Effect of mobile phone intervention for diabetes on glycaemic control: a meta-analysis

AIMS

  To assess the effect of mobile phone intervention on glycaemic control in diabetes self-management.

METHODS

We searched three electronic databases (PubMed, EMBASE and Cochrane Library) using the following terms: diabetes or diabetes mellitus and mobile phone or cellular phone, or text message. We also manually searched reference lists of relevant papers to identify additional studies. Clinical studies that used mobile phone intervention and reported changes in glycosylated haemoglobin (HbA(1c) ) values in patients with diabetes were reviewed. The study design, intervention methods, sample size and clinical outcomes were extracted from each trial. The results of the HbA(1c) change in the trials were pooled using meta-analysis methods.

RESULTS

  A total of 22 trials were selected for the review. Meta-analysis among 1657 participants showed that mobile phone interventions for diabetes self-management reduced HbA(1c) values by a mean of 0.5% [6 mmol/mol; 95% confidence interval, 0.3-0.7% (4-8 mmol/mol)] over a median of 6 months follow-up duration. In subgroup analysis, 11 studies among Type 2 diabetes patients reported significantly greater reduction in HbA(1c) than studies among Type 1 diabetes patients [0.8 (9 mmol/mol) vs. 0.3% (3 mmol/mol); P=0.02]. The effect of mobile phone intervention did not significantly differ by other participant characteristics or intervention strategies.

CONCLUSIONS

  Results pooled from the included trials provided strong evidence that mobile phone intervention led to statistically significant improvement in glycaemic control and self-management in diabetes care, especially for Type 2 diabetes patients.

Increased expression of programmed cell death protein 1 on NK cells inhibits NK-cell-mediated anti-tumor function and indicates poor prognosis in digestive cancers

Abnormal expression of activating/inhibitory receptors leads to natural killer (NK) cells dysfunction in tumor. Here we show that programmed cell death protein 1 (PD-1), a well-known immune checkpoint of T cells, is highly expressed on peripheral and tumor-infiltrating NK cells from patients with digestive cancers including esophageal, liver, colorectal, gastric and biliary cancer. The increased PD-1 expression on NK cells indicates poorer survival in esophageal and liver cancers. Blocking PD-1/PD-L1 signaling markedly enhances cytokines production and degranulation and suppresses apoptosis of NK cells in vitro. PD-1/PD-L1 exerts inhibitory effect through repressing the activation of PI3K/AKT signaling in NK cells. More importantly, a PD-1 blocking antibody was found to significantly suppress the growth of xenografts in nude mice, and this inhibition of tumor growth was completely abrogated by NK depletion. These findings strongly suggested that PD-1 is an inhibitory regulator of NK cells in digestive cancers. PD-1 blockade might be an efficient strategy in NK cell-based tumor immunotherapy.

Photoregulation of the Formation and Dissociation of a DNA Duplex by Using the cis-trans Isomerization of Azobenzene

The duplex-forming activity of an oligonucleotide has been photoregulated by making use of the isomerization of an azobenzene moiety in the side chain. When the azobenzene moiety is isomerized from the trans form to the cis form upon photoirradiation, the melting temperature of the duplex between the oligonucleotide and its complementary counterpart is significantly lowered, and the duplex is largely dissociated into two single-stranded oligonucleotides (shown schematically).

A novel cationic lipid greatly enhances plasmid DNA delivery and expression in mouse lung

Effective gene therapy for lung tissue requires the use of efficient vehicles to deliver the gene of interest into lung cells. When plasmid DNA encoding chloramphenicol acetyltransferase (CAT) was administered intranasally to BALB/c mice without carrier lipids, CAT activity was detected in mouse lung extracts. Plasmid DNA delivered with optimally formulated commercially available transfection reagents expressed up to 10-fold more CAT activity in lung than observed with naked DNA alone. Liposome formulations consisting of (+/-)-N-(3-aminopropyl)-N,N-dimethyl-2,3-bis (dodecyloxy)-1-propanaminium bromide (GAP-DLRIE) plus the neutral colipid dioleoylphosphatidylethanolamine (DOPE) enhanced CAT expression by more than 100-fold relative to plasmid DNA alone. A single administration of GAP-DLRIE liposome-CAT DNA complexes to mouse lung elicited peak expression at days 1-4 posttransfection, followed by a gradual return to baseline by day 21 postadministration. Readministration of GAP-DLRIE liposome CAT complexes at day 21 led to another transient peak of reporter gene expression. Histological examination of lungs treated with GAP-DLRIE complexed beta-galactosidase DNA revealed that alveolar epithelial cells were the primary locus of expression and that up to 1% of all alveoli contained epithelial cells expressing the transgene.

