[Relationship between C-C chemokine receptor type 2 and P38 mitogen-activated protein kinase signaling pathway in the spinal cord of rats with bone cancer pain].

Objective: To investigate the relationship between C-C chemokine receptor type 2(CCR2) and P38 mitogen-activated protein kinase (P38MAPK) signaling pathway in the spinal cord of rats and further clarify the mechanism of bone cancer pain (BCP). Methods: A total of 92 healthy female SD rats, of which 60 were subjected to behavioral tests using a ciliary mechanical stimulation needle. SD rats were randomly divided into six groups: sham operation group (group S), bone cancer pain group (group B), sham operation + DMSO solvent group (group SD), bone cancer pain + DMSO solvent group (group BD), sham operation + RS102895 CCR2 inhibitor group (group SR), bone cancer pain + RS102895 CCR2 inhibitor group (group BR), and Von Frey was used in the behavioral test. Another 32 SD rats were randomly divided into the following 8 groups (n=4): sham operation group (group S), bone cancer pain 5 d group (group B5), bone cancer pain 9 d group (group B9), bone cancer pain 14 d group (group B14), bone cancer pain + DMSO solvent group (group BD), bone cancer pain + RS102895 CCR2 inhibitor 0.5 h group (group BR0.5 h), bone cancer pain + RS102895 CCR2 inhibitor 4 h group (group BR4 h), bone cancer pain + RS102895 CCR2 inhibitor 12 h group (group BR12 h). Western blot was used to detect the expression of P38, p-P38 and CCR2 in spinal cord of rats. Results: At day 5, 7, 9, 14, 21 post-injection, mechanical withdrawal thresholds of group S were(30.9±1.5), (31.9±1.2), (32.0±1.1), (31.6±1.5), (32.2±1.4)g respectively, the mechanical withdrawal thresholds of group B were( 26.4±0.7), (24.4±0.8), (21.4±0.8), (13.5±0.4), (9.9±0.2)g respectively, the mechanical withdrawal thresholds in group B decreased obviously versus group S, and the differences were statistically significant(t=-13.177, -16.660, -23.778, -35.574, -48.401, all P<0.01). At day 9 post-injection, the mechanical withdrawal thresholds in SD, BD, SR and BR groups were (32.4±1.7), (19.4±1.1), (32.1±1.3), (26.3±1.0) g respectively, the difference was statistically significant (F=224.681, P<0.01), and the mechanical withdrawal thresholds in group BD decreased obviously versus group SD, while the mechanical withdrawal thresholds in group BR increased obviously versus group BD. The expression levels of p-P38 in spinal cord of group S, group B5, group B9 and group B14 were(0.08±0.03), (0.20±0.05), (0.40±0.17), (0.65±0.14)respectively, the expression levels of CCR2 were(0.08±0.04), (0.18±0.05), (0.30±0.09), (0.58±0.07)respectively, the difference was statistically significant(F=19.123, 40.746, all P<0.01), and the expression of p-P38 and CCR2 in group B9 were showed a significant up-regulation versus group S. The expression levels of p-P38 in spinal cord of group BD, group BR0.5 h, group BR4 h and group BR12 h were (0.57±0.06), (0.17±0.11), (0.03±0.01), (0.25±0.11)respectively, and the difference was statistically significant(F=29.582, P<0.01). The expression of p-P38 in group BR0.5 h, BR4 h, BR12 h showed a significant down-regulation versus group BD. Conclusion: CCR2 in the spinal cord may be involved in the development of bone cancer pain by activating P38MAPK signaling pathway in rats.

[Clinical characteristics of 11 patients with Vibrio vulnificus infection and the establishment of a rapid diagnosis procedure for this disease].

