Effect of risperidone on proliferation and apoptosis of MC3T3-E1 cells

Risperidone accelerates bone loss in mice models of schizophrenia by inhibiting osteoblast autophagy

Background

Risperidone (RIS) is the first-line drug in the clinical treatment of schizophrenia, and long-term use may lead to bone loss and even osteoporosis. This study investigated whether the mechanism of RIS-induced bone loss is related to autophagy.

Methods

The schizophrenia mice were established with the administration of MK-801. Then, RIS were injected, or autophagy inducer rapamycin (RAPA) co-injected for 8 weeks. Cognitive performance was determined by the novel object recognition and Open field tests. Bone loss of schizophrenia mice were assessed using microCT, H&E staining, ALP staining, ARS staining and WB, respectively. Autophagy of schizophrenia mice were detected by immunofluorescence, transmission electron microscopy (TEM) and WB, respectively. In addition, osteogenic differentiation of MC3T3-E1 and BMSCs cells were assessed using H&E staining, ALP staining, ARS staining and WB, respectively.

Results

In the present study, we found that RIS treatment can promote bone loss in schizophrenia mice and inhibit osteogenic differentiation of MC3T3-E1 and BMSCs cells. Interesting, the number of autophagosome and autophagy-related protein expression were decreased after RIS treatment. However, the bone loss and inhibition of osteogenic differentiation induced by RIS in schizophrenia mice were reversed by autophagy inducer RAPA.

Conclusion

RIS significantly increased bone loss and inhibited osteogenic differentiation in schizophrenia mice; the underlying mechanism entails suppressing osteoblast autophagy.

Transcriptome analysis to explore the mechanism of downregulated TNIK influencing the effect of risperidone

Background

Risperidone is one of the most reliable and effective antipsychotics for schizophrenia treatment. However, the mechanism of action of risperidone is not yet fully understood. Traf2 and Nck-interacting protein kinase (TNIK), a schizophrenia susceptibility gene, is associated with risperidone treatment response. Our previous in vitro experiments confirmed that downregulated TNIK affected the effect of risperidone on downstream targets. However, the effect of downregulated TNIK on risperidone-induced molecular expression remains to be further explored.

Methods

Transcriptome analysis was performed on U251 cells subjected to risperidone, TNIK siRNA, and no treatment, respectively. Compared to the no-treatment group, two groups of DEGs were screened out and then intersected with the schizophrenia-related genes to screen the cross-talk genes. Those DEGs were analyzed using GO and KEGG. STRING and Cytoscape were used to construct a protein-protein interaction (PPI) network for the cross-talk gene.

Results

The results showed that the parathyroid hormone synthesis, secretion, and action were significantly enriched after risperidone treatment. Downregulated TNIK could have an impact on the collagen-containing extracellular matrix, signaling receptor activator activity, and PI3K-Akt signaling pathway. Interestingly, bone mineralization function and calcium signaling pathway were enriched in the cross-talk genes. Additionally, FGFR2, FGF1, and FGFR might be the potential targets for TNIK affecting the effects of risperidone.

Conclusion

The study indicated that risperidone primarily influences functions and/or pathways associated with bone metabolism, potentially contributing to the adverse effect of osteoporosis. Our study may offer a novel perspective on investigating the mechanisms underlying the adverse effects of risperidone.

Dissolving microarray patches for transdermal delivery of risperidone for schizophrenia management

Schizophrenia is a psychiatric disorder that results from abnormal levels of neurotransmitters in the brain. Risperidone (RIS) is a common drug prescribed for the treatment of schizophrenia. RIS is a hydrophobic drug that is typically administered orally or intramuscularly. Transdermal drug delivery (TDD) could potentially improve the delivery of RIS. This study focused on the development of RIS nanocrystals (NCs), for the first time, which were incorporated into dissolving microneedle array patches (DMAPs) to facilitate the drug delivery of RIS. RIS NCs were formulated via wet-media milling technique using poly(vinylalcohol) (PVA) as a stabiliser. NCs with particle size of 300 nm were produced and showed an enhanced release profile up to 80 % over 28 days. Ex vivo results showed that 1.16 ± 0.04 mg of RIS was delivered to both the receiver compartment and full-thickness skin from NCs loaded DMAPs compared to 0.75 ± 0.07 mg from bulk RIS DMAPs. In an in vivo study conducted using female Sprague Dawley rats, both RIS and its active metabolite 9-hydroxyrisperidone (9-OH-RIS) were detected in plasma samples for 5 days. In comparison with the oral group, DMAPs improved the overall pharmacokinetic profile in plasma with a ∼ 15 folds higher area under the curve (AUC) value. This work has represented the novel delivery of the antipsychotic drug, RIS, through microneedles. It also offers substantial evidence to support the broader application of MAPs for the transdermal delivery of poorly water-soluble drugs.

