Modification of P13K- and MAPK-dependent chemotaxis in aortic vascular smooth muscle cells by protein kinase CBII

Hyperglycemia increases expression of platelet-derived growth factor (PDGF)-beta receptor and potentiates chemotaxis to PDGF-BB in human aortic vascular smooth muscle cells (VSMCs) via PI3K and ERK/MAPK signaling pathways. The purpose of this study was to determine whether increased activation of protein kinase C (PKC) isoforms had a modulatory effect on the PI3K and ERK/MAPK pathways, control of cell adhesiveness, and movement. All known PKC isoforms were assessed but only PKC alpha and PKC beta II levels were increased in 25 mmol/L glucose. However, only PKC beta II inhibition affected (decreased) PI3K pathway and MAPK pathway activities and inhibited PDGF-beta receptor upregulation in raised glucose, and specific MAPK inhibition was required to completely block the effect of glucose. In raised glucose conditions, activity of the ERK/MAPK pathway, PI3K pathway, and PKC beta II were all sensitive to aldose reductase inhibition. Chemotaxis to PDGF-BB (360 pmol/L), absent in 5 mmol/L glucose, was present in raised glucose and could be blocked by PKC beta II inhibition. Formation of lamellipodia was dependent on PI3K activation and filopodia on MAPK activation; both lamellipodia and filopodia were eliminated when PKC beta II was inhibited. FAK phosphorylation and cell adhesion were reduced by PI3K inhibition, and although MAPK inhibition prevented chemotaxis, it did not affect FAK phosphorylation or cell adhesiveness. In conclusion, chemotaxis to PDGF-BB in 25 mmol/L glucose is PKC beta II-dependent and requires activation of both the PI3K and MAPK pathways. Changes in cell adhesion and migration speed are mediated mainly through the PI3K pathway.

Phase II study of ISIS 3521, an antisense oligodeoxynucleotide to protein kinase C alpha, in patients with previously treated low-grade non-Hodgkin's lymphoma

Background: The purpose of this study was to assess the efficacy and safety of ISIS 3521, an antisense phosphorothioate oligonucleotide to protein kinase C in patients with relapsed low-grade non-Hodgkin's lymphoma (NHL). Patients and methods: Twenty-six patients received ISIS 3521 (2 mg/kg/day) as a continuous infusion over 21 days of each 28-day cycle. Results: The median age of the patients was 53 years (range 37–77). Histological subtypes were low-grade follicular lymphoma (n=22) and B-cell small lymphocytic lymphoma (n=4). Twenty-one (81%) had stage III/IV disease. The median number of previous lines of chemotherapy was two (range one to six). A total of 87 cycles of ISIS 3521 were administered. Twenty-three patients were assessable for response. Three patients achieved a partial response. No complete responses were observed. Ten patients had stable disease. Grade 3–4 toxicity was as follows: neutropenia (3.8%) and thrombocytopenia (26.9%). Conclusions: ISIS 3521 has demonstrated anti-tumour activity in patients with relapsed low-grade NHL. There may be a potential role for this agent in combination with conventional chemotherapy for advanced low-grade lymphoma, and further trials are warranted.

Preparation of Potential Cell-Permeant Nucleoside-2',3'-Cyclic Phosphate Precursors

Uridine-3'-phosphorothiolate triesters bearing lipophilic moieties were prepared via Michaelis-Arbuzov chemistry. Subsequent deprotection of the S-cholesteryl phosphorothiolate triester afforded the corresponding diester which underwent spontaneous Cyclization to cleanly afford uridine 2',3'-cyclic phosphate. This transesterification reaction could be expedited by treatment with iodine under mild, neutral conditions.

Human coronavirus 229E nonstructural protein 13: characterization of duplex-unwinding, nucleoside triphosphatase, and RNA 5'-triphosphatase activities.

