SCARNA10 regulates p53 acetylation-dependent transcriptional activity.

The tumor suppressor p53 is involved in variety of cell progresses including cell cycle arrest, apoptosis, DNA repair, senescence, cell metabolism and ferroptosis. Here, we identified lncRNA SCARNA10 (Small Cajal Body-Specific RNA 10) as a novel cellular factor that interacts with the DNA binding domain (DBD) of p53. Upon binding the DBD of p53 and CREB-binding protein (CBP), SCARNA10 promotes the acetylation of p53, and activates p53-mediated transcriptional activation. Overexpress or knockdown SCARNA10 leads to up (or down)-regulation of p53-mediated transcriptional activation, whereas not affecting p53 protein levels. Moreover, SCARNA10 directly activates transcription by increasing the acetylation of p53 C-terminal domain (CTD) without affecting p53 phosphorylation at Ser15. These results indicate that SCARNA10 is a novel factor which regulates p53 acetylation-dependent transcriptional activity and tumor suppression.

Vascular and Liver Homeostasis in Juvenile Mice Require Endothelial Cyclic AMP-Dependent Protein Kinase A.

During vascular development, endothelial cAMP-dependent protein kinase A (PKA) regulates angiogenesis by controlling the number of tip cells, and PKA inhibition leads to excessive angiogenesis. Whether this role of endothelial PKA is restricted to embryonic and neonatal development or is also required for vascular homeostasis later on is unknown. Here, we show that perinatal (postnatal days P1-P3) of later (P28-P32) inhibition of endothelial PKA using dominant-negative PKA expressed under the control of endothelial-specific Cdh5-CreERT2 recombinase (dnPKAiEC mice) leads to severe subcutaneous edema, hypoalbuminemia, hypoglycemia and premature death. These changes were accompanied by the local hypersprouting of blood vessels in fat pads and the secondary enlargement of subcutaneous lymphatic vessels. Most noticeably, endothelial PKA inhibition caused a dramatic disorganization of the liver vasculature. Hepatic changes correlated with decreased gluconeogenesis, while liver albumin production seems to be unaffected and hypoalbuminemia is rather a result of increased leakage into the interstitium. Interestingly, the expression of dnPKA only in lymphatics using Prox1-CreERT2 produced no phenotype. Likewise, the mosaic expression in only endothelial subpopulations using Vegfr3-CreERT2 was insufficient to induce edema or hypoglycemia. Increased expression of the tip cell marker ESM1 indicated that the inhibition of PKA induced an angiogenic response in the liver, although tissue derived pro- and anti-angiogenic factors were unchanged. These data indicate that endothelial PKA is a gatekeeper of endothelial cell activation not only in development but also in adult homeostasis, preventing the aberrant reactivation of the angiogenic program.

Synergistic neuroprotective effects of hyperbaric oxygen and N-acetylcysteine against traumatic spinal cord injury in rat.

BACKGROUND: The mitochondrial dysfunction and following oxidative stress, as well as the spread of inflammation plays major roles in the failure to regenerate following severe spinal cord injury (SCI). In this regard, we investigated the neuroprotective effects of hyperbaric oxygen (HBO), as an anti-apoptotic and anti-inflammatory agent, and N-acetylcysteine (NAC), as a mitochondrial enhancer, in SCI. MATERIAL AND METHODS: Seventy-five female adult Wistar rats divided into five groups (n = 15): laminectomy alone (Sham) group, SCI group, HBO group (underwent SCI and received HBO), NAC group (underwent SCI and received NAC), and HBO+NAC group (underwent SCI and simultaneously received NAC and HBO). At the end of study, spinal cord tissue samples were taken for evaluation of biochemical profiles including malondialdehyde (MDA), catalase (CAT), superoxide dismutase (SOD) and glutathione (GSH) levels, immunohistochemistry for caspase-3 as well as gene expressions of interleukin (IL)-10, tumor necrosis factor alpha (TNF-α), and IL-1ß. Stereological assessments were performed to determine the total volumes, central cavity volumes and as well as numerical density of the neural and glial cells in traumatic area. Moreover, neurological functions were evaluated by the Basso-Beattie-Bresnehan (BBB) and electromyography (EMG). RESULTS: Our results showed that the stereological parameters, biochemical profiles (except MDA) and neurological function were significantly higher in each HBO, NAC and HBO+NAC groups compared to the SCI group, and were highest in HBO+NAC ones. The transcript for IL-10 gene was significantly upregulated in all treatment regimens compared to SCI group, and was highest in HBO+NAC ones. While expression of TNF-α and IL-1ß, latency, as well as density of apoptosis cells in caspase-3 evaluation significantly more decreased in HBO+NAC group compared to other groups. CONCLUSION: Overall, using combined therapy with HBO and NAC has synergistic neuroprotective effects in SCI treatment.

Endothelial PKA activity regulates angiogenesis by limiting autophagy through phosphorylation of ATG16L1.