Heterogeneous fatty acylation of Src family kinases with polyunsaturated fatty acids regulates raft localization and signal transduction

Fatty acylation of Src family kinases is essential for localization of the modified proteins to the plasma membrane and to plasma membrane rafts. It has been suggested that the presence of saturated fatty acyl chains on proteins is conducive for their insertion into liquid ordered lipid domains present in rafts. The ability of unsaturated dietary fatty acids to be attached to Src family kinases has not been investigated. Here we demonstrate that heterogeneous fatty acylation of Src family kinases occurs and that the nature of the attached fatty acid influences raft-mediated signal transduction. By using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, we show that in addition to 14:0 (myristate), 14:1 and 14:2 fatty acids can be attached to the N-terminal glycine of the Src family kinase Fyn when the growth media are supplemented with these dietary fatty acids. Moreover, we synthesized novel iodinated analogs of oleate and stearate, and we showed that heterogeneous S-acylation can occur on cysteine residues within Fyn as well as Galpha, GAP43, and Ras. Modification of Fyn with unsaturated or polyunsaturated fatty acids reduced its raft localization and resulted in decreased T cell signal transduction. These studies establish that heterogeneous fatty acylation is a widespread occurrence that serves to regulate signal transduction by membrane-bound proteins.

The 1-aminocyclopropane-1-carboxylate synthase gene family of Arabidopsis thaliana

Genomic sequences encoding five divergent 1-aminocyclopropane-1-carboxylic acid (ACC) synthase polypeptides (ACC1, ACC2, ACC3, ACC4, and ACC5) have been isolated from Arabidopsis thaliana by using heterologous cDNAs and PCR fragments amplified from genomic DNA with degenerate oligonucleotide primers. Each gene is located on a different chromosome in the Arabidopsis genome. The genes are differentially expressed during development and in response to environmental stimuli. Protein-synthesis inhibition derepresses the expression of all genes but most dramatically derepresses that of ACC2, suggesting that their expression may be under negative control. The sequence of ACC2 was determined, and its transcription initiation site was defined. Authenticity of the polypeptide encoded by the gene was confirmed by expression experiments in Escherichia coli. The predicted size of the protein is 55,623 Da, and it contains the 11 invariant amino acid residues conserved between aminotransferases and ACC synthases from various plant species. Comparative analysis of structural and expression characteristics of ACC synthase genes from Arabidopsis and other plant species suggests that the sequence divergence of the ACC synthase genes and possibly the distinct regulatory networks governing the expression of ACC synthase subfamilies arose early in plant evolution and before the divergence of monocots and dicots.

Agrobacterium tumefaciens-mediated transformation of yeast

Agrobacterium tumefaciens transfers a piece of its Ti plasmid DNA (transferred DNA or T-DNA) into plant cells during crown gall tumorigenesis. A. tumefaciens can transfer its T-DNA to a wide variety of hosts, including both dicotyledonous and monocotyledonous plants. We show that the host range of A. tumefaciens can be extended to include Saccharomyces cerevisiae. Additionally, we demonstrate that while T-DNA transfer into S. cerevisiae is very similar to T-DNA transfer into plants, the requirements are not entirely conserved. The Ti plasmid-encoded vir genes of A. tumefaciens that are required for T-DNA transfer into plants are also required for T-DNA transfer into S. cerevisiae, as is vir gene induction. However, mutations in the chromosomal virulence genes of A. tumefaciens involved in attachment to plant cells have no effect on the efficiency of T-DNA transfer into S. cerevisiae. We also demonstrate that transformation efficiency is improved 500-fold by the addition of yeast telomeric sequences within the T-DNA sequence.