Objective: To analyze the clinical characteristics of patients with Vibrio vulnificus infection, share diagnosis and treatment experience, and establish a rapid diagnosis procedure for this disease. Methods: This study was a retrospective case series study. From January 2009 to November 2022, 11 patients with Vibrio vulnificus infection who met the inclusion criteria were admitted to the Department of Burns and Wound Repair of Guangdong Provincial People's Hospital Affiliated to Southern Medical University. The gender, age, time of onset of illness, time of admission, time of diagnosis, route of infection, underlying diseases, affected limbs, clinical manifestations and signs on admission, white blood cell count, hemoglobin, platelet count, C-reactive protein (CRP), alanine transaminase (ALT), aspartate transaminase (AST), creatinine, procalcitonin, albumin, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and blood sodium levels on admission, culture results and metagenomic next-generation sequencing (mNGS) results of pathogenic bacteria and the Vibrio vulnificus drug susceptibility test results during hospitalization, treatment methods, length of hospital stay, and outcomes of all patients were recorded. Comparative analysis was conducted on the admission time and diagnosis time of patients with and without a history of exposure to seawater/marine products, as well as the fatality ratio and amputation of limbs/digits ratio of patients with and without early adequate antibiotic treatment. For the survived patients with hand involvement, the hand function was assessed using Brunnstrom staging at the last follow-up. Based on patients' clinical characteristics and treatment conditions, a rapid diagnosis procedure for Vibrio vulnificus infection was established. Results: There were 7 males and 4 females among the patients, aged (56±17) years. Most of the patients developed symptoms in summer and autumn. The admission time was 3.00 (1.00, 4.00) d after the onset of illness, and the diagnosis time was 4.00 (2.00, 8.00) d after the onset of illness. There were 7 and 4 patients with and without a history of contact with seawater/marine products, respectively, and the admission time of these two types of patients was similar (P>0.05). The diagnosis time of patients with a history of contact with seawater/marine products was 2.00 (2.00, 5.00) d after the onset of illness, which was significantly shorter than 9.00 (4.25, 13.00) d after the onset of illness for patients without a history of contact with seawater/marine products (Z=-2.01, P<0.05). Totally 10 patients had underlying diseases. The affected limbs were right-hand in 8 cases, left-hand in 1 case, and lower limb in 2 cases. On admission, a total of 9 patients had fever; 11 patients had pain at the infected site, and redness and swelling of the affected limb, and 9 patients each had ecchymosis/necrosis and blisters/blood blisters; 6 patients suffered from shock, and 2 patients developed multiple organ dysfunction syndrome. On admission, there were 8 patients with abnormal white blood cell count, hemoglobin, and albumin levels, 10 patients with abnormal CRP, procalcitonin, and NT-proBNP levels, 5 patients with abnormal creatinine and blood sodium levels, and fewer patients with abnormal platelet count, ALT, and AST levels. During hospitalization, 4 of the 11 wound tissue/exudation samples had positive pathogenic bacterial culture results, and the result reporting time was 5.00 (5.00, 5.00) d; 4 of the 9 blood specimens had positive pathogenic bacterial culture results, and the result reporting time was 3.50 (1.25, 5.00) d; the mNGS results of 7 wound tissue/exudation or blood samples were all positive, and the result reporting time was 1.00 (1.00, 2.00) d. The three strains of Vibrio vulnificus detected were sensitive to 10 commonly used clinical antibiotics, including ciprofloxacin, levofloxacin, and amikacin, etc. A total of 10 patients received surgical treatment, 4 of whom had amputation of limbs/digits; all patients received anti-infection treatment. The length of hospital stay of 11 patients was (26±11) d, of whom 9 patients were cured and 2 patients died. Compared with that of the 6 patients who did not receive early adequate antibiotic treatment, the 5 patients who received early adequate antibiotic treatment had no significant changes in the fatality ratio or amputation of limbs/digits ratio (P>0.05). In 3 months to 2 years after surgery, the hand function of 8 patients was assessed, with results showing 4 cases of disabled hands, 2 cases of incompletely disabled hands, and 2 cases of recovered hands. When a patient had clinical symptoms of limb redness and swelling and a history of contact with seawater/marine products or a pre-examination triage RiCH score of Vibrio vulnificus sepsis ≥1, the etiological testing should be initiated immediately to quickly diagnose Vibrio vulnificus infection. Conclusions: Vibrio vulnificus infection occurs most frequently in summer and autumn, with clinical manifestations and laboratory test results showing obvious infection characteristics, and may be accompanied by damage to multiple organ functions. Both the fatality and disability ratios are high and have a great impact on the function of the affected limbs. Early diagnosis is difficult and treatment is easily delayed, but mNGS could facilitate rapid detection. For patients with red and swollen limbs accompanied by a history of contact with seawater/marine products or with a pre-examination triage RiCH score of Vibrio vulnificus sepsis ≥1, the etiological testing should be initiated immediately to quickly diagnose Vibrio vulnificus infection.

MiR-127-3p targets KIF3B to inhibit the development of oral squamous cell carcinoma.

