. Clinical trials have demonstrated its safety with significant improvements in some functional outcome and cognitive domain measures. To determine the efficacy and safety of MLC901 (NeuroAiD II) vs placebo in adult patients with moderate TBI. This is a multicenter randomized double-blind placebo-controlled trial that aims to enroll 120 adult patients with moderate TBI receiving standard of care in 2 arms: MLC901 vs placebo for a treatment period of 6 months with a further follow-up of 3 months. The total duration of the study is 9 months. The primary end point is Glasgow Outcome Scale Extended (GOS-E) at 6 months. Other assessments include mortality at 6 months, GOS-E, Glasgow Coma Scale, Montreal Cognitive Assessment Filipino Version, Frontal Assessment Battery Conflicting Instructions and Go-No-Go, Rivermead Post-Concussion Symptom Questionnaire, Barthel Index, Hospital Anxiety and Depression Scale, and Health related Quality of life (EQ-5D) at 1, 3, 6, and 9 months. Cerebral swelling at baseline and at 1 and 2 weeks will also be documented. Adverse events and drug compliance will also be monitored. We expect to find a significant improvement in functional and cognitive outcomes in patients who were given MLC901. Previous studies on the effect of MLC901 in adult patients with moderate TBI showed positive results; However, these studies are limited by the small number of patients. This study will establish a more definitive role of MLC901 in improving functional and cognitive outcomes in patients with moderate TBI.

Phosphodiesterase (PDE) 4 inhibition boosts Schwann cell myelination in a 3D regeneration model

Phosphodiesterase 4 (PDE4) inhibitors have been extensively researched for their anti-inflammatory and neuroregenerative properties. Despite the known neuroplastic and myelin regenerative properties of nonselective PDE4 inhibitors on the central nervous system, the direct impact on peripheral remyelination and subsequent neuroregeneration has not yet been investigated. Therefore, to examine the possible therapeutic effect of PDE4 inhibition on peripheral glia, we assessed the differentiation of primary rat Schwann cells exposed in vitro to the PDE4 inhibitor roflumilast. To further investigate the differentiation promoting effects of roflumilast, we developed a 3D model of rat Schwann cell myelination that closely resembles the in vivo situation. Using these in vitro models, we demonstrated that pan-PDE4 inhibition using roflumilast significantly promoted differentiation of Schwann cells towards a myelinating phenotype, as indicated by the upregulation of myelin proteins, including MBP and MAG. Additionally, we created a unique regenerative model comprised of a 3D co-culture of rat Schwann cells and human iPSC-derived neurons. Schwann cells treated with roflumilast enhanced axonal outgrowth of iPSC-derived nociceptive neurons, which was accompanied by an accelerated myelination speed, thereby showing not only phenotypic but also functional changes of roflumilast-treated Schwann cells. Taken together, the PDE4 inhibitor roflumilast possesses a therapeutic benefit to stimulate Schwann cell differentiation and, subsequently myelination, as demonstrated in the biologically relevant in vitro platform used in this study. These results can aid in the development of novel PDE4 inhibition-based therapies in the advancement of peripheral regenerative medicine.

Study on in vitro differentiation of human adenoid-derived mesenchymal stem cells into olfactory sensory neurons

Objective: To investigate the feasibility of isolation and culture of human adenoid-derived mesenchymal stem cells (aMSCs) in vitro, and to observe the differentiation of aMSCs into olfactory sensory neurons. Methods: Adenoid tissues surgically removed from children with adenoid hypertrophy in the Second Xiangya Hospital of Central South University from September to November of 2020 were collected. The adenoid tissues were digested and isolated by trypsin and then cultured with adhesion method. The expressions of cell surface antigens CD45, CD73 and CD90 on aMSCs of P5 generation were tested by flow cytometry, and the ability of osteogenic and adipogenic induction were used to identify cell differentiation ability. Then, aMSCs were induced into differentiation by retinoic acid (RA), sonic hedgehog (SHH), basic fibroblast growth factor (bFGF), RA+SHH, RA+bFGF, SHH+bFGF and RA+SHH+bFGF, respectively. The morphology of differentiated cells was observed under inverted microscope. The expression of β-tubulin 3, which was the specific marker of sensory neuron, the expressions of growth associated protein-43 (GAP43) and olfactory maker protein (OMP), which were the specific markers of olfactory sensory neuron, were detected by immunofluorescence antibody assay. The expression intensities were compared by Chi-square test of four-grid table data. Results: aMSCs were successively isolated and cultured from human adenoid tissues. P0 cells generation had good adhesion and proliferation performance. P2 cells were basically purified. P5 cells expressed CD73 and CD90 with the purity of 99.3% and 99.75% respectively, without CD45 expression. P5 cells had a good ability of osteogenic differentiation and adipogenic differentiation. Neuron-like morphology and expression of β-tubulin 3 were found in differentiated cells after induced by RA, SHH, or bFGF, respectively. An induction of expression of GAP43 was found in differentiated cells of bFGF+SHH group and RA+SHH+bFGF group, without expression of OMP of each group. The intensity of GAP43 expression of RA+SHH+bFGF group was stronger than that of bFGF+SHH group (χ2=17.48, P<0.005). Conclusions: aMSCs can be cultured from human adenoid tissues, with the stably passaged and good differentiation ability. As a new population of mesenchymal stem cells, aMSCs have the neuroregenerative properties and could differentiate into immature olfactory sensory neurons under the induction of RA+SHH+bFGF in vitro.

