Many inflammation-associated diseases, including cancers, increase in women after menopause and with obesity. In contrast to anti-inflammatory actions of 17β-estradiol, we find estrone, which dominates after menopause, is pro-inflammatory. In human mammary adipocytes, cytokine expression increases with obesity, menopause, and cancer. Adipocytecancer cell interaction stimulates estrone- and NFκB-dependent pro-inflammatory cytokine upregulation. Estrone- and 17β-estradiol-driven transcriptomes differ. EstroneERα stimulates NFκB-mediated cytokine gene induction; 17β-estradiol opposes this. In obese mice, estrone increases and 17β-estradiol relieves inflammation. Estrone drives more rapid ER+ breast cancer growth in vivo. HSD17B14, which converts 17β-estradiol to estrone, associates with poor ER+ breast cancer outcome. Estrone and HSD17B14 upregulate inflammation, ALDH1 activity, and tumorspheres, while 17β-estradiol and HSD17B14 knockdown oppose these. Finally, a high intratumor estrone17β-estradiol ratio increases tumor-initiating stem cells and ER+ cancer growth in vivo. These findings help explain why postmenopausal ER+ breast cancer increases with obesity, and offer new strategies for prevention and therapy.Endothelial cell (EC)-derived signals contribute to organ regeneration, but angiocrine metabolic communication is not described. We found that EC-specific loss of the glycolytic regulator pfkfb3 reduced ischemic hindlimb revascularization and impaired muscle regeneration. This was caused by the reduced ability of macrophages to adopt a proangiogenic and proregenerative M2-like phenotype. Mechanistically, loss of pfkfb3 reduced lactate secretion by ECs and lowered lactate levels in the ischemic muscle. Addition of lactate to pfkfb3-deficient ECs restored M2-like polarization in an MCT1-dependent fashion. Lactate shuttling by ECs enabled macrophages to promote proliferation and fusion of muscle progenitors. Moreover, VEGF production by lactate-polarized macrophages was increased, resulting in a positive feedback loop that further stimulated angiogenesis. Finally, increasing lactate levels during ischemia rescued macrophage polarization and improved muscle reperfusion and regeneration, whereas macrophage-specific mct1 deletion prevented M2-like polarization. In summary, ECs exploit glycolysis for angiocrine lactate shuttling to steer muscle regeneration from ischemia.Obesity is genetically heterogeneous with monogenic and complex polygenic forms. Using exome and targeted sequencing in 2,737 severely obese cases and 6,704 controls, we identified three genes (PHIP, DGKI, and ZMYM4) with an excess burden of very rare predicted deleterious variants in cases. In cells, we found that nuclear PHIP (pleckstrin homology domain interacting protein) directly enhances transcription of pro-opiomelanocortin (POMC), a neuropeptide that suppresses appetite. Obesity-associated PHIP variants repressed POMC transcription. Our demonstration that PHIP is involved in human energy homeostasis through transcriptional regulation of central melanocortin signaling has potential diagnostic and therapeutic implications for patients with obesity and developmental delay. Additionally, we found an excess burden of predicted deleterious variants involving genes nearest to loci from obesity genome-wide association studies. Genes and gene sets influencing obesity with variable penetrance provide compelling evidence for a continuum of causality in the genetic architecture of obesity, and explain some of its missing heritability.The ketogenic diet is used to treat neurological and metabolic symptoms of disease, but the extent of its influences across organ systems remains unclear. Ang et al., 2020 reveal that ketone bodies induced by the diet inhibit specific bacteria of the gut microbiota and suppress pro-inflammatory T cells in the intestine.Mitochondrial fission is sustained through contact with several organelles, including the endoplasmic reticulum, lysosomes, and the actin cytoskeleton. Nagashima et al. YD23 manufacturer (2020) now demonstrate that PI(4)P-containing Golgi-derived vesicles also modulate mitochondrial fission, driven by Arf1 and PI(4)KIIIβ activity, identifying a new organelle contact involved in maintaining mitochondrial homeostasis.Itaconate is an immunometabolite with anti-inflammatory and anti-microbial properties. Riquelme et al. (2020) demonstrate that pathogenic Pseudomonas aeruginosa drives itaconate production by macrophages, which it then uses as a carbon source for biofilm formation, allowing it to persist during infection and suppress inflammation.Amphetamine (AMPH), mainly used in the treatment of attention deficit hyperactivity disorder and narcolepsy, has weight loss properties, although with detrimental cardiovascular effects. In this issue, Mahú et al. (2020) describe the effect of a new derivative of AMPH, “PEGyAMPH,” a brain-spared anti-obesity drug that alters sympathetic activity without cardiovascular side effects.In this issue of Cell Metabolism, Pirinen et al. (2020) show that disruption in NAD+ homeostasis is a key component of the pathogenesis of mitochondrial myopathy in humans that can be targeted by the administration of the NAD+ precursor niacin, identifying NAD+ boosting as a potential treatment for this devastating disease.In the era of a pandemic, networking opportunities have evaporated, and researchers are reinventing ways to connect with the community. It is our pleasure to build some of those connections, especially for young authors, by introducing you to eleven scientists whose work is featured in this issue. Here, they share their diverse and splendid journeys-from early concepts to the fruition of published work.We are excited to announce that the Cell Metabolism Advisory Board has grown to better represent the metabolism community. We are honored to present these leaders as they share their perspectives. From taking unexpected journeys to pushing for a stronger future, they emphasize the indisputable value of curiosity, teamwork, diversity, and support.The crustacean hyperglycemic hormone (CHH) neuropeptide family has multiple functions in the regulation of hemolymph glucose levels, molting, ion, and water balance and reproduction. In crab species, three neuroendocrine tissues the eyestalk ganglia (medulla terminalis X-organ and -sinus gland = ES), the pericardial organ (PO), and guts synthesize a tissue-specific isoforms of CHH neuropeptides. Recently the presence of the mandibular organ-inhibiting hormone (MOIH) was reported in the stomatogastric nervous system (STNS) that regulates the rhythmic muscle movements in esophagus, cardiac sac, gastric and pyloric ports of the foregut. In this study, we aimed to determine the presence of a tissue-specific CHH isoform in the Jonah crab, Cancer borealis using PCR with degenerate primers and 5′, 3′ rapid amplification of cDNA ends (RACE) in the ES. PO, and STNS. The analysis of CHH sequences shows that C. borealis has one type of CHH isoform, unlike other crab species. We also isolated the cDNA sequence of molt-inhibiting hormone (MIH) in the ES and MOIH in the ES and STNS.