OBJECTIVE: Recently, increased microRNAs have been shown to play an important role in the pathogenesis and progression of human cancers, including oral squamous cell carcinoma (OSCC). In this study, we focused on the function of microRNA-127-3p (miR-127-3p) associated with OSCC carcinogenesis. PATIENTS AND METHODS: MiR-127-3p and KIF3B expressions were observed via quantitative Real-time polymerase chain reaction (qRT-PCR) or Western blot in OSCC. The functions of mR-127-3p and KIF3B were investigated through MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) and transwell assays. And luciferase reporter assay was performed to confirm the relationship between mR-127-3p and KIF3B. RESULTS: First, down-regulation of miR-127-3p was identified in OSCC, which was associated with malignant clinicopathological features and poor prognosis in OSCC patients. Functionally, overexpression of miR-127-3p led to inhibition of cell proliferation and metastasis in OSCC. Further, KIF3B was confirmed to be a direct target of miR-127-3p. Moreover, upregulation of KIF3B was also observed in OSCC, which promoted tumorigenesis of OSCC. In particular, the upregulation of KIF3B partially attenuated the inhibitory effect of miR-127-3p on the development of OSCC. CONCLUSIONS: MiR-127-3p targeted KIF3B to inhibit the development of OSCC through suppressing cell proliferation, migration and invasion.

Bone-filling mesh container versus percutaneous kyphoplasty in treating Kümmell's disease.

Kümmell's disease (eponymous name for osteonecrosis and collapse of a vertebral body due to ischemia and non-union of anterior vertebral body wedge fractures after major trauma) cannot heal spontaneously. Bone-filling mesh container (BFMC) can significantly relieve pain, help the correction of kyphosis, and may prevent cement leakage. This pilot study may provide the basis for the design of future studies. PURPOSE: To compare the effectiveness and safety of BFMC and percutaneous kyphoplasty (PKP) for treatment of Kümmell's disease. METHODS: From August 2016 to May 2018, 40 patients with Kümmell's disease were admitted to Guizhou Provincial People's Hospital. Among them, 20 patients (20 vertebral bodies) received PKP (PKP group) and the other 20 received BFMC (BFMC group). Operation time, Visual Analogue Scale (VAS), Oswestry Disability Index (ODI), Cobb's angle changes, and related complications were recorded. RESULTS: All patients underwent operations successfully. VAS scores and ODI of both groups at each postoperative time point were lower than preoperatively, with statistically significant difference (p < 0.05). Postoperative Cobb's angle of both groups postoperatively was lower than preoperatively (p < 0.05). Cement leakage occurred in eight vertebrae (8/20) in the PKP group and in one vertebra (1/20) in the BFMC group. No complications such as pulmonary embolism, paraplegia, or perioperative death occurred during operation in both groups. Adjacent vertebral refractures occurred in five patients (5/20) in the PKP group and in four patients (4/20) in the BFMC group, with no significant difference in the incidence rate of refractures in both groups but the material is too small to verify statistically. CONCLUSIONS: Both PKP and BFMC technologies can significantly relieve pain and help the correction of kyphosis while treating Kümmell's disease. Moreover, the BMFC may prevent cement leakage.

Jujube leaf green tea extracts inhibits hepatocellular carcinoma cells by activating AMPK.

Here we evaluated the anti-hepatocellular carcinoma activity by the Jujube leaf green tea extracts (JLGTE). We showed that JLGTE exerted anti-proliferative, cytotoxic and pro-apoptotic activities against HepG2 and primary human hepatocellular carcinoma cells. It was however non-cytotoxic to the normal hepatocytes. JLGTE activated AMP-activated protein kinase (AMPK) signaling, which was required for its cytotoxicity against hepatocellular carcinoma cells. Silence of AMPKα1, via targeted short hairpin RNAs or CRISPR-Cas9 genome editing, inhibited JLGTE-induced AMPK activation and HepG2 cell apoptosis. Further, in-activation of AMPK by a dominant negative AMPKα1 (T172A) also alleviated JLGTE's cytotoxicity against HepG2 cells. On the other hand, forced-activation of AMPK by introduction of a constitutively-active AMPKα1 (T172D) mimicked JLGTE's actions and led to HepG2 cell apoptosis. These results suggest that JLGTE inhibits human hepatocellular carcinoma cells possibly via activating AMPK.

Programmed cell death and aerenchyma formation in roots.