Сhronically Administered BDNF Dipeptide Mimetic GSB-106 Prevents the Depressive-like Behavior and Memory Impairments after Transient Middle Cerebral Artery Occlusion in Rats.

A dipeptide mimetic of the BDNF loop 4, bis (N-monosuccinyl-L-seryl-L-lysine) hexamethylenediamide, GSB-106, was designed and synthesized by V.V. Zakusov Research Institute of Pharmacology. The compound activated in vitro TrkB, MAPK/ERK, PI3K/AKT, and PLCγ, like full-length BDNF. In vivo, GSB-106 exhibited antidepressant-like, neuroprotective and neuroregenerative properties. The aim of this work was to study the effects of GSB-106 on depressive-like behavior, cognitive impairments, as well as on hippocampal neuroplasticity in an experimental model of ischemic stroke. Male Wistar rats were subjected to 60 minutes of transient middle cerebral artery occlusion (MCAO). Dipeptide GSB-106 was administered intraperitoneally at a dose of 0.1 mg/kg/day for 21 days after surgery. 30-40 days after MCAO, the depressive-like state in the forced swimming test and memory impairment in the novel object recognition test were assessed. Then, the content of CREB, as a neuroplasticity marker, was assessed in the ipsilateral hippocampus. Rats in MCAO group showed depression-like behavior (increase in immobility time in the forced swimming test by 22% compared to sham group), impairments in short-term and long-term memory (decrease in the discrimination index in the novel object recognition test by 70% and 50%, respectively), and a decrease in immunoreactivity to CREB (cAMP response element-binding protein) in the hippocampus by 36% as compared with the sham group. GSB-106 completely prevented the behavior impairments and counteracted the reduction of immunoreactivity to CREB in the hippocampus. The BDNF dipeptide mimetic GSB-106 is promising for further development as a drug for the treatment of poststroke neuropsychiatric disorders.

Glia from the central and peripheral nervous system are differentially affected by paclitaxel chemotherapy via modulating their neuroinflammatory and neuroregenerative properties.

Glia are critical players in defining synaptic contacts and maintaining neuronal homeostasis. Both astrocytes as glia of the central nervous system (CNS), as well as satellite glial cells (SGC) as glia of the peripheral nervous system (PNS), intimately interact with microglia, especially under pathological conditions when glia regulate degenerative as well as regenerative processes. The chemotherapeutic agent paclitaxel evokes peripheral neuropathy and cognitive deficits; however, the mechanisms underlying these diverse clinical side effects are unclear. We aimed to elucidate the direct effects of paclitaxel on the function of astrocytes, microglia, and SGCs, and their glia-glia and neuronal-glia interactions. After intravenous application, paclitaxel was present in the dorsal root ganglia of the PNS and the CNS of rodents. In vitro, SGC enhanced the expression of pro-inflammatory factors and reduced the expression of neurotrophic factor NT-3 upon exposure to paclitaxel, resulting in predominantly neurotoxic effects. Likewise, paclitaxel induced a switch towards a pro-inflammatory phenotype in microglia, exerting neurotoxicity. In contrast, astrocytes expressed neuroprotective markers and increasingly expressed S100A10 after paclitaxel exposure. Astrocytes, and to a lesser extent SGCs, had regulatory effects on microglia independent of paclitaxel exposure. Data suggest that paclitaxel differentially modulates glia cells regarding their (neuro-) inflammatory and (neuro-) regenerative properties and also affects their interaction. By elucidating those processes, our data contribute to the understanding of the mechanistic pathways of paclitaxel-induced side effects in CNS and PNS.

