IntroductionSeptic shock syndrome resulting from excessive host immune responses induced by infectious organisms is a leading cause of death in hospitalized patients. [1][2][3] Pathophysiologic changes in sepsis involve the pathogen-induced uncontrolled release from immune cells, particularly monocytes and macrophages, of proinflammatory mediators. 4 Gram-negative bacterial infection is one of the major causes of systemic bacterial sepsis. 5 Lipopolysaccharide (LPS), a constituent of the Gram-negative outer membrane, is the leading cause of sepsis. LPS induces a rapid increase of proinflammatory mediators, leading to lethal systemic tissue damage and multiple organ failure, which mimics the inflammatory responses of septic syndrome. 6 In mammals, membrane-bound CD14 and toll-like receptor 4 (TLR4)-MD-2 participate in cellular recognition of LPS. 7 Binding of LPS to TLR4 triggers the activation of members of the mitogen-activated protein kinase (MAPK) pathway including p38, p42/p44 extracellular signal-regulated kinase (ERK1/2), and c-Jun N-terminal kinase (JNK). 8 In resting unstimulated cells, nuclear factor-B (NF-B), a heterodimeric complex composed of 50-and 65-kDa (p50/p65) protein subunits, 9 retains as an inactive complex bound to inhibitory B␣ (IB␣) in the cytoplasm. While the cells are under proinflammatory stimulation by LPS, phosphorylation and degradation of IB␣ permit NF-B nuclear translocation and promote the expression of inflammatory genes including inducible nitric oxide synthase (iNOS), tumor necrosis factor-␣ (TNF-␣), and others. 9Thrombomodulin (TM) is a 557 amino acid type I glycosylated transmembrane protein 10 with an NH 2 -terminal lectinlike region (domain 1; D1) followed by 6 epidermal growth factor (EGF)-like structures (domain 2; D2), an O-glycosylation site-rich domain (domain 3; D3), a transmembrane domain (domain 4; D4), and a cytoplasmic tail domain (domain 5; D5). TM domain 2 (TMD2) EGF-like structures are responsible for the anticoagulant activity of TM via the alteration of thrombin substrate specificity. TMD2-thrombin complex sequentially activates anticoagulant protein C inactivating procoagulant cofactors Va and VIIIa. 11 TM expression also occurs in keratinocytes, 12 polymorphonuclear neutrophils (PMNs), 13 monocytes, 14 and endothelial cells, 15 indicating additional functions of TM besides anticoagulation. 16 Indeed TM domains function as an adhesion molecule, 17 an angiogenic factor, 18 and an anti-inflammatory agent through protein C-dependent and -independent mechanisms. 16,19 Recently, anti-inflammatory activity of TM domain 1 (TMD1) was implied by observing that mice with a deleted TM lectinlike domain (TM LeD/LeD ) become more sensitive to LPS challenge through the suppressed expression of adhesion molecules via NFB and MAPK signaling pathways. 20 Moreover, mice with a mutation in the TM gene (TM pro/pro ) strongly reduce the capacity to generate activated protein C, an anti-inflammatory agent in treatment of sepsis. 21 Mice harboring the latter mutation display an u...
Several peptide fragments of streptokinase (SK) were prepared by incubating SK with immobilized human plasmin (hPlm) and purified by h.p.l.c. with a reverse-phase phenyl column. The N-terminal sequences, amino acid compositions and molecular masses of these peptide fragments were determined. The SK peptide fragment of 36 kDa consisting of Ser60-Lys387 (SK-p), was the only peptide fragment that could be tightly bound to immobilized hPlm. Another three large SK peptide fragments, SK-m, SK-n and SK-o, with molecular masses of 7 kDa, 18 kDa and 30 kDa, and consisting of Ile1-Lys59, Glu148-Lys333, Ser60-Lys333 respectively, were also obtained from the supernatant of the reaction mixture. The purified SK-p had high affinity with hPlm and could activate human plasminogen (hPlg) with a kPlg one-sixth that of the native SK. SK-o had low affinity with hPlm and could also activate hPlg, although the catalytic constant was less than 1% of the native SK. SK-n, as well as SK-m, which is the N-terminal 59 amino acid peptide of the native SK, had no activator activity. However, SK-m could enhance the activator activity of both SK-o and SK-p and increase their second-order rate constants by two- and six-fold respectively. It was concluded from these studies that (1) SK-o, the Ser60-Lys333 peptide of SK, was essential for minimal SK activator activity, (2) the C-terminal peptide of SK-p, Ala334-Lys387, was essential for high affinity with hPlm, and (3) the N-terminal 59-amino-acid peptide was important in maintaining the proper conformation of SK to have its full activator activity.
Approximately half of the patients with type C hepatitis do not have a history of parenteral exposure. The route of nonparenteral infection remains unknown. To evaluate the possible role of body fluids, the existence of hepatitis C virus (HCV) RNA in saliva, urine, seminal fluid, and ascites was examined by "nested" polymerase chain reaction (PCR). Amplification of the HCV 5' noncoding sequences was carried out. The amplified product was confirmed by Southern blot hybridization and restriction endonuclease digestion. Among 34 patients with chronic liver disease who were positive for anti-HCV and serum HCV RNA, the prevalence of HCV RNA in body fluids was 100% (7/7) in ascites, 48% (15/31) in saliva, 24% (4/17) in seminal fluid, and 7% (2/29) in urine. The body fluids collected from 3 healthy subjects and 5 patients with chronic liver disease who were positive for anti-HCV but negative for serum HCV RNA were all negative for HCV RNA. Hence, the potential infectivity of body fluids in patients testing negative for serum HCV RNA can probably be discounted. Conversely, the presence of HCV RNA in saliva and seminal fluid of patients positive for serum HCV RNA suggests sexual and household contact as likely modes of nonparenteral transmission of type C hepatitis. Furthermore, the high prevalence of HCV RNA in ascites and saliva may have important implications in medical and dental practice.
Circadian clock, an endogenous time-setting mechanism, allows plants to adapt to unstable photoperiod conditions and induces flowering with proper timing. In Arabidopsis, the central clock oscillator was formed by a series of interlocked transcriptional feedback loops, but little is known in rice so far. By MutMap technique, we identified the candidate gene OsLHY from a later flowering mutant lem1 and further confirmed it through genetic complementation, RNA interference knockdown, and CRISPR/Cas9-knockout. Global transcriptome profiling and expression analyses revealed that OsLHY might be a vital circadian rhythm component. Interestingly, oslhy flowered later under ≥12 h day length but headed earlier under ≤11 h day length. qRT-PCR results exhibited that OsLHY might function through OsGI-Hd1 pathway. Subsequent one-hybrid assays in yeast, DNA affinity purification qPCR, and electrophoretic mobility shift assays confirmed OsLHY could directly bind to the CBS element in OsGI promoter. Moreover, the critical day length (CDL) for function reversal of OsLHY in oslhy (11-12 h) was prolonged in the double mutant oslhy osgi (about 13.5 h), indicating that the CDL set by OsLHY was OsGI dependent. Additionally, the dual function of OsLHY entirely relied on Hd1, as the double mutant oslhy hd1 showed the same heading date with hd1 under about 11.5, 13.5, and 14 h day lengths. Together, OsLHY could fine-tune the CDL by directly regulating OsGI, and Hd1 acts as the final effector of CDL downstream of OsLHY. Our study illustrates a new regulatory mechanism between the circadian clock and photoperiodic flowering.
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