Lysigenous aerenchyma contributes to the ability of plants to tolerate low-oxygen soil environments, by providing an internal aeration system for the transfer of oxygen from the shoot. However, aerenchyma formation requires the death of cells in the root cortex. In maize, hypoxia stimulates ethylene production, which in turn activates a signal transduction pathway involving phosphoinositides and Ca2+. Death occurs in a predictable pattern, is regulated by a hormone (ethylene) and provides an example of programmed cell death.

Transduction of an Ethylene Signal Is Required for Cell Death and Lysis in the Root Cortex of Maize during Aerenchyma Formation Induced by Hypoxia.

Ethylene has been implicated in signaling cell death in the lysigenous formation of gas spaces (aerenchyma) in the cortex of adventitious roots of maize (Zea mays) subjected to hypoxia. Various antagonists that are known to modify particular steps in signal transduction in other plant systems were applied at low concentrations to normoxic and hypoxic roots of maize, and the effect on cell death (aerenchyma formation) and the increase in cellulase activity that precedes the appearance of cell degeneration were measured. Both cellulase activity and cell death were inhibited in hypoxic roots in the presence of antagonists of inositol phospholipids, Ca2+- calmodulin, and protein kinases. By contrast, there was a parallel promotion of cellulase activity and cell death in hypoxic and normoxic roots by contact with reagents that activate G-proteins, increase cytosolic Ca2+, or inhibit protein phosphatases. Most of these reagents had no effect on ethylene biosynthesis and did not arrest root extension. These results indicate that the transduction of an ethylene signal leading to an increase in intracellular Ca2+ is necessary for cell death and the resulting aerenchyma development in roots of maize subjected to hypoxia.

Induction of Enzymes Associated with Lysigenous Aerenchyma Formation in Roots of Zea mays during Hypoxia or Nitrogen Starvation.

Either hypoxia, which stimulates ethylene biosynthesis, or temporary N starvation, which depresses ethylene production, leads to formation of aerenchyma in maize (Zea mays L.) adventitious roots by extensive lysis of cortical cells. We studied the activity of enzymes closely involved in either ethylene formation (1-amino-cyclopropane-1-carboxylic acid synthase [ACC synthase]) or cell-wall dissolution (cellulase). Activity of ACC synthase was stimulated in the apical zone of intact roots by hypoxia, but not by anoxia or N starvation. However, N starvation, as well as hypoxia, did enhance cellulase activity in the apical zone, but not in the older zones of the same roots. Cellulase activity did not increase during hypoxia or N starvation in the presence of aminoethoxyvinylglycine, an inhibitor of ACC synthase, but this inhibition of cellulase induction was reversed during simultaneous exposure to exogenous ethylene. Together these results indicate both the role of ethylene in signaling cell lysis in response to two distinct environmental factors and the significance of hypoxia rather than anoxia in stimulation of ethylene biosynthesis in maize roots.

Mesangial cells from diabetic NOD mice constitutively secrete increased amounts of insulin-like growth factor-I.

Experimental evidence has suggested that insulin-like growth factor-I (IGF-I) may contribute to diabetic complications. Previously, we and others have shown that normal glomerular mesangial cells have receptors for, synthesize, and exhibit a mitogenic response to IGF-I. We investigated the IGF-I response in cells derived from a genetic model of diabetes, the nonobese diabetic (NOD) mouse. Mesangial cell lines were derived from diabetic (D-NOD) and nondiabetic adult mice. D-NOD cells released more IGF-I into the supernatant and had a decreased binding of IGF-I to surface receptors. Analysis according to Scatchard revealed a decreased number of receptor sites on D-NOD cells, although the structure of the IGF-I receptor visualized by cross-linking was identical for both cell types. Preincubation of D-NOD cells with an antibody to IGF-I resulted in an increase in the number of receptor sites. This suggested that autocrine IGF-I was responsible for the decrease in D-NOD receptor number and that diabetes had resulted in a stable phenotypic change.

Long-term effects of thrombin require sustained activation of the functional thrombin receptor.

