Inducible gene expression of moricin, a unique antibacterial peptide from the silkworm (Bombyx mori)

Molecular cloning of cDNAs encoding moricin, a novel antibacterial peptide from the silkworm (Bombyx mori), was performed using a fat-body cDNA library. A reverse-transcription PCR product encoding a partial nucleotide sequence of moricin was used as a probe. Nucleotide sequencing of four positive clones revealed two types of moricin cDNAs designated moricin 1 and 2. cDNAs for moricin 1 and 2 shared 97.2% identity in their nucleotide sequences. Although one amino acid residue (Phe6) of moricin 1 in the putative signal peptide was replaced with Lys6 in moricin 2, amino acid sequences of their mature portions were identical. Moricin gene expression in B. mori larvae injected with Escherichia coli was observed in fat-bodies, haemocytes and the Malpighian tubule, but not in other tissues like the midgut and silk glands. Accumulation of moricin gene transcripts induced by E. coli reached a maximum level 8 h after injection and persisted up to 48 h. It was confirmed that lipopolysaccharide (LPS) and lipid A, which are cell-wall components of E. coli, triggered moricin gene expression. Comparison of gene expression between moricin 1 and 2 by PCR using specific primers indicated that moricin 2 gene was more strongly expressed than moricin 1 gene. A genomic clone encoding moricin 2 was screened from a B. mori genomic library using a moricin cDNA as a probe. Regulatory motifs for gene expression such as nuclear-factor-kappaB-binding-site-like sequence (kappaB site) and nuclear-factor-interleukin-6-binding-site-like sequence (NF-IL-6 site) were found in the 5'-upstream regulatory region. An electrophoretic-mobility-shift assay revealed that there are bacterial LPS-inducible nuclear proteins that can bind to the kappaB site and other sites in the regulatory region.

Macrophage infiltration and heme oxygenase-1 expression correlate with angiogenesis in human gliomas

Macrophages are key participants in angiogenesis. In this study on human brain tumors, we first investigated whether macrophage infiltration is associated with angiogenesis and malignant histological appearance. Immunostaining of macrophages and small vessels in resected glioma specimens indicated that numbers of infiltrating macrophages and small vessel density were higher in glioblastomas than in astrocytomas or anaplastic astrocytomas. Macrophage infiltration was closely correlated with vascular density in human gliomas. Heme oxygenase-1 (HO-1), which is the rate-limiting enzyme in heme catabolism, was also associated with activated macrophages. Expression of mRNA encoding HO-1 was correlated with macrophage infiltration and vascular density in human glioma samples. Infiltrating macrophages were positively stained with anti-HO-1 antibody by immunohistochemical analysis, and in situ hybridization for HO-1 indicated that HO-1 was expressed in infiltrating macrophages in gliomas. HO-1 gene may be a useful marker for macrophage infiltration as well as neovascularization in human gliomas.

cDNA cloning and gene expression of cecropin D, an antibacterial protein in the silkworm, Bombyx mori

We have isolated a cDNA clone encoding a cecropin D precursor from the fat body of Bombyx mori larvae immunized with bacteria by means of differential display. The cDNA contains 298 bp with a coding region of 183 bp for 61 amino acids plus a termination codon (TAG), a 5'-untranslated region of 36 bp, and a 3'-untranslated region of 79 bp including the poly(A) tail. There is a polyadenylation signal sequence of AATAAA at position 266, 43 nucleotides downstream from the termination codon TAG. The homology of the deduced amino acids is greater to the cecropin D precursor from Hyalophora cecropia (67% identity) than to the precursors of cecropins A and B from B. mori (49% to both). Northern blotting analyses reveal that the gene expression of cecropin D is detectable by 4 h after the bacterial injection and reaches the maximal level at 24 h. That high level is maintained up to 48 h post-immunization. Additionally, the gene is expressed mainly in the fat body and slightly in hemocytes, but it is undetectable in other tissues such as the midgut, the Malpighian tubule and silk gland.