Utilization of the rpoB gene as a specific chromosomal marker for real-time PCR detection of Bacillus anthracis

The potential use of Bacillus anthracis as a weapon of mass destruction poses a threat to humans, domesticated animals, and wildlife and necessitates the need for a rapid and highly specific detection assay. We have developed a real-time PCR-based assay for the specific detection of B. anthracis by taking advantage of the unique nucleotide sequence of the B. anthracis rpoB gene. Variable region 1 of the rpoB gene was sequenced from 36 Bacillus strains, including 16 B. anthracis strains and 20 other related bacilli, and four nucleotides specific for B. anthracis were identified. PCR primers were selected so that two B. anthracis-specific nucleotides were at their 3' ends, whereas the remaining bases were specific to the probe region. This format permitted the PCR reactions to be performed on a LightCycler via fluorescence resonance energy transfer (FRET). The assay was found to be specific for 144 B. anthracis strains from different geographical locations and did not cross-react with other related bacilli (175 strains), with the exception of one strain. The PCR assay can be performed on isolated DNA as well as crude vegetative cell lysates in less than 1 h. Therefore, the rpoB-FRET assay could be used as a new chromosomal marker for rapid detection of B. anthracis.

Environmental factors and Parkinson's disease: a case-control study in China

We studied the role of environment in the development of Parkinson's disease (PD) in China, where industrialization is relatively recent and the population geographically stable. Using a case-control method, we investigated the relationship between PD and exposure to the following factors before disease onset: place of residence, source of drinking water, environmental and occupational exposure to various agricultural and industrial processes. Occupational or residential exposure to industrial chemicals, printing plants, or quarries was associated with an increased risk of developing PD. In contrast, living in villages and exposure to the common accompaniments of village life, wheat growing and pig raising, were associated with a decreased risk for PD. PD cases and controls did not differ with respect to other factors investigated. These findings are consistent with the hypothesis that environmental exposure to certain industrial chemicals may be related to the development of PD.

Cycloxygenase-2 activity promotes cognitive deficits but not increased amyloid burden in a model of Alzheimer’s disease in a sex-dimorphic pattern

Administration of non-steroidal anti-inflammatory agents reduces the risk of developing Alzheimer's disease in normal aging populations, an effect that may occur from inhibition of the cyclooxygenases, the rate-limiting enzymes in the formation of prostaglandins. In this study, we investigated whether increased activity of cyclooxygenase-2 (COX-2), the inducible isoform of cyclooxygenase, potentiates disease progression in a transgenic mouse model of Alzheimer's disease. To study the functional effects of COX-2 activity, male and female bigenic mice (amyloid precursor protein with Swedish mutation [APPswe]-presenilin-1 protein with deletion of exon 9 [PS1dE9] and trigenic COX-2/APPswe-PS1dE9) were behaviorally tested +/-administration of the selective COX-2 inhibitor celecoxib. Behavioral testing included a three-trial Y maze that measures spatial working and recognition memories and an open field task that tested levels of hyperactivity. Overexpression of COX-2 in APPswe-PS1dE9 mice resulted in specific deficits in spatial working memory in female but not male mice. These sex-specific deficits were abolished by pharmacological inhibition of COX-2 activity. Importantly, COX-2-associated deficits were dependent on co-expression of all three transgenes since COX-2 single transgenic and APPswe-PS1dE9 bigenic mice showed normal memory. Quantification of amyloid plaque load and total Abeta 40 and 42 peptides did not reveal significant differences in trigenic versus bigenic mice treated with either vehicle or celecoxib. Taken together, these data indicate an interaction between the effects of COX-2 and Abeta peptides on cognition that occurs in a sex-specific manner in the absence of significant changes in amyloid burden. These findings suggest that pathological activation of COX-2 may potentiate the toxicity of Abeta peptides, particularly in females, without significantly affecting Abeta accumulation.

Gene chemistry: functionally and conformationally intact fluorescent plasmid DNA

We describe an effective approach using a peptide nucleic acid (PNA) "clamp" to directly and irreversibly modify plasmid DNA, without affecting either its supercoiled conformation or its ability to be efficiently transcribed. To demonstrate this approach a highly fluorescent preparation of plasmid DNA was generated by hybridizing a fluorescently labeled PNA to the plasmid. Fluorescent plasmid prepared in this way was neither functionally nor conformationally altered. PNA binding was sequence specific, saturable, extremely stable, and did not influence the nucleic acid intracellular distribution. This method was utilized for the first time to study the biodistribution of conformationally and functionally intact plasmid DNA in living cells after cationic lipid-mediated transfection. A fluorescent plasmid expressing green fluorescent protein (GFP) enabled simultaneous colocalization of both plasmid and expressed protein in living cells and in real time. GFP was shown to be expressed in cells containing detectable nuclear fluorescent plasmid. The fluorescent PNA-labeled plasmid revealed a marked difference in the nuclear uptake between oligonucleotide and plasmid, suggesting that nuclear entry of plasmid may require cell division. This detection method provides a way to simultaneously monitor the intracellular localization and expression of plasmid DNA in living cells, and to elucidate the mechanism of plasmid delivery and its nuclear import with synthetic gene delivery systems.

