Macrophages (MFs) are heterogeneous and metabolically flexible, with metabolism strongly affecting immune activation. A classic response to proinflammatory activation is increased flux through glycolysis with a downregulation of oxidative metabolism, whereas alternative activation is primarily oxidative, which begs the question of whether targeting glucose metabolism is a viable approach to control MF activation. We created a murine model of myeloid-specific glucose transporter GLUT1 (Slc2a1) deletion. Bone marrow-derived MFs (BMDM) from Slc2a1 M2/2 mice failed to uptake glucose and demonstrated reduced glycolysis and pentose phosphate pathway activity. Activated BMDMs displayed elevated metabolism of oleate and glutamine, yet maximal respiratory capacity was blunted in MF lacking GLUT1, demonstrating an incomplete metabolic reprogramming. Slc2a1 M2/2 BMDMs displayed a mixed inflammatory phenotype with reductions of the classically activated pro-and anti-inflammatory markers, yet less oxidative stress. Slc2a1 M2/2 BMDMs had reduced proinflammatory metabolites, whereas metabolites indicative of alternative activation-such as ornithine and polyamines-were greatly elevated in the absence of GLUT1. Adipose tissue MFs of lean Slc2a1 M2/2 mice had increased alternative M2-like activation marker mannose receptor CD206, yet lack of GLUT1 was not a critical mediator in the development of obesity-associated metabolic dysregulation. However, Ldlr 2/2 mice lacking myeloid GLUT1 developed unstable atherosclerotic lesions. Defective phagocytic capacity in Slc2a1 M2/2 BMDMs may have contributed to unstable atheroma formation. Together, our findings suggest that although lack of GLUT1 blunted glycolysis and the pentose phosphate pathway, MF were metabolically flexible enough that inflammatory cytokine release was not dramatically regulated, yet phagocytic defects hindered MF function in chronic diseases.

To determine the role of CYP1B1 in the gender difference in response to Ang II-induced hypertension, female Cyp1b1+/+ and Cyp1b1−/− mice were infused with Ang II (700 ng/kg/min) or vehicle with/without ovariectomy. In addition, mice were treated with the CYP1B1 inhibitor, 2,3′,4,5′-tetramethoxystilbene (TMS, 300 μg/kg, every 3rd day, i.p.), and 17-β-estradiol metabolites, 2-hydroxyestradiol (2-OHE), 4-OHE, or 2-methoxyestradiol (2-MeE2) (1.5 mg/kg/day, i.p., for 2 weeks), and systolic blood pressure (SBP) measured. Ang II increased SBP more in Cyp1b1−/− than in Cyp1b1+/+ mice (119±3 to 171±11 mmHg vs. 120±4 to 149±4 mmHg, P<0.05). Ang II caused cardiovascular remodeling and endothelial dysfunction, and increased vascular reactivity and oxidative stress in Cyp1b1−/− but not Cyp1b1+/+mice. The Ang II-induced increase in SBP was enhanced by ovariectomy and TMS in Cyp1b1+/+ but not Cyp1b1−/− mice. 2-OHE did not alter Ang II-induced increase in SBP in Cyp1b1+/+ mice but minimized it in Cyp1b1−/− mice, whereas 4-OHE enhanced Ang II-induced increase in SBP in Cyp1b1+/+ mice but did not alter the increased SBP in Cyp1b1−/− mice. 2-OHE-derived catechol-O-methyltransferase metabolite, 2-MeE2, inhibited Ang II-induced increase in SBP in Cyp1b1−/− mice. Ang II increased plasma levels of 2MeE2 in Cyp1b1+/+ but not Cyp1b1−/− mice, and increased activity of cardiac extracellular signal-regulated kinase 1/2, p38 mitogen-activated kinase, c-Src, and Akt in Cyp1b1−/− but not Cyp1b1+/+ mice. These data suggest that CYP1B1 protects against Ang II-induced hypertension and associated cardiovascular changes in female mice, most likely mediated by 2-MeE2-inhibiting oxidative stress and the activity of these signaling molecules.

Immune checkpoint blockade (ICB) has improved outcomes in some cancers. A major limitation of ICB is that most patients fail to respond, which is partly attributable to immunosuppression. Obesity appears to improve immune checkpoint therapies in some cancers, but impacts on breast cancer (BC) remain unknown. In lean and obese mice, tumor progression and immune reprogramming were quantified in BC tumors treated with anti-programmed death-1 (PD-1) or control. Obesity augments tumor incidence and progression. Anti-PD-1 induces regression in lean mice and potently abrogates progression in obese mice. BC primes systemic immunity to be highly responsive to obesity, leading to greater immunosuppression, which may explain greater anti-PD-1 efficacy. Anti-PD-1 significantly reinvigorates antitumor immunity despite persistent obesity. Laminin subunit beta-2 (Lamb2), downregulated by anti-PD-1, significantly predicts patient survival. Lastly, a microbial signature associated with anti-PD-1 efficacy is identified. Thus, anti-PD-1 is highly efficacious in obese mice by reinvigorating durable antitumor immunity.

Previously, we showed that Cyp1b1 gene disruption minimizes angiotensin II-induced hypertension and associated pathophysiological changes in male mice. This study was conducted to test the hypothesis that cytochrome P450 1B1-generated metabolites of testosterone, 6β-hydroxytestoterone and 16α-hydroxytestosterone, contribute to angiotensin II-induced hypertension and its pathogenesis. Angiotensin II infusion for 2 weeks increased cardiac cytochrome P450 1B1 activity and plasma levels of 6β-hydroxytestosterone, but not 16α-hydroxytestosterone, in Cyp1b1+/+ mice without altering Cyp1b1 gene expression; these effects of angiotensin II were not observed in Cyp1b1−/− mice. Angiotensin II-induced increase in systolic blood pressure and associated cardiac hypertrophy, and fibrosis, measured by intracardiac accumulation of α-smooth muscle actin, collagen and transforming growth factor-β, and increased nicotinamide adenine dinucleotide phosphate oxidase activity and production of reactive oxygen species; these changes were minimized in Cyp1b1−/− or castrated Cyp1b1+/+ mice, and restored by treatment with 6β-hydroxytestoterone. In Cyp1b1+/+ mice, 6β-hydroxytestosterone did not alter the angiotensin II-induced increase in systolic blood pressure; the basal systolic blood pressure was also not affected by this agent in either genotype. Angiotensin II or castration did not alter cardiac, angiotensin II type 1 receptor, angiotensin converting enzyme, Mas receptor, or androgen receptor mRNA levels in Cyp1b1+/+ or in Cyp1b1−/− mice. These data suggest that the testosterone metabolite, 6β-hydroxytestosterone, contributes to angiotensin II-induced hypertension and associated cardiac pathogenesis in male mice, most likely by acting as a permissive factor. Moreover, cytochrome P450 1B1 could serve as a novel target for developing agents for treating renin-angiotensin and testosterone-dependent hypertension and associated pathogenesis in males.