Pubertal genitofemoral nerve division induces testicular ascent in adult rats

BACKGROUND/PURPOSE

Ascending testes, which normally are located at the bottom of the scrotum in early infancy and later ascend back out of the scrotum, have been reported by several investigators. However, little is known about the effect of the division of the genitofemoral nerve (GFN) on testicular ascent as boys grow. The purpose of this study is to investigate whether the division of the proximal genitofemoral nerve in prepubertal rats induces testicular ascent in adulthood.

METHODS

Thirty-day-old Wistar King A Rats (n = 27) underwent a unilateral proximal GFN transection on either the right or left side. At 150 days of age, the rats were killed, and their testicular position was examined. The length of the processus vaginalis was measured, and the testes were removed and weighed. Sham-operated rats were used as controls (n = 10). Student's t and the chi2 test were used for the statistical analysis.

RESULTS

At 150 days of age, 21 of the 27 operated rats (77.8%) showed unilateral testicular ascent on the operated side. All testes were located at the bottom of the scrotum in sham-operated control rats (20 testes). Both the length of the processus vaginalis and the testicular weight were decreased significantly more on the operated side than in the sham-operated rats.

CONCLUSIONS

These findings suggest that the proximal division of the genitofemoral nerve in prepubertal rats may induce a relative ascent of the testis by preventing the growth of the processus vaginalis in adulthood. In patients with such ascending testes, an abnormal development or accidental trauma of the genitofemoral nerve may be involved in testicular ascent.

Induction of gene expression of antibacterial proteins by chitin oligomers in the silkworm, Bombyx mori

Activation of antibacterial protein genes by various chitin oligomers (from dimer to hexamer) was investigated by Northern blot analysis using cDNAs encoding cecropin B, attacin and lebocin from Bombyx mori as probes. All chitin oligomers tested were found to strongly trigger expression of cecropin B, attacin and lebocin genes. Furthermore, gene expression triggered by chitin oligomers was confirmed to occur specifically in the fat body and haemocytes. These results suggest that chitin oligomers have the same characteristics as those of lipopolysaccharide (LPS) and peptidoglycan in triggering gene expression of insect antibacterial proteins.

Does proximal genitofemoral nerve division induce testicular maldescent or ascent in the rat?

OBJECTIVE

To investigate whether the division of the proximal genitofemoral nerve (GFN) in neonatal rats induces testicular undescent or ascent in adulthood.

MATERIALS AND METHODS

Neonatal Wistar King A rats underwent a unilateral proximal GFN transection on either the right or left side. At the age of 30 days, testicular descent was examined in all rats and the position of the testis recorded. The animals were allowed to develop further and the position of the testis re-examined at the age of 90-180 days, when the testes were removed and weighed. Sham-operated rats were used as controls.

RESULTS

At the age of 30 days, four of the 46 (9%) operated rats showed a unilateral undescended testis on the operated side. At the age of 90-180 days, 43 rats were re-examined (three rats died before re-examination); 34 (79%) of these rats showed undescended testes on the operated side. The occurrence of cryptorchidism was significantly higher in the 90-180-day-old mature rats than in 30-day-old prepubertal rats (P<0.01). The mean (sd) weight of the undescended testes, at 2.36 (0.21) mg/g body weight, was significantly less than that of the contralateral scrotal testes, at 3.83 (0.23) mg/g; P<0.01) and of the control testes at the age of 90-180 days. In the sham-operated rats, all testes were located at the bottom of the scrotum at 30 days of age and no rats showed any testicular ascent thereafter.

CONCLUSIONS

The proximal division of the GFN in neonatal rats not only causes inguinoscrotal testicular maldescent but may also induce testicular ascent in adulthood. Testicular ascent may thus be caused by some intrauterine disorders of the GFN in patients with ascending testis.

Dieldrin and picrotoxinin modulation of GABA(A) receptor single channels

The insecticide dieldrin is known to suppress the GABA(A) receptor-channel complex in a manner similar to that of picrotoxin. To elucidate the more detailed mechanisms of dieldrin and picrotoxin interactions with the GABA system, single-channel patch clamp experiments were performed using rat dorsal root ganglion neurons in primary culture. Dieldrin did not alter the open time distribution and mean current amplitude or the distribution of burst duration and the mean burst duration. However, the mean closed time was prolonged indicating that dieldrin decreased the channel open probability. Previous studies have demonstrated that dieldrin and picrotoxin share the common binding site on the GABA receptor. Thus, the effects of picrotoxinin on the GABA(A) receptor single channels were also examined. Dieldrin and picrotoxinin had similar effects at the single-channel level. These changes of single-channel parameters explain the suppressive effects of these chemicals on GABA-induced whole-cell currents.