Regulation of tumor necrosis factor alpha-mediated apoptosis of rheumatoid arthritis synovial fibroblasts by the protein kinase Akt

OBJECTIVE

To determine if tumor necrosis factor alpha (TNFalpha)-driven proliferation of rheumatoid arthritis synovial fibroblasts (RASF) is associated with up-regulation of the activity of serine/threonine kinase B/Akt and with survival of RASF.

METHODS

Staining of phosphorylated Akt was done using anti-phosphorylated Thr308 Akt antibody. Levels of phosphorylated Akt were analyzed by Western blot and Akt activity was analyzed using a kinase assay. TUNEL staining was used to analyze the cytotoxicity of TNFalpha treatment or TNFalpha combined with either the Akt activity inhibitor wortmannin, an adenovirus expressing dominant-negative mutant (AdAkt-DN), or an adenovirus expressing phosphatase and tensin homolog deleted on chromosome 10 (AdPTEN).

RESULTS

The levels of phosphorylated Akt were higher in RASF than in osteoarthritis synovial fibroblasts (OASF), as demonstrated by immunohistochemical staining, immunoblot analysis, and an Akt kinase assay. The levels of phosphorylated Akt and Akt kinase activity were increased by stimulation of primary RASF with TNFalpha (10 ng/ml). Treatment of RASF with the phosphatidylinositol 3-kinase inhibitor wortmannin (50 nM) plus TNFalpha resulted in apoptosis of 60 +/- 8% (mean +/- SEM) of RASF within 24 hours. This proapoptosis effect was specific for Akt, since equivalent levels of apoptosis were observed upon TNFalpha treatment of RASF transfected with AdAkt-DN and with AdPTEN, which opposes the action of Akt.

CONCLUSION

These results indicate that phosphorylated Akt acts as a survival signal in RASF and contributes to the stimulatory effect of TNFalpha on these cells by inhibiting the apoptosis response. This effect was not observed in OASF and may reflect the pathophysiologic changes associated with the proliferating synovium in rheumatoid arthritis.

Phenylalanine ammonia-lyase gene organization and structure

Phenylalanine ammonia-lyase (PAL; EC 4.3.1.5) genomic sequences were isolated from bean (Phaseolus vulgaris L.) genomic libraries using elicitor-induced bean PAL cDNA sequences as a probe. Southern blot hybridization of genomic DNA fragments revealed three divergent classes of PAL genes in the bean genome. Polymorphic forms were observed within each class. The nucleotide sequences of two PAL genes, gPAL2 (class II) and gPAL3 (class III), were determined. gPAL2 contains an open reading frame encoding a polypeptide of 712 amino acids, interrupted by a 1720 bp intron in the codon for amino acid 130. gPAL3 encodes a polypeptide of 710 amino acids showing 72% similarity with that encoded by gPAL2, and contains a 447 bp intron at the same location. At the nucleotide level, gPAL2 and gPAL3 show 59% sequence similarity in exon I, 74% similarity in exon II, and extensive sequence divergence in the intron, 5' and 3' flanking regions. S1 nuclease protection identified transcription start sites of gPAL2 and gPAL3 respectively 99 bp and 35 bp upstream from the initiation codon ATG, and showed that gPAL2 but not gPAL3 was activated by elicitor, whereas both were activated by wounding of hypocotyls. The 5' flanking region of both genes contain TATA and CAAT boxes, and sequences resembling the SV40 enhancer core. gPAL2 contains a 40 bp palindromic sequence and a 22 bp motif that are also found at similar positions relative to the TATA box in 5' flanking regions of other elicitor-induced bean genes.

