Bushen Huoxue Acupuncture Inhibits NLRP1 Inflammasome-Mediated Neuronal Pyroptosis in SAMP8 Mouse Model of Alzheimer's Disease

Electroacupuncture extends the time window of thrombolytic therapy in rats by reducing disruptions of blood-brain barrier and inhibiting GSDMD-mediated pyroptosis

OBJECTIVE

Thrombolytic therapy is the primary treatment for acute ischemic stroke. Extending the therapeutic time window can effectively reduce the harmful side effects associated with thrombolytic therapy. Although electroacupuncture (EA) has been shown to extend this time window, the specific mechanisms remain unclear.

METHODS

We developed an embolic stroke model in rats and administered EA during thrombolytic therapy with recombinant tissue plasminogen activator (rt-PA) either 4.5 or 6 h after stroke onset. Neurological deficits were evaluated at 2 and 24 h post-stroke. Brain tissue was collected for analysis using 2,3,5-triphenyl tetrazolium chloride (TTC) staining, water content measurement, blood-brain barrier (BBB) permeability assessment, electron microscopy, and TUNEL assay. Immunofluorescence staining, western blotting, and enzyme-linked immunosorbent assays were employed to quantify the expression of proteins related to BBB integrity and pyroptosis.

RESULTS

Neuronal damage and BBB disruption along with increased expression of pyroptosis-related proteins were observed following thrombolytic therapy at the 6-hour mark. EA treatment improved neurological outcomes, reduced infarct volume, and alleviated BBB disruption. EA also inhibited the expression of matrix metalloproteinase 9 (MMP9) and enhanced the expression of tissue inhibitor of metalloproteinases 1 (TIMP1), helping to maintain BBB integrity. Furthermore, EA reduced the expression of pyroptosis-related proteins, including gasdermin D (GSDMD), interleukin-1β (IL-1β), and interleukin-18 (IL-18). EA also reduced the co-expression of GSDMD and MMP9 in brain tissues.

CONCLUSIONS

EA may be a promising therapeutic approach for extending the thrombolytic therapy window by protecting the BBB and inhibiting GSDMD-mediated pyroptosis.

Bushen Huoxue acupuncture ameliorates Alzheimer's disease by upregulating MARCHF3 to induce NLRP3 ubiquitination and inhibit caspase-1-dependent pyroptosis

Alzheimer's disease (AD) is a common neurodegenerative disorder that places a heavy burden on patients and society. Hippocampal neuronal loss is a hallmark of AD progression. Therefore, understanding the mechanism underlying hippocampal neuronal death would be of great importance for the diagnosis and treatment of AD. This study aimed to explore the molecular mechanism via which Bushen Huoxue Acupuncture inhibits hippocampal neuronal pyroptosis in AD. Senescence-accelerated mouse prone 8 (SAMP8) mice were used as a model of AD. Bushen Huoxue Acupuncture was performed in four acupoints: "Baihui acupoint" (GV20), "Shenshu acupoint" (BL23), "Xuehai acupoint" (SP10), and "Geshu acupoint" (BL17). Morris water maze was used to test cognitive function in mice. IHC staining was used to test mice's Aβ1-42, MARCHF1 and MARCHF3 expression. Terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) staining was used for observing hippocampal neuronal apoptosis. The mRNA expression levels of pyroptosis markers MARCHF1, MARCHF3, NLRP3, caspase-1, GSDMD, IL-1β, and IL-18 mRNA in AD mice were determined by quantitative reverse transcription polymerase chain reaction (qRT-PCR). The protein expression of NLRP3, caspase-1 and GSDMD-N was tested by Western blotting. IL-1β and IL-18 protein levels were measured by Enzyme-Linked Immunosorbent Assay (ELISA). SH-SY5Y cells were used to establish an AD model following Aβ1-42 treatment. Western blot was used to detect the NLRP3, MARCHF1 and MARCHF3 proteins following Aβ1-42 treatment. The endogenous Co-IP assay in combination with immunoblotting for ubiquitin signals was used to detect of NLRP3 ubiquitination level. We found that Bushen Huoxue Acupuncture protected cognitive impairment in AD mice. Bushen Huoxue Acupuncture inhibited hippocampal neuronal pyroptosis and the secretion of inflammatory cytokines in vivo. In SH-SY5Y cells, we found that Aβ1-42 decreased the binding of E3 ubiquitin-protein ligase MARCHF1 or MARCHF3 with NLRP3, and the ubiquitination of NLRP3. In conclusion, Bushen Huoxue Acupuncture ameliorates AD by upregulating MARCHF3 to induce NLRP3 ubiquitination and inhibits caspase-1-dependent pyroptosis.

