Chemerin is resident to vascular tunicas and contributes to vascular tone

Vascular chemerin from PVAT contributes to norepinephrine and serotonin-induced vasoconstriction and vascular stiffness in a sex-dependent manner

The adipokine chemerin supports normal blood pressure and contributes to adiposity-associated hypertension, evidenced by falls in mean arterial pressure in Dahl SS rats given an antisense oligonucleotide against chemerin. In humans, circulating chemerin is positively associated with hypertension and aortic stiffness. Mechanisms of chemerin's influence on vascular health and disease remain unknown. We identified chemerin production in the vasculature-the blood vessel and its perivascular adipose tissue (PVAT). Here, using RNAScope, qPCR, isometric contractility, high-frequency ultrasound imaging, and Western blot in the Dahl SS rat, we test the hypothesis that endogenous chemerin amplifies agonist-induced vasoconstriction through the chemerin1 receptor and that chemerin drives aortic stiffness in the thoracic aorta. CMKLR1 (chemerin1) expression was higher in the media, and Rarres2 (chemerin) expression was higher in the PVAT. Chemerin1 receptor antagonism via selective inhibitor CCX832 reduced maximal contraction to norepinephrine (NE) and serotonin (5-HT), but not angiotensin II, in isolated thoracic aorta (PVAT intact) from male Dahl SS rat. In females, CCX832 did not alter contraction to NE or 5-HT. Male, but not female, genetic chemerin knockout Dahl SS rats had lower aortic arch pulse wave velocity than wild types, indicating chemerin's role in aortic stiffness. Aortic PVAT from females expressed less chemerin protein than males, suggesting PVAT as the primary source of active chemerin. We show that chemerin made by the PVAT amplifies NE and 5-HT-induced contraction and potentially induces aortic stiffening in a sex-dependent manner, highlighting the potential for chemerin to be a key factor in blood pressure control and aortic stiffening.NEW & NOTEWORTHY Chemerin1 receptor inhibition reduced norepinephrine (NE) and 5-HT-induced vasoconstriction in males. Genetic chemerin knockout (KO) resulted in lower pulse wave velocity in males. Differences in chemerin abundance in aorta perivascular adipose tissue (APVAT) may explain sex-dependent role of chemerin.

Statins Prevent the Deleterious Consequences of Placental Chemerin Upregulation in Preeclampsia

BACKGROUND

Chemerin, an inflammatory adipokine, is upregulated in preeclampsia, and its placental overexpression results in preeclampsia-like symptoms in mice. Statins may lower chemerin.

METHODS

Chemerin was determined in a prospective cohort study in women suspected of preeclampsia and evaluated as a predictor versus the sFlt-1 (soluble fms-like tyrosine kinase-1)/PlGF (placental growth factor) ratio. Chemerin release was studied in perfused placentas and placental explants with or without the statins pravastatin and fluvastatin. We also addressed statin placental passage and the effects of chemerin in chorionic plate arteries.

RESULTS

Serum chemerin was elevated in women with preeclampsia, and its addition to a predictive model yielded significant effects on top of the sFlt-1/PlGF ratio to predict preeclampsia and its fetal complications. Perfused placentas and explants of preeclamptic women released more chemerin and sFlt-1 and less PlGF than those of healthy pregnant women. Statins reversed this. Both statins entered the fetal compartment, and the fetal/maternal concentration ratio of pravastatin was twice that of fluvastatin. Chemerin constricted plate arteries, and this was blocked by a chemerin receptor antagonist and pravastatin. Chemerin did not potentiate endothelin-1 in chorionic plate arteries. In explants, statins upregulated low-density lipoprotein receptor expression, which relies on the same transcription factor as chemerin, and NO release.

CONCLUSIONS

Chemerin is a biomarker for preeclampsia, and statins both prevent its placental upregulation and effects, in an NO and low-density lipoprotein receptor-dependent manner. Combined with their capacity to improve the sFlt-1/PlGF ratio, this offers an attractive mechanism by which statins may prevent or treat preeclampsia.