Neuroprotective and Neuroregenerative Properties of Dimeric Dipeptide Mimetics of Individual NGF and BDNF Loops Under Conditions of an Experimental Ischemic Stroke Model

Neuroprotective and Neuroregenerative Properties of Dimeric Dipeptide Mimetics of Individual NGF and BDNF Loops Under Conditions of an Experimental Ischemic Stroke Model

Novel Therapies in Olfactory Disorders.

Purpose of ReviewTo summarize and critically review the recent literature on novel treatments for olfactory disorders (OD).Recent FindingsEmerging therapies in the management of OD include multiple vitamins and supplements, biologics, neuromodulators, and intranasal agents. There is also an active investigation into treatments that harness the neuroregenerative properties of the olfactory epithelium, such as platelet-rich plasma and stem cell transplantation.SummarySuccessful management of OD is multimodal and tailored to the underlying etiology. As the findings of further investigations accrue, the management of OD will undoubtedly continue to be advanced and refined, and likely harness the intrinsic neuroregenerative properties of the olfactory system.

Bone marrow mesenchymal stromal cells in a 3D system produce higher concentration of extracellular vesicles (EVs) with increased complexity and enhanced neuronal growth properties

PurposeExtracellular vesicles (EVs) derived from mesenchymal stromal cells (MSCs) have been demonstrated to possess great potential in preclinical models. An efficient biomanufacturing platform is necessary for scale up production for clinical therapeutic applications. The aim of this study is to investigate the potential differences in neuro-regenerative properties of MSC-derived EVs generated in 2D versus 3D culture systems.MethodHuman bone marrow MSCs (BM-MSCs) were cultured in 2D monolayer and 3D bioreactor systems. EVs were isolated using ultracentrifugation followed by size and concentration measurements utilizing dynamic light scattering (NanoSight) and by fluorescence staining (ExoView). Mouse trigeminal ganglia (TG) neurons were isolated from BALB/c mice and cultured in the presence or absence of EVs derived from 2D or 3D culture systems. Neuronal growth and morphology were monitored over 5 days followed by immunostaining for β3 tubulin. Confocal images were analyzed by Neurolucida software to obtain the density and length of the neurites.ResultsThe NanoSight tracking analysis revealed a remarkable increase (24-fold change) in the concentration of EVs obtained from the 3D versus 2D culture condition. ExoView analysis showed a significantly higher concentration of CD63, CD81, and CD9 markers in the EVs derived from 3D versus 2D conditions. Furthermore, a notable shift toward a more heterogeneous phenotype was observed in the 3D-derived EVs compared to those from 2D culture systems. EVs derived from both culture conditions remarkably induced neurite growth and elongation after 5 days in culture compared to untreated control. Neurolucida analysis of the immunostaining images (β3 tubulin) showed a significant increase in neurite length in TG neurons treated with 3D- versus 2D-derived EVs (3301.5 μm vs. 1860.5 μm, P < 0.05). Finally, Sholl analysis demonstrated a significant increase in complexity of the neuronal growth in neurons treated with 3D- versus 2D-derived EVs (P < 0.05).ConclusionThis study highlights considerable differences in EVs obtained from different culture microenvironments, which could have implications for their therapeutic effects and potency. The 3D culture system seems to provide a preferred environment that modulates the paracrine function of the cells and the release of a higher number of EVs with enhanced biophysical properties and functions in the context of neurite elongation and growth.

Pineal Gland from the Cell Culture to Animal Models: A Review.

This review demonstrates current literature on pineal gland physiology, pathology, and animal model experiments to concisely explore future needs in research development with respect to pineal gland function and neuro-regenerative properties. The pineal gland plays an integral role in sleep and recovery by promoting physiologic circadian rhythms via production and release of melatonin. Yet, the current literature shows that the pineal gland has neuroprotective effects that modulate both peripheral and central nerve injuries through several direct and indirect mechanisms, such as angiogenesis and induction of growth factors and anti-inflammatory mediators. Animal models have also shown correlations between pineal gland function and metabolic homeostasis. Studies have shown that a functional pineal gland is essential in preventing and slowing the progression of certain diseases such as diabetes, osteoporosis, vertebral osteoarthritis, and neurodegenerative processes. Lastly, the array of cell culturing methods and animal models that can be used to further develop the study of pineal gland function and nervous system injury were reviewed.