Thioredoxin-1 Protects Neurons Through Inhibiting NLRP1-Mediated Neuronal Pyroptosis in Models of Alzheimer's Disease

Alzheimer's disease (AD) is the most common neurodegenerative disease all over the world. In the last decade, accumulating proofs have evidenced that neuroinflammation is intimately implicated in the pathogenesis of AD and activation of NOD-like receptor family pyrin domain-containing 1 (NLRP1) inflammasome can induce neuronal pyroptosis and in turn lead to neuronal loss in AD. Thioredoxin-1 (Trx-1), a multifunctional molecule with anti-inflammation in human tissues, displays crucial neuroprotective roles in AD. Our previous research preliminarily found that Trx-1 inhibition enhanced the expression of NLRP1, caspase-1, and gasdermin D (GSDMD) in Aβ25-35-treated PC12 cells. However, it is largely unknown if Trx-1 can inhibit NLRP1-mediated neuronal pyroptosis in AD neurons. In this study, it was verified that the protein levels of NLRP1, caspase-1, and GSDMD were significantly increased in Aβ25-35-treated mouse HT22 and primary hippocampal neurons. Suppression of Trx-1 with PX-12, a selective inhibitor of Trx-1, or Trx-1 knockdown further activated NLRP1-mediated neuronal pyroptosis. On the contrary, lentivirus infection-mediated Trx-1 overexpression in differentiated PC12 cells dramatically reversed expression of NLRP1, caspase-1, and GSDMD. Furthermore, Trx-1 overexpression mediated by adeno-associated virus in the hippocampal tissues of APP/PS1 mice likewise attenuated the activation of NLRP1-mediated neuronal pyroptosis, as well as reduced the hippocampal deposition of Aβ and ameliorated the cognitive function of APP/PS1 mice. In conclusion, this article predicates a novel molecular mechanism by which Trx-1 exploits neuroprotection through attenuating NLRP1-mediated neuronal pyroptosis in AD models, suggesting that Trx-1 may be a promising therapeutic target for AD.

The Relationship Between Alzheimer's Disease and Pyroptosis and the Intervention Progress of Traditional Chinese Medicine

Alzheimer's disease (AD) is a progressive neurodegenerative disease caused by multiple causes. The main pathological features of AD are β-amyloid (Aβ) deposition, hyperphosphorylation of Tau protein, and progressive neuronal loss. Pyroptosis is one of the main forms of neuronal death, which is mainly caused by the activation of Gasdermin protein by upstream signals and the release of its N-terminal domain on the cell membrane. Studies have shown that there is a close relationship between Alzheimer's disease (AD) and pyroptosis. Therefore, this paper summarizes the relationship between pyroptosis and its molecular mechanism and AD, as well as the related research of traditional Chinese medicine in the treatment of AD by regulating pyroptosis, in order to provide a new direction for the study of AD pathogenesis based on pyroptosis pathway.

Pyroptosis in health and disease: mechanisms, regulation and clinical perspective

Pyroptosis is a type of programmed cell death characterized by cell swelling and osmotic lysis, resulting in cytomembrane rupture and release of immunostimulatory components, which play a role in several pathological processes. Significant cellular responses to various stimuli involve the formation of inflammasomes, maturation of inflammatory caspases, and caspase-mediated cleavage of gasdermin. The function of pyroptosis in disease is complex but not a simple angelic or demonic role. While inflammatory diseases such as sepsis are associated with uncontrollable pyroptosis, the potent immune response induced by pyroptosis can be exploited as a therapeutic target for anti-tumor therapy. Thus, a comprehensive review of the role of pyroptosis in disease is crucial for further research and clinical translation from bench to bedside. In this review, we summarize the recent advancements in understanding the role of pyroptosis in disease, covering the related development history, molecular mechanisms including canonical, non-canonical, caspase 3/8, and granzyme-mediated pathways, and its regulatory function in health and multiple diseases. Moreover, this review also provides updates on promising therapeutic strategies by applying novel small molecule inhibitors and traditional medicines to regulate pyroptosis. The present dilemmas and future directions in the landscape of pyroptosis are also discussed from a clinical perspective, providing clues for scientists to develop novel drugs targeting pyroptosis.