Development of intranasal implantable devices for schizophrenia treatment

In this work the preparation and characterisation of intranasal implants for the delivery of risperidone (RIS) is described. The aim of this work is to develop better therapies to treat chronic conditions affecting the brain such as schizophrenia. This type of systems combines the advantages of intranasal drug delivery with sustained drug release. The resulting implants were prepared using biodegradable materials, including poly(caprolactone) (PCL) and poly(lactic-co-glycolic acid) (PLGA). These polymers were combined with water-soluble compounds, such as poly(ethylene glycol) (PEG) 600, PEG 3000, and Tween® 80 using a solvent-casting method. The resulting implants contained RIS loadings ranging between 25 and 50%. The obtained implants were characterised using a range of techniques including thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), attenuated total reflectance-Fourier transform infrared (ATR-FTIR), X-ray diffraction (XRD), and Scanning Electron Microscopy (SEM). Moreover, in vitro RIS release was evaluated showing that the addition of water-soluble compounds exhibited significant faster release profiles compared to pristine PCL and PLGA-based implants. Interestingly, PCL-based implants containing 25% of RIS and PLGA-based implants loaded with 50% of RIS showed sustained drug release profiles up to 90 days. The former showed faster release rates over the first 28 days but after this period PLGA implants presented higher release rates. The permeability of RIS released from the implants through a model membrane simulating nasal mucosa was subsequently evaluated showing desirable permeation rate of around 2 mg/day. Finally, following in vitro biocompatibility studies, PCL and PLGA-based implants showed acceptable biocompatibility. These results suggested that the resulting implants displayed potential of providing prolonged drug release for brain-targeting drugs.

Effects of Psychotropic Drugs on Ribosomal Genes and Protein Synthesis

Altered protein synthesis has been implicated in the pathophysiology of several neuropsychiatric disorders, particularly schizophrenia. Ribosomes are the machinery responsible for protein synthesis. However, there remains little information on whether current psychotropic drugs affect ribosomes and contribute to their therapeutic effects. We treated human neuronal-like (NT2-N) cells with amisulpride (10 µM), aripiprazole (0.1 µM), clozapine (10 µM), lamotrigine (50 µM), lithium (2.5 mM), quetiapine (50 µM), risperidone (0.1 µM), valproate (0.5 mM) or vehicle control for 24 h. Transcriptomic and gene set enrichment analysis (GSEA) identified that the ribosomal pathway was altered by these drugs. We found that three of the eight drugs tested significantly decreased ribosomal gene expression, whilst one increased it. Most changes were observed in the components of cytosolic ribosomes and not mitochondrial ribosomes. Protein synthesis assays revealed that aripiprazole, clozapine and lithium all decreased protein synthesis. Several currently prescribed psychotropic drugs seem to impact ribosomal gene expression and protein synthesis. This suggests the possibility of using protein synthesis inhibitors as novel therapeutic agents for neuropsychiatric disorders.

Possible involvement of apoptosis in the antipsychotics side effects: A minireview

Antipsychotics are used in the treatment of schizophrenia and other psychiatric disorders. Generally they are divided into typical and atypical ones, according to the fact that atypical antipychotics induce less side effects and are more effective in terms of social and cognitive improvements. Their pharmacological effects are mediated via broad range of receptors that consequently influence different cellular signaling pathways. Antipsychotics produce udesirable side effects that range from relatively minor to life-threatening ones. In vitro and in vivo studies have pointed to neurotoxic effect exerted by some antipsychotics and have shown that apoptosis might play role in some side effects induced by antipsyschotics, including tardive dyskinesia, weight gain, agranulocytosis, osteoporosis, myocarditis, etc. Although cumulative data have suggested safety of atypical antipsychotics use during pregnancy some of them have been shown to induce apoptotic neurodegenerative and structural changes in fetal brains with long-lasting impact on cognitive impairment of offsprings. Typical antipsychotics seem to be more cytotoxic than atypical ones. Recently, epidemiological studies have shown lower incidence of cancer in schizophrenic patients what suggest ability of antipsychotics to suppress risk of cancer development. Some antipsychotics have been reported to inhibit cancer cell proliferation and induce their apoptosis. Thus, antipsychotics apoptotic effect may be used as a tool in the treatmnet of some types of cancer, especially in combinatorial therapies. In this minireview, we focused on pro- and anti-apototic or "Dr. Jekyll and Mr. Hyde" effects of antipsychotics, which can be involved in their side effects, as well as their promising therapeutical indications. This article is protected by copyright. All rights reserved.

