Hypertensive Stimuli Indirectly Stimulate Lymphangiogenesis through Immune Cell Secreted Factors.

(1) Background: Renal immune cells and lymphatic vessel (LV) density have been reported previously to be increased in multiple mouse models of hypertension (HTN). However, whether interstitial levels of HTN stimuli such as angiotensin II, salt, or asymmetric dimethylarginine have a direct or indirect effect on lymphangiogenesis is unknown. We hypothesized that these 3 HTN stimuli directly increase lymphatic endothelial cell (LEC) proliferation, LEC 3-D matrix invasion and vessel formation, and sprouting of mouse mesometrial LVs. (2) Methods: Human LECs (hLECs) and mouse LECs (mLECs) were treated with HTN stimuli while explanted mouse mesometrial LVs were treated with either the same HTN stimuli or with HTN stimuli-conditioned media. Conditioned media was prepared by treating murine splenocytes with HTN stimuli. (3) Results: HTN stimuli had no direct effect on hLEC or mLEC proliferation. Treatment of hLECs with HTN stimuli increased the number of lumen-forming structures and invasion distance (both p < 0.05) in the 3-D matrix but decreased the average lumen diameter and the number of cells per invading structure (both p < 0.05). Conditioned media from HTN-stimuli-treated splenocytes significantly attenuated the decrease in sprout number (aside from salt) and sprout length of mouse mesometrial LVs that is found in the HTN stimuli alone. (4) Conclusions: These data indicate that HTN stimuli indirectly prevent a decrease in lymphangiogenesis through secreted factors from HTN-stimuli-treated immune cells.

Hypertension induces gonadal macrophage imbalance, inflammation, lymphangiogenesis, and dysfunction.

Hypertension (HTN) is associated with gonadal dysfunction and impaired reproductive health in both men and women. An imbalance in the systemic and renal proinflammatory (M1)/anti-inflammatory (M2) macrophage ratio, increased inflammation, and inflammation-associated lymphangiogenesis have been observed in animals with HTN. However, the impact of HTN on gonadal macrophages, inflammation, and lymphatics remains obscure. We hypothesized that salt-sensitive HTN (SSHTN) and HTN alters gonadal macrophage polarization, which is associated with inflammation, inflammation-associated lymphangiogenesis, and reproductive dysfunction. Flow cytometry analyses revealed a significant increase in M1 macrophages in the testes of SSHTN and nitro-L-arginine methyl ester hydrochloride (L-NAME)-induced HTN (LHTN) mice, with a concurrent decrease in M2 macrophages in SSHTN mice yet an increase in M2 macrophages in LHTN mice. Ovaries from SSHTN mice exhibited an increase in M1 and a decrease in M2 macrophages, while ovaries from LHTN mice had a significant increase in M2 and a decrease in M1 macrophages. Gene expression patterns of proinflammatory cytokines revealed gonadal inflammation in all hypertensive mice. Increased lymphatic vessel density in the gonads of both male and female hypertensive mice was confirmed by immunofluorescence staining for lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1). HTN adversely affected the expression pattern of steroidogenic enzymes, hormone receptors, and secretory proteins in both the testes and ovaries. In line with these results, male hypertensive mice also presented with decreased sperm concentration, and increased percentage of sperm with abnormal morphology, damaged acrosome, and nonfunctional mitochondrial activity. These data demonstrate that HTN alters gonadal macrophage polarization, which is associated with gonadal inflammation, inflammation-associated lymphangiogenesis, and dysfunction.