Study on the Effects of Acupuncture with the "Yizhi Tiaoshen" Acupoint Formula on Blood Oxygen Metabolism and Neural Function in Key Brain Regions of AD Rats

Purpose

Exploring the effects of acupuncture at the "Yizhi Tiaoshen" acupoint on blood oxygen metabolism and neurological function changes in the brain regions of AD model rats.

Methods

The AD model was replicated by intraperitoneal injection of D-galactose combined with bilateral hippocampal CA1 injection of Okadaic acid (OA). Thirty rats with successfully replicated model were selected through Morris water maze experiment and randomly divided into model group, donepezil hydrochloride group, and acupuncture group, with 10 rats in each group. After treatment, fNIRs were used to detect changes in Oxy Hb, Deoxy Hb, and Total Hb in the cerebral cortex of rats in each group, in order to evaluate the neurological function changes in key brain areas.

Results

The escape latency of the donepezil hydrochloride group and the acupuncture group was shortened, the number of crossings through the original platform increased, and the duration of stay in the quadrant where the original platform was located was prolonged. Based on fNIRs detection, the main differential channels of blood oxygen metabolism in AD rats were identified as 2-2 and 8-7, corresponding to the prefrontal and parietal lobes, respectively. The concentrations of Oxy Hb and Total Hb were significantly increased in both treatment groups, while the concentration of Deoxy Hb was significantly decreased.

Conclusion

Acupuncture with the "Yizhi Tiaoshen" acupoint formula and donepezil hydrochloride can improve the learning and memory function of AD rats, and its mechanism may be related to improving blood oxygen metabolism in the prefrontal and parietal regions and protecting neuronal function.

From inflammatory signaling to neuronal damage: Exploring NLR inflammasomes in ageing neurological disorders

The persistence of neuronal degeneration and damage is a major obstacle in ageing medicine. Nucleotide-binding oligomerization domain (NOD)-like receptors detect environmental stressors and trigger the maturation and secretion of pro-inflammatory cytokines that can cause neuronal damage and accelerate cell death. NLR (NOD-like receptors) inflammasomes are protein complexes that contain NOD-like receptors. Studying the role of NLR inflammasomes in ageing-related neurological disorders can provide valuable insights into the mechanisms of neurodegeneration. This includes investigating their activation of inflammasomes, transcription, and capacity to promote or inhibit inflammatory signaling, as well as exploring strategies to regulate NLR inflammasomes levels. This review summarizes the use of NLR inflammasomes in guiding neuronal degeneration and injury during the ageing process, covering several neurological disorders such as Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, stroke, and peripheral neuropathies. To improve the quality of life and slow the progression of neurological damage, NLR-based treatment strategies, including inhibitor-related therapies and physical therapy, are presented. Additionally, important connections between age-related neurological disorders and NLR inflammasomes are highlighted to guide future research and facilitate the development of new treatment options.

A review on traditional Chinese medicine natural products and acupuncture intervention for Alzheimer's disease based on the neuroinflammatory

Alzheimer's disease (AD) is a neurodegenerative disease with insidious onset and progressive development. It is clinically characterized by cognitive impairment, memory impairment and behavioral change. Chinese herbal medicine and acupuncture are important components of traditional Chinese medicine (TCM), and are commonly used in clinical treatment of AD. This paper systematically summarizes the research progress of traditional Chinese medicine natural products and acupuncture treatment of AD, which combined with existing clinical and preclinical evidence, based on a comprehensive review of neuroinflammation, and discusses the efficacy and potential mechanisms of traditional Chinese medicine natural products and acupuncture treatment of AD. Resveratrol, curcumin, kaempferol and other Chinese herbal medicine components can significantly inhibit the neuroinflammation of AD in vivo and in vitro, and are candidates for the treatment of AD. Acupuncture can alleviate the memory and cognitive impairment of AD by improving neuroinflammation, synaptic plasticity, nerve cell apoptosis and reducing the production and aggregation of amyloid β protein (Aβ) in the brain. It has the characteristics of early, safe, effective and benign bidirectional adjustment. The purpose of this paper is to provide a basis for improving the clinical strategies of TCM for the treatment of AD.

