Induction of T-Kininogen and Tumor Necrosis Factor-α by Macrophage Migration Inhibitory Factorin vivo

Administration of lipopolysaccharide (LPS) induces inflammation and tissue injuries that occasionally results in disseminated intravascular coagulation (DIC). This process is believed to be mediated by vasoactive molecules such as kinins and leads to endothelial damage and obstruction of the microcirculation. In this study, we evaluated the involvement of T-kininogen and macrophage migration inhibitory factor (MIF) in endotoxin-induced systemic inflammation. T-Kininogen is a protein unique to the rat and known as an acute-phase protein in response to endotoxins. Similarly, MIF functions as a proinflammatory cytokine and glucocorticoid-induced immunoregulator. First, we examined the effects of anti-MIF antibody on Wistar King male rats (ca 400 g) treated with intraperitoneal injection of LPS. At 6 hours after LPS injection (5 mg/kg), the platelet counts had decreased from 85 +/- 12.8 (x 10(4)/microL) to 8.8 +/- 2.6 (x 10(4)/microL). We treated these rats with the anti-rat MIF antibody (5 mg gamma G immunoglobulin [IgG] fraction/kg) 2 hours prior to LPS injection. This treatment prevented the decrease in platelet counts (45.6 +/- 5.6 [x 10(4)/microL]). Next, we examined the potential of MIF for production of T-kininogen. Intraperitoneal injection of rat MIF significantly upregulated the serum content of T-kininogen at the dose of 500 microg MIF/head. These results imply that MIF and T-kininogen might function in concert in the event of endotoxin-induced inflammation.

High molecular weight kininogen as substrate for cathepsin B

We investigated the influence of pH and divalent cations (Zn2+, Mg2+ and Ca2+) on high molecular weight kininogen processing by cathepsin B. At pH 6.3, high molecular weight kininogen is hydrolyzed by cathepsin B at three sites generating fragments of 80, 60 and 40 kDa. Cathepsin B has kininogenase activity at this pH which is improved in the absence of divalent cations. At pH 7.35, high molecular weight kininogen is slightly cleaved by cathepsin B into fragments of 60 kDa, and cathepsin B kininogenase activity is impaired. Our results suggest that high molecular weight kininogen is a substrate for cathepsin B under pathophysiological conditions.

Absence of ligand-induced regulation of kinin receptor expression in the rabbit

The induction of B(1) receptors (B(1)Rs) and desensitization or down-regulation of B(2) receptors (B(2)Rs) as a consequence of the production of endogenous kinins has been termed the autoregulation hypothesis. The latter was investigated using two models based on the rabbit: kinin stimulation of cultured vascular smooth muscle cells (SMCs) and in vivo contact system activation (dextran sulphate intravenous injection, 2 mg kg(-1), 5 h). Rabbit aortic SMCs express a baseline population of B(1)Rs that was up-regulated upon interleukin-1beta treatment ([(3)H]-Lys-des-Arg(9)-BK binding or mRNA concentration evaluated by RT - PCR; 4 or 3 h, respectively). Treatment with B(1)R or B(2)R agonists failed to alter B(1)R expression under the same conditions. Despite consuming endogenous kininogen (assessed using the kinetics of immunoreactive kinin formation in the plasma exposed to glass beads ex vivo) and producing hypotension mediated by B(2)Rs in anaesthetized rabbits, dextran sulphate treatment failed to induce B(1)Rs in conscious animals (RT - PCR in several organs, aortic contractility). By contrast, lipopolysaccharide (LPS, 50 microg kg(-1), 5 h) was an effective B(1)R inducer (kidney, duodenum, aorta) but did not reduce kininogen reserve. We tested the alternate hypothesis that endogenous kinin participate in LPS induction of B(1)Rs. Kinin receptor antagonists (icatibant combined to B-9858, 50 microg kg(-1) of each) failed to prevent or reduce the effect of LPS on B(1)R expression. Dextran sulphate or LPS treatments did not persistently down-regulate vascular B(2)Rs (jugular vein contractility assessed ex vivo). The kinin receptor autoregulation hypothesis is not applicable to primary cell cultures derived from a tissue known to express B(1)Rs in a regulated manner (aorta). The activation of the endogenous kallikrein-kinin system is ineffective to induce B(1)Rs in vivo in an experimental time frame sufficient for B(1)R induction by LPS.

