Table 3.

microRNAs (miRs) studies in patients with depressive disorders.

Reference	Sample Characteristics	Tissue	Diagnosis	Platform	miRNAs Associated	Main Findings
Uchida et al. [94] 2008	SH-SY5Y cells and Male rats Fisher 344 (F344) and Sprague-Dawley (SD) control with repeated restraint stress	Neuron cell lines Hypothalamic paraventricular nucleus	------	-----	miR-18a	Overexpressed in repeated restraint stress model. Its expression inhibits translation of the glucocorticoid receptor in neuron cell culture.
Vreugdenhil et al. [97,111] 2009	NS1 cells	Neuron cell lines	------	Luciferase reporter assay	miR-18a and miR-124a	miR-18a and miR-124a decrease protein expression of glucocorticoid receptor by luciferase reporter assay in NS1 cells.
Caputo et al. [101] 2011	HeLa cells	Cervix epithelial cell line	Schizophrenia	Luciferase reporter assay	miR-132 and miR-182	These miRNAs regulate the expression of BDNF by Allele-Specific Binding [101].
Smalheiser et al. [98] 2012	Antidepressant-free depressed suicide (n = 18) and well-matched non-psychiatric control subjects (n = 17)	Tissue, prefrontal cortex (Brodmann Area 9)	Depression	PCR miltiplex	miR-142-5p, miR-137, miR-489, miR-148b, miR-101, miR-324-5p, miR-301a, miR-146a, miR-335, miR-494, miR-20b, miR-376a*, miR-190, miR-155, miR-660, miR-130a, miR-27a, miR-497, miR-10a, miR-20a, miR-142-3p	miRs significantly downregulated in the prefrontal cortex of depressed patients compared with normal controls, many of them implicated in cellular growth and differentiation and some of them showed high synaptic enrichment [98,99].
Belzeaux et al. [96] 2012	16 severe MDE patients and 13 matched controls	Peripheral blood mononuclear cells	Major depressive episode	Microarray SurePrint G3 Human GE 8 x 60 K	miR-107, miR-133a, miR-148a, miR-200c, miR-381, miR-425-3p, miR-494, miR-517b, miR-579, miR-589, miR-636, miR-652, miR-941, miR-1243	miRs significantly deregulated between MDE patients and controls. These miRs help finding a gene combination useful to predict treatment response [96].
Bocchio-Chiavetto et al. [100] 2013	10 patients with MD, the sample was extracted before and after treatment	Blood	MDD	TaqMan Array Human MicroRNA A + B Cards Set v3.0	UP: miR-130b*, miR-505*, miR-29b-2*, miR-26b, miR-22*, miR-26a, miR-664, miR-494, let-7d, let-7g, let-7e, let-7f, miR-629, miR-106b*, miR-103, miR-191, miR-128, miR-502-3p, miR-374b, miR-132, miR-30d, miR-500, miR-589, miR-183, miR-574-3p, miR-140-3p, miR-335, miR-361-5p. DOWN: miR-34c-5p and miR-770-5p	Associated with neuronal brain function, such as neuroactive ligand–receptor interaction, axon guidance, long-term potentiation and depression [100].
Li et al. [33] 2013	40 patients and 40 healthy controls	Serum	MDD	Real time PCR	miR-132 and miR-182	The expression of these miRs was negatively correlated with BDNF expression [33].
Fan et al. [112] 2014	81 MDD patients and 46 healthy controls	Peripheral blood mononuclear cells	MDD	Affymetrix miRNA 3.0 array	miRNA-26b, miRNA-1972, miRNA-4485, miRNA-4498, and miRNA-4743	Overexpressed in MDD patients, and would regulate pathways associated with nervous system and brain functions [112].
Wan et al. [113] 2015	1° cohort: 6 depressed and 6 control patients. 2° cohort: 32 MDD patients and 21 healthy individuals	Peripheral blood mononuclear cells	MDD	microRNA PCR Panel (V3.M)	let-7d-3p, miR-34a-5p, miR-221-3p, miR-451a	Potential MDD biomarkers [113].
Wang et al. [114] 2015	169 patients and 52 controls	Plasma	Depression	Serum/Plasma Focus microRNA PCR Panel	miR-144-5p	miR-144-5p levels are associated with depressive symptoms, and the detection of this miR in plasma could be a potential peripheral biomarker for pathologic processes related to depression [114].

MDE: Major depressive episode.