Investigating aberrantly expressed microRNAs in peripheral blood mononuclear cells from patients with treatment‑resistant schizophrenia using miRNA sequencing and integrated bioinformatics

Pharmacogenetic intervention improves treatment outcomes in Chinese adult men with schizophrenia

To investigate the clinical application value of pharmacogenetic testing in individualized drug therapy for adult male patients with schizophrenia. A total of 186 adult patients with schizophrenia were enrolled and randomised into the pharmacogenetic (PGx) intervention group and the standard care group. In the PGx intervention group, PGx testing was performed, and the medication regimen was adjusted according to the results of the pharmacogenomic analysis. In contrast, in the standard care group, patients were treated according to the physician's medication experience. Differences in the primary indicator of schizophrenia, the Positive and Negative Symptom Scale (PANSS), and the secondary efficacy measures, the Clinical Global Impressions-Severity of Illness scale (CGI-SI) and Clinical Global Impressions-Global Improvement (CGI-GI) scale, were compared between the intervention and standard care groups. At baseline, the PGx intervention group consisted of 109 individuals, while the standard care group had 77 participants. After 12 weeks of treatment, 49 individuals withdrew from the PGx group (a dropout rate of 45.0%), and 34 withdrew from the standard care group (a dropout rate of 44.2%), with no significant difference in dropout rates between the two groups. The PANSS score reduction rate in the PGx intervention group significantly exceeded that of the standard care group during weeks 3, 6, and 12 of follow-up (P < 0.05). At the 12th week, the PGx intervention group achieved a treatment response rate of 81.7%, significantly surpassing the 48.8% of the standard care group (odds ratio of 4.67, 95% confidence interval of 1.96-11.41; P = 0.001). Furthermore, the PGx intervention was significantly more effective than standard care regardless of whether the patient had a first episode or a relapse (P < 0.05). Furthermore, the Global Assessment of Functioning (GAF) scores and the Personal and Social Performance Scale (PSP) score changes in the PGx intervention group were both significantly different from those in the standard care group (P < 0.05). It is noteworthy that the PGx intervention similarly improves the prognostic outcomes for patients with and without a family history of mental disorders. In conclusion, the application of a PGx intervention treatment model based on PGx testing can significantly improve medication efficacy and shorten the time to achieve the effects of medication in schizophrenia.

Peripheral biomarkers of treatment-resistant schizophrenia: Genetic, inflammation and stress perspectives

Treatment-resistant schizophrenia (TRS) often results in severe disability and functional impairment. Currently, the diagnosis of TRS is largely exclusionary and emphasizes the improvement of symptoms that may not be detected early and treated according to TRS guideline. As the gold standard, clozapine is the most prescribed selection for TRS. Therefore, how to predict TRS in advance is critical for forming subsequent treatment strategy especially clozapine is used during the early stage of TRS. Although mounting studies have identified certain clinical factors and neuroimaging characteristics associated with treatment response in schizophrenia, the predictors for TRS remain to be explored. Biomarkers, particularly for peripheral biomarkers, show great potential in predicting TRS in view of their predictive validity, noninvasiveness, ease of testing and low cost that would enable their widespread use. Recent evidence supports that the pathogenesis of TRS may be involved in abnormal neurotransmitter systems, inflammation and stress. Due to the heterogeneity of TRS and the lack of consensus in diagnostic criteria, it is difficult to compare extensive results among different studies. Based on the reported neurobiological mechanisms that may be associated with TRS, this paper narratively reviews the updates of peripheral biomarkers of TRS, from genetic and other related perspectives. Although current evidence regarding biomarkers in TRS remains fragmentary, when taken together, it can help to better understand the neurobiological interface of clinical phenotypes and psychiatric symptoms, which will enable individualized prediction and therapy for TRS in the long run.

Recent advancements in biomarker research in schizophrenia: mapping the road from bench to bedside

Schizophrenia (SZ) is a severe progressive neurodegenerative as well as disruptive behavior disorder affecting innumerable people throughout the world. The discovery of potential biomarkers in the clinical scenario would lead to the development of effective methods of diagnosis and would provide an understanding of the prognosis of the disease. Moreover, breakthrough inventions for the treatment and prevention of this mysterious disease could evolve as a result of a thorough understanding of the clinical biomarkers. In this review, we have discussed about specific biomarkers of SZ an emphasis has been laid to delineate (1) diagnostic biomarkers like neuroimmune biomarkers, metabolic biomarkers, oligodendrocyte biomarkers and biomarkers of negative and cognitive symptoms, (2) therapeutic biomarkers like various neurotransmitter systems and (3) prognostic biomarkers. All the biomarkers were evaluated in drug-naïve (at least for 4 weeks) patients in order to achieve a clear comparison between schizophrenic patients and healthy controls. Also, an attempt has been made to elucidate the potential genes which serve as predictors and tools for the determination of biomarkers and would ultimately help in the prevention and treatment of this deadly illness.

miRNAs as potential diagnostic biomarkers and pharmacogenomic indicators in psychiatric disorders

The heterogeneity of psychiatric disorders and the lack of reliable biomarkers for prediction and treatments follow-up pose difficulties towards recognition and understanding of the molecular basis of psychiatric diseases. However, several studies based on NGS approaches have shown that miRNAs could regulate gene expression during onset and disease progression and could serve as potential diagnostic and pharmacogenomics biomarkers during treatment. We provide herein a detailed overview of circulating miRNAs and their expression profiles as biomarkers in schizophrenia, bipolar disorder and major depressive disorder and their role in response to specific treatments. Bioinformatics analysis of miR-34a, miR-106, miR-134 and miR-132, which are common among SZ, BD and MDD patients, showed brain enrichment and involvement in the modulation of critical signaling pathways, which are often deregulated in psychiatric disorders. We propose that specific miRNAs support accurate diagnosis and effective precision treatment of psychiatric disorders.

miR-218-2 regulates cognitive functions in the hippocampus through complement component 3-dependent modulation of synaptic vesicle release

microRNA-218 (miR-218) has been linked to several cognition related neurodegenerative and neuropsychiatric disorders. However, whether miR-218 plays a direct role in cognitive functions remains unknown. Here, using the miR-218 knockout (KO) mouse model and the sponge/overexpression approaches, we showed that miR-218-2 but not miR-218-1 could bidirectionally regulate the contextual and spatial memory in the mice. Furthermore, miR-218-2 deficiency induced deficits in the morphology and presynaptic neurotransmitter release in the hippocampus to impair the long term potentiation. Combining the RNA sequencing analysis and luciferase reporter assay, we identified complement component 3 (C3) as a main target gene of miR-218 in the hippocampus to regulate the presynaptic functions. Finally, we showed that restoring the C3 activity in the miR-218-2 KO mice could rescue the synaptic and learning deficits. Therefore, miR-218-2 played an important role in the cognitive functions of mice through C3, which can be a mechanism for the defective cognition of miR-218 related neuronal disorders.