Biochemical characterization of proliferative and differentiated SH-SY5Y cell line as a model for Parkinson's disease

Proliferation of SH-SY5Y neuroblastoma cells on confined spaces

BACKGROUND

Microfluidics offers precise drug delivery and continuous monitoring of cell functions, which is crucial for studying the effects of toxins and drugs. Ensuring proper cell growth in these space-constrained systems is essential for obtaining consistent results comparable to standard Petri dishes.

NEW METHOD

We investigated the proliferation of SH-SY5Y cells on circular polycarbonate chambers with varying surface areas. SH-SY5Y cells were chosen for their relevance in neurodegenerative disease research.

RESULTS

Our study demonstrates a correlation between the chamber surface area and SH-SY5Y cell growth rates. Cells cultured in chambers larger than 10 mm in diameter exhibited growth comparable to standard 60-mm dishes. In contrast, smaller chambers significantly impeded growth, even at identical seeding densities. Similar patterns were observed for HeLaGFP cells, while 16HBE14σ cells proliferated efficiently regardless of chamber size. Additionally, SH-SY5Y cells were studied in a 12-mm diameter sealed chamber to assess growth under restricted gas exchange conditions.

COMPARISON WITH EXISTING METHODS

Our findings underscore the limitations of small chamber sizes in microfluidic systems for SH-SY5Y cells, an issue not typically addressed by conventional methods.

CONCLUSIONS

SH-SY5Y cell growth is highly sensitive to spatial constraints, with markedly reduced proliferation in chambers smaller than 10 mm. This highlights the need to carefully consider chamber size in microfluidic experiments to achieve cell growth rates comparable to standard culture dishes. The study also shows that while SH-SY5Y and HeLaGFP cells are affected by chamber size, 16HBE14σ cells are not. These insights are vital for designing effective microfluidic systems for bioengineering research.

The SH-SY5Y cell line: a valuable tool for Parkinson's disease drug discovery

INTRODUCTION

Owing to limited efficient treatment strategies for highly prevalent and distressing Parkinson's disease (PD), an impending need emerged for deciphering new modes and mechanisms for effective management. SH-SY5Y-based in vitro neuronal models have emerged as a new possibility for the elucidation of cellular and molecular processes in the pathogenesis of PD. SH-SY5Y cells are of human origin, adhered to catecholaminergic neuronal attributes, which consequences in imparting wide acceptance and significance to this model over conventional in vitro PD models for high-throughput screening of therapeutics.

AREAS COVERED

Herein, the authors review the SH-SY5Y cell line and its value to PD research. The authors also provide the reader with their expert perspectives on how these developments can lead to the development of new impactful therapeutics.

EXPERT OPINION

Encouraged by recent research on SH-SY5Y cell lines, it was envisaged that this in vitro model can serve as a primary model for assessing efficacy and toxicity of new therapeutics as well as for nanocarriers' capacity in delivering therapeutic agents across BBB. Considering the proximity with human neuronal environment as in pathogenic PD conditions, SH-SY5Y cell lines vindicated consistency and reproducibility in experimental results. Accordingly, exploitation of this standardized SH-SY5Y cell line can fast-track the drug discovery and development path for novel therapeutics.

Active compounds from Calendula officinalis flowers act via PI3K and ERK signaling pathways to offer neuroprotective effects against Parkinson's disease

Calendula officinalis flowers, associated with diverse biological effects, could be utilized as functional food ingredients to play a crucial role in human health. In this study, we examined the anti-PD activity of C. officinalis flower extracts and investigated their bioactive compounds and molecular mechanisms based on LC-MS/MS assay, bioinformatic exploration and in vitro treatment of SH-SY5Y cells. C. officinalis extracts exhibited significant positive effects on the length and fluorescence density of the dopaminergic neuron region in zebrafish larvae. At 10 μg/mL, the extract restored the length to 96.54% and fluorescence density to 87.77% of the control values, which was equivalent to the effect of a positive drug, indicating the extract's powerful potential to alleviate PD symptoms. Five active compounds, including chlorogenic acid, 3,4-dicaffeoylquinic acid (DA), rutin, isorhamnetin 3-O-glucoside (IG) and calenduloside E (CE) were identified in extracts by LC-QTOF-MS/MS. Hsp90α, PI3K and ERK were revealed as core targets of DA, IG and CE in relation to anti-PD activity. The compounds docked deeply within the pocket region of Hsp90α protein, and their binding energies (∆G b) were -6.93 kcal/mol (DA), -6.51 kcal/mol (IG) and -3.03 kcal/mol (CE), respectively. Subsequently, they concurrently activated the PI3K/Akt signaling pathway and inhibited the ERK signaling pathway, thereby preventing neuronal death and alleviating neuronal degeneration. These compounds from C. officinalis could be potent nutraceutical agents with protective properties that may shield dopaminergic neurons against the damage caused by PD. Our findings provide a basis for utilizing the C. officinalis flowers in functional foods.