Thrombin is a potent activator of human glomerular epithelial cells (HGEC). Here we compare short-term and long-term effects of thrombin and thrombin receptor agonist peptide (TRAP) which selectively activates the functional thrombin receptor. TRAP, as thrombin, increases intracellular free Ca2+ concentration and acts synergistically with growth factors possessing tyrosine kinase receptors on DNA synthesis. Thrombin induces synthesis of proteins of the fibrinolytic system and cell proliferation if it is present for at least 8 h. TRAP alone does not stimulate protein synthesis and is not mitogenic. However, in the presence of the aminopeptidase inhibitor amastatin all long-term effects of thrombin can be fully mimicked by TRAP. In conclusion, different effects of thrombin and TRAP may be related to the degradation of TRAP by cellular ectoenzymes. The recently cloned thrombin receptor accounts for early intracellular signals and long-term cellular effects that require sustained activation of this receptor.

Collagen and collagenase mRNAs in normal and sclerotic glomeruli: predictors of progression and response to therapy.

Progressive glomerulosclerosis is associated with decreasing kidney function, eventuating in end-stage renal failure. There are multiple components of the extracellular matrix, and the exact composition in various renal diseases is not known. Thus, we examined some of the major components of the extracellular matrix (ECM) in murine and human glomerular diseases. We studied matrix synthesis and degradation at the level of gene expression and ECM composition in the intact glomerulus. To determine whether the composition of sclerosis was similar among diseases, we examined a normal mouse strain and compared it with strains which spontaneously developed glomerulosclerosis. The baseline levels of matrix components varied between different mouse strains, and this level correlated with their propensity to develop glomerulosclerosis. In addition, when glomerulosclerosis was induced, the baseline ECM mRNA level predicted the subsequent outcome. We studied mice transgenic for bovine growth hormone, since they develop progressive glomerulosclerosis. Treatment with heparin substantially decreased the lesions without changes in type IV collagen mRNAs. However, there was an up-regulation of both the mRNA and enzyme activity for the 92 kD matrix metalloproteinase. In contrast, when these mice were treated with either angiotensin converting enzyme inhibitors or angiotensin II (Ang II) receptor antagonists, the glomerulosclerosis was accentuated histologically and the ECM synthetic and degradative mRNAs were elevated. These data suggest that the mRNA levels reflect response to therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Quantification and modulation of thrombomodulin activity in isolated rat and human glomeruli.

Thrombomodulin (TM), the endothelial cell surface receptor for thrombin-mediated activation of protein C and of its anticoagulant system, is involved in maintaining vascular nonthrombogenicity, and depressed TM activity may induce intravascular fibrin formation. TM antigen was previously found by immunohistochemical methods in rabbit glomeruli. We therefore attempted to identify the corresponding TM activity in isolated detergent-solubilized rat and human glomeruli. Like purified lung TM, rat glomeruli extracts accelerated the hydrolysis by activated protein C of the chromogenic substrate S-2238 in the presence of 10 nM thrombin, as determined by spectrophotometry. One mg glomerular protein promoted the formation of 681 +/- 115 nmol activated protein C, the equivalent of the amount generated by 845 ng of purified rabbit TM. TM activity correlated with the protein content of the glomerular extracts (r = 0.94). These extracts prolonged rat plasma activated partial thromboplastin time. Incubation of glomeruli with tumor necrosis factor-alpha (TNF) or E. coli lipopolysaccharide depressed their TM-like activity in a dose and time dependent manner. Incubation with TNF suppressed their anticoagulant activity. In human glomeruli, TM activity was also found at a level which corresponded to their TM antigen content, and was determined by ELISA with mouse monoclonal antibody. These results indicate that measurement of glomerular TM activity might help to clarify the mechanisms of intraglomerular fibrin deposition in renal diseases.

Intact Leaves Exhibit a Climacteric-Like Rise in Ethylene Production before Abscission.

The rate of ethylene production by intact, attached leaves of cotton plants (Gossypium hirsutum L.) during aging and senescence was studied using a continuous flow system that allowed air around enclosed leaves to be scrubbed to collect and assay ethylene. Senescence of lower leaves began around 150 d after planting in a controlled environment room. A progressive decline in the ethylene production rate was observed when comparing the 3rd, 6th, and 10th leaves from the base with each other. Ethylene production rates of individual leaves also declined over a 50-d period. However, as leaves began to appear chlorotic, a peak of ethylene production occurred that lasted for about 4 d followed by abscission. This peak involved a 3-fold or greater increase in the rate of ethylene production. The data indicate that intact leaves experience a climacteric-like surge in ethylene production after visible symptoms of senescence appear. This "ethylene climacteric" is apparently the signal that initiates hydrolysis of cell walls in the abscission zone.