Fertility and histological studies of the contralateral testes in two different intra- and extra-abdominal rat models of unilateral cryptorchidism

OBJECTIVE

To investigate the effect of location of the testis on both testicular development and fertility in unilateral cryptorchidism.

MATERIAL AND METHODS

Forty-nine Wistar King A newborn male rats were divided into three groups. In group 1 (15 rats) intra-abdominal unilateral cryptorchidism were created by the intra-abdominal fixation of the testis in the neonatal period. In group 2 (16 rats) extra-abdominal unilateral cryptorchidism was created by extra-abdominal fixation of the gubernaculum in the neonatal period. In group 3, 18 rats underwent a sham operation as controls. At 90 days of age, fertility was then assessed in each rat by housing it with two mature virgin females for 2 weeks. Thereafter, at 115-120 days of age, the rats were killed and their testes removed for histological examination.

RESULTS

There was no significant difference in the pregnancy rate between females coupled with rats from any group, but the mean number of offspring was significantly lower in females coupled with rats in group 1 than in group 2. Furthermore, histological examination of both the cryptorchid and contralateral scrotal testes showed more severe changes in the intra-abdominal than the extra-abdominal testes.

CONCLUSION

These results suggest that intra-abdominal cryptorchid testes are significantly more impaired than extra-abdominal cryptorchid testes, and that such impairment might be caused by exposure of the testis to a higher temperature. The more severely impaired undescended testes may thus induce the degeneration of the contralateral scrotal testis and thereby cause subfertility in the intra-abdominal unilateral cryptorchid rat model.

Novel biological functions of interleukin-4: formation of tube-like structures by vascular endothelial cells in vitro and angiogenesis in vivo

The effect of interleukin-4 (IL-4) on angiogenesis was studied in vitro and in vivo. Human recombinant IL-4 significantly stimulated the formation of tube-like structures in collagen gels by bovine aortic endothelial cells as well as by human microvascular endothelial cells. Human recombinant IL-4 at 50-500 U/ml stimulated by about two- to threefold the formation of tubes by bovine aortic endothelial cells; the rate was comparable to that of basic fibroblast growth factor. Tube formation was almost completely inhibited by the addition of IL-4 receptor neutralizing antibody. Administration of rat recombinant IL-4 led to neovascularization when implanted in the rat cornea. Findings suggest that IL-4 may be a mediator of the immune system as well as an inducer of angiogenesis.

Fertility and histological studies in a unilateral cryptorchid rat model during early and late adulthood

OBJECTIVE

To investigate the effect of age on fertility and testicular development in rats with untreated unilateral undescended testes.

MATERIALS AND METHODS

Newborn male Wistar King-A rats were divided into two groups. In group 1, a mechanical model of unilateral undescended testis was created by performing extra-abdominal fixation of the gubernaculum in the neonatal period, and in group 2, sham-operated rats were used as controls. At 90 days old (early adulthood), the fertility of both groups was assessed by mating the rats with mature virgin females for 2 weeks. Thereafter, some of the rats were killed and their testes examined histologically, while the remaining rats were allowed to develop further. At the age of 180 days (late adulthood), fertility was re-assessed in the same way. All the rats were then killed and their testes removed for histological examination.

RESULTS

There was no significant difference in pregnancy rate of females mated with males from either group in early adulthood. However, in late adulthood there was a significant reduction in pregnancy rate in females coupled with cryptorchid rats compared with that of females coupled with control rats. There was a significant degeneration of the unilateral cryptorchid testes compared with control testes in both early and late adulthood. In contrast, there were no significant changes in histological development between the contralateral scrotal testes and the controls in early adulthood, although they were significantly different from the controls in late adulthood.

CONCLUSION

These results suggest that fertility is affected by ageing in untreated unilateral cryptorchidism; this may be induced by extensive damage not only in the undescended testes, but also in the contralateral scrotal testis, in this mechanically induced model of unilateral cryptorchidism.

