Dynamic control of ZSCAN4 expression in chronic pancreatitis under inflammation and regeneration. ZSCAN4 expression patterns in tissues taken from patients with chronic alcoholic pancreatitis and autoimmune pancreatitis. A: a representative ZSCAN4 immunostaining of the pancreas from an unaffected individual. Arrow, a ZSCAN4+ cell. B: a representative ZSCAN4 immunostaining of the pancreas from a patient with chronic alcoholic pancreatitis. ZSCAN4+ cells are scattered in the pancreas. A number of ZSCAN4+ cells in the islet of Langerhans are dramatically increased in sections of alcoholic pancreatitis. C: a representative ZSCAN4 immunostaining of the duct region of the pancreas from a patient with untreated autoimmune pancreatitis. ZSCAN4+ cells increase in tissues on chronic inflammation. Arrows, a small-sized pancreatic duct containing a few ZSCAN4+ cells. D: a representative ZSCAN4 immunostaining of the acinar region of the pancreas from a patient with untreated autoimmune pancreatitis. ZSCAN4+ cells are scattered throughout the pancreas with autoimmune pancreatitis. E: a representative ZSCAN4 immunostaining of the pancreas from a patient with autoimmune pancreatitis under the maintenance corticosteroid therapy for 3 mo. A large number of ZSCAN4+ cells are seen in pancreatic ducts, the islet of Langerhans, and regenerating pancreatic acinar cells. F: a representative ZSCAN4 immunostaining of the pancreas from a patient with autoimmune pancreatitis under the maintenance corticosteroid therapy for 12 mo. Note that immunoreactivity for ZSCAN4 almost disappeared and returned to a basal level at fully regenerated tissues. G: the no. of ZSCAN4+ cells per high-power field (HPF) in each condition is summarized (n = 3–5, mean ± SD). Normal subjects, 1.8 ± 1.3; alcoholic pancreatitis (AL-CP), 118.8 ± 97.0; autoimmune pancreatitis pretreatment (AIP pre), 193.0 ± 56.0; autoimmune pancreatitis 3 mo after the initiation of corticosteroid treatment (AIP 3m Tx), 208.7 ± 23.4; autoimmune pancreatitis 1 yr after the initiation of corticosteroid treatment (AIP 1y Tx), 0.6 ± 0.9. *P < 0.01 and **P < 0.05.