Isolation of human β-defensin-4 in lung tissue and its increase in lower respiratory tract infection

Background

Human β-defensin-4 (hBD-4), a new member of the β-defensin family, was discovered by an analysis of the genomic sequence. The objective of this study was to clarify hBD-4 expression in human lung tissue, along with the inducible expression in response to infectious stimuli, localization, and antimicrobial activities of hBD-4 peptides. We also investigated the participation of hBD-4 in chronic lower respiratory tract infections (LRTI) by measuring the concentrations of hBD-4 peptides in human bronchial epithelial lining fluid (ELF).

Methods

The antimicrobial activity of synthetic hBD-4 peptides against E. coli and P. aeruginosa was measured by radial diffusion and colony count assays. We identified hBD-4 in homogenated human lung tissue by reverse-phase high-performance liquid chromatography coupled with a radioimmunoassay (RIA). Localization of hBD-4 was studied through immunohistochemical analysis (IHC). We investigated the effects of lipopolysaccharide (LPS) on hBD-4 expression and its release from small airway epithelial cells (SAEC). We collected ELF from patients with chronic LRTI using bronchoscopic microsampling to measure hBD-4 concentrations by RIA.

Results

hBD-4 exhibited salt-sensitive antimicrobial activity against P. aeruginosa. We detected the presence of hBD-4 peptides in human lung tissue. IHC demonstrated the localization of hBD-4-producing cells in bronchial and bronchiolar epithelium. The levels of hBD-4 peptides released from LPS-treated SAECs were higher than those of untreated control cells. ELF hBD-4 was detectable in 4 of 6 patients with chronic LRTI, while the amounts in controls were all below the detectable level.

Conclusion

This study suggested that hBD-4 plays a significant role in the innate immunity of the lower respiratory tract.     

Life history variation among years in a brackish water type of the Ninespine Stickleback, <Emphasis Type="Italic">Pungitius pungitius</Emphasis>

The life history variation in a brackish water type of the Ninespine Stickleback Pungitius pungitius collected over 3 years was studied by examining the strontium (Sr) and calcium (Ca) concentrations in the otoliths. The life histories showed the fish were either brackish water residents or anadromous throughout those years. 74–78% of the fish had the former life history and 22–26% the latter. The composition of each life history was constant throughout the 3 years, and the occurrence of the “anadromous” novel life history found previously is a general phenomenon in this species.     

Surgical influence of pancreatectomy on the function and count of circulating dendritic cells in patients with pancreatic cancer

Background: Dendritic cells (DCs) are important for an immune surveillance. Myeloid DCs (DC1) are important for an effective antitumor immune system. The function and count of circulating DC1 (cDC1) in hosts with a malignant tumor would be defective. This study focused on analyzing the immunological features of cDC1 in patients with pancreatic cancer during the perioperative period. Materials and methods: Thirty-two pancreatic cancer patients who underwent pancreatectomy and 18 age-matched healthy individuals as controls were enrolled in this study. The perioperative cDC count, the stimulatory capacity of cDC1 against allogeneic T cells and TGF-β1 level in the serum were measured. The cDC count was measured at 12 months after the operation. Results: The preoperative cDC1/cDC2 ratio, cDC1 count, and stimulatory capacity of cDC1 were impaired in patients in comparison to controls (P<0.05). The serum TGF-β1 level was significantly higher in patients than controls (P<0.001). The stimulatory capacity of cDC1 recovered after pancreatectomy (P<0.05). The serum TGF-β1 level significantly decreased after the operation (P<0.05); however, they were still significantly higher than controls (P<0.05). Although the cDC1/cDC2 ratio and the cDC1 count did not increase after the pancreatectomy, they recovered as the controls’ level at 12 months after the pancreatectomy in disease-free patients (P<0.05) and the serum TGF-β1 level in those patients at 12 months after the operation significantly decreased compared with those at the postoperative period (P<0.05). Conclusion: Surgical resection of pancreatic cancer could be associated with improved cDC1 function. When a patient remained disease free, the recovery of cDC1 counts was observed approximately 12 months after pancreatectomy. Further strategy will be needed to improve immune function in patients with pancreatic cancer.     

Enhanced tolerance to ozone and drought stresses in transgenic tobacco overexpressing dehydroascorbate reductase in cytosol

Ascorbate (vitamin C) is a potent antioxidant protecting plants against oxidative damage imposed by environmental stresses such as ozone and drought. Dehydroascorbate reductase (DHAR; EC 1.8.5.1) is one of the two important enzymes functioning in the regeneration of ascorbate (AsA). To examine the protective role of DHAR against oxidative stress, we developed transgenic tobacco plants overexpressing cytosolic DHAR gene from Arabidopsis thaliana . Incorporation of the transgene in the genome of tobacco plants was confirmed by polymerase chain reaction and Southern blot analysis, and its expression was confirmed by Northern and Western blot analyses. These transgenic plants exhibited 2.3–3.1 folds higher DHAR activity and 1.9–2.1 folds higher level of reduced AsA compared with non-transformed control plants. The transgenic plants showed maintained redox status of AsA and exhibited an enhanced tolerance to ozone, drought, salt, and polyethylene glycol stresses in terms of higher net photosynthesis. In this study, we report for the first time that the elevation of AsA level by targeting DHAR overexpression in cytosol properly provides a significantly enhanced oxidative stress tolerance imposed by drought and salt.     

Observations on Cryptosporidium life cycle stages during excystation

Cryptosporidium parvum (HNJ-1 strain, genotype 2) merozoites were released from oocysts directly during an incubation and excystation procedure without bleach treatment. They were polymorphic, mostly spindle-shaped; others were bean shaped, actively motile, and underwent division. Merozoites survived for short time-period in an in vitro culture system, but could not be established in a subsequent cultivation effort in RPMI medium.     

Trehalose, the insect blood sugar, inhibits loading of diacylglycerol by lipophorin from the fat body in locusts

Trehalose, the insect blood sugar, was found to inhibit diacylglycerol uptake by lipophorin from the fat body in vitro. Trehalose inhibited diacylglycerol uptake by about 40%-50% at various physiological concentrations. This suggests that trehalose may play a dual role in the hemolymph, i.e. serving as the insect's fuel and as a regulator in lipid transport.     

Role of O-acetyl-l-serine in the coordinated regulation of the expression of a soybean seed storage-protein gene by sulfur and nitrogen nutrition

The composition of seed storage proteins is regulated by sulfur and nitrogen supplies. Under conditions of a low sulfur-to-nitrogen ratio, accumulation of the β-subunit of β-conglycinin, a sulfur-poor seed storage protein of soybean (Glycine max [L.] Merr.), is elevated, whereas that of glycinin, a sulfur-rich storage protein, is reduced. Using transgenic Arabidopsis thaliana [L.] Heynh., it was found that the promoter from the gene encoding the β-subunit of β-conglycinin up-regulates gene expression under sulfur deficiency and down-regulates gene expression under nitrogen deficiency. To obtain an insight into the metabolic control of this regulation, the concentrations of metabolites related to the sulfur assimilation pathway were determined. Among the metabolites, O-acetyl-l-serine (OAS), one of the precursors of cysteine biosynthesis, accumulated to higher levels under low-sulfur and high-nitrogen conditions in siliques of transgenic A. thaliana. The pattern of OAS accumulation in response to various levels of sulfur and nitrogen was similar to that of gene expression driven by the β-subunit promoter. Elevated levels of OAS accumulation were also observed in soybean cotyledons cultured under sulfur deficiency. Moreover, OAS applied to in-vitro cultures of immature soybean cotyledons under normal sulfate conditions resulted in a high accumulation of the β-subunit mRNA and protein, whereas the accumulation of glycinin was reduced. These changes were very similar to the responses observed under conditions of sulfur deficiency. Our results suggest that the level of free OAS mediates sulfur- and nitrogen-regulation of soybean seed storage-protein composition. Received: 6 February 1999 / Accepted: 16 March 1999     

In vivo fascicle behavior of synergistic muscles in concentric and eccentric plantar flexions in humans.

Ultrasonography was used to directly measure in vivo fascicle behavior of the medial gastrocnemius (MG) and soleus (SOL) muscles while the subjects (n=6 men) performed maximal voluntary concentric and eccentric plantar flexions at 60, 120, 180 and 240 deg/s. Fascicle shortening and lengthening velocities of MG, obtained from fascicle length changes over time, were significantly higher than those of SOL at +/-120, +/-180 and +240 deg/s, possibly reflecting physiological and mechanical differences between these muscles. On the other hand, the effective fascicle shortening and lengthening velocities, defined as the velocities in the longitudinal direction of muscle belly, were not significantly different between MG and SOL. This could be due to difference in fascicle architecture and/or the existence of mechanical linkages between these muscles. Moreover, when the contribution of tendinous tissues to muscle-tendon complex length change was determined from fascicle length, pennation angle, moment arm and joint angle, it accounted for approximately 50% in both concentric and eccentric trials, but showed considerable intra-subject variations. This result quantifiably demonstrates the importance of tendinous tissues in isokinetically controlled joint movements.