Molecular cloning and nucleotide sequence of a cytochrome P450 cDNA from a pyrethroid-resistant mosquito, Culex quinquefasciatus say

A novel cDNA clone encoding a cytochrome P450 was screened from a gut cDNA library of permethrin-resistant Culex quinquefasciatus larvae. Nucleotide sequence of the clone designated CYP6E1 was determined. This is the first full-length sequence of a mosquito P450 cDNA. Comparison of the deduced amino acid sequence of CYP6E1 to those of other known cytochrome P450s indicates that this clone belongs to CYP6 family. In addition, a phylogenetic analysis of CYP6E1 primary structure showed that it is related to CYP6A and CYP6C subfamilies. Polymerase chain reaction (PCR) using primers designed on the basis of the nucleotide sequence of the cDNA showed that mRNA encoding CYP6E1 is present in permethrin-susceptible larvae as well as -resistant larvae, suggesting the ubiquitous distribution of CYP6E1.

Modulation of the neuronal nicotinic acetylcholine receptor-channel by the nitromethylene heterocycle imidacloprid

Nitromethylene heterocycle insecticides are known to act on the nicotinic acetylcholine receptor-channel. The effects of the nitromethylene heterocycle, imidacloprid, on the nicotinic acetylcholine receptor-channel of clonal rat phaeochromocytoma (PC12) cells were studied using whole-cell and single-channel patch clamp methods. Imidacloprid suppressed carbachol-induced whole-cell currents in a dose-dependent manner, and this compound itself generated small currents. Multiple conductance states of single-channel currents were also evoked by imidacloprid at the nicotinic acetylcholine receptor-channels. The most frequently generated single-channel currents showed two conductance states, 25.4 and 9.8 pS, which were identical to the conductance states of acetylcholine-generated currents. The mean open time and burst duration of the main conductance currents induced by imidacloprid were shorter than those induced by acetylcholine. Co-application of imidacloprid and acetylcholine caused some interactions at the two conductance states. Mean open time and mean burst duration of the main conductance state currents evoked by acetylcholine were decreased by the co-application of imidacloprid as compared with those induced by acetylcholine alone. In conclusion, imidacloprid has both multiple agonist and antagonist effects on the neuronal nicotinic acetylcholine receptor-channels.

In vitro metabolism of pyriproxyfen by microsomes from susceptible and resistant housefly larvae

Levels of cytochrome P450 and b5 were investigated in microsomal enzymes of houseflies from the gut and fat body of the third instar larvae of a pyriproxyfen-resistant strain (YPPF) and two pyriproxyfen-susceptible strains (YS and SRS). In comparison to the YS and SRS strains, YPPF microsomes had higher levels of total cytochrome P450s in both the gut and fat body. Furthermore, microsomes from the gut and fat body of YPPF larvae were found to have a much greater ability to hydroxylate aniline than YS larvae. In vitro metabolism studies of pyriproxyfen indicated that the metabolic rates were much higher in both the gut and fat body of YPPF larvae than of YS and SRS larvae. The major metabolites of pyriproxyfen in houseflies were identified to be 4'-OH-pyriproxyfen and 5"-OH-pyriproxyfen. Cytochrome P450 inhibitors, piperonyl butoxide (PB) and 2-propynyl 2,3,6-trichlorophenyl ether (PTPE), decreased the metabolic rates significantly in all three strains. This study confirmed that microsomal cytochrome P450 monooxygenases play an important role in the pyriproxyfen resistance of the housefly. Furthermore, it suggests that the fat body must be as important as the gut for the metabolism of pyriproxyfen in resistant housefly larvae.

