Switch from stress response to homeobox transcription factors in adipose tissue after profound fat loss.

BACKGROUND: In obesity, impaired adipose tissue function may promote secondary disease through ectopic lipid accumulation and excess release of adipokines, resulting in systemic low-grade inflammation, insulin resistance and organ dysfunction. However, several of the genes regulating adipose tissue function in obesity are yet to be identified. METHODOLOGY/PRINCIPAL FINDINGS: In order to identify novel candidate genes that may regulate adipose tissue function, we analyzed global gene expression in abdominal subcutaneous adipose tissue before and one year after bariatric surgery (biliopancreatic diversion with duodenal switch, BPD/DS) (n = 16). Adipose tissue from lean healthy individuals was also analyzed (n = 13). Two different microarray platforms (AB 1700 and Illumina) were used to measure the differential gene expression, and the results were further validated by qPCR. Surgery reduced BMI from 53.3 to 33.1 kg/m(2). The majority of differentially expressed genes were down-regulated after profound fat loss, including transcription factors involved in stress response, inflammation, and immune cell function (e.g., FOS, JUN, ETS, C/EBPB, C/EBPD). Interestingly, a distinct set of genes was up-regulated after fat loss, including homeobox transcription factors (IRX3, IRX5, HOXA5, HOXA9, HOXB5, HOXC6, EMX2, PRRX1) and extracellular matrix structural proteins (COL1A1, COL1A2, COL3A1, COL5A1, COL6A3). CONCLUSIONS/SIGNIFICANCE: The data demonstrate a marked switch of transcription factors in adipose tissue after profound fat loss, providing new molecular insight into a dichotomy between stress response and metabolically favorable tissue development. Our findings implicate homeobox transcription factors as important regulators of adipose tissue function.

Effective Hemostasis in Severe Mesenteric Vein Laceration with Tachosil(®), using a Low- or Non-thrombogenic Patch to Prevent Tachosil(®)-induced Thrombosis.

Fibrinogen- and thrombin-coated collagen fleece (FTCC) facilitates surgical hemostasis, and is of particular value during resection of parenchymatous organs. Since thrombosis may ensue if the preparation is unintentionally applied intravascularly, it has not been recommended for treating lacerations of large veins, and no previous reports describe its use in vein repair. Our observations in two patients suggest, however, that FTCC might be indicated for hemostasis in vein injury where vascular suture is difficult or not possible, provided a low- or non-thrombogenic patch is interposed to prevent FTCC-induced vein thrombosis. Our two patients had severe lacerations of the proximal superior mesenteric vein (SMV) not amenable to conventional vein repair. Rapid hemostasis was obtained without suturing using Tachosil(®), an FTCC preparation, covered with omentum. In the first patient hemostasis was obtained at the expense of vein thrombosis, apparently due to contact between the coagulant-containing side of Tachosil(®) and the inside of the vein wall. In our second patient we therefore put a small patch of parietal peritoneum on the section of the Tachosil(®) targeted to cover the vein tear to avoid direct contact between Tachosil(®) and the vein lumen. Ultrasound examination 3 days postoperatively, and autopsy 11.5 months later showed that the vein was widely patent with no stenosis or thrombus. Our observations in these two patients were that an FTCC-omentum pack alone secured rapid hemostasis in severe SMV laceration, and when a peritoneal patch was interposed between FTCC and a lacerated SMV, FTCC-induced vein thrombosis did not occur.