Phox homology domains specifically bind phosphatidylinositol phosphates

The recruitment of specific cytosolic proteins to intracellular membranes through binding phosphorylated derivatives of phosphatidylinositol (PtdIns) controls such processes as endocytosis, regulated exocytosis, cytoskeletal organization, and cell signaling. Protein modules such as FVYE domains and PH domains that bind specifically to PtdIns 3-phosphate (PtdIns-3-P) and polyphosphoinositides, respectively, can direct such membrane targeting. Here we show that two representative Phox homology (PX) domains selectively bind to specific phosphatidylinositol phosphates. The PX domain of Vam7p selectively binds PtdIns-3-P, while the PX domain of the CPK PI-3 kinase selectively binds PtdIns-4,5-P(2). In contrast, the PX domain of Vps5p displays no binding to any PtdInsPs that were tested. In addition, the double mutant (Y42A/L48Q) of the PX domain of Vam7p, reported to cause vacuolar trafficking defects in yeast, has a dramatically decreased level of binding to PtdIns-3-P. These data reveal that the membrane targeting function of the Vam7p PX domain is based on its ability to associate with PtdIns-3-P, analogous to the function of FYVE domains.

Crystal structure of the catalytic domain of protein-tyrosine phosphatase SHP-1

The crystal structures of the protein-tyrosine phosphatase SHP-1 catalytic domain and the complex it forms with the substrate analogue tungstate have been determined and refined to crystallographic R values of 0.209 at 2.5 A resolution and 0.207 at 2.8 A resolution, respectively. Despite low sequence similarity, the catalytic domain of SHP-1 shows high similarity in secondary and tertiary structures with other protein-tyrosine phosphatases (PTPs). In contrast to the conformational changes observed in the crystal structures of PTP1B and Yersinia PTP, the WPD loop (Trp419-Pro428) in the catalytic domain of SHP-1 moves away from the substrate binding pocket after binding the tungstate ion. Sequence alignment and structural analysis suggest that the residues in the WPD loop, especially the amino acid following Asp421, are critical for the movement of WPD loop on binding substrates and the specific activity of protein-tyrosine phosphatases. Our mutagenesis and kinetic measurements have supported this hypothesis.

Function of COX-2 and prostaglandins in neurological disease

Induction of COX-2 expression and enzymatic activity promotes neuronal injury in a number of models of neurological disease. Inhibition of COX-2 activity, either genetically or pharmacologically, has been shown to be neuroprotective in rodent models of stroke, Parkinson's disease, and amyotrophic lateral sclerosis. Inhibition of COX activity with nonsteroidal anti-inflammatory drugs (NSAIDs) reduces inflammation and amyloid accumulation in murine transgenic models of Familial Alzheimer's disease, and the use of NSAIDs decreases the risk of developing Alzheimer's disease in healthy aging populations. COX-mediated neuronal injury is presumed be due to downstream effects of one or more prostaglandin products including PGE2, PGD2, PGF2alpha, PGI2 (prostacylin) and TXA2 (thromboxane) that effect cellular changes through activation of specific prostaglandin receptor subtypes and second messenger systems. In this proceeding, we review recent data demonstrating effects of prostaglandin signaling on neuronal viability that are paradoxically protective, when taken in the context that COX-2 induces neuronal injury in the setting of excitotoxicity. Conversely, in the context of an inflammatory stimulus, the EP2 receptor enhances neuronal injury. These findings argue for an additional level of complexity in the prostaglandin response in neurological disease.

A selective inhibitor of the osteoclastic V-H(+)-ATPase prevents bone loss in both thyroparathyroidectomized and ovariectomized rats

A potent and selective inhibitor of the osteoclastic V-H(+)-ATPase, (2Z,4E)-5-(5,6-dichloro-2-indolyl)-2-methoxy-N-(1,2,2,6, 6-pentamethylpiperidin-4-yl)-2,4-pentadienamide (SB 242784), was evaluated in two animal models of bone resorption. SB 242784 completely prevented retinoid-induced hypercalcemia in thyroparathyroidectomized (TPTX) rats when administered orally at 10 mg/kg. SB 242784 was highly efficacious in the prevention of ovariectomy-induced bone loss in the rat when administered orally for 6 months at 10 mg/kg/d and was partially effective at 5 mg/kg/d. Its activity was demonstrated by measurement of bone mineral density (BMD), biochemical markers of bone resorption, and histomorphometry. SB 242784 was at least as effective in preventing bone loss as an optimal dose of estrogen. There were no adverse effects of compound administration and no effects on kidney function or urinary acidity. Selectivity of the inhibitor was further studied using an in situ cytochemical assay for bafilomycin-sensitive V-H(+)-ATPase using sections of osteoclastoma and numerous other tissues. SB 242784 inhibited the osteoclast enzyme at 1,000-fold lower concentrations than enzymes in any of the other tissues evaluated. SB 242784 demonstrates the utility of selective inhibition of the osteoclast V-H(+)-ATPase as a novel approach to the prevention of bone loss in humans.