Effect of retinoic acid on morphological changes of human pancreatic cancer cells on collagen gels: a possible association with the metastatic potentials

Pancreatic carcinoma is an invasive and metastasizing type of malignancy. We established six pancreatic cancer cell lines from human pancreatic carcinomas, three highly metastatic lines (KP-1NL, KP-4, and SUIT-2) and three minimally metastatic lines (KP-2, KP-3, and BxPC-3). The three highly metastatic cell lines grew in a fibroblastoid pattern on collagen gels, whereas the three minimally metastatic cell lines grew in an epithelioid pattern under similar conditions. Western blot and Northern blot analyses indicated much higher levels of E-cadherin in the three minimally metastatic cell lines relative to the three highly metastatic cell lines. When the effect of all-trans-retinoic acid on the growth patterns of the three highly metastatic lines was examined, we observed a dramatic change from fibroblastoid to epithelioid growth in SUIT-2 cells. Although all six cell lines had comparable levels of retinoic acid receptor-gamma, retinoic acid receptor-beta was expressed only in SUIT-2 cells. Treating SUIT-2 cells with retinoic acid also induced the upregulation of E-cadherin expression. When SUIT-2 cells were treated with retinoic acid receptor-specific agonists, 13-cis-retinoic acid and Am555S, a morphological change from fibroblastoid to epithelioid growth was induced. Retinoic acid receptor-specific antagonists, LE135 and LE540, inhibited retinoic acid-induced change of the growth patterns. The effect of retinoic acid and its derivatives on the growth pattern was discussed in a possible association with their antimetastatic activities of pancreatic cancer.

A novel member of lebocin gene family from the silkworm, Bombyx mori

We screened genomic clones encoding lebocin, an antibacterial peptide from the silkworm, Bombyx mori. Two positive clones were obtained and their nucleotide sequences indicated that they contain no introns. The deduced amino acid sequences revealed that one clone (Leb 3) encoded lebocin 3 and another (Leb 4) is a new member of the lebocin gene family. Gene expression of both Leb 3 and Leb 4 was shown to be induced by lipopolysaccharide and to occur tissue-specifically in the fat body and hemocytes. Our results suggest that lebocin as well as cecropin forms a multiple gene family in B. mori.

Acetylcholinesterase (ACE) staining shows the abnormal innervation of a pulled-through rectum in a case of repaired anorectal malformation

Abnormal innervation of the anorectum was noted in relation to anal incontinence in a case of repaired high-type anorectal malformation (ARM). A ten-year-old boy presented with anal incontinence after reconstructive surgery of ARM with a recto-urethral fistula. An anorectal manometrical examination revealed both an adequate tonus of the anal sphincter muscles and the absence of rectoanal reflex relaxation. And a barium enema showed a narrow region in the rectosigmoid colon, which was similar to that of Hirschsprung's disease (HD). Furthermore, an acetylcholinesterase (ACE) histochemical study of the rectal suction biopsies revealed an increased number of ACE-positive nerve fibers in the lamina propria mucosae and muscularis mucosae of the pulled-through colon. At the same time, however, some ganglia cells were also observed in the submucosa of the affected rectosigmoid colon and these cells could not be found in HD. Although the mechanism by which the abnormally innervated parasympathetic nerve fibers arose in the pulled-through colon remains unclear, this neuronal abnormality is considered to be the cause of anal incontinence in this case.

Involvement of interleukin-8, vascular endothelial growth factor, and basic fibroblast growth factor in tumor necrosis factor alpha-dependent angiogenesis

Tumor necrosis factor alpha (TNF-alpha) is a macrophage/monocyte-derived polypeptide which modulates the expression of various genes in vascular endothelial cells and induces angiogenesis. However, the underlying mechanism by which TNF-alpha mediates angiogenesis is not completely understood. In this study, we assessed whether TNF-alpha-induced angiogenesis is mediated through TNF-alpha itself or indirectly through other TNF-alpha-induced angiogenesis-promoting factors. Cellular mRNA levels of interleukin-8 (IL-8), vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and their receptors were increased after the treatment of human microvascular endothelial cells with TNF-alpha (100 U/ml). TNF-alpha-dependent tubular morphogenesis in vascular endothelial cells was inhibited by the administration of anti-IL-8, anti-VEGF, and anti-bFGF antibodies, and coadministration of all three antibodies almost completely abrogated tubular formation. Moreover, treatment with Sp1, NF-kappaB, and c-Jun antisense oligonucleotides inhibited TNF-alpha-dependent tubular morphogenesis by microvascular endothelial cells. Administration of a NF-kappaB antisense oligonucleotide almost completely inhibited TNF-alpha-dependent IL-8 production and partially abrogated TNF-alpha-dependent VEGF production, and an Sp1 antisense sequence partially inhibited TNF-alpha-dependent production of VEGF. A c-Jun antisense oligonucleotide significantly inhibited TNF-alpha-dependent bFGF production but did not affect the production of IL-8 and VEGF. Administration of an anti-IL-8 or anti-VEGF antibody also blocked TNF-alpha-induced neovascularization in the rabbit cornea in vivo. Thus, angiogenesis by TNF-alpha appears to be modulated through various angiogenic factors, both in vitro and in vivo, and this pathway is controlled through paracrine and/or autocrine mechanisms.

