佐久間 康成

BACKGROUND: Globally, prevalence of metabolic dysfunction-associated steatotic liver disease (MASLD) is increasing, and there is an urgent need to develop innovative therapies that promote liver regeneration following hepatectomy for this disease. Surgical excision is a key therapeutic approach with curative potential for liver tumors. However, hepatic steatosis can lead to delayed liver regeneration and higher post-operative complication risk. Mesenchymal stem cells-conditioned medium (MSC-CM) is considered a rich source of paracrine factors that can repair tissues and restore function of damaged organs. Meanwhile, hydrogels have been widely recognized to load MSC secretome and achieve sustained release. This study aimed to evaluate the therapeutic effect of hydrogel-encapsulated MSC-CM on liver regeneration following partial hepatectomy (PHx) in a rodent model of diet-induced hepatic steatosis. METHODS: Male Lewis rats were fed with a methionine and choline-deficient diet. After 3 weeks of feeding, PHx was performed and rats were randomly allocated into two groups that received hydrogel-encapsulated MSC-CM or vehicle via the intra-mesenteric space of the superior mesenteric vein (SMV). RESULTS: The regeneration of the remnant liver at 30 and 168 h after PHx was significantly accelerated, and the expressions of proliferating cell nuclear antigen were significantly enhanced in the MSC-CM group. MSC-CM treatment significantly increased hepatic ATP and β-hydroxybutyrate content at 168 h after PHx, indicating that MSC-CM fosters regeneration not only in volume but also in functionality. The number of each TUNEL- and cleaved caspase-3 positive nuclei in hepatocytes at 9 h after PHx were significantly decreased in the MSC-CM group, suggesting that MSC-CM suppressed apoptosis. MSC-CM increased serum immunoregulatory cytokine interleukin-10 and interleukin-13 at 30 h after PHx. Additionally, mitotic figures and cyclin D1 expression decreased and hepatocyte size increased in the MSC-CM group, implying that this mode of regeneration was mainly through cell hypertrophy rather than cell division. CONCLUSIONS: MSC-CM represents a novel therapeutic approach for patients with MASLD requiring PHx.

BACKGROUND: Although congenital portosystemic shunts (CPSSs) are increasingly being recognized, the optimal treatment strategies and natural prognosis remain unclear, as individual CPSSs show different phenotypes. METHODS: The medical records of 122 patients who were diagnosed with CPSSs at 15 participating hospitals in Japan between 2000 and 2019 were collected for a retrospective analysis based on the state of portal vein (PV) visualization on imaging. RESULTS: Among the 122 patients, 75 (61.5%) showed PV on imaging. The median age at the diagnosis was 5 months. The main complications related to CPSS were hyperammonemia (85.2%), liver masses (25.4%), hepatopulmonary shunts (13.9%), and pulmonary hypertension (11.5%). The prevalence of complications was significantly higher in patients without PV visualization than in those with PV visualization (P < 0.001). Overall, 91 patients (74.6%) received treatment, including shunt closure by surgery or interventional radiology (n = 82) and liver transplantation (LT) or liver resection (n = 9). Over the past 20 years, there has been a decrease in the number of patients undergoing LT. Although most patients showed improvement or reduced progression of symptoms, liver masses and pulmonary hypertension were less likely to improve after shunt closure. Complications related to shunt closure were more likely to occur in patients without PV visualization (P = 0.001). In 25 patients (20.5%) without treatment, those without PV visualization were significantly more likely to develop complications related to CPSS than those with PV visualization (P = 0.011). CONCLUSION: Patients without PV visualization develop CPSS-related complications and, early treatment using prophylactic approaches should be considered, even if they are asymptomatic. LEVEL OF EVIDENCE: Level III.