Housing Temperature Influences Atypical Antipsychotic Drug-Induced Bone Loss in Female C57BL/6J Mice

Atypical antipsychotic (AA) drugs, such as risperidone, are associated with endocrine and metabolic side effects, including impaired bone mineral density (BMD) acquisition and increased fracture risk. We have previously shown that risperidone causes bone loss through the sympathetic nervous system and that bone loss is associated with elevated markers of thermogenesis in brown and white adipose tissue. Because rodents are normally housed in sub‐thermoneutral conditions, we wanted to test whether increasing housing temperature would protect against bone loss from risperidone. Four weeks of risperidone treatment in female C57BL/6J mice at thermoneutral (28°C) housing attenuated risperidone‐induced trabecular bone loss and led to a low‐turnover bone phenotype, with indices of both bone formation and resorption suppressed in mice with risperidone treatment at thermoneutrality, whereas indices of bone resorption were elevated by risperidone at room temperature. Protection against trabecular bone loss was not absolute, however, and additional evidence of cortical bone loss emerged in risperidone‐treated mice at thermoneutrality. Taken together, these findings suggest thermal challenge may be in part responsible for bone loss with risperidone treatment and that housing temperature should be considered when assessing bone outcomes of treatments that impact thermogenic pathways. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

The Synergistic Effect of Nicotine and Staphylococcus aureus on Peri-Implant Infections

Smoking is considered a key risk factor for implant survival; however, how it interacts with the pathogens in peri-implant infections is not clear. Here, we identified that nicotine, the key component of cigarette smoking, can interact with Staphylococcus aureus and synergistically induce peri-implant infections in a rat osteolysis model. The nicotine–S. aureus combination group increased the gross bone pathology, osteolysis, periosteal reactions, and bone resorption compared to the nicotine or S. aureus single treated group (p < 0.05). Nicotine did not promote the proliferation of S. aureus both in vitro and in vivo, but it can significantly upregulate the expression of staphylococcal protein A (SpA), a key virulence factor of S. aureus. The nicotine–S. aureus combination also synergistically activated the expression of RANKL (receptor activator of nuclear factor-kappa B ligand, p < 0.05) to promote the development of peri-implant infections. The synergistic effects between nicotine and S. aureus infection can be a new target to reduce the peri-implant infections.

Production and identification of peptides with activity promoting osteoblast proliferation from meat dregs of Pinctada martensii

As a by-product of pearl production, Pinctada martensii meat dregs have a high level of protein but cannot be fully utilized. In this study, P. martensii meat dregs were first hydrolyzed by three pepsin enzymes, resulting in neutral proteinase enzymatic hydrolysate that had a higher effect on stimulating the proliferation of MC3T3-E1 cells, and cell proliferation increases of 37.37 ± 0.03%. Subsequently, after purification of alcohol precipitation, ultrafiltration, and Superdex G-25 gel chromatography, five fractions were further separated and purified in which fraction ZP2 could effectively improve cell proliferation induced an increase of 43.95 ± 0.03% in MC3T3-E1 cells growth. Consequently, with the help of alkaline phosphatase and methyl thiazolyl tetrazolium assay, five novel peptides (FDNEGKGKLPEEY, FWDGRDGEVDGFK, VLQTDNDALGKAK, IVLDSGDGVTH, and MVAPEEHP) derived from fraction ZP2 with the strongest osteogenic activity were screened, and their sequences were identified using Orbitrap Fusion Lumos Tribrid Orbital liquid chromatography-mass spectrometry. Therefore, the research results demonstrated that P. martensii meat could be used as a promising material for producing food additives for improving osteoporosis. PRACTICAL APPLICATIONS: In this study, after enzymolysis and purification, the fraction ZP2, derived from Pinctada martensii meat dregs were found to have a better activity of promoting osteoblast proliferation, showing the higher osteogenic activity with an increase of 43.95 ± 0.03% in terms of cell proliferation. It is beneficial to realize the high value and resource utilization of P. martensii meat dregs as a by-product of pearl production. The research demonstrated that the meat dregs of P. martensii could be used as an attractive material for producing active peptides in functional foods. In addition, the molecular weight of the peptides we identified from the ZP2 fraction is suitable for the proliferation of MC3T3-E1 cells, which lays a foundation for the further synthesis of peptides that promote the high proliferation activity of osteocytes.