Photocontrol of DNA duplex formation by using azobenzene-bearing oligonucleotides

The duplex-forming activities of oligonucleotides can be photomodulated by incorporation of an azobenzene unit. Upon isomerizing the trans-azobenzene to the cis form by irradiation with UV light, the T(m) value of the duplex (with the complementary DNA) is lowered so that the duplex is dissociated. The duplex is formed again when the cis-azobenzene is converted to the trans-azobenzene by irradiation with visible light. The photoregulation is successful irrespective of the position of the azobenzene unit in the oligonucleotides. The trans-azobenzene in the oligonucleotides intercalates between two DNA base pairs in the duplexes and stabilizes them because of a favorable enthalpy change. The nonplanar structure of a cis-azobenzene is unfavorable for such an interaction. These photoresponsive oligonucleotides are promising candidates for the regulation of various bioreactions.

All Brn3 genes can promote retinal ganglion cell differentiation in the chick

Targeted gene disruption studies in the mouse have demonstrated crucial roles for the Brn3 POU domain transcription factor genes, Brn3a, Brn3b, Brn3c (now called Pou4f1, Pou4f2, Pou4f3, respectively) in sensorineural development and survival. During mouse retinogenesis, the Brn3b gene is expressed in a large set of postmitotic ganglion cell precursors and is required for their early and terminal differentiation. In contrast, the Brn3a and Brn3c genes, which are expressed later in ganglion cells, appear to be dispensable for ganglion cell development. To understand the mechanism that causes the functional differences of Brn3 genes in retinal development, we employed a gain-of-function approach in the chick embryo. We find that Brn3b(l) and Brn3b(s), the two isoforms encoded by the Brn3b gene, as well as Brn3a and Brn3c all have similar DNA-binding and transactivating activities. We further find that the POU domain is minimally required for these activities. Consequently, we show that all these Brn3 proteins have a similar ability to promote development of ganglion cells when ectopically expressed in retinal progenitors. During chick retinogenesis, cBrn3c instead of cBrn3b exhibits a spatial and temporal expression pattern characteristic of ganglion cell genesis and its misexpression can also increase ganglion cell production. Based on these data, we propose that all Brn3 factors are capable of promoting retinal ganglion cell development, and that this potential may be limited by the order of expression in vivo.

Global changes in interleukin-6-dependent gene expression patterns in mouse livers after partial hepatectomy

Liver regeneration following 70% partial hepatectomy leads to rapid activation of genes in the remnant liver. Interleukin-6 deficient (IL-6 -/-) mice have impaired liver regeneration and abnormalities in immediate early gene expression. In this study, the gene expression program in the IL-6 +/+ and -/- livers at 2 hours posthepatectomy was examined with a cDNA array representing 588 highly regulated mouse genes. Thirty-six percent of the 103 immediate early genes were induced differently in IL-6 +/+ compared with IL-6 -/- livers, implying regulation by IL-6. IL-6 treatment of the IL-6 -/- mice in the absence of hepatectomy induced a much smaller set of genes in the liver, suggesting that IL-6 cooperates with other hepatectomy-induced factors to activate the large number of genes. Northern blot analyses were used to verify gene expression data obtained from the arrays. The expression of urokinase type plasminogen activator receptor (uPAR) and plasminogen activator inhibitor-1 (PAI-1), critical components of the urokinase plasminogen activator (uPA) system, was lower and delayed in IL-6 -/- livers. Despite the fact that active uPAR/uPA complex is critical for hepatocyte growth factor (HGF) activation, no differences were detected between the IL-6 +/+ and -/- livers in HGF activation as measured by receptor phosphorylation. On the contrary, the mitogen-activated protein kinase (MAPK) pathway was activated in IL-6 +/+ livers early during regeneration but remarkably delayed in IL-6 -/- livers. Defective liver regeneration may be explained by the large number of gene activation pathways altered in IL-6 -/- livers and further supports the finding that IL-6 is necessary for normal liver regeneration.