CCL2 and pulmonary arterial hypertension: In addition to this, the intestines levels of inflammatory cytokines IL-10 and MCP-1 were elevated in the SuHx group of mice in the present study, a result that supports that changes in intestinal microbial metabolites promote perivascular inflammation, and proliferation of pulmonary vascular smooth muscle cells, which triggers lung injury and pulmonary vascular remodeling, and ultimately leads to pulmonary arterial hypertension (Karoor et al., 2021; Song et al., 2021; Huang et al., 2022).