Evidence for bradykinin mediation of carrageenin-induced inflammatory pain: a study using kininogen-deficient Brown Norway Katholiek rats

Inflammatory pain was induced following an intradermal injection of carrageenin into rat paws, and the hyperalgesia was measured in terms of withdrawal time following thermal pain stimulation of the inflamed paw. This hyperalgesia was significantly less in kininogen-deficient Brown Norway (B/N)-Katholiek rats, which also showed less swelling in carrageenin-induced paw edema, than in normal B/N-Kitasato rats at 1 approximately 4 hr after the carrageenin injection (at the early phase). However, 24 hr after the injection, hyperalgesia and the swelling volume of the kininogen-deficient rats were almost the same as those in normal rats. The bradykinin B2 receptor antagonist FR173657, (E)-3-(6-acetamido-3-pyridyl)-N-[N-[2,4-dichloro-3-[(2-methyl-8-quinolinyl)oxymethyl]phenyl]-N-methylaminocarbonylmethyl]acrylamide, attenuated the carrageenin-induced swelling and hyperalgesia of the normal rats at the early phase to almost the levels of the B/N-Katholiek rats. Pretreatment with indomethacin, a cyclooxygenase inhibitor, also inhibited the carrageenin-induced responses significantly in normal rats. These results indicate that bradykinin, acting on the B2 receptor, is the main mediator at the early phase of inflammatory pain of carrageenin edema and that prostaglandins, produced by cyclooxygenase, potentiate the effects of bradykinin.

Reduction of sodium deoxycholic acid-induced scratching behaviour by bradykinin B2 receptor antagonists

1. Subcutaneous injection of sodium deoxycholic acid into the anterior of the back of male ddY mice elicited dose-dependent scratching of the injected site with the forepaws and hindpaws. 2. Up to 100 microg of sodium deoxycholic acid induced no significant increase in vascular permeability at the injection site as assessed by a dye leakage method. 3. Bradykinin (BK) B2 receptor antagonists, FR173657 and Hoe140, significantly decreased the frequency of scratching induced by sodium deoxycholic acid. 4. Treatment with aprotinin to inhibit tissue kallikrein reduced the scratching behaviour induced by sodium deoxycholic acid, whereas treatment with soybean trypsin inhibitor to inhibit plasma kallikrein did not. 5. Although injection of kininase II inhibitor, lisinopril together with sodium deoxycholic acid did not alter the scratching behaviour, phosphoramidon, a neutral endopeptidase inhibitor, significantly increased the frequency of scratching. 6. Homogenates of the skin excised from the backs of mice were subjected to gel-filtration column chromatography followed by an assay of kinin release by trypsin from each fraction separated. Less kinin release from the fractions containing kininogen of low molecular weight was observed in the skin injected with sodium deoxycholic acid than in normal skin. 7. The frequency of scratching after the injection of sodium deoxycholic acid in plasma kininogen-deficient Brown Norway Katholiek rats was significantly lower than that in normal rats of the same strain, Brown Norway Kitasato rats. 8. These results indicate that BK released from low-molecular-weight kininogen by tissue kallikrein, but not from high-molecular-weight kininogen by plasma kallikrein, may be involved in the scratching behaviour induced by the injection of sodium deoxycholic acid in the rodent.

Zidovudine potentiates local and systemic inflammatory responses in the rat

The effect of chronic treatment with zidovudine (AZT) on the inflammatory response was examined in the rat. AZT was administered orally for 36 days. On day 35, inflammation was induced by hindpaw injection of 1% carrageenan lambda. Paw edema over a 24-hour period was used as a marker of the local inflammatory reaction. On day 36, quantification of immunoreactive T-kininogen and alpha 1-inhibitor-3 in liver and serum was used to assess the systemic inflammatory response. Albumin was selected as a protein whose concentration is modified only slightly or not at all during the acute-phase response. Animals treated with AZT transiently exhibited significantly greater (18%) paw edema 3 hours after carrageenan injection. AZT treatment alone induced a 1.8-fold increase in serum T-kininogen concentration, but it had no effect on albumin and alpha 1-inhibitor-3. In rats with inflamed paws, AZT administration led to a significant increase in liver (3.4-fold) and serum (1.8-fold) immunoreactive T-kininogen content. Dot blot analysis of total RNA isolated from liver correlated with the protein measurements. Our results indicate that chronic treatment with AZT potentiates the nonspecific local and the systemic inflammatory responses in the rat.