The human coronavirus 229E (HCoV-229E) replicase gene-encoded nonstructural protein 13 (nsp13) contains an N-terminal zinc-binding domain and a C-terminal superfamily 1 helicase domain. A histidine-tagged form of nsp13, which was expressed in insect cells and purified, is reported to unwind efficiently both partial-duplex RNA and DNA of up to several hundred base pairs. Characterization of the nsp13-associated nucleoside triphosphatase (NTPase) activities revealed that all natural ribonucleotides and nucleotides are substrates of nsp13, with ATP, dATP, and GTP being hydrolyzed most efficiently. Using the NTPase active site, HCoV-229E nsp13 also mediates RNA 5'-triphosphatase activity, which may be involved in the capping of viral RNAs.

Cyclin G associated kinase interacts with interleukin 12 receptor beta2 and suppresses interleukin 12 induced IFN-gamma production.

BACKGROUND: Although severe encephalopathy has been proposed as a possible contraindication to the use of noninvasive positive-pressure ventilation (NPPV), increasing clinical reports showed it was effective in patients with impaired consciousness and even coma secondary to acute respiratory failure, especially hypercapnic acute respiratory failure (HARF). To further evaluate the effectiveness and safety of NPPV for severe hypercapnic encephalopathy, a prospective case-control study was conducted at a university respiratory intensive care unit (RICU) in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) during the past 3 years. METHODS: Forty-three of 68 consecutive AECOPD patients requiring ventilatory support for HARF were divided into 2 groups, which were carefully matched for age, sex, COPD course, tobacco use and previous hospitalization history, according to the severity of encephalopathy, 22 patients with Glasgow coma scale (GCS) <10 served as group A and 21 with GCS = 10 as group B. RESULTS: Compared with group B, group A had a higher level of baseline arterial partial CO2 pressure ((102 +/- 27) mmHg vs (74 +/- 17) mmHg, P <0.01), lower levels of GCS (7.5 +/- 1.9 vs 12.2 +/- 1.8, P <0.01), arterial pH value (7.18 +/- 0.06 vs 7.28 +/- 0.07, P <0.01) and partial O(2) pressure/fraction of inspired O(2) ratio (168 +/- 39 vs 189 +/- 33, P <0.05). The NPPV success rate and hospital mortality were 73% (16/22) and 14% (3/22) respectively in group A, which were comparable to those in group B (68% (15/21) and 14% (3/21) respectively, all P > 0.05), but group A needed an average of 7 cm H2O higher of maximal pressure support during NPPV, and 4, 4 and 7 days longer of NPPV time, RICU stay and hospital stay respectively than group B (P <0.05 or P <0.01). NPPV therapy failed in 12 patients (6 in each group) because of excessive airway secretions (7 patients), hemodynamic instability (2), worsening of dyspnea and deterioration of gas exchange (2), and gastric content aspiration (1). CONCLUSIONS: Selected patients with severe hypercapnic encephalopathy secondary to HARF can be treated as effectively and safely with NPPV as awake patients with HARF due to AECOPD; a trial of NPPV should be instituted to reduce the need of endotracheal intubation in patients with severe hypercapnic encephalopathy who are otherwise good candidates for NPPV due to AECOPD.

CDK11(p58) protein kinase activity is associated with Bcl-2 down-regulation in pro-apoptosis pathway.

CDK11(p58), a G2/M-specific protein kinase, has been shown to be associated with apoptosis in many cell lines, with largely unknown mechanisms. Our previous study proved that CDK11(p58)-enhanced cycloheximide (CHX)-induced apoptosis in SMMC-7721 hepatocarcinoma cells. Here we report for the first time that ectopic expression of CDK11(p58) down-regulates Bcl-2 expression and its Ser70, Ser87 phosphorylation in CHX-induced apoptosis in SMMC-7721 cells. Overexpression of Bcl-2 counteracts the pro-apoptotic activity of CDK11(p58). Furthermore, we confirm that the kinase activity of CDK11(p58) is essential to the down-regulation of Bcl-2 as well as apoptosis. Taken together, these results demonstrate that CDK11(p58) down-regulates Bcl-2 in pro-apoptosis pathway depending on its kinase activity, which elicits survival signal in hepatocarcinoma cells.