Skip to main content
Fig. 5 | Acta Neuropathologica Communications

Fig. 5

From: Retinal ischemia induces α-SMA-mediated capillary pericyte contraction coincident with perivascular glycogen depletion

Fig. 5

Changes in pericyte morphology during ischemia and recanalisation in vivo suggest pericyte contraction. a In vivo luminal diameters of the visualized microvessels (i.e. those with blood flow) at pericyte locations after recanalisation (green; n = 441 microvessels in three recanalized retinae) were significantly smaller compared to pre-ischemic retinae (yellow; n = 143 microvessels in four pre-ischemic retinae, P < 0.0001, Student’s t-test). b Morphological analysis of DsRed-fluorescent pericytes imaged with AOSLO in vivo disclosed that the pericyte soma rounded up protruding away from the lumen in accordance with a contracted morphology after 1 h of ischemia and remained so after recanalisation. Pericyte shapes at each stage are illustrated on the right and schematically represented at the bottom. The graph shows the distribution of the somatic DsRed signal and, discloses that the soma extended longer along the vertical axis after 1-h of ischemia and during recanalization compared to pre-ischemia (P = 0.005, ANOVA and Tukey’s test; yellow, n = 72 pericytes in four pre-ischemic retinae; blue, n = 226 pericytes in three 0-1 h ischemic retinae; red, n = 125 pericytes in four 1-2 h ischemic retinae; green, n = 530 pericytes in three recanalized retinae). The vertical lines projected from the 50% of the peak signal values show that the soma fluorescence condensed after 1-h of ischemia and during recanalization in line with a contracted cell body profile (red and green scheme at the bottom). The processes were also shortened along the horizontal axis after recanalisation (green scheme at the bottom, P = 0.021, ANOVA and Tukey’s test). c Whole-mount retinae from NG2-DsRed mice treated with lectin were examined ex vivo after completing in vivo recordings, which clearly illustrated that the ischemia-induced microvascular constrictions were colocalized with DsRed+ pericytes (arrows, luminal diameters are given next to the arrows). d Ex vivo analysis of DsRed+ pericyte morphology after labeling pericyte basement membrane with lectin confirms that soma protruded away from the lumen and assumed a circular shape after 1 h of ischemia (P = 0.006, ANOVA and Dunnett’s test) and recanalisation (P = 0.01, ANOVA and Dunnett’s test) compared to non-ischemic retinae as illustrated by their shape factor calculated with the formula, f = x/2y (x horizontal, y vertical axis and f = 1 = sphere, f > 1, horizontal ellipse; blue, 1.25 ± 0.06, n = 530 pericytes in three non-ischemic retinae; red, 1.00 ± 0.02, n = 655 pericytes in three 1 h-ischemic retinae; green, 1.03 ± 0.016, n = 387 pericytes in three recanalisated retinae). e-m Representative examples of pericyte morphology under pre-ischemic (e-g), ischemic (h-j), and recanalisated conditions (k-m). The basement membrane of NG2-DsRed pericytes (f, i and l) was labeled with lectin (e, h and k). Scale bar in C = 10 μm; scale bar in e-m = 5 μm

Back to article page