Chloramphenicol and the inflammatory response in the rat. Upregulation of the gene for T2-kininogen in liver

Recent observations have indicated that cytokine and glucocorticoid mediators of the inflammatory response in mammals interfere with mitochondrial respiratory capacity of cultured cells. Here, we report studies on the effect of the antibiotic chloramphenicol (CAP), a potent mitochondrial protein synthesis and respiratory inhibitor, on the inflammatory response in the rat. CAP was injected daily (i.p.) at doses of 30, 100 and 300 mg kg-1 during a period of 10 days. Acute inflammation was induced on day 10 by s.c. injection of carrageenan into the hindpaws. Paw edema reaction and liver and serum expression of the acute phase protein T-kininogen were used as markers of the local and systemic inflammatory response, respectively. Albumin was selected as a liver protein whose expression is little or not affected in inflamed rats. We found that the swelling process induced locally by carrageenan injection was significantly altered in rats treated with CAP at the dose level of 300 mg kg-1. The inhibitory effect of CAP was transient, extending up to 3 hr after carrageenan injection. CAP was observed also to alter the mitochondrial respiratory capacity of liver cells, reducing cytochrome C oxidase activity up to 50%. In contrast, liver immunoreactive T-kininogen content and the T2-kininogen mRNA steady-state level were found to increase in a dose-related manner in CAP-treated animals. These values were slightly different from those recorded in control rats inflamed with carrageenan. No significant increase of T-kininogen serum content was seen at all dose levels of CAP injected. Among inflamed animals, those exposed long-term to CAP had elevated liver and serum T-kininogen content and t2-kininogen mRNA steady-state levels. Expression of the gene for albumin was not affected in rats treated or not with CAP. The present observations indicate that CAP influences both local and systemic inflammatory responses in the rat.

Met-Lys-bradykinin-Ser, the kinin released from human kininogen by human pepsin

This study was carried out to show the site in kininogen, using synthetic substrates, that is cleaved by a purified human pepsin component with a molecular weight of 35,000 daltons. The study used 4 (four) intramolecularly quenched fluorogenic substrates containing N- and C-terminal sequences around the methionyl-lysyl-bradykinin (MLBK) region of kininogen: Abz-LMKRP-Eddnp, Abz-MISLMKRP-Eddnp, Abz-FRSSR-Eddnp and Abz-RPPGFSPFRSSRQ-Eddnp. The hydrolysis on N-terminal sequences Abz-LMKRP-Eddnp and Abz-MISLMKRP-EDDnp occurred at L-M linkage and on C-terminal sequences Abz-FRSSR-Eddnp, and Abz-RPPGFSPFRSSRQ-Eddnp occurred at S-S linkage. The released peptide Abz-RPPGFSPFRS was able to contract rat uterus muscle. The results suggest that Met-Lys-Bradykinin-Ser, should be the peptide released from human kininogen by a purified human pepsin component.

Degradation of T-kininogen by cathepsin D and matrix metalloproteinases

Cathepsin D, matrix metalloproteinase (MMP)-2, MMP-3 (stromelysin), and MMP-9 were isolated from rat granulomatous tissues. HT1080 human fibrosarcoma cells and rheumatoid synovial cell CM. At acidic conditions, cathepsin D cleaved T-kininogen into small peptides and released Met-T-kinin-Leu (kinin precursor), but failed to release kinin. MMP-3 cleaved T-kininogen into a 57 kDa fragment as measured by SDS-PAGE and Western blot analysis using anti-T-kininogen antiserum. On the other hand, no degradation of T-kininogen occurred during incubation with MMP-2 or MMP-9100/1) at pH 7.5 for 7 h.

[An experimental model of depletion of the blood kallikrein-kinin system]

A new way of kallikrein-kinin system exhaustion in experiments on animals is suggested. This approach consists in a simultaneous rise in the activity of kinin formation and destruction. It is shown that insignificant activation of the kallikrein system and kininase activity leads to activation of the kinin system and rise in active kinin levels. A 1.5-3-fold increase in the total activity of kallikrein and a simultaneous 3-6-fold increase in kininase activity cause exhaustion of the blood kallikrein-kinin system in 2 hours and makes active kinin formation impossible by the body's requirements when the synthesis of kinin system components is maintained.

