Table 1.

Low gene transcription and/or enzyme activities of mGPD, PC, ATPCL and SCOT in pancreatic islets from humans with type 2 diabetes compared with those from non-diabetic controls

Enzyme	Gene expression (% of non-diabetic control)				Islets enzyme activity (nmol min−1 [mg homogenate protein−1])
	Individual values			Average values	Non-diabetic control	T2DM	T2DM relative to control (%)
mGPD	74	45	54	58±7 (3)c	23±2.5 (4)	6.2±0.7 (4)	27a
PC e	85	82		84	2.3±0.2 (4)	0.8±0.06 (5)	35a
PCC
PCCα	90	40	61	64±12 (3)d	15±2 (4)	13±3 (5)	87d
PCCβ	71	45	63	60±6 (3)b
ATPCL	43	61	37	47±6 (3)b	28±4 (4)	12±3 (5)	43c
SCOT	40	48		44	3.8±0.6 (3)	0, 0.3	8
Aspartate aminotransferase
Cyto	59	90		75	505±54 (4)	434±6 (4)	86d
Mito	105	109		107
Malate dehydrogenase
Cyto	63	94		79	3000±220 (4)	3100±320 (4)	103d
Mito	71	73	40	61±9 (3)c
Malic enzyme
Malic enzyme 1	90	140	120	117±12 (3)d	31±3 (4)	31±4 (4)	100d
Malic enzyme 2	80	91	110	94±7 (3)d
Malic enzyme 3	70	90	100	87±7 (3)d
NADP IDH
Cyto	77	44	54	58±8 (3)c	85±14 (4)	147±29 (5)	173d
Mito	300	340		320

‘Gene expression’ indicates the signal strength of mRNAs that encode subunits or isoforms of enzymes from islets of a diabetic donor compared with those from a non-diabetic donor probed in the same mRNA microarray chip. Enzyme activities are the total enzyme activity in the homogenate or cytosol of whole cells

Results are expressed as the individual values and as the mean±SE when the number (in parentheses) of samples ≥3. The SEs of control gene expression values (not shown) were 9.8% or lower in all cases

^ap≤0.005

^bp≤0.01

^cp≤0.05

^dnot significant, for averages of diabetic islets vs control islets when enough samples available to permit statistical analysis

^eSignals of the PC gene were very weak

cyto, cytosolic; mito, mitochondrial; T2DM, type 2 diabetes mellitus