Complement is required for the induction of endotoxic fever in guinea pigs and mice

(1) Cobra venom factor (CVF)-induced hypocomplementemia dose-dependently attenuates the febrile responses of guinea pigs and mice to intraperitoneally (ip) but not to intravenously (iv) injected endotoxic bacterial lipopolysaccharide (LPS). (2) Iv but not ip LPS causes fever in complement component 3 (C3) gene-ablated mice, but neither iv nor ip LPS evokes a body core temperature (T_c) rise when WT and these mice's C5a receptors type 1 are blocked. C5 knockout mice also do not develop fever following either iv or ip LPS. C5a thus appears to be a critical mediator of LPS fever. (3) C5 knockouts develop fever in response to intracerebroventricularly (icv) injected LPS or prostaglandin (PG)E₂; the site of action of C5a is therefore peripheral rather than central. (4) The initiation of the febrile responses to both iv and ip LPS is temporally correlated with the appearance of LPS in the liver's Kupffer cells (Kc). (5) PGE₂ is released by liver in immediate response to the injection of CVF into the portal vein of anesthetized guinea pigs; its level rises quickly to its maximum. LPS injected similarly also evokes a quick release of PGE₂ from the liver; it, however, is prevented by prior hypocomplementation. (6) Neither LPS nor IL-1β induces PGE₂ release from Kc in vitro within the first hour after treatment, but serum C and C plus LPS or IL-1β very quickly trigger PGE₂ increases of similar magnitudes, catalyzed non-differentially by cyclooxygenase (COX)-1 and COX-2. Kc would thus appear to be the principal site of action of C5a, inducing the release of PGE₂. (7) PGE₂ is detectable in the plasma of conscious guinea pigs in temporal correlation with the onset of the T_c rise following ip LPS; cytokines appear significantly later. (8) Taken together, these results indicate that LPS-activated C, rather than LPS or IL-1β by itself, triggers PGE₂ release by Kc. This PGE₂ could be the factor that stimulates vagal afferents, thereby providing the signal to the brain that mediates the febrile response.     

Roles of Prostaglandins D2 and E2 in Interleukin-1-Induced Activation of Norepinephrine Turnover in the Brain and Peripheral Organs of Rats

Abstract: Possible roles of prostaglandins (PGs) in interleukin-1 (IL-1)-induced activation of noradrenergic neurons were examined by assessing norepinephrine (NE) turnover in the brain and peripheral organs of rats. An intraperitoneal injection of human recombinant IL-1β accelerated NE turnover in the hypothalamus, spleen, lung, diaphragm, and pancreas. A similar increase in NE turnover was also observed after intracerebroventricular injection of corticotropin-releasing hormone (CRH). Pretreatment with indomethacin (cyclooxygenase inhibitor) abolished the IL-1-induced, but not the CRH-induced, increase in hypothalamic and splenic NE turnover. To elucidate which eicosanoid-cyclooxygenase product(s) is responsible for accelerating NE turnover, PGD₂, PGE₂, PGF_2α, U-46619 (stable thromboxane A₂ analogue), or carbacyclin (stable prostacyclin analogue) was administered intracerebroventricularly. Among them, PGE₂ was the only eicosanoid effective in increasing NE turnover in spleen, whereas PGD₂ was effective in the hypothalamus. The stimulative effect of PGD₂ was abolished by pretreatment with intracerebroventricular injection of a CRH antiserum. These results suggest that the action of IL-1 is mediated through PGD₂ production to activate the noradrenergic neurons in the hypothalamus, and through PGE₂ production to increase sympathetic nerve activity in spleen.     

The deceleration of the heart frequency in the waterfleaDaphnia magna by adrenoceptor agonists and antagonists

Beat-to-beat measurements with 30 micro-seconds accuracy were carried out in order to determine the chronotropic effects on the heart ofDaphnia magna induced by adrenoceptor agonists and antagonists dissolved in water. Agonists and antagonists were either ineffective or lowered the heart frequency (P < 0.05). In addition, the negative chronotropic effect of the agonist epinephrine could not be blocked by the antagonist propranolol. It may, therefore, well be that the drug actions were not mediated through adrenoceptors.     