The cAMP-dependent protein kinase A (PKA) regulates various cellular functions in health and disease. In endothelial cells PKA activity promotes vessel maturation and limits tip cell formation. Here, we used a chemical genetic screen to identify endothelial-specific direct substrates of PKA in human umbilical vein endothelial cells (HUVEC) that may mediate these effects. Amongst several candidates, we identified ATG16L1, a regulator of autophagy, as novel target of PKA. Biochemical validation, mass spectrometry and peptide spot arrays revealed that PKA phosphorylates ATG16L1α at Ser268 and ATG16L1ß at Ser269, driving phosphorylation-dependent degradation of ATG16L1 protein. Reducing PKA activity increased ATG16L1 protein levels and endothelial autophagy. Mouse in vivo genetics and pharmacological experiments demonstrated that autophagy inhibition partially rescues vascular hypersprouting caused by PKA deficiency. Together these results indicate that endothelial PKA activity mediates a critical switch from active sprouting to quiescence in part through phosphorylation of ATG16L1, which in turn reduces endothelial autophagy.

cAMP-dependent protein kinase A (PKA) regulates angiogenesis by modulating tip cell behavior in a Notch-independent manner.

cAMP-dependent protein kinase A (PKA) is a ubiquitously expressed serine/threonine kinase that regulates a variety of cellular functions. Here, we demonstrate that endothelial PKA activity is essential for vascular development, specifically regulating the transition from sprouting to stabilization of nascent vessels. Inhibition of endothelial PKA by endothelial cell-specific expression of dominant-negative PKA in mice led to perturbed vascular development, hemorrhage and embryonic lethality at mid-gestation. During perinatal retinal angiogenesis, inhibition of PKA resulted in hypersprouting as a result of increased numbers of tip cells. In zebrafish, cell autonomous PKA inhibition also increased and sustained endothelial cell motility, driving cells to become tip cells. Although these effects of PKA inhibition were highly reminiscent of Notch inhibition effects, our data demonstrate that PKA and Notch independently regulate tip and stalk cell formation and behavior.

c-Myc modulates microRNA processing via the transcriptional regulation of Drosha.

The c-Myc oncogenic transcription factor is known to regulate microRNA (miRNA) expression at the transcriptional level. However, little is known about the function of c-Myc in miRNA processing. Here, we report that Drosha, one of the most important components of the miRNA processing machinery, is a c-Myc target gene. c-Myc transactivates drosha mRNA expression, thus upregulating the Drosha protein level. A chromatin immunoprecipitation (ChIP) experiment revealed that c-Myc binds directly to the E-box of the drosha promoter. Both in vitro and in vivo microRNA processing assays demonstrated that c-Myc promotes miRNA processing by upregulating the Drosha expression level. Overall, our study reveals a previously unrecognised function of c-Myc in miRNA processing and provides valuable insight into a new aspect of how c-Myc regulates microRNA expression.

Siva1 inhibits p53 function by acting as an ARF E3 ubiquitin ligase.

The tumour suppressor alternative reading frame (ARF) is one of the most frequently mutated proteins in human cancer. It has been well established that ARF is able to stabilize and activate p53 by directly inhibiting Mdm2. ARF-mediated p53 activation in response to oncogenic stress is thought to be an important determinant of protection against cancer. However, little is known regarding the control of ARF in cells. Here, we show that Siva1 is a specific E3 ubiquitin ligase of ARF. Siva1 physically interacts with ARF both in vitro and in vivo. Through direct interaction, Siva1 promotes the ubiquitination and degradation of ARF, which in turn affects the stability of p53. Functionally, Siva1 regulates cell cycle progression and cell proliferation in an ARF/p53-dependent manner. Our results uncover a novel regulatory mechanism for the control of ARF stability, thereby revealing an important function of Siva1 in the regulation of the ARF-Mdm2-p53 pathway.

[Characteristics of the confined space accident and its medical rescue strategy].

OBJECTIVE: To investigate the characteristics of the confined space accident and its medical rescue strategy. METHODS: Thirty-six patients with emergency rescue in the five confined space accident during June 2009 to July 2012 were retrospectively analyzed. RESULTS: Twenty-nine people were caught in four confined space accidents caused by building collapse and 7 people were caught in one confined space accident caused by a tower of babel blast furnace damage which caused severe gas and hydrogen sulfide poisoning. For the 36 wounded, the shortest rescue time was 1.5 hours and the longest was 10.5 hours. Fourteen people were killed (mortality rate 38.89%). Characteristics of the confined space accident: the wounded activity environment was very harsh, the wounded were restricted particularly, the wounded injuries were diverse, the psychological depression was very common. The confined space environment and the complexity of wounded disease determined its medical rescue specificity and were very different from the usual trauma emergency. CONCLUSIONS: Confined space accident caused very painful casualties. The key reason is that the relevant personnel failed to clearly recognize the potential risks in the confined space or nearby, making the confined space into another "quiet killer". This problem needs to be paid highly attention.

[Observation on 27 elderly women in britain with lymphedema syndrome treated by acupuncture combined with medicine].

OBJECTIVE: To observe clinical effect of acupuncture combined with medicine therapy for elderly women in Britain with lymphedema syndrome. METHODS: Twenty-seven cases were classified according to syndrome differentiation of TCM into cold congealing and dampness obstruction type (11 cases), qi-blood stagnation type (12 cases) and downward attack of damp-heat type (4 cases). They were treated with acupuncture at main points Zusanli (ST 36), Yanglingquan (GB 34), Yinglingquan (SP 9), Sanyinjiao (SP 6), Taichong (LR 3), Fenglong (ST 40), Xuehai (SP 10), Fengshi (GB 31), Futu (ST 32), Liangqiu (ST 34), Weizhong (BL 40), etc., twice each week and oral administration of modified Duhuojisheng Decoction, Huangqiwuwu Decoction and Simiao San Decoction, respectively, meanwhile washing the affected limb with again decoction of remaining gruffs one medicament each day. They were treated for 12 weeks. RESULTS: Twelve cases were clinically cured, accounting for 44.4%, 14 cases were effective, accounting for 51.9%; and 1 case was ineffective, accounting for 3.7%. CONCLUSION: Acupuncture combined with medicine has a good therapeutic effect on lymphedema syndrome.