Acupuncture as a Complementary Therapy for Alzheimer's Disease

 Alzheimer's disease (AD) is a significant global medical concern due to the aging population. AD is featured by gradual cognitive impairment, impacting daily functioning and causing behavioral and personality changes, causing disruptive psychiatric symptoms. While pharmacological interventions are the primary clinical approach, their efficacy is variable and limited. Acupuncture, with its distinctive theoretical framework and treatment approach, has garnered attention as a non-pharmacological intervention for AD through extensive preclinical and clinical research. Neurobiological investigations into the machinery of acupuncture in AD have provided compelling evidence of its therapeutic efficacy and unique advantages. This review commences with an in-depth exploration of acupuncture's clinical applications, emphasizing its various parameters and its potential combination with first-line drugs and other therapies in the context of AD. Subsequently, we delve into the underlying therapeutic mechanisms of acupuncture in AD. Finally, we summarize these aspects, highlight current study limitations, and offer recommendations for future research. Taken together, in a rapidly aging society, both clinical application and mechanistic exploration of acupuncture in AD treatment have gained momentum. This trajectory suggests that acupuncture will continue to make significant strides in AD therapeutics as research progresses.

Effect of acupuncture on neuroinflammation in animal models of Alzheimer's disease: A preclinical systematic review and meta-analysis

Background

Despite neuroinflammation being an important component of the pathology of Alzheimer's disease (AD), effective therapies to alleviate neuroinflammation are still lacking. Many animal experiments in AD have found that acupuncture may ameliorate cognition by decreasing neuroinflammation and modulating cytokines, but its effects have not been systematically examined. We aimed to assess its efficacy on neuroinflammation in AD and to investigate the potential mechanisms.

Materials and methods

The following databases were searched from inception until 24 August 2022: Web of Science, EMBASE, PubMed, the Cochrane Library, and China National Knowledge Infrastructure. Animal studies that reported the efficacy of acupuncture on neuroinflammation in AD were included. The SYRCLE Robt was utilized to evaluate methodological quality. Stata 17 was utilized to conduct a meta-analysis of cytokine levels and the results of the Morris water maze.

Results

23 studies were included, with a total of 417 rats/mice. The overall quality of all included reports was medium. The results indicated that acupuncture significantly reduced the expressions of pro-inflammatory cytokines which included IL-1β [SMD = -3.50, 95% CI (-4.31, -2.69); I 2 = 78.6%] (P < 0.05), TNF-α [SMD = -3.05, 95% CI (-3.86, -2.24); I 2 = 69.6%] (P < 0.05), IL-6 [SMD = -3.22, 95% CI (-4.62, -1.81); I 2 = 77.6%] and enhanced the expressions of anti-inflammatory cytokines including IL-4 [SMD = 2.77, 95% CI (1.95, 3.59); I 2 = 33.9%] (P < 0.05), IL-10 [SMD = 1.84, 95% CI (1.20, 2.49); I 2 = 41.0%] (P < 0.05) in an animal model of AD. Regarding the Morris water maze, compared to the control group, the acupuncture group showed a shorter escape latency [SMD = -2.23, 95% CI (-2.89, -1.57); I 2 = 79.2%] (P < 0.05), longer duration in platform quadrant [SMD = 2.34, 95% CI (1.44, 3.23); I 2 = 81.7%] (P < 0.05), and increased platform crossing number [SMD = 2.79, 95% CI (2.06, 3.53); I 2 = 71.9%] (P < 0.05).

Conclusion

Acupuncture may reduce neuroinflammation in AD by modulating cytokine expression. This modulation significantly improved cognitive function in animal models of AD.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42022354878.