Blood coagulation, fibrinolytic and inhibitory profiles in renal transplant recipients: comparison of cyclosporine and azathioprine

Renal transplant recipients treated with cyclosporine (CS) have been reported to be at increased risk of thrombotic complications. The present study was intended to examine the blood coagulation, fibrinolytic, and inhibitory systems in such patients. Eight transplant recipients on maintenance immunosuppression with CS and prednisone were studied. Five transplant recipients maintained on azathioprine (AZA) and prednisone and 32 normal volunteers served as controls. Plasma antigen concentrations and/or activities of various proteins in the above pathways were measured. Both the CS and AZA groups exhibited significant elevations of factor IX activity, von Willebrand factor (vWF), D-dimer, protein C and tissue type plasminogen activator (t-PA) levels when compared with the normal controls. In addition, CS group showed a significant elevation of alpha 2-macroglobulin activity and AZA group showed a significant reduction in factor XII activity when compared with the normal controls. Comparison of data from CS and AZA groups revealed higher factor XII activity and vWF concentration in the former group. In conclusion, transplant recipients treated with long-term cyclosporine and prednisone exhibited significant elevation of plasma vWF, D-dimer and protein C concentrations. In addition, both CS and AZA-treated transplant recipients showed increased plasma concentrations of D-dimer and t-PA. The latter observations suggest in vivo thrombin generation, fibrin formation and degradation.

The sequence HGLGHGHEQQHGLGHGH in the light chain of high molecular weight kininogen serves as a primary structural feature for zinc-dependent binding to an anionic surface

The histidine-glycine-rich region of the light chain of cleaved high molecular weight kininogen (HK) is thought to be responsible for binding to negatively charged surfaces and initiation of the intrinsic coagulation, fibrinolytic, and kinin-forming systems. However, the specifically required amino acid sequences have not been delineated. An IgG fraction of a monoclonal antibody (MAb) C11C1 to the HK light chain was shown to inhibit by 66% the coagulant activity and by 57% the binding of HK to the anionic surface of kaolin at a concentration of 1.5 microM and 27 microM, respectively. Proteolytic fragments of HK were produced by successive digestion with human plasma kallikrein and factor XIa (FXIa). Those polypeptides that bound tightly (Kd = 0.77 nM) to a C11C1 affinity column were eluted at pH 3.0 and purified by membrane filtration. On 15% SDS polyacrylamide electrophoresis, the approximate M(r) was 7.3 kDa (range 6.2-8.1 kDa). Based on N-terminal sequencing, this polypeptide (1(2)), which extends from the histidine residue 459 to a lysine at position 505, 509, 511, 512, 515, or 520, inhibits by 50% the coagulant activity expressed by HK at a concentration of 22 microM. The synthetic peptide HGLGHGH representing the N-terminal of the 1(2)) fragment was synthesized, tested, and found at 4 mM to inhibit the procoagulant activity of HK 50%. A synthetic heptadecapeptide, HGLGHGHEQQHGLGHGH (residues 459-475) included within the 1(2) fragment, and with the ability to bind zinc, inhibited 50% of the HK coagulant activity at a concentration of 325 microM in the absence and presence of added Zn2+ (30 microM). The specific binding of 125I-HK to a negatively charged surface (kaolin) was inhibited 50% by unlabeled HK (5 microM). HGLGHGH, at a concentration of 7.0 mM, inhibited the binding to kaolin by 50%. The heptadecapeptide inhibited the specific binding of 125I-HK to kaolin by 50%, at a concentration of 2.3 mM, in the absence of Zn2+. In contrast, when Zn2+ was added, the concentration to achieve 50% inhibition decreased to 630 microM, indicating that Zn2+ was required to attain a favorable conformation for binding. Moreover, the 1(2) fragment was found to inhibit 50% of the 125I-HK binding to kaolin at a concentration of 380 microM. These results suggest that residues contained within the 1(2) fragment, notably HGLGHGHEQQHGLGHGH, serves as a primary structural feature for binding to a negatively charged surface.