Table 6.

Summary of circulating SENAs associated with disease state and severity of Parkinson’s disease in human patients

SENA	Study population	Sample type	RNA/DNA name	Findings	References
miRNA	73 HC 75 PD	Plasma	miR-153	Downregulated in PD patients compared to HC Expression positively correlates with disease duration and severity	[415]
	78 HC 78 PD	PBMC	miR- 34a, miR-125a	Reduced in PD patients Expression inversely correlates with disease severity	[429]
	50 HC 68 PD	Serum	miR-374a-5p	Decreased in PD patients Expression is negatively correlated with disease severity	[176]
	126 HC 148 PD	Serum	miR-30c-5p, miR-373	Upregulated in PD patients Expression positively correlates with disease severity	[454]
	44 HC 82 PD	Serum	miR-132-3p, miR-146a-5p	Decreased in PD patients Expression negatively correlates with disease severity	[341]
	14 HC 15 PD	Plasma-derived pure small extracellular vesicles	miR‑34a‑5p	Downregulated in PD patients Expression inversely correlates with disease duration and severity	[136]
	14 HC 30 PD	PBMC	miR-27a-3p	Decreased in PD patients (all stages) Expression negatively correlates with disease severity	[104]
			miR-27b-3p	Increased in PD patients (early stage) Expression decreased along with the disease severity
	24 HC 23 PD	Serum	miR-214	Upregulated in early stage PD patients Expression negatively correlates with disease duration, severity of anxiety and non-motor symptoms	[426]
	60 HC 80 PD	Serum	miR-150	Reduced in PD patients Expression inversely correlates with blood levels of pro-inflammatory cytokines	[212]
	25 HC 33 PD	PBMC	miR-376a	Increased in PD patients Expression positively correlates with disease severity	[17]
	16 HC 36 PD	PBMC	miR-885, miR-17	Upregulated in PD patients Expression positively correlates with disease severity	[24]
			miR-361	Downregulated in PD patients Expression positively correlates with disease severity
	222 HC 269 PD	Plasma	miR-132	Increased in PD patients Expression is positively related with the disease duration and severity	[433]
	43 HC 37 PD	PBMC	miR-155-5p	Elevated in PD patients Downregulation by L-dopa treatment	[38]
	80 HC 80 PD	Serum	miR-29a, miR-29c	Decreased in PD patients Expression negatively correlates with disease severity	[18]
	42 HC 44 PD	CSF	miR-144-5p, miR-200a-3p, miR-542-3p	Upregulated in PD patients Expression is positively associated with disease severity	[270]
	112 HC 138 PD	Serum	miR-221	Reduced in PD patients Expression positively correlates with disease severity	[247]
lncRNA	84 HC 97 PD	Serum	TUG1	Upregulated in PD patients compared to HC Expression positively correlates with disease severity and blood levels of pro-inflammatory cytokines	[54]
	13 HC 32 PD	Plasma-derived exosomes	MKRN2–42:1	Decreased in PD patients Expression is positively associated with disease severity	[395]
	196 HC 228 PD	Serum	MALAT1	Increased in PD patients Expression positively correlates with cognitive impairment, motor symptoms severity and blood levels of pro-inflammatory cytokines	[428]
	78 HC 78 PD	PBMC	ANRIL	Elevated in PD patients Expression positively correlates with disease severity	[429]
	30 HC 30 PD	Plasma	MEG3	Decreased in PD patients Expression negatively correlates with disease stage, severity of non-motor symptoms and cognitive decline	[314]
	85 HC 93 PD	Neuronal-derived plasma exosomes	linc-POU3F3	Upregulated in PD patients Expression positively correlates with disease stage, motor symptoms severity and cognitive impairment	[484]
	93 HC 99 PD	Serum	RMST	Increased in PD patients Expression positively correlates with disease severity and blood levels of pro-inflammatory cytokines	[47]
circRNA	100 HC 300 PD	Plasma	circ_0085869, circ_0004381, circ_0017204, circ_0090668	Upregulated in PD patients (all stages) compared to HC Increased in early PD (stage 1) patients compared to HC Elevated levels in late PD (stage 2–5) compared to early PD (stage 1) patients	[472]
	40 PD	Plasma	circEPS15	Expression inversely correlates with motor symptoms severity	[476]
	6 HC 6 PD	Whole blood-derived exosomes	circ_0001535 circ_0000437	Elevated in PD patients Reduced in PD patients after 2-week multidisciplinary rehabilitation	[92]
cfDNA	20 HC 20 PD	CSF	8-OHdG (oxidized cfDNA)	Increased concentration in PD patients Concentration positively correlated with duration of disease	[166]
	10 HC 56 PD	CSF	mtDNA	Reduced copy number in PD patients compared to HC No correlation with cognitive impairment	[310]
	262 HC 363 PD	Peripheral white blood cells	mtDNA	Decreased copy number in PD patients No correlation with cognitive impairment	[309]
	12 HC 21 PD	CSF	mtDNA	Reduced copy number in PD patients compared to HC Higher proportion of mtDNA molecules with deletions in PD patients	[308]

8-OHdG: 8-hydroxy-2-deoxyguanosine; ANRIL: antisense non-coding RNA in the INK locus; cfDNA: cell-free DNA; circRNA, circular RNA; CSF: cerebrospinal fluid; HC: healthy control; linc-POU3F3: long intergenic noncoding RNA POU class 3 homeobox 3; lncRNAs: long non-coding RNA; MALAT1: metastasis associated lung adenocarcinoma transcript 1; MEG3: maternally expressed 3; miRNA: microRNA; MKRN2: makorin ring finger protein 2; mtDNA: mitochondrial DNA; PBMC: peripheral blood mononuclear cells; PD: Parkinson’s Disease; RMST: rhabdomyosarcoma 2-associated transcript; SENA: self-extracellular nucleic acid; TUG1: taurine-upregulated gene 1