Deficiency of M-LP/Mpv17L leads to development of β-cell hyperplasia and improved glucose tolerance via activation of the Wnt and TGF-β pathways

M-LP/Mpv17L is a protein that was initially identified during screening of age-dependently expressed genes in mice. We have recently demonstrated that M-LP/Mpv17L-knockout (M-LP/Mpv17L-KO) in human hepatoma cells leads to a reduction of cellular cyclic nucleotide phosphodiesterase (PDE) activity, and that in vitro-synthesized M-LP/Mpv17L possesses PDE activity. These findings suggest that M-LP/Mpv17L functions as an atypical PDE, even though it has none of the well-conserved catalytic region or other structural motifs characteristic of the PDE family. In this study, we found that M-LP/Mpv17L-KO mice developed β-cell hyperplasia and improved glucose tolerance. Deficiency of M-LP/Mpv17L in islets from KO mice at early postnatal stages or siRNA-mediated suppression of M-LP/Mpv17L in rat insulinoma cells led to marked upregulation of lymphoid enhancer binding factor 1 (Lef1) and transcription factor 7 (Tcf7), key nuclear effectors in the Wnt signaling pathway, and some of the factors essential for the development and maintenance of β-cells. Moreover, at the protein level, increases in the levels of phosphorylated β-catenin and glycogen synthase kinase-3β (GSK-3β) were observed, indicating activation of the Wnt and TGF-β signaling pathways. Taken together, these findings suggest that protein kinase A (PKA)-dependent phosphorylations of β-catenin and GSK-3β, the key mediators of the Wnt and/or TGF-β signaling pathways, are the most upstream events triggering β-cell hyperplasia and improved glucose tolerance caused by M-LP/Mpv17L deficiency.

Fu's subcutaneous needling for subcutaneous adhesions and scar hyperplasia in the neck region: A case report

RATIONALE

Lymphadenectomy for tongue cancer in the neck region is often accompanied by local impaired mobility, gland damage, difficult in swallowing, and postoperative complication and seriously affects patients life quality. We reported a case of subcutaneous adhesions and scar hyperplasia in the neck region after lymphadenectomy for tongue lesions accompanied by impaired neck mobility and difficult in swallowing was treated using Fu's subcutaneous needling (FSN) treatment.

PATIENT CONCERNS

A 55-year-old male with tongue cancer received surgical intervention with lymphadenectomy 8 years ago was revealed a 15 cm-long curved surgical incision in the neck region and surrounded by numerous scar tissues.

DIAGNOSIS

Post-operation subcutaneous adhesions and scar hyperplasia in the neck region after lymphadenectomy was diagnosed.

INTERVENTIONS

FSN treatment was performed 2 to 3 times per week for 1 month to sway the affected tightened muscle and dissociate the superficial fascia beneath the scar resulted in a considerable improvement in neck movement.

OUTCOMES

The Vancouver Scar Scale (VSS) was as follows: color (M) - 1; vascular distribution (V) - 0, thickness (H) - 2, and flexibility (P) - 4, with a total of 7 points before FSN treatment. The VSS after 1 month of FSN treatment was as follows: M1, V0, H2, and P2, with a total of 5 points. Neck mobility in different directions, i.e., stretching to the back of the neck and laterally bending the neck to the left and/or right side, was improved (P < .05).

LESSONS

At present, treatment of chronic scar hyperplasia has certain side effects and limitations. FSN is safe and convenient, with minimal destruction of the superficial fascia, having evident effects of dissociating tissue adhesion under scars and compensating for deficiencies in scar hyperplasia treatment. It can provide new ideas for future treatments.

Inflammation-induced IgE promotes epithelial hyperplasia and tumour growth

IgE is the least abundant circulating antibody class but is constitutively present in healthy tissues bound to resident cells via its high-affinity receptor, FcεRI. The physiological role of endogenous IgE antibodies is unclear but it has been suggested that they provide host protection against a variety of noxious environmental substances and parasitic infections at epithelial barrier surfaces. Here we show, in mice, that skin inflammation enhances levels of IgE antibodies that have natural specificities and a repertoire, VDJ rearrangements and CDRH3 characteristics similar to those of IgE antibodies in healthy tissue. IgE-bearing basophils are recruited to inflamed skin via CXCL12 and thymic stromal lymphopoietin (TSLP)/IL-3-dependent upregulation of CXCR4. In the inflamed skin, IgE/FcεRI-signalling in basophils promotes epithelial cell growth and differentiation, partly through histamine engagement of H1R and H4R. Furthermore, this IgE response strongly drives tumour outgrowth of epithelial cells harbouring oncogenic mutation. These findings indicate that natural IgE antibodies support skin barrier defences, but that during chronic tissue inflammation this role may be subverted to promote tumour growth.

Systematic review with network meta-analysis: endoscopic techniques for dysplasia surveillance in inflammatory bowel disease

BACKGROUND

International guidelines recommend dysplasia surveillance in IBD.

AIM

To compare endoscopic techniques for dysplasia surveillance METHODS: We searched MEDLINE, Embase, CENTRAL for randomised trials through May 2019. We estimated odds ratios (ORs) for binary and mean differences (MDs) for continuous outcomes, using frequentist random-effects network meta-analysis. We assessed study risk of bias and appraised evidence certainty using GRADE.

