Fig 2: Improved photoreceptor survival after retinal detachment in Pkm2 −/− mice. (a) Representative photomicrographs of TUNEL-stained photoreceptors (green) after 72 hours of retinal detachment. Nuclei of retinal cells are stained with DAPI (blue). INL, inner nuclear layer; ONL, outer nuclear layer. (b) Quantification of TUNEL-positive cells in the ONL. n ≥ 12 sections per group. (c) Caspase 8 activity in detached retinas after 3 days as detected by luminescent assay. N = 3 animals per group; Mean ± SEM; *p < 0.05; ***p < 0.005. (d) Retinal sections of attached and detached retina, 2 months after creation of detachment in Pkm2 +/+ and Pkm2 −/− mice, respectively. (e) Graph summarizing ONL cell viability between attached and detached retina after 2-month detachment. Cell survival was significantly higher in Pkm2 −/− mice as compared to Pkm2 +/+ mice. (f) Graph summarizing ONL area changes between attached and detached retina after 2-month detachment. ONL area was significantly higher in Pkm2 −/− mice as compared to Pkm2 +/+ mice. N = 5 animals per group; Mean ± SEM; *p < 0.05; ***p < 0.005.

Fig 3: Experimental retinal detachment decreases PKM2 tyrosine phosphorylation. (a) Western blot analysis showing decreased levels of PKM2 tyrosine phosphorylation (Y105) as a function of time after experimental retinal detachment in rats. Equal amounts of protein were loaded in each lane. (b) Quantitative analysis of phosphorylated PKM2 levels normalized to total PKM2 as a function of time. N = 3 animals per time point; Mean ± SEM; Att-attached retina; Det-detached retina.

Fig 4: Glucose metabolism was upregulated in cisplatin-resistant A549/DDP cells. (a) Detection of cisplatin inhibition in cisplatin-sensitive or cisplatin-resistant A549 cells and A549/DDP cells. (b) Glucose consumption and (c) lactate production were measured in cisplatin-sensitive or cisplatin-resistant A549 cells and A549/DDP cells. Expression of glucose metabolism enzymes at the protein level or the mRNA level in cisplatin-sensitive or cisplatin-resistant A549 and A549/DDP cells by (d) western blot and (e) RT-PCR analysis. The results are presented as mean ± S.D. (n = 3); the experimental results are presented in triplicate. HK1, hexokinase 1; HK2, hexokinase 2; PFKP, platelet-type phosphofructokinase; PKM1/2, Pyruvate Kinase M1/2; PKM2, pyruvate kinase M2; GLUT1, glucose transporter 1; PDH, pyruvate dehydrogenase; LDHA, lactate dehydrogenase A.

Fig 5: Quantitative PCR analysis of glucose metabolism pathways in retinas from photoreceptor-specific, Pkm2 conditional knockout mice. (a) Scatter plot comparing the normalized expression of genes involved in glucose metabolism between Pkm2 +/− mice and Pkm2 +/+ mice. (b) Scatter plot comparing the normalized expression of genes involved in glucose metabolism between Pkm2 −/−mice and Pkm2 +/+ mice. The central solid line indicates unchanged gene expression. The dashed outer lines represent the fold change cut-off, which was set to 2. Red solid dots represent those genes that had a fold change greater than 2. Black solid dots represent those genes that did not surpass the fold change cut-off. N = 3–5 animals per group.