p300 or CBP is required for insulin-stimulated glucose uptake in skeletal muscle and adipocytes.

While current thinking posits that insulin signaling to glucose transporter 4 (GLUT4) exocytic translocation and glucose uptake in skeletal muscle and adipocytes is controlled by phosphorylation-based signaling, many proteins in this pathway are acetylated on lysine residues. However, the importance of acetylation and lysine acetyltransferases to insulin-stimulated glucose uptake is incompletely defined. Here, we demonstrate that combined loss of the acetyltransferases E1A binding protein p300 (p300) and cAMP response element binding protein binding protein (CBP) in mouse skeletal muscle caused a complete loss of insulin-stimulated glucose uptake. Similarly, brief (i.e., 1 hour) pharmacological inhibition of p300/CBP acetyltransferase activity recapitulated this phenotype in human and rodent myotubes, 3T3-L1 adipocytes, and mouse muscle. Mechanistically, these effects were due to p300/CBP-mediated regulation of GLUT4 exocytic translocation and occurred downstream of Akt signaling. Taken together, we highlight a fundamental role for acetylation and p300/CBP in the direct regulation of insulin-stimulated glucose transport in skeletal muscle and adipocytes.

Sirtuin 1 is not required for contraction-stimulated glucose uptake in mouse skeletal muscle.

While it has long been known that contraction robustly stimulates skeletal muscle glucose uptake, the molecular steps regulating this increase remain incompletely defined. The mammalian ortholog of Sir2, sirtuin 1 (SIRT1), is an NAD+-dependent protein deacetylase that is thought to link perturbations in energy flux associated with exercise to subsequent cellular adaptations. Nevertheless, its role in contraction-stimulated glucose uptake has not been described. The objective of this study was to determine the importance of SIRT1 to contraction-stimulated glucose uptake in mouse skeletal muscle. Using a radioactive 2-deoxyglucose uptake (2DOGU) approach, we measured ex vivo glucose uptake in unstimulated (rested) and electrically stimulated (100 Hz contraction every 15 s for 10 min; contracted) extensor digitorum longus (EDL) and soleus from ∼15-wk-old male and female mice with muscle-specific knockout of SIRT1 deacetylase activity and their wild-type littermates. Skeletal muscle force decreased over the contraction protocol, although there were no differences in the rate of fatigue between genotypes. In EDL and soleus, loss of SIRT1 deacetylase activity did not affect contraction-induced increase in glucose uptake in either sex. Interestingly, the absolute rate of contraction-stimulated 2DOGU was ∼1.4-fold higher in female compared with male mice, regardless of muscle type. Taken together, our findings demonstrate that SIRT1 is not required for contraction-stimulated glucose uptake in mouse skeletal muscle. Moreover, to our knowledge, this is the first demonstration of sex-based differences in contraction-stimulated glucose uptake in mouse skeletal muscle.NEW & NOTEWORTHY Here, we demonstrate that glucose uptake in response to ex vivo contractions is not affected by the loss of sirtuin 1 (SIRT1) deacetylase function in muscle, regardless of sex or muscle type. Interestingly, however, similar to studies on insulin-stimulated glucose uptake, we demonstrate that contraction-stimulated glucose uptake is robustly higher in female compared with the male skeletal muscle. To our knowledge, this is the first demonstration of sex-based differences in contraction-stimulated glucose uptake in skeletal muscle.

Counting-based cell-free DNA screening test fails to identify triploidy-A case report.

Although noninvasive prenatal testing (NIPT) is a good test with high sensitivity and specificity for trisomy 21, 18, and 13, it remains a screening test and cannot be used for diagnostic purposes. It is important to consider the outcomes of this test and interpret the results and offer consultation accordingly.

Induction of matrix metalloproteinase-9 by galectin-7 through p38 MAPK signaling in HeLa human cervical epithelial adenocarcinoma cells.

The expression of matrix metalloproteinase-9 (MMP-9) has been reported in various cancers. Its expression is associated with tumorigenesis and tumor metastasis. Studies have shown that galectin-7, a beta-galactoside-binding animal lectin, is involved in various processes including the suppression of tumor growth. However, a recent study reported that the development of thymic lymphoma is accelerated by galectin-7 expression. In this report, we demonstrate that the expression of MMP-9 was increased by galectin-7 in human cervix epithelial cells (HeLa). When the galectin-7 gene was transfected to HeLa cells with the ECFP vector, the expression of MMP-9 mRNA increased, as compared to non-transfected cells. As a result, MMP-9 protein levels also increased, as indicated by Western blot and gelatin zymography. In addition, galectin-7-transfected cells exhibited increased invasion in the matrigel invasion system. Expression of MMP-9 is involved in several signaling pathways by various stimulation factors. Therefore, we investigated how the signaling pathway in galectin-7-transfected cells differs from that of non-transfected cells. Upon transfection of galectin-7, p38 MAPK was activated and SB203580, a chemical inhibitor of p38 MAPK, reversed the effects of galectin-7. These results indicate that galectin-7 increases the expression of MMP-9 through the p38 MAPK signaling pathway.