Dopamine-Induced Oligomers of α-Synuclein Inhibit Amyloid Fibril Growth and Show No Toxicity

Parkinson's disease is characterized by the selective death of dopaminergic neurons in the midbrain and accumulation of amyloid fibrils composed of α-synuclein (αSyn). Current treatment involves approaches that compensate the death of dopaminergic neurons by increasing the dopamine levels in remaining cells. However, dopamine can interact with αSyn and produce oligomeric species which were reported to be toxic in many models. We studied formation of dopamine-induced αSyn oligomers and their effect on the αSyn aggregation. Using the Thioflavin T kinetic assay, we have shown that small oligomers efficiently inhibit αSyn fibrillization by binding to fibril ends and blocking the elongation. Moreover, all the fractions of oligomer species proved to be nontoxic in the differentiated SH-SY5Y cell model and showed negligible neurotoxicity on isolated rat synaptosomes. The observed inhibition is an important insight in understanding of dopamine-enhancing therapy on Parkinson's disease progression and explains the absence of pathology enhancement.

Acrylamide Induces Neurotoxicity in SH-SY5Y Cells via NLRP3-mediated Pyroptosis

Acrylamide (ACR), a soft electrophile, is a typical environmental and food contaminant that presents potential health hazards and, consequently, is attracting increasing attention in the quest for its control. ACR neurotoxicity has been widely reported in experimental animals and attributed to neuroinflammation; however, the mechanisms involved therein require clarification. In this study, we used a neuron cell model to investigate the mechanisms of ACR-induced neuroinflammation and pyroptosis. The results showed that ACR treatment induced lytic cell death morphologically under both the canonical pyroptotic pathway (NOD-like receptor protein 3 (NLRP3)-apoptosis-associated speck-like protein containing CARD (ASC)-cysteinyl aspartate specific proteinase 1 (caspase-1)-gasdermin D (GSDMD)-interleukin-1β (IL-1β)/interleukin-18 (IL-18)) and an alternative pyroptotic pathway (cysteinyl aspartate specific proteinase 3 (caspase-3)-gasdermin E (GSDME)-IL-1β/IL-18) in SH-SY5Y cells. Moreover, the lactate dehydrogenase (LDH) production, cytokines release, and lytic cell death induced by ACR were diminished by caspase-1 and -3 inhibitors. Furthermore, the knockdown of caspase-1 by small interfering RNA attenuated ACR-induced lytic cell death, suggesting that canonical pyroptosis (the NLRP3-caspase 1-GSDMD-IL-1β signaling axis) played a primary role in the ACR-induced pyroptosis. Of the two pyroptotic-related pathways, the NLRP3 inflammasome cascade was activated first within the 6-h period of ACR exposure, while the activation of the alternative pyroptotic pathway was delayed. Collectively, these results indicate that ACR mainly induces NLRP3-related neuroinflammation and pyroptosis in SH-SY5Y cells, which is, thus, suggestive of an alternative mechanism for ACR-induced neurotoxicity.

Citronellol Prevents 6-OHDA-Induced Oxidative Stress, Mitochondrial Dysfunction, and Apoptosis in Parkinson Disease Model of SH-SY5Y Cells via Modulating ROS-NO, MAPK/ERK, and PI3K/Akt Signaling Pathways

Parkinson disease is a neurodegenerative disorder distinguished by dopaminergic shortage in the striatum and the accumulation of α-synuclein neuronal aggregates in the brains of patients. Since, there is no accurate treatment available for Parkinson disease, researches are designed to alleviate the pathognomonic symptoms such as neuroinflammation, oxidative stress, mitochondrial dysfunction, and apoptosis. Accordingly, a number of compounds have been reported to inhibit these pathognomonic symptoms. In this study, we have assessed the neuroprotective potential of citronellol against 6-OHDA-induced neurotoxicity in SH-SY5Y cells. The results found that citronellol treatment effectively hindered the cell death caused by 6-OHDA and thereby maintaining the cell viability in SH-SY5Y cells at 50 µg/mL concentration. As expected, the citronellol treatment significantly reduced the 6-OHDA-induced secretion of inflammatory factors (IL-1β, IL-6, and TNF-α), which was obtained through ELISA technique. Similarly, citronellol hindered the 6-OHDA-induced oxidative stress by lowering the intracellular ROS and NO level and MDA leakage along with increased expression of SOD level in SH-SY5Y cells. The JC-1 staining showed that 6-OHDA increased the number of green fluorescent dots with ruptured mitochondrial membrane potential, while citronellol increased the amount of red fluorescent, showing the rescue potential against the 6-OHDA-induced mitochondrial dysfunction. Furthermore, citronellol hampered the 6-OHDA-induced apoptosis via the suppression of Bcl-2/Bax pathway. The western blotting results hypothesized that citronellol rescued SH-SY5Y cells from 6-OHDA-induced neurotoxicity via modulating ROS-NO, MAPK/ERK, and PI3K/Akt signaling pathways. However, further clinical trials are required to verify the anti-Parkinson efficacy.