Mechanism of pyroptosis in neurodegenerative diseases and its therapeutic potential by traditional Chinese medicine

Neurodegenerative diseases (NDs) are disorders characterized by degenerative degeneration of neurons and loss of their function. NDs have a complicated pathophysiology, of which neuroinflammation and neuronal death are significant factors. The inflammatory process known as pyroptosis ("fiery death") is caused by a family of pore-forming proteins called Gasdermins (GSDMs), which appears downstream from the activation of the inflammasome. Clear evidence of enhanced pyroptosis-related proteins activity in common NDs has coincided with abnormal aggregation of pathological proteins (such as Aβ, tau, α-synuclein et al.), making pyroptosis an attractive direction for the recent study of NDs. The purpose of this review is to provide an overview of the molecular mechanisms driving pyroptosis, the mechanistic links between pyroptosis and NDs, and emerging therapeutic strategies in Traditional Chinese Medicine (TCM) to inhibit pyroptosis for the treatment of NDs.

The role of NLRP3 inflammasome-mediated pyroptosis in ischemic stroke and the intervention of traditional Chinese medicine

Ischemic stroke (IS) is the second leading cause of death and disability in the world. Pyroptosis, a form of programmed cell death initiated by caspases, participates in the occurrence and development of IS. Because it can increase cell membrane permeability, mediate the release of inflammatory factors, and aggravate inflammation, inhibiting this process can significantly reduce the pathological injury of IS. The nucleotide binding oligomerization domain-like receptor family pyrin domain protein 3 (NLRP3) is a multiprotein complex whose activation is the core link of pyroptosis. In recent years, studies have reported that traditional Chinese medicine (TCM) could regulate pyroptosis mediated by NLRP3 inflammasome through multi-channel and multi-target networks and thus exert the effect against IS. This article reviews 107 papers published in recent years in PubMed, Chinese National Knowledge Infrastructure (CNKI), and WanFang Data in recent years. It has found that the activation factors of NLRP3 inflammasome include ROS, mitochondrial dysfunction, K⁺, Ca²⁺, lysosome rupture, and trans-Golgi breakdown. TLR4/NF-κB/NLRP3, ROS/TXNIP/NLRP3, AMPK/Nrf2/NLRP3, DRP1/NLRP3, TAK1/JNK/NLRP3 signaling pathways regulate the initiation and assembly of the NLRP3 inflammasome, subsequently induce pyroptosis, affecting the occurrence and development of IS. TCM can affect the above signaling pathways and regulate the pyroptosis mediated by NLRP3 inflammasome, so as to play a protective role against IS, which provides a new entry point for discussing the pathological mechanism of IS and a theoretical basis for developing TCM treasure house.

Pyroptosis as a candidate therapeutic target for Alzheimer’s disease

Pyroptosis is a form of cell death mediated by inflammasomes and gasdermins, and the relevance of pyroptosis to neurodegenerative diseases is currently receiving increasing attention. Alzheimer’s disease (AD) is a chronic progressive neurodegenerative disease that is closely associated with neuroinflammation. Its main pathological features include β-amyloid (Aβ) deposition, Tau protein hyperphosphorylation and neuronal loss. Aβ, tau-induced microglia pyroptosis and polarization leading to neuroinflammation play an important role in the pathogenesis of AD. Studying the pathogenesis and treatment of AD based on cellular pyroptosis has become a new direction in AD research. In this paper, we review the research progress of pyroptosis and will focus on the pathogenic roles of pyroptosis in AD and the role of targeted inhibition of inflammasome-dependent pyroptosis in AD treatment. These results deepen our understanding of the pathogenesis of AD and provide ideas for the development of new drugs based on the regulation of pyroptosis in AD patients.

Mechanisms of NLRP3 activation and pathology during neurodegeneration

Inflammasomes are multiprotein complexes that are mainly present in resident and infiltrating immune cells in the central nervous system. Inflammasomes function as intracellular sensors of immunometabolic stress, infection and changes in the local microenvironment. Inflammasome assembly in response to these 'danger signals', triggers recruitment and cluster-dependent activation of caspase-1 and the subsequent proteolytic activation of inflammatory cytokines such as interleukin-1β and interleukin-18. This is typically followed by a form of inflammatory cell death through pyroptosis. Since the discovery of inflammasomes in 2002, they have come to be recognized as central regulators of acute and chronic inflammation, a hallmark of progressive neurological diseases. Indeed, over the last decade, extensive inflammasome activation has been found at the sites of neuropathology in all progressive neurodegenerative diseases. Disease-specific misfolded protein aggregates which accumulate in neurodegenerative diseases, such as alpha synuclein or beta amyloid, have been found to be important triggers of NLRP3 inflammasome activation in the central nervous system. Together, these discoveries have transformed our understanding of how chronic inflammation is triggered and sustained in the central nervous system, and how it can contribute to neuronal death and disease progression in age-related neurodegenerative diseases. Therapeutic strategies around inhibition of NLRP3 activation in the central nervous system are already being evaluated to determine their effectiveness to slow progressive neurodegeneration. This review summarizes current understanding of inflammasomes in the most prevalent neurodegenerative diseases and discusses current knowledge gaps and inflammasome inhibition as a therapeutic strategy.

