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Electrical stimulation (ES) is emerging as a non-pharmacological neuromodulation strategy, but its direct impact on human dopaminergic neurons and its relationship to rapid-acting antidepressant mechanisms remain unclear. This study aimed to investigate whether brief biphasic low-frequency low-intensity (LF-LI) ES can induce structural and molecular plasticity in human induced pluripotent stem cell (iPSC)-derived mesencephalic dopaminergic neurons, identify the underlying signaling mechanisms, and evaluate its potential to rescue cortisol-induced impairments as in-vitro endocrine model of depression. iPSC-derived dopaminergic neurons were exposed to LF-LI ES using a custom culture-compatible stimulator, and structural plasticity was quantified three days later by computer-assisted morphometry. Pharmacological blockers, quantitative PCR and Western blot analyses were employed to assess calcium influx, brain-derived neurotrophic factor (BDNF)-TrkB-extracellular signal-regulated kinase (ERK)-mTOR signaling, and dopamine D3 auto-receptor roles in mediating LF-LI ES effects. A single 1h LF-LI ES session at 4 mA induced robust increases in maximal dendrite length, primary dendrite number, and soma area, comparable to 1 μM ketamine. LF-LI ES rapidly enhanced ERK and p70-S6K phosphorylation and required L-type voltage-gated calcium channels, TrkB and mTOR, as their inhibition prevented structural remodeling. LF-LI ES increased dopamine D3 auto-receptors mRNA, and its antagonism attenuated LF-LI ES-induced plasticity. In cortisol-treated neurons, LF-LI ES fully reversed dendritic hypotrophy and soma shrinkage. In conclusion, brief LF-LI ES elicits long-lasting, ketamine-like structural and molecular plasticity in human dopaminergic neurons and rescues stress hormone-induced impairments, supporting LF-LI ES-based neuromodulation approaches targeting dopaminergic circuits in major depressive disorder and treatment-resistant depression. Show less

Post-traumatic stress disorder (PTSD) is a debilitating neuropsychiatric condition triggered by severe trauma, characterised by dysregulated fear circuitry, hippocampal atrophy with impaired neurogenesis, chronic neuroinflammation, neuroendocrine dysregulation, and disrupted prefrontal-limbic connectivity. Existing treatments are largely symptomatic, failing to address underlying neurobiological deficits. Emerging regenerative approaches using human stem cells, particularly induced pluripotent stem cell-derived neural progenitor cells (iPSC-NPCs), human embryonic stem cells (hESCs), mesenchymal stem cells (MSCs), and their extracellular vesicles (EVs), offer mechanistic plausibility for neural repair via direct neuronal replacement, paracrine neurotrophic support (e.g., BDNF, GDNF, VEGF), immunomodulation (e.g., shifting microglia to anti-inflammatory phenotypes), and promotion of synaptic plasticity and epigenetic reprogramming. Preclinical evidence remains limited and largely indirect, with sparse PTSD-specific studies (e.g., one report of iPSC-NPC transplantation reducing fear behaviour and enhancing hippocampal BDNF/neuronal density in a rat model) supplemented by convergent data from adjacent CNS injury paradigms. MSC- and iPSC-derived EVs, enriched with regulatory miRNAs (e.g., miR-124, miR-21, miR-146a), emerge as a safer, cell-free alternative with strong immunomodulatory potential and greater translational feasibility. However, reproducibility is constrained by model variability, lack of independent replication, and absence of PTSD-focused clinical trials. Major challenges include tumorigenicity risks (especially for pluripotent-derived cells), immune rejection, epigenetic/genomic instability, manufacturing scalability, stringent regulatory requirements, and elevated ethical thresholds for invasive therapies in a non-lethal psychiatric disorder. This review examines how stem cell actions align with PTSD brain changes, critically assesses the limited evidence, and suggests a careful translational plan. Show less

Acute spinal cord injury (SCI) results in irreversible neurological deficits. We hypothesized that local transplantation of bone marrow mesenchymal stem cells (BMSCs) combined with erythropoietin (EPO) would inhibit glial scarring and accelerate functional recovery. To quantify the therapeutic efficacy and underlying mechanisms of BMSCs+EPO versus BMSCs alone in a rat model of acute SCI. Forty SD rats (T10 Allen 60 g·cm impact) were randomized to sham, SCI, SCI+BMSCs, or SCI+BMSCs+EPO ( At 4 weeks, BBB scores in the BMSCs+EPO group reached 12.7 ± 1.5, representing a 54% increase over the BMSCs-alone group (8.3 ± 0.7, BMSCs+EPO exerts synergistic neuroprotective effects, achieving superior locomotor recovery compared with BMSCs monotherapy, and represents a promising adjuvant strategy for acute SCI. Show less