Possible roles of calcium and ammonium in the development of bitter pit in apple

Apple trees ( Malus pumila Mill . var. domestica Fuji/ Malus prunifolia rootstock) showed a high susceptibility to bitter pit when supplyed with ammonium salt instead of nitrate (control) in the nutrient solution. When apple fruit was affected by bitter pit, a lower calcium as well as a higher nitrogen and ammonium-nitrogen contents was observed in the fruit flesh near the calyx end. The activity of the mitochondrial Ca²⁺-uptake of the fruit flesh near the calyx end was higher when the tree was grown with ammonium salt than when grown with nitrate. Both the activities of succinate: cytochrome c oxidoreductase and the mitochondrial Ca²⁺-uptake per g of tissue were higher in affected fruit than in healthy fruit. Each of chlorpromazine, N-(6-aminohexyl)-5-chloro-l-napthalenesulfonamide (W-7) and N-(6-aminohexyl)-l-naphthalenesulfonamide (W-5), calmodulin antagonists, was infiltrated into the fruit for 20 min under reduced pressure (about 1 × 10⁴ Pa). Few days later, numerous bitter pit-like spots were observed in both fruit treated with W-7 and chlorpromazine, while only a few spots were observed after the infiltration with W-5, a less potent calmodulin antagonist. A possible mechanism for the occurrence of bitter pit is discussed.     

Differential processing of human and rat E1 α precursors of the branched-chain α-keto acid dehydrogenase complex caused by an N-terminal proline in the rat sequence

The N-terminal sequences of the E1 α, E1β and E2 subunits of the human branched-chain α-keto acid dehydrogenase complex have been determined by microsequencing. The N-termini of human E1β and E2 subunits (Val and Gly, respectively) are indentical to those of the corresponding rat and bovine subunits. However, the N-terminus of the human E1 α subunit (Ser) is identical to bovine, but differs from the rat E1 α (Phe0 subunit. Comparison of the N-terminal sequences of human and rat E1 α subunits shows that the serine residue at the + 1 position in the human sequence is replaced by a proline residue in the rat sequence. The presence of the proline residue apparently causes a 5′-shift by one residue in the cleavage site by the mitochondrial processing peptidase in the rat sequence, when compared to the human sequence. The results provide evidence that the mitochondrial processing peptidase cannot cleave an X-pro bond, similar to trypsin, chymotrypsinand microsomal signal peptidases.     

Noradrenergic Inhibition and α2-Adrenergic Stimulation of Melatonin Secretion in the Pigeon

Adrenergic regulatory mechanisms of melatonin synthesis and secretion were studied in the pigeon in vivo. Late-afternoon intraperitoneal injection of noradrenaline (NA; 1 mg/kg) resulted in a significant decrease in plasma melatonin levels in 3 h. The same effect was seen after phenylephrine treatment (1 mg/kg i.p.), indicating that an alpha 1-adrenergic mechanism may mediate the inhibition. Propranolol treatment had no effect on plasma melatonin levels, supporting this concept. Detomidine (1 mg/kg i.p.), an alpha 2-adrenergic agonist, increased melatonin levels. This stimulatory effect was blocked by yohimbine, an alpha 2-adrenergic antagonist. However, yohimbine alone had no effect on the plasma melatonin levels, suggesting that alpha 2-adrenergic transmission is not primarily responsible for the nocturnal stimulation of melatonin synthesis and secretion in the pigeon.     

Pharmacological characterization of the histamine uptake system in HL-60 human promyelocytic leukemia cells

Serotonin and histamine H₁, H₂ receptor agonists or antagonists inhibited [³H]histamine uptake by HL-60 cells, according to the following order of potency: impromidine >4-MH>histamine>AET>PEA and: cimetidine, histamine>diphenhydramine, serotonin. It is concluded that histamine uptake by HL-60 cells was specifically controlled by the H₂ type histamine receptor and that this active process might be involved in pathophysiological regulations in leukemic and normal granulocytic precursors and in the control of histamine levels in peripheral blood and tissues in man.     