Discovery of styrylaniline derivatives as novel alpha-synuclein aggregates ligands

Parkinson's disease (PD) is the second most common neurodegenerative disorder. Early diagnosis is the key to treatment but is still a great challenge in the clinic now. The discovery of alpha-synuclein (α-syn) aggregates ligands has become an attractive strategy to meet the early diagnosis of PD. Herein, we designed and synthesized a series of styrylaniline derivatives as novel α-syn aggregates ligands. Several compounds displayed good potency to α-syn aggregates with K_d values less than 0.1 μM. The docking study revealed that the hydrogen bonds and cation-pi interaction between ligands and α-syn aggregates would be crucial for the activity. The representative compound 7-16 not only detected α-syn aggregates in both SH-SY5Y cells and brain tissues prepared from two kinds of α-syn preformed-fibrils-injected mice models but also showed good blood-brain barrier penetration characteristics in vivo with a brain/plasma ratio over 1.0, which demonstrates its potential as a lead compound for further development of in vivo imaging agents.

Super-assembled silica nanoprobes for intracellular Zn(II) sensing and reperfusion injury treatment through in situ MOF crystallization

The production of excess free zinc ions (Zn²⁺) in cells has been identified as an important cause of cell injury or apoptosis after ischemia reperfusion. Thus, developing a nanosystem with multiple therapeutic functions to significantly eliminate multiple cell injury factors is of great interest. Here, a super-assembled nanosystem consisting of a polyethylene glycol (PEG) surface-modified mesoporous silica nanoparticle (MSN) encapsulating 2-methylimidazole (2MI) and a Zn²⁺ probe (PZn) was fabricated. The 2MI-P@MSN nanoassemblies showed a "turn-on" fluorescence signal at 476 nm toward zinc ions due to the presence of PZn. Besides, zeolitic imidazolate framework-8 (ZIF-8) could be assembled on the site intracellularly after 2MI chelating with free zinc ions. The experimental results revealed that 2MI-P@MSN exhibited excellent biocompatibility and non-cytotoxicity, and was able to provide satisfactory protection to OGD/R-treated cells based on zinc ion adsorption and the antioxidant effect of ZIF-8, which could effectively improve the survival rate of reperfusion injury cells from 52% to 73%. Notably, selective and quantitative sensing of Zn²⁺ was successfully carried out in the cells. This strategy highlights the potential of the detection, absorption and assembly of excess zinc ions simultaneously for cell therapy, which provides a promising therapeutic method for ischemic stroke, oxidative damage and diseases associated with zinc ion accumulation.

Protective effects of medium chain triglyceride diet in a mouse model of Dravet syndrome

OBJECTIVE

Dravet syndrome (DS) is a severe developmental and epileptic encephalopathy with early childhood onset. Patients with DS do not respond well to antiepileptic drugs and have only a few treatment options available. Here, we evaluated the effect of medium chain triglyceride (MCT) diet therapy in a mouse model of DS.

METHODS

Scn1a^R1407X/+ DS mice were given diets supplemented with MCTs with varying ratios of decanoic (C10) and octanoic (C8) acid or a control diet for 4 weeks. Video monitoring was performed to evaluate spontaneous convulsive seizure frequency. Susceptibility to hyperthermia-induced seizures was also examined. Medium chain fatty acids, and mitochondrial and antioxidant markers were assessed in brain homogenate.

RESULTS

Dietary intervention with MCTs significantly prolonged survival and reduced convulsive seizure frequency during the critical period of highest seizure occurrence in the Scn1a^R1407X/+ DS mice. Moreover, MCT diet therapy showed protective effects against hyperthermia-induced seizures. We demonstrated that coadministration of C10/C8 was effective at reducing both seizures and mortality, whereas C10 alone only reduced mortality, suggesting that the ratio of C10 to C8 in the MCT is an important factor for efficacy. When C10 and C8 are supplemented at an 80:20 ratio in the diet, C10 accumulates in the brain in high enough concentrations to enhance brain energy metabolism by both stimulating mitochondrial enrichment and increasing its antioxidant status.

SIGNIFICANCE

The results from this study indicate that MCT diet therapy may provide therapeutic benefits in DS. Future clinical studies would elucidate whether these positive effects are mirrored in human patients.