Cerebral palsy (CP), the most prevalent pediatric motor disorder with significant cognitive comorbidity (> 50%), lacks therapies addressing both impairments in moderate-to-severe cases. This study demonstrates that human umbilical cord mesenchymal stem cell-derived exosomes (hUCMSC-Exos) exert profound therapeutic effects in a rat model of moderate-to-severe CP established via bilateral carotid artery occlusion with hypoxia. Intravenously administered hUCMSC-Exos displayed sustained brain retention and significantly restored motor coordination and cognitive function. The recovery was primarily mediated through enhanced remyelination driven by promoted oligodendrocyte maturation and differentiation (elevated oligodendrocyte lineage transcription factor 2 and myelin basic protein). Concurrently, the treatment attenuated key pathological processes involving sustained neuroinflammatory responses (reduced ionized calcium-binding adapter molecule 1, tumor necrosis factor-α, and interleukin-6) while elevating brain-derived neurotrophic factor. Our findings establish hUCMSC-Exos as a promising dual-modality therapy for moderate-to-severe CP, mechanistically linked to robust remyelination and coordinated modulation of core disease mechanisms. Show less

Recent studies have indicated that stem cells could provide therapeutic benefits in several neurological conditions, including Alzheimer's disease (AD). Adipose-derived stem cells (ADSCs) offer many advantages in that they are readily available from individual hosts, are robust, and secrete many factors that promote neuronal growth and homeostasis. We transfected ADSCs with a viral construct for brain-derived neurotrophic factor (BDNF) and examined the effects of transplanting these cells into the hippocampus of 7-mo-old APPswe/PS1dE9 mice. After 6 mo, the hippocampus was examined for stem-cell survival, effects on BDNF and neprilysin-2 (NEP-2) levels, dendritic morphology using microtubule associated protein 2 (MAP2) immunohistochemistry, and amyloid plaque load. We found that transplanted BDNF-ADSCs had survived after 6 mo. BDNF and NEP-2 levels were higher than sham controls, and dendritic architecture was improved. In addition, amyloid plaque numbers were reduced. BDNF-ADSCs appear to confer benefits by simultaneously enhancing amyloid clearance and promoting neuronal structural repair. This multifaceted approach highlights the potential of engineering stem cells to target multiple pathophysiological hallmarks of AD, positioning BDNF-ADSCs as a powerful and synergistic cell-gene therapy strategy for this devastating disorder. Show less

Neurological disorders cause over 11 million deaths annually worldwide, highlighting the urgent need for new therapeutic strategies to improve current treatment outcomes. Nerve growth factor (NGF) is a key regulator of neuronal survival, and modifying mesenchymal stem cells (MSC) to enhance their neurotrophic activity is a promising therapeutic strategy. However, the broader molecular consequences of NGF overexpression in MSC remain unclear. This study examined how NGF overexpression affects neurotrophin secretion and apoptosis-related protein expression in Wharton's jelly MSC (WJ-MSC). WJ-MSC were lentivirally transduced to overexpress NGF and differentiated for 12 days. NGF, BDNF, TrkA, TrkB, IL-13, and TNF-α were quantified using ELISA (n = 3 biological replicates; assays in duplicate). Thirty-five apoptosis-related proteins were assessed using the Proteome Profiler Human Apoptosis Array (assays in duplicate). Data were analyzed using one-way ANOVA or multiple t-test. NGF overexpression increased extracellular NGF (↑∼220 %, p < 0.0001) and reduced BDNF secretion (↓∼35 %, p < 0.05). Soluble phosphorylated TrkA/TrkB increased significantly in supernatants (↑30-60 %, p < 0.05). IL-13 rose modestly without statistical significance, and TNF-α remained undetectable. Early proteome changes showed upregulation of pro-apoptotic proteins (p21 ↑97 %, phospho-p53 ↑30 %) with concurrent reductions in anti-apoptotic markers (BCL2 ↓66 %, HSP60 ↓58 %). After 12 days, the apoptotic profile remained predominantly pro-apoptotic, despite selective increases in BCLXL (↑92 %), clusterin (↑102 %), and survivin (↑38 %) indicating only partial compensatory responses. NGF overexpression enhances neurotrophin-related signaling but produces a sustained pro-apoptotic shift in WJ-MSC, suggesting limited benefit for cell survival. These findings require confirmation using functional apoptosis assays and in vivo models. Show less