Secretome from hypoxia-conditioned adipose-derived mesenchymal stem cells promotes the healing of gastric mucosal injury in a rodent model

Studies have indicated that the definitive engraftment and transdifferentiation potential of stem cells do not seem crucial for its property of tissue repair. Our previous study showed that transplantation of adipose-derived mesenchymal stem cells (ADMSCs) enhanced the healing of sutured gastric perforation. This study aimed to investigate the paracrine role of ADMSCs in the experimental gastric mucosal injury. Normoxia-conditioned medium (Nor CM) and hypoxia (HPO) CM were obtained after culturing ADMSCs in 20% O₂ and 5% O₂ for 48 h. Cell migration, proliferation, viability, and angiogenesis in vitro were significantly enhanced upon incubation with CM, especially the HPO CM. Experiments in vivo using a rodent model of gastric ulcer demonstrated that HPO CM treatment significantly accelerated wound healing by suppressing inflammation and promoting neovascularization and re-epithelization. Meanwhile, the infusion of HPO CM activated the COX₂-PGE₂ axis both in vitro and in vivo. And the upregulation of COX₂ was further dependent on the activation of ErK1/2-MAPK pathway. In addition, vascular endothelial growth factor, tissue inhibitors of metalloproteinases-1, and chemokine (C-C motif) ligand 20 (CCL-20) were analyzed as being highly abundant factors secreted by ADMSCs under hypoxic condition. Notably, the blockade of CCL-20 abrogated the HPO CM-induced COX₂ signaling in the primary gastric mucosal epithelial cells, while incubation with recombinant CCL-20 increased the expression of COX₂. In conclusion, the secretome from hypoxia-conditioned ADMSCs facilitates the repair of gastric mucosal injury through the enhancement of angiogenesis and re-epithelization, as well as the activation of COX₂-PGE₂ axis with a paracrine activity involving CCL-20 factor.     

Domain movement of iron sulfur protein in cytochrome bc1 complex is facilitated by the electron transfer from cytochrome b(L) to b(H)

The key step of the "protonmotive Q-cycle" mechanism for cytochrome bc1 complex is the bifurcated oxidation of ubiquinol at the Qp site. ISP is reduced when its head domain is at the b-position and subsequent move to the c1 position, to reduce cytochrome c1, upon protein conformational changes caused by the electron transfer from cytochrome b(L) to b(H). Results of analyses of the inhibitory efficacy and the binding affinity, determined by isothermal titration calorimetry, of Pm and Pf, on different redox states of cytochrome bc1 complexes, confirm this speculation. Pm inhibitor has a higher affinity and better efficacy with the cytochrome b(H) reduced complex and Pf binds better and has a higher efficacy with the ISP reduced complex.     

Immunoregulatory effect of mesenchymal stem cell via mitochondria signaling pathways in allergic asthma

Asthma is a complicated lung disease, which has increased morbidity and mortality rates in worldwide. There is an overlap between asthma pathophysiology and mitochondrial dysfunction and MSCs may have regulatory effect on mitochondrial dysfunction and treats asthma. Therefore, immune-modulatory effect of MSCs and mitochondrial signaling pathways in asthma was studied.After culturing of MSCs and producing asthma animal model, the mice were treated with MSCs via IV via IT. BALf's eosinophil Counting, The levels of IL-4, −5, −13, −25, –33, INF-γ, Cys-LT, LTB4, LTC4, mitochondria genes expression of COX-1, COX-2, ND1, Nrf2, Cytb were measured and lung histopathological study were done.BALf's eosinophils, the levels of IL-4, −5, −13, −25, –33, LTB4, LTC4, Cys-LT, the mitochondria genes expression (COX-1, COX-2, Cytb and ND-1), perivascular and peribronchial inflammation, mucus hyper-production and hyperplasia of the goblet cell in pathological study were significantly decreased in MSCs-treated asthma mice and reverse trend was found about Nrf-2 gene expression, IFN-γ level and ratio of the INF-γ/IL-4.MSC therapy can control inflammation, immune-inflammatory factors in asthma and mitochondrial related genes, and prevent asthma immune-pathology.