RESULTS

Eighteen trials (2638 participants) were included. Standard definition white-light endoscopy (OR 0.44, 95% CI 0.26-0.73; high certainty) and i-SCAN (OR 0.47, 95% CI 0.25-0.90; moderate certainty) had lower odds of detecting neoplasia than chromoendoscopy. Fujinon intelligent colour enhancement (FICE), standard definition white-light endoscopy and i-SCAN had lower odds for this outcome than full spectrum high definition white-light endoscopy (ORs 0.02 to 0.15; low certainty). Standard definition white-light endoscopy had lower odds of detecting nonpolypoid neoplasia than full spectrum high definition white-light endoscopy, narrow band imaging, chromoendoscopy and high definition white-light endoscopy (ORs 0.01-0.14; moderate certainty). Full spectrum high definition white-light endoscopy ranked as the best technique for both outcomes (moderate certainty). Standard definition white-light endoscopy had lower odds of detecting neoplasia by target biopsy (OR 0.27, 95% CI 0.08-0.91) and had shorter procedure time (MD -14.81 minutes, 95% CI -25.03, -4.06) than chromoendoscopy (moderate certainty).

CONCLUSIONS

Chromoendoscopy, high definition white-light endoscopy, narrow band imaging, autofluorescence, FICE and full spectrum high definition white-light endoscopy may be comparable for dysplasia surveillance. Standard definition white-light endoscopy and i-SCAN probably provide lower yields for neoplasia identification. Full spectrum high definition white-light endoscopy may represent the first-line approach.

Inhibitory effects of scoparone from chestnut inner shell on platelet-derived growth factor-BB-induced vascular smooth muscle cell migration and vascular neointima hyperplasia

BACKGROUND

Compounds of the inner shell of chestnut (Castanea crenata) have diverse biological activities, including anti-cancer and anti-oxidant activities. Here we explored the effects of an extract of chestnut inner shells and of its bioactive component scoparone on vascular smooth muscle cell migration and vessel damage.

RESULTS

The ethanol extract of chestnut inner shells, containing 11 major compounds, inhibited platelet-derived growth factor (PDGF)-BB-induced migration of rat aortic smooth muscle cells (RASMCs). Among these compounds, scoparone (6,7-dimethoxycoumarin) suppressed RASMC migration and wound healing in response to PDGF-BB but did not affect RASMC proliferation. In RASMCs, scoparone inhibited the PDGF-BB-induced rat aortic sprout outgrowth and attenuated the PDGF-BB-mediated increase in phosphorylation of mitogen-activated protein kinases (MAPKs), p38 MAPK and extracellular signal-regulated kinase 1/2. The in vivo administration of scoparone resulted in the attenuation of neointima formation in balloon-injured carotid arteries of rats.

CONCLUSION

These findings demonstrate that scoparone, found in chestnut inner shells, may inhibit cell migration through suppression of the phosphorylation of MAPKs in PDGF-BB-treated RASMCs, probably contributing to the reduction of neointimal hyperplasia induced after vascular injury. Therefore, scoparone and chestnut inner shell may be a potential agent or functional food, respectively, for the prevention of vascular disorders such as vascular restenosis or atherosclerosis. © 2019 Society of Chemical Industry.

A Flow Dynamic Rationale for Accelerated Vascularized Composite Allotransplant Rejection

BACKGROUND

From 1996 to 2000, Diefenbeck et al. carried out six knee vascularized composite allotransplants. The allotransplants were composed of bone, soft tissue, and femoral vascular pedicle (25 to 40 cm). All rejected between 14 and 56 months. Failures were attributed to chronic rejection. In 2008, the Louisville team lost their fourth patient's hand transplant at 8 months. During the rejection workup, intraoperative findings noted a thickened arterial pedicle attributed to intimal hyperplasia with significant fibrotic perivascular tissue and a near "no-flow phenomenon." No cutaneous rejection was appreciated and failure was attributed to chronic rejection.

METHODS

Data were collected from two teams, one in Germany and the other in Louisville, Kentucky. The population under study consisted of the six knee and one hand transplants. The factor of interest was the long donor arterial pedicle. The outcome measurements were transplant survival time and histopathologic results.

RESULTS

There are only seven published vascularized composite allotransplant cases where a donor artery longer than 25 cm was used. This cohort represents a 100 percent accelerated failure rate. The cause of these losses remains unexplained. The donor arteries suffered from T-cell-mediated rejection and ischemia-induced media/adventitial necrosis.

CONCLUSIONS

We hypothesize that the donor artery rejected at an accelerated rate because of ischemia caused by disruption of the external vasa vasorum in conjunction with intimal hyperplasia induced by T-cell-mediated rejection that led to disruption of the Windkessel effect. Loss of this effect presented as intimal hyperplasia accelerated by ischemia causing an expedited transplant failure.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

Aberrant G-protein coupled hormone receptor in adrenal diseases

The regulation of cortisol or aldosterone production when ACTH of pituitary origin or the renin-angiotensin systems are suppressed in primary adrenal Cushing's syndrome or in primary aldosteronism is exerted by diverse genetic and molecular mechanisms. In addition to recently identified mutations in various genes implicated in the cyclic AMP or ion channel pathways, steroidogenesis is not really autonomous as it is frequently regulated by the aberrant adrenocortical expression of diverse hormone receptors, particularly G-protein coupled hormone receptors (GPCR) which can substitute for the normal function of ACTH or angiotensin-II. In addition, paracrine or autocrine production of ligands for the aberrant GPCR such as ACTH or serotonin is found in some adrenal tumors or hyperplasias and participates in a complex regulatory loop causing steroid excess. Targeted therapies to block the aberrant ligands or their receptors could become useful in the future, particularly for patients with bilateral source of steroid excess.

Radial artery neointimal hyperplasia after transradial PCI-Serial optical coherence tomography volumetric study

Aims

Transradial catheterization (TRC) is a dominant access site for coronary catheterization and percutaneous coronary interventions (PCI) in many centers. Previous