Effect of photodynamic therapy on expression of HRAS, NRAS and caspase 3 genes at mRNA levels, apoptosis of head and neck squamous cell carcinoma cell line

Application of liposomal nanoparticles of berberine in photodynamic therapy of A549 lung cancer spheroids

Application of liposomes is a critical strategy in drug delivery and increase cellular uptake of drugs having low water solubility. Berberine (BBR) is a bioactive compound found in several plants, including Goldenseal, Barberry, and Oregon grape. It has garnered attention for its various health benefits, particularly in metabolic health and antimicrobial activity. However, one of the challenges associated with BBR is its water solubility. Moreover, BBR has photosensitizing potential via absorbance of light and generation of free radicals. Hence, to improve water solubility and bioavailability, one of the important strategies employed is using lipid-based carriers to enhance solubility. In this study we employed liposomes to deliver BBR in A549 lung cancer spheroid cells to enhance photodynamic therapy efficacies. Results from the EDS and UV-Vis spectroscopy revealed that the BBR had been loaded onto liposomes, with three peaks appearing between 250 and 450 nm. Morphology of Lipo@BBR nanocomplex was in wavy crest shape and the size was 56.99 ± 3.74 nm in SEM and TEM analysis, respectively. FTIR data illustrated that Lipo@BBR has four significant peaks at 1250, 1459, 1736, and 2907 cm-1. DLS data showed that Lipo@BBR has a negative surface charge with a -10.7 Zeta Potential (mV). Additionally, based on Zetasizer measurements, the size of Lipo@BBR complex was 82.7 ± 6.5. Cytotoxicity assay investigation with MTT assay presented that IC50 of Lipo@BBR in PDT was 10 ± 0.5 μg/mL that led to a volume reduction of the A549 spheroids after five sessions of PDT fractionation (total light dose was set at 25 J/cm2). qPCR and immunofluorescence results demonstrated that Lipo@BBR increases the BAX/BCL2 ratio in A549 spheroid cells, hence improving PDT efficiency. In conclusion, our results illustrated that safe dose of Lipo@BBR (10 ± 0.5 μg/mL) in PDT fractionation protocol can be one of the strategies to suppress the tumor volume and cell death proliferation. Authors recommend using Lipo@BBR nanocomplex in PDT fractionation as well as more in vivo investigation is warranted.

Photodynamic treatment modulates various GTPase and cellular signalling pathways in Tauopathy

The application of photo-excited dyes for treatment is known as photodynamic therapy (PDT). PDT is known to target GTPase proteins in cells, which are the key proteins of diverse signalling cascades which ultimately modulate cell proliferation and death. Cytoskeletal proteins play critical roles in maintaining cell integrity and cell division. Whereas, it was also observed that in neuronal cells PDT modulated actin and tubulin resulting in increased neurite growth and filopodia. Recent studies supported the role of PDT in dissolving the extracellular amyloid beta aggregates and intracellular Tau aggregates, which indicated the potential role of PDT in neurodegeneration. The advancement in the field of PDT led to its clinical approval in treatment of cancers, brain tumour, and dermatological acne. Although several question need to be answered for application of PDT in neuronal cells, but the primary studies gave a hint that it can emerge as potential therapy in neural cells.

Blockade of adenosine A2A receptor alleviates cognitive dysfunction after chronic exposure to intermittent hypoxia in mice

Obstructive sleep apnea-hypopnea syndrome (OSAHS) is widely known for its multiple systems damage, especially neurocognitive deficits in children. Since their discovery, adenosine A_2A receptors (A_2ARs) have been considered as key elements in signaling pathways mediating neurodegenerative diseases such as Huntington's and Alzheimer's, as well as cognitive function regulation. Herein, we investigated A_2AR role in cognitive impairment induced by chronic intermittent hypoxia (CIH). Mice were exposed to CIH 7 h every day for 4 weeks, and intraperitoneally injected with A_2AR agonist CGS21680 or A_2AR antagonist SCH58261 half an hour before IH exposure daily. The 8-arm radial arm maze was utilized to assess spatial memory after CIH exposures.To validate findings using pharmacology, the impact of intermittent hypoxia was investigated in A_2AR knockout mice. CIH-induced memory dysfunction was manifested by increased error rates in the radial arm maze test. The behavioral changes were associated with hippocampal pathology, neuronal apoptosis, and synaptic plasticity impairment. The stimulation of adenosine A_2AR exacerbated memory impairment with more serious neuropathological damage, attenuated long-term potentiation (LTP), syntaxin down-regulation, and increased BDNF protein. Moreover, apoptosis-promoting protein cleaved caspase-3 was upregulated while anti-apoptotic protein Bcl-2 was downregulated. Consistent with these findings, A_2AR inhibition with SCH58261 and A_2AR deletion exhibited the opposite result. Overall, these findings suggest that A_2AR plays a critical role in CIH-induced impairment of learning and memory by accelerating hippocampal neuronal apoptosis and reducing synaptic plasticity. Blockade of adenosine A_2A receptor alleviates cognitive dysfunction after chronic exposure to intermittent hypoxia in mice.