During mouse development, the sophisticated vascular network of the lung is established from embryonic day (E)Ϸ10.5 and continues to develop postnatally. This network is composed of endothelial cells enclosed by vascular smooth muscle, pericytes, and other mesenchymal cells. Recent in vivo lineage labeling studies in the developing heart and intestine suggest that some of the vascular smooth muscle cells arise from the surface mesothelium. In the developing lung, the Wilm's tumor 1 gene (Wt1) is expressed only in the mesothelial cells. Therefore, we lineage-labeled the mesothelium in vivo by using a Wt1-Cre transgene in combination with either Rosa26R lacZ , Rosa26R CAG-hPLAP , or Rosa26R EYFP reporter alleles. In all three cases, cells derived from lineage-labeled mesothelium are found inside the lung and as smooth muscle actin (SMA) and PDGF receptor-beta positive cells in the walls of pulmonary blood vessels. To corroborate this finding, we used 5-(and-6)-carboxy-2 ,7 -dichlorofluorescein diacetate, succinimidyl ester ''mixed isomers'' (CCFSE) dye to label mesothelial cells on the surface of the embryonic lung. Over the course of 72-h culture, dye-labeled cells also appear within the lung mesenchyme. Together, our data provide evidence that mesothelial cells serve as a source of vascular smooth muscle cells in the developing lung and suggest that a conserved mechanism applies to the development of blood vessels in all coelomic organs.lineage tracing ͉ blood vessel ͉ embryo ͉ pleura

Phytochemicals such as indole-3-carbinol (I3C) and sulforaphane are components of cruciferous vegetables which exhibit antitumorigenic activity associated with altered carcinogen metabolism and detoxification. Diindolylmethane (DIM) is a major acid-catalyzed metabolite of I3C formed in the gut that binds to the aryl hydrocarbon receptor (AhR) and treatment of MCF-7 human breast cancer cells with 10-50 microM DIM resulted in rapid formation of the nuclear AhR complex and induction of CYP1A1 gene expression was observed at concentrations >50 microM. Previous studies have demonstrated that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a high affinity AhR ligand, inhibits 17beta-estradiol (E2)-induced responses in MCF-7 cells and growth of E2-dependent 7,12-dimethylbenzanthracene (DMBA)-induced mammary tumors in female Sprague-Dawley rats. Results of this study show that like TCDD, DIM inhibits E2-induced proliferation of MCF-7 cells, reporter gene activity in cells transiently transfected with an E2-responsive plasmid (containing a frog vitellogenin A2 gene promoter insert) and down-regulates the nuclear estrogen receptor. Moreover, DIM (5 mg/kg every other day) also inhibits DMBA-induced mammary tumor growth in Sprague-Dawley rats and this was not accompanied by induction of hepatic CYP1A1-dependent activity. Thus, DIM represents a new class of relatively non-toxic AhR-based antiestrogens that inhibit E2-dependent tumor growth in rodents and current studies are focused on development of analogs for clinical treatment of breast cancer.

Traumatic brain injury (TBI) is a leading cause of mortality and disability worldwide. Although treatment guidelines have been developed, no best treatment option or medicine for this condition exists. Recently, mesenchymal stem cells (MSCs)-derived exosomes have shown lots of promise for the treatment of brain disorders, with some results highlighting the neuroprotective effects through neurogenesis and angiogenesis after TBI. However, studies focusing on the role of exosomes in the early stages of neuroinflammation post-TBI are not sufficient. In this study, we investigated the role of bone mesenchymal stem cells (BMSCs)-exosomes in attenuating neuroinflammation at an early stage post-TBI and explored the potential regulatory neuroprotective mechanism. We administered 30 μg protein of BMSCs-exosomes or an equal volume of phosphate-buffered saline (PBS) via the retro-orbital route into C57BL/6 male mice 15 min after controlled cortical impact (CCI)-induced TBI. The results showed that the administration of BMSCs-exosomes reduced the lesion size and improved the neurobehavioral performance assessed by modified Neurological Severity Score (mNSS) and rotarod test. In addition, BMSCs-exosomes inhibited the expression of proapoptosis protein Bcl-2-associated X protein (BAX) and proinflammation cytokines, tumor necrosis factor-α (TNF-α) and interleukin (IL)-1β, while enhancing the expression of the anti-apoptosis protein B-cell lymphoma 2 (BCL-2). Furthermore, BMSCs-exosomes modulated microglia/macrophage polarization by downregulating the expression of inducible nitric oxide synthase (INOS) and upregulating the expression of clusters of differentiation 206 (CD206) and arginase-1 (Arg1). In summary, our result shows that BMSCs-exosomes serve a neuroprotective function by inhibiting early neuroinflammation in TBI mice through modulating the polarization of microglia/macrophages. Further research into this may serve as a potential therapeutic strategy for the future treatment of TBI.