Enhanced Sensitivity to Ethylene in Nitrogen- or Phosphate-Starved Roots of Zea mays L. during Aerenchyma Formation.

Adventitious roots of maize (Zea mays L. cv TX 5855), grown in a well-oxygenated nutrient solution, were induced to form cortical gas spaces (aerenchyma) by temporarily omitting nitrate and ammonium (-N), or phosphate (-P), from the solution. Previously this response was shown (MC Drew, CJ He, PW Morgan [1989] Plant Physiology 91: 266-271) to be associated with a slower rate of ethylene biosynthesis, contrasting with the induction of aerenchyma by hypoxia during which ethylene production is strongly stimulated. In the present paper, we show that aerenchyma formation induced by nutrient starvation was blocked, under noninjurious conditions, by addition of low concentrations of Ag(+), an inhibitor of ethylene action, or of aminoethoxyvinyl glycine, an inhibitor of ethylene biosynthesis. When extending roots were exposed to low concentrations of ethylene in air sparged through the nutrient solution, N or P starvation enhanced the sensitivity to exogenous ethylene at concentrations as low as 0.05 microliters ethylene per liter air, promoting a more rapid and extensive formation of aerenchyma than in unstarved roots. We conclude that temporary deprivation of N or P enhances the sensitivity of ethylene-responsive cells of the root cortex, leading to cell lysis and aerenchyma.

Presence of diabetic complications in type 1 diabetic patients correlates with low expression of mononuclear cell AGE-receptor-1 and elevated serum AGE.

BACKGROUND: Receptors for advanced glycation endproducts (AGE-R) mediate AGE turnover, but can also trigger inflammatory genes that promote diabetic tissue injury and diabetic complications (DC). High AGE levels and reduced AGE-R sites in kidneys of NOD mice prone to type 1 diabetes (T1D) and to renal disease (RD) suggested that impaired AGE-R function may contribute to RD in these mice. MATERIALS AND METHODS: In this study, after confirming reduced AGE-R1 expression in NOD mouse peritoneal macrophages, we tested for differences in AGE-R1, -R2, and -R3 gene expression in 54 human subjects by RT-PCR and Western analysis. Fresh peripheral blood mononuclear cells (PBMN) were isolated from 36 persons: 18 T1D patients with severe RD (DC); 11 age-and DM-duration matched patients without DC (n-DC); and 7 normal volunteers (NL). EBV-transformed lymphoblasts were obtained from an additional 18 subjects (12 T1D patients, 6 with and 6 without DC, and 6 nondiabetics). RESULTS: AGE-R1 mRNA and protein of PBMN from n-DC patients were enhanced (p < .05 versus NL) in proportion to serum AGE levels (sAGE) (p < .005 versus NL). In contrast, PBMN from DC patients exhibited no up-regulation of AGE-R1 mRNA or protein, despite higher sAGE levels (p < .005 versus NL). A similar unresponsiveness in AGE-R1 gene expression was observed in EBV-transformed lymphoblasts from DC patients versus NL (p < .01), but not in n-DC (p = NS). AGE-R2 and -R3 mRNA and protein levels were enhanced in both T1D groups (DC > n-DC) (n-DC AGE-R3, p < .05, DC AGE-R3, p < .05) compared to NL. AGE-R2 mRNA levels correlated with sAGE levels (r = .61, p < .05), and with creatinine clearance (r = -.63, p < .05). No differences were noted in AGE-R2 and -R3 mRNA expression in cultured cells. CONCLUSIONS: The consistent pattern of elevated serum AGE and low expression of AGE-R1 gene in macrophages from T1D mice (NOD), fresh PBMN and EBV-transformed cells from T1D patients with advanced DC suggests ineffective regulation of R1-mediated AGE turnover, possibly of genetic basis.

Decreased Ethylene Biosynthesis, and Induction of Aerenchyma, by Nitrogen- or Phosphate-Starvation in Adventitious Roots of Zea mays L.