NLRP1 Inflammasome Activation in the Hippocampal Formation in Alzheimer's Disease: Correlation with Neuropathological Changes and Unbiasedly Estimated Neuronal Loss

Neuroinflammation is one of the core pathological features of Alzheimer's disease (AD) as both amyloid β (Aβ) and tau monomers and oligomers can trigger the long-term pro-inflammatory phenotype of microglial cells with consequent overactivation of the inflammasomes. To investigate the NLRP1 inflammasome activation in AD, we analyzed the expression of NLRP1, ASC, cleaved gasdermin (cGSDMD), and active caspase-6 (CASP-6) proteins in each hippocampal subdivision (hilar part of CA3, CA2/3, CA1, subiculum) of postmortem tissue of 9 cognitively healthy controls (HC) and 11 AD patients whose disease duration varied from 3 to 7 years after the clinical diagnosis. The total number of neurons, along with the total number of neurofibrillary tangles (NFTs), were estimated in Nissl- and adjacent modified Bielschowsky-stained sections, respectively, using the optical disector method. The same 9 HC and 11 AD cases were additionally semiquantitatively analyzed for expression of IBA1, HLA-DR, and CD68 microglial markers. Our results show that the expression of NLRP1, ASC, and CASP-6 is present in a significantly greater number of hippocampal formation neurons in AD brains compared to controls, suggesting that the NLRP1 inflammasome is more active in the AD brain. None of the investigated inflammasome and microglial markers were found to correlate with the age of the subjects or the duration of AD. However, besides positive correlations with microglial IBA1 expression in the subiculum and with microglial CD68 expression in the CA1 field and subiculum in the AD group, the overall NLRP1 expression in the hippocampal formation was positively correlated with the number of NFTs, thus providing a causal link between neuroinflammation and neurofibrillary degeneration. The accumulation of AT8-immunoreactive phosphorylated tau proteins that we observed at nuclear pores of large pyramidal neurons of the Ammon's horn further supports their role in the extent of neuronal dysfunction and degeneration in AD. This is important because unlike fibrillar amyloid-β deposits that are not related to dementia severity, total NFTs and neuron numbers in the hippocampal formation, especially in the CA1 field, are the best correlates of cognitive deterioration in both human brain aging and AD. Our findings also support the notion that the CA2 field vulnerability is strongly linked to specific susceptibilities to different tauopathies, including primary age-related tauopathy. Altogether, these findings contrast with reports of nonsignificant microglial activation in aged nonhuman primates and indicate that susceptibility to inflammasome activation may render the human brain comparatively more vulnerable to neurodegenerative changes and AD. In conclusion, our results confirm a key role of NLRP1 inflammasome in AD pathogenesis and suggest NLRP1 as a potential diagnostic marker and therapeutic target to slow or prevent AD progression.

Research Progress of Pyroptosis in Alzheimer's Disease

Alzheimer's disease (AD) is a disease characterized by insidious and progressive neurodegeneration, with clinical syndromes of memory and visuospatial skills damage. The pathogenic mechanism of AD is complex in which neural inflammation and neuron death play important roles. Pyroptosis, an inflammatory programmed cell death, has been reported to be involved in neuron death. Pyroptosis is executed by the protein family of gasdermins which punch pores on plasma membrane when activated by the upstream signals including the activation of NLRP3 and caspases, and subsequently triggers the inflammatory cascades featured by the release of interleukin (IL) -1β and IL-18. Herein, we summarized the current research on the roles of neuron pyroptosis in AD, aiming to provide a comprehensive view of the molecular mechanisms underlying AD pathogenesis and potential therapeutic targets for AD.

