BDNF and miRNAs in acupuncture-regulated neuroplasticity: Emerging mechanisms and therapeutic strategies.

The trend of global population aging is closely associated with a rising incidence of neurodegenerative diseases (NDs), including stroke, Alzheimer disease, Parkinson disease, and depression. These conditions, characterized by progressive neuronal loss, currently pose a significant challenge due to the lack of curative therapies. Brain-derived neurotrophic factor (BDNF) serves as a critical regulator of synaptic plasticity, a fundamental mechanism believed to underpin essential cognitive and motor functions such as learning, memory formation, and recovery. Decreased BDNF and deficits in BDNF signaling leads to the pathogenesis of NDs. Numerous studies support the therapeutic potential of acupuncture in managing NDs. Its beneficial effects are largely attributed to the ability to elevate BDNF expression and potentiate associated neurotrophic signaling. Beyond direct BDNF modulation, acupuncture exerts regulatory effects on specific micro-RNAs (miRNAs). This includes miRNAs that directly target BDNF transcripts for posttranscriptional control, as well as others that independently influence molecules critical for maintaining synaptic plasticity. The binding of acupuncture-elevated BDNF to its high-affinity receptor, Tropomyosin-related kinase B (Trk-B), initiates the activation of key downstream signaling cascades, including phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT), mitogen-activated protein kinase/extracellular signal-related kinase (MAPK/ERK) and phospholipase C-γ (PLCγ) pathways which are involved in synaptic plasticity, survival, proliferation and differentiation of neurons. In this review, we present the effects of acupuncture on BDNF, miRNAs and the downstream signal transduction pathways of BDNF in NDs and the review may partly elucidate the biological molecular mechanisms of acupuncture in the therapy of NDs.