Plants of Zea mays L. cv TX5855 were grown in a complete, well oxygenated nutrient solution then subjected to nutrient starvation by omitting either nitrate and ammonium or phosphate from the solution. These treatments induced the formation of aerenchyma close to the apex of the adventitious roots that subsequently emerged from the base of the shoot, a response similar to that shown earlier to be induced by hypoxia. Compared with control plants supplied with all nutrients throughout, N- or P-starvation consistently depressed the rates of ethylene release by excised, 25 mm apical segments of adventitious roots. Some enzymes and substrates of the ethylene biosynthetic pathway were examined. The content of 1-amino cyclopropane-1-carboxylic acid (ACC) paralleled the differences in ethylene production rates, being depressed by N or P deficiency, while malonyl-ACC showed a similar trend. Activity of ACC synthase and of ethylene forming enzyme (g(-1) fresh weight) was also greater in control roots than in nutrient starved ones. These results indicate that much of the ethylene biosynthetic pathway is slowed under conditions of N- or P-starvation. Thus, by contrast to the effects of hypoxia, the induction of aerenchyma in roots of Zea mays by nutrient starvation is not related to an enhanced biosynthesis and/or accumulation of ethylene in the root tips.

Thrombin stimulation of renal cells.

Numerous glomerular and vascular nephritides are associated with fibrin formation and deposition within the kidney. Thrombin, which induces fibrin formation, also exerts numerous cellular effects on both circulating cells and intrinsic glomerular cells through the activation of the functional thrombin receptor. By immunohistochemistry and in situ hybridization, we demonstrated the constitutive expression of the functional thrombin receptor in the normal human kidney. Both glomerular epithelial and mesangial cells in culture also express the functional thrombin receptor, as shown by the binding of a specific monoclonal antibody against this receptor and Northern blot analysis. Thrombin has a potent mitogenic effect on cultured glomerular cells, suggesting that it could be at least, in part, one of the mediators that induces glomerular cell proliferation in glomerular diseases. Furthermore, we demonstrated that thrombin upregulates the synthesis of plasminogen activators and their type 1 inhibitor in these cells. Thrombin induces protein kinase C activation and an increase in intracellular calcium in these cells. Finally, we demonstrated that the functional thrombin receptor is internalized after addition of thrombin and thrombin receptor-activating peptide (homologous internalization) and also after phorbol myristate acetate addition (heterologous internalization).

Differential expression of renal AGE-receptor genes in NOD mice: possible role in nonobese diabetic renal disease.

BACKGROUND: Nonobese diabetic mice (NOD) are prone to glomerular pathology, which is accelerated with the onset of diabetes. Advanced glycation end product (AGE) interactions with AGE-receptors (AGE-Rs) in kidneys can contribute to glomerular injury and diabetic nephropathy (DN). The significant elevation in kidney AGE deposits noted in prediabetic NOD mice suggested that delayed AGE turnover in this model may contribute to its propensity toward DN. METHODS: To explore whether excess tissue AGE was linked to altered AGE-R status in the kidney, mRNA/protein expression, and of several AGE-Rs [AGE-R1, AGE-R2, AGE-R3, scavenger receptor II (ScR-II), and receptor for AGE (RAGE)], was determined in renal cortex and in mesangial cells (MCs) isolated from ND-, D-NOD, and ILE mice (N = 20 per group). Ligand binding, receptor site number, and affinity were determined in MCs from the same mouse groups. RESULTS: Prediabetic NOD kidney AGE-R1 mRNA and protein level were threefold lower than that of ILE mice (P < 0.01), while AGE-R3 mRNA was enhanced by twofold (P < 0.05) and AGE-R2, RAGE, and ScR-II mRNA remained close to normal (ILE). The onset of diabetes in NOD mice, while enhancing AGE-R1 mRNA expression by approximately twofold, failed to raise it above the normal (ILE) level, despite increases in tissue, and serum AGE. The latter was associated with higher elevation in AGE-R3 (sixfold, P < 0.05), RAGE (twofold, P = NS), and ScR-II mRNA (2. 8-fold, P = NS) above control. MCs from prediabetic NOD mice showed a threefold lower level of AGE-R1 mRNA (P < 0.02 vs. ILE) and AGE-R1-protein, and AGE-binding activity (<40% of control ILE). In contrast, AGE-R3 mRNA was enhanced (twofold), while AGE-R2 showed no change. Cultured ND-NOD MCs displayed only one fourth of the AGE-binding sites/cell present on ILE MCs (1.6 x 10(6) vs. 6.6 x 10(6), P < 0.05), which after the onset of diabetes rose to the normal range (7.0 x 10(6)/cell), but failed to exceed it. CONCLUSIONS: Reduced AGE-R1 gene expression in this strain may contribute to delayed AGE removal from and early AGE deposition in kidney tissues. This may act as a trigger for those AGE-R genes involved in growth-promoting changes, leading to DN in this strain.