Figure 3. Acute starvation induces markers of autophagy and senescence. After 3 h of acute starvation with Hepes-buffered HBSS, several markers of autophagy were increased (Lamp-1, BNIP3, LC3). Similarly, after 4 h of acute starvation with HBSS, a panel of markers for cell cycle arrest [p21(WAF1/CIP1), p19(ARF), p16(INK4A), p53, β-galactosidase] were all increased. Conversely, markers of cell cycle progression were significantly decreased (phospho-RB and cyclin D1). Blotting with β-actin is shown as a control for equal protein loading.