Mechanism Underlying Acupuncture Therapy in Spinal Cord Injury: A Narrative Overview of Preclinical Studies

Spinal cord injury (SCI) results from various pathogenic factors that destroy the normal structure and function of the spinal cord, subsequently causing sensory, motor, and autonomic nerve dysfunction. SCI is one of the most common causes of disability and death globally. It leads to severe physical and mental injury to patients and causes a substantial economic burden on families and the society. The pathological changes and underlying mechanisms within SCI involve oxidative stress, apoptosis, inflammation, etc. As a traditional therapy, acupuncture has a positive effect promoting the recovery of SCI. Acupuncture-induced neuroprotection includes several mechanisms such as reducing oxidative stress, inhibiting the inflammatory response and neuronal apoptosis, alleviating glial scar formation, promoting neural stem cell differentiation, and improving microcirculation within the injured area. Therefore, the recent studies exploring the mechanism of acupuncture therapy in SCI will help provide a theoretical basis for applying acupuncture and seeking a better treatment target and acupuncture approach for SCI patients.

Thioredoxin-1 inhibits amyloid-β25-35-induced activation of NLRP1/caspase-1/GSDMD pyroptotic pathway in PC12 cells

BACKGROUND

Alzheimer's disease (AD), the most common neurodegenerative disease, is charactered by these accepted pathological features, such as β-amyloid (Aβ) plaques outside the neurons and neurofibrillary tangles inside the neurons. In recent years, several studies have demonstrated that pyroptosis is associated with the development of AD process. However, whether Aβ_25-35 induces pyroptosis is still unclear. Thioredoxin-1 (Trx-1), an intracellular multifunctional protein, showed neuroprotective roles by inhibiting the neurotoxicity of Aβ, attenuating the apoptosis of brain neurons and improving the spatial learning and memory ability in AD models. Whether Trx-1 could inhibit pyroptosis in AD needs to be further investigated.

METHODS AND RESULTS

In the present study, MTT assay was employed to detected the viability. Western blotting was employed to detect the protein levels. Enzyme linked immunosorbent assay was used to examine the intracellular and extracellular levels of IL-18 and IL-1β. Chronic Aβ_25-35 treatment remarkedly compromised the viability of PC12 cells, increased the expression of NOD-like receptor pyrin domain containing 1 (NLRP-1), caspase-1 and gasdermin D (GSDMD), and promoted the extracellular release of interleukin (IL)-18 and IL-1β. Simultaneously, Aβ_25-35 treatment also significantly reduced the intracellular protein levels of Trx-1. Pharmacological inhibition of Trx-1 activity further decreased the cell viability, activated the NLRP-1/caspase-1/GSDMD pyroptotic pathway, and exacerbated the extracellular release of IL-18 and IL-1β.

CONCLUSIONS

These data suggest that Trx-1 may play a potential inhibitory effect on Aβ_25-35-induced pyroptosis.

Spinal Tuina Improves Cognitive Impairment in Cerebral Palsy Rats through Inhibiting Pyroptosis Induced by NLRP3 and Caspase-1

Cerebral palsy (CP) is a severe cerebral disease with high mortality and morbidity, which leads to great challenges for the suffering children and their families. Hence, the need for the efficacious and safe treatments is urgent. As a physical therapy arising from traditional Chinese medicine (TCM), Tuina has shown multiple effects on various diseases, including cerebral palsy. Nevertheless, the detailed mechanisms of Tuina on CP remain unknown, which impedes its further clinical application. Herein, we explored the effects of Tuina on CP and its potential mechanisms. Thirty Sprague Dawley (SD) male rats were randomly divided into sham, model, and Tuina groups (model + Tuina). CP rat model was established by hypoxia-ischemia via permanent occlusion of left common carotid artery and hypoxia for 2.5 hours caused by anaerobic environment, which was subsequently followed by onset of Tuina treatment from postnatal day 7 (P7) to P49. After completion of Tuina treatment, the behavioral tests showed that Tuina treatment not only improved the retarded body weight and impaired motor balance function, but also ameliorated weakened learning and memory function of CP rats. Moreover, immunohistochemistry and western blot also revealed a reduced expression of NLRP3 inflammasome and corresponding pyroptosis-related molecules induced by NLRP3 in CP rats after Tuina treatment. Therefore, our study indicated that Tuina treatment may improve impaired neurocognitive function of CP rats, which was possibly realised via inhibiting NLRP3-induced pyroptosis.