Motility studies of the esophagus in a case of esophageal atresia before primary anastomosis and in experimental models

Esophageal motility was assessed in a case of long-gap esophageal atresia (EA) without tracheoesophageal fistula before primary anastomosis, in addition esophageal manometrical studies were also experimentally performed in mongrel dogs to investigate the pathogenesis of the motility disorders in successfully repaired EA. Coordinated peristaltic contractions were observed between the proximal and distal esophageal pouch when swallowing before primary anastomosis in EA. In addition, these contractions induced a reflex relaxation of the lower esophageal sphincter (LES) as seen in the normal esophagus at the age of 8 months. At the age of 28 days, however, the LES showed an unstable pressure profile and the absence of a reflex relaxation in response to the contractions of the proximal esophageal pouch. On the other hand, experimental studies were carried out on six mongrel dogs weighing 12-15 kg. In group 1 (n = 3), the esophagus was divided at the level of the tracheal carina and both the proximal and distal pouches were closed separately. In group II (n = 3), the esophageal branches of the vagal nerves were divided between the level of the aortic arch and the esophageal diaphragmatic hiatus. Postoperatively, coordinated peristaltic contractions were shown between the proximal and distal esophageal pouches in group I, although the vagotomized esophagus showed abnormal simultaneous contractions in group II. These results suggested that even if the esophageal continuity is disrupted, the coordinated peristaltic contractions are propagated between the proximal and distal esophagus before primary anastomosis in EA, and thus postoperative esophageal motility disorders may result from the surgical damage to the vagus during operative procedures.

Prenatal phthalate causes cryptorchidism postnatally by inducing transabdominal ascent of the testis in fetal rats

Phathalate esters, which are commonly used as plasticizers for polyvinyl chloride, are also well known to disturb Sertoli cells. This study aims to show the effect of prenatally administered phthalate on testicular descent in pre- and postnatal rats. Pregnant rats were exposed to mono-n-butyl phthalate (MBP) by gavage from the 15th to the 18th gestational days. Rats administered with solvent only were used as controls. In 20-day-old fetuses (n = 15), the degree of transabdominal testicular ascent in relation to the bladder neck was thus found to be significantly higher in MBP-treated rats than that of the controls (n = 19). In addition, in MBP-treated male offspring (n = 26), 22 rats showed either bilateral or unilateral cryptorchidism at the age of 30 to 40 days old, and the occurrence of cryptorchidism was 84.6%. By contrast, the occurrence of cryptorchidism was 0% in the control rats (n = 15, P < .001). It is therefore suggested that prenatal exposure to MBP may disturb the Sertoli cells and elevate the fetal testes relative to the bladder neck while also inducing cryptorchidism postnatally. Sertoli cells may thus play an important role in the transabdominal descent of the testis by secreting Müllerian-inhibiting substance (MIS), which is known to act as a putative mediator of the transabdominal phase.

