Therapeutic efficacy of splenectomy is attenuated by necroinflammation of the liver in patients with liver cirrhosis

Splenectomy ameliorates liver cirrhosis by restoring the gut microbiota balance

BACKGROUND

Dysbiosis of gut microbiota is frequent in liver cirrhosis (LC) patients, and splenectomy (SP) has been reported to improve LC. Herein, we report the effects of SP on gut microbiota, especially on Veillonella parvula, a Gram-negative coccus of the gastrointestinal tract, in LC mice, and the underlying mechanism.

METHODS

LC mice models were induced by tail vein injection of concanavalin A (ConA), followed by SP. 16 s rRNA sequencing was conducted to analyze the effects of ConA induction and SP on mouse gut microbiota and the gene expression affected by gut microbiota. LC mice receiving SP were gavaged with Veillonella parvula. Likewise, hepatic stellate cells (HSC) and hepatocytes (HC) were induced with conditioned medium (CM) of Veillonella parvula.

RESULTS

SP alleviated LC in mice by restoring gut barrier function and maintaining gut microbiota balance, with Veillonella as the key genus. The Veillonella parvula gavage on LC mice reversed the ameliorative effect of SP. The CM of Veillonella parvula promoted the activation of HSC and the release of IL-6, IL-1β, and TNF-α. Also, the CM of Veillonella parvula induced HC pyroptosis and the release of ALT and AST. Veillonella parvula represented an imbalance in the gut microbiota, thus enhancing gut-derived endotoxins in the liver with the main target being Tlr4/Nlrp3. Inhibition of Tlr4 blocked Veillonella parvula-induced HC damage, HSC activation, and subsequent LC progression.

CONCLUSION

SP-mediated gut microbiota regulation ameliorates ConA-related LC progression by inhibiting Tlr4/Nlrp3 in the liver.

Endotheliopathy of liver sinusoidal endothelial cells in liver disease

Liver is the largest solid organ in the abdominal cavity, with sinusoid occupying about half of its volume. Under liver disease, hemodynamics in the liver tissue dynamically change, resulting in injury to liver sinusoidal endothelial cells (LSECs). We discuss the injury of LSECs in liver diseases in this article. Generally, in noninflamed tissues, vascular endothelial cells maintain quiescence of circulating leukocytes, and unnecessary blood clotting is inhibited by multiple antithrombotic factors produced by the endothelial cells. In the setting of inflammation, injured endothelial cells lose these functions, defined as inflammatory endotheliopathy. In chronic hepatitis C, inflammatory endotheliopathy in LSECs contributes to platelet accumulation in the liver tissue, and the improvement of thrombocytopenia by splenectomy is attenuated in cases with severe hepatic inflammation. In COVID-19, LSEC endotheliopathy induced by interleukin (IL)-6 trans-signaling promotes neutrophil accumulation and platelet microthrombosis in the liver sinusoids, resulting in liver injury. IL-6 trans-signaling promotes the expression of intercellular adhesion molecule-1, chemokine (C-X-C motif) ligand (CXCL1), and CXCL2, which are the neutrophil chemotactic mediators, and P-selectin, E-selectin, and von Willebrand factor, which are involved in platelet adhesion to endothelial cells, in LSECs. Restoring LSECs function is important for ameliorating liver injury. Prevention of endotheliopathy is a potential therapeutic strategy in liver disease.

Liver regeneration after splenectomy in patients with liver cirrhosis

AIM

Splenectomy is a well-known procedure to improve thrombocytopenia and liver function in patients with liver cirrhosis (LC). However, the effect of splenectomy on liver regeneration remains unclear. The aim of this study is to investigate the effect of splenectomy on liver regeneration.

METHODS

Twenty patients with LC who underwent splenectomy were included in this study. Liver and splenic volumes were measured by a 3-D simulation imaging system. Liver volume (LV) and clinicopathological data were compared before and 6 months after splenectomy. Thereafter, patients were divided into two groups: the elevated LV group and the reduced LV group. Patient characteristics were compared between the two groups.

RESULTS

Postoperative LV was increased in 14 patients compared with the preoperative state. Thrombocytopenia, leukopenia, total bilirubin and prothrombin time were improved after splenectomy. In the elevated LV group, four patients exhibited improved Child-Pugh grades after splenectomy, whereas no patients demonstrated improvement in the reduced LV group. The elevated LV group exhibited high albumin level, good indocyanine green retention rate at 15 min and large splenic volume compared with the same measurements in the decreased group. Patients with larger spleen volumes and higher albumin values before splenectomy showed increased rates of LV after splenectomy.

CONCLUSION

Splenectomy for patients with LC improved pancytopenia and liver function. Especially, in patients with large spleen and high albumin levels, considerable increases in LV and improved liver function were observed.