A Review of NeuroAiDTM II (MLC901) Development in Alzheimer’s Disease Treatment: Promises of A Multimodal Pathway

Background: Alzheimer’s disease (AD) is a clinical and economic burden on society. Without new treatment, the impact of AD on society could triple by 2050. Aim: After a brief overview of treatments and challenges of new drug developments for AD, we reviewed the preclinical and clinical development program of NeuroAiD (MLC901, MLC601). Method: A literature search was conducted by using different web sources. The initial screening was based on keywords contained in the subtitles of each corresponding paragraphs of this article. We sorted the reviewed publications by relevance and publication date selecting 74 references out of the 319 initially shortlisted for review. Review: Since 1998, only symptomatic drugs were marketed. Intensive research has continued, aimed at delaying the onset of the disease and/or slowing its progression. However, the predictive value of delaying the onset of AD remains debated. Since 2003, aducanumab is the first new treatment approved and registered by US-FDA as an amyloid beta-directed antibody indicated for the treatment of Alzheimer’s disease under post-marketing conditions. Traditional medicines (TM) have shown interesting results, but many of TM clinical studies leave much to be desired from a methodological point of view. Among TM, NeuroAiD (MLC901/601), a botanical-derived combination, acts in a multimodal pathway combining neuroprotective and neuroregenerative properties. It has demonstrated sustained symptomatic benefits, slowing the disease progression in AD with a good safety profile. Discussion/Conclusions: The discovery of treatments preventing or slowing down the disease progression, are necessary to get reliable diagnostic tools to confirm AD diagnosis, and follow its evolution and long-term therapy. A growing consensus is emerging on the need for a multi-factorial approach to the treatment and the development of suitable AD drug combinations. Such an approach has been that of TM for a long time. This is the case for NeuroAiD, that it may be integrated safely either after symptomatic treatments have failed or on top of symptomatic treatments.

A concise review of the orofacial mesenchymal stromal cells as a novel therapy for neurological diseases and injuries.

Orofacial mesenchymal stromal cells (OFMSCs) are mesenchymal stromal cells isolated from the oral and facial regions, which possess typical mesenchymal stromal cell features such as self-renewing, multilineage differentiation, and immunoregulatory properties. Recently, increasing studies have been carried out on the neurotrophic and neuroregenerative properties of OFMSCs as well as their potential to treat neurological diseases. In this review, we summarize the current evidence and discuss the prospects regarding the therapeutic potential of OFMSCs as a new approach to treat different neurological diseases and injuries.

Characterization of Zymosan-Modulated Neutrophils With Neuroregenerative Properties.

Recent studies using advanced techniques such as single cell RNA sequencing (scRNAseq), high parameter flow cytometry, and proteomics reveal that neutrophils are more heterogeneous than previously appreciated. Unique subsets have been identified in the context of bacterial and parasitic infections, cancer, and tissue injury and repair. The characteristics of infiltrating neutrophils differ depending on the nature of the inflammation-inciting stimulus, the stage of the inflammatory response, as well as the tissue microenvironment in which they accumulate. We previously described a new subpopulation of immature Ly6Glow neutrophils that accumulate in the peritoneal cavity 3 days following intraperitoneal (i.p.) administration of the fungal cell wall extract, zymosan. These neutrophils express markers of alternative activation and possess neuroprotective/regenerative properties. In addition to inducing neurite outgrowth of explanted neurons, they enhance neuronal survival and axon regeneration in vivo following traumatic injury to the optic nerve or spinal cord. In contrast, the majority of neutrophils that accumulate in the peritoneal fluid 4 hours following i.p. zymosan injection (4h NΦ) have features of conventional, mature Ly6Ghi neutrophils and lack neuroprotective or neuroregenerative properties. In the current study, we expand upon on our previously published observations by performing a granular, in-depth analysis of these i.p. zymosan-modulated neutrophil populations using scRNAseq and high parameter flow cytometry. We also analyze cell lysates of each neutrophil population by liquid chromatography/mass spectrometry. Circulating blood neutrophils, harvested from naive mice, are analyzed in parallel as a control. When samples were pooled from all three groups, scRNAseq revealed 11 distinct neutrophil clusters. Pathway analyses demonstrated that 3d NΦ upregulate genes involved in tissue development and wound healing, while 4h NΦ upregulate genes involved in cytokine production and perpetuation of the immune response. Proteomics analysis revealed that 3d NΦ and 4h NΦ also express distinct protein signatures. Adding to our earlier findings, 3d NΦ expressed a number of neuroprotective/neuroregenerative candidate proteins that may contribute to their biological functions. Collectively, the data generated by the current study add to the growing literature on neutrophil heterogeneity and functional sub-specialization and might provide new insights in elucidating the mechanisms of action of pro-regenerative, neuroprotective neutrophil subsets.