Scanning electron microscopy shows inhibited gubernacular development in relation to undescended testes in oestrogen-treated mice

The morphological relationship between transabdominal testicular descent and the 'swelling reaction' of the gubernaculum was investigated in oestrogen-treated fetal mice by using scanning electron microscopy (scanning EM). In addition, flutamide was also administered to pregnant mice to determine whether androgens cause gubernacular growth and transabdominal testicular descent in offspring. In oestrogen-treated fetal mice, scanning EM showed that both the gubernacular 'swelling reaction' and transabdominal testicular descent were inhibited, in addition to inhibition of Müllerian duct regression. The gubernaculum showed a flat, thin bulb (widest diameter 0.25 +/- 0.04 mm) and an elongated cord (1.28 +/- 0.41 mm) after oestrogen treatment in utero, which was significantly different in appearance from that in normal control mice (width 0.44 mm +/- 0.06 mm, p < 0.001; length 0.27 +/- 0.19 mm, p < 0.0001). However, flutamide-treated mice showed much more normal gubernacular enlargement and transabdominal testicular descent. The width of the gubernacular bulb after flutamide exposure was 0.44 +/- 0.05 mm, which was comparable to that in control animals; the length of the intra-abdominal gubernaculum (0.44 +/- 0.15 mm) was slightly longer than in controls (p < 0.02). These results suggest that both the swelling reaction of the gubernaculum and transabdominal testicular migration are blocked by prenatal exposure to oestrogen. However, oestrogen exposure of the fetus does not block the swelling reaction of the gubernaculum by acting as an antiandrogen.

Elicitors triggering the simultaneous gene expression of antibacterial proteins of the silkworm, Bombyx mori

Various elicitors were examined by Northern blot analysis to investigate the simultaneous induction of gene expression of antibacterial proteins such as cecropin B, attacin and lebocin from the silkworm, Bombyx mori. Lipopolysaccharide (LPS), lipid A, 2-keto-3-deoxyoctonate (KDO) and peptidoglycan (PG) triggered efficiently and simultaneously the gene expression of antibacterial proteins. Effects of inhibitors for signal transduction on the gene expression of Bombyx mori (Bm) cecropin B triggered by lipid A were observed using isolated adherent hemocytes consisting of granular cells and plasma cells. H-7, H-89 but not W-7 inhibited gene expression, suggesting that protein kinase C and A but not myosine light chain kinase may participate in signal transduction.

Angiogenesis as a new target for cancer treatment

Neovascularization is often required for rapid growth of solid tumors and also limits vascular metastasis of tumor cells. Neovascularization-targeting agents are a recent innovation that may be a novel means of anticancer therapy. These antiangiogenic drugs have been developed by targeting cell proliferation of vascular endothelial cells, basement-membrane-degrading enzymes, angiogenic factors/receptors, extracellular matrix, angiogenesis signaling, and cell-cell/cell-matrix interactions. In this report, we describe how tumor angiogenesis occurs and how antiangiogenic agents are developed.

Involvement of the transcription factor NF-kappaB in tubular morphogenesis of human microvascular endothelial cells by oxidative stress

Oxygen radicals are induced under various pathologic conditions associated with neovascularization. Oxygen radicals modulate angiogenesis in cultured human microvascular endothelial cells by an unknown mechanism. Treatment of human microvascular endothelial cells for 15 min with 0.1 to 0.5 mM hydrogen peroxide (H2O2) or 100 U of tumor necrosis factor alpha per ml induced tubular morphogenesis in type I collagen gels. Gel shift assays with nuclear extracts demonstrated that H2O2 increases the binding activities of two transcription factors, NF-kappaB and AP-1, but not of Spl. Tumor necrosis factor alpha increased the binding activities of all three factors. A supershift assay with specific antibodies against JunB, JunD, and c-Jun (Jun family) showed that the antibody against c-Jun supershifted the AP-1 complex after H2O2 treatment. Coadministration of the antisense sequence of NF-kappaB inhibited H2O2-dependent tubular morphogenesis, and the antisense c-Jun oligonucleotide caused partial inhibition. The angiogenic factor responsible for H2O2-induced tubular morphogenesis was examined. Cellular mRNA levels of vascular endothelial growth factor and interleukin-8 (IL-8), but not those of transforming growth factor alpha, were increased after treatment with 0.5 mM H2O2. Coadministration of anti-IL-8 antibody inhibited tubular morphogenesis enhanced by H2O2, and IL-8 itself also enhanced the formation of tube-like structures. Treatment with antisense NF-kappaB oligonucleotide completely blocked H2O2-dependent IL-8 production by endothelial cells. The tubular morphogenesis of vascular endothelial cells after treatment with oxidative stimuli and its possible association with NF-kappaB and IL-8, is examined.