Platelets of mice heterozygous for neurobeachin, a candidate gene for autism spectrum disorder, display protein changes related to aberrant protein kinase A activity

Table 1 Morphological and functional characteristics of blood platelets haploinsufficient for Neurobeachin

		Nbea^+/+	Nbea^+/-	P
Platelet count (10³/μl)		943.6 ± 41.9	864.9 ± 42.2	0.20
Mean platelet volume (fL)		6.52 ± 0.11	6.61 ± 0.12	0.58
Flow cytometry
	Forward scatter (AU)	13,683.3 ± 667.3	13,853.8 ± 255.9	0.83
	Side scatter (AU)	1,038.5 ± 21.5	1,012.4 ± 13.3	0.34
	Platelets/cell total (%)	9.88 ± 0.53	8.46 ± 0.57	0.10
Dense granules
	Number/platelet	0.445 ± 0.028	0.441 ± 0.028	0.94
	Surface area (nm²)	18,063.1 ± 696.2	14,331.3 ± 649.7	<0.001
	Dense-core area (nm²)	2,375.4 ± 251.2	1,706.4 ± 183.0	0.52
	Halo area (nm²)	15,687.7 ± 654.1	12,624.9 ± 607.4	0.001
Dense granule classification
	Type 1 (%)	13.4	10.6	0.73
	Type 2 (%)	26.7	29.3
	Type 3 (%)	1.4	1.9
	Type 4 (%)	58.5	58.2
Serotonin content
	Serum (ng/μl)	1.99 ± 0.25	2.21 ± 0.14	0.45
	Platelets (μg/10⁹ PLTs)	7.59 ± 1.62	6.84 ± 1.61	0.75
Aggregation (amplitude %)
	Collagen (5 μg/ml)	54.4 ± 5.7	52.8 ± 3.8	0.82
ATP secretion (μM)
	Collagen (5 μg/ml)	1.58 ± 0.41	1.71 ± 0.67	0.87

Platelet count and size were investigated in 10 mice/genotype. Dense granule morphology (MWU test) and classification was analyzed in 200 platelets/genotype. Dense granule classification was based on the study by Weiss et al.[35] and the total amount of dense granules counted per genotype was set at 100% yielding the above-mentioned separate percentage per dense granules type. The distribution of the dense granules into the classification types was compared between Nbea^+/- and Nbea^+/+ mice using the Pearson Chi-square test. Serotonin content was measured in eight mice/genotype. Platelet function was assessed in four mice/genotype. ATP secretion and aggregation were measured for 5 minutes after collagen stimulation. Unless stated otherwise, parameters were compared between genotypes using the two-tailed t-test. Data are represented as mean ± standard error of the mean. AU, arbitrary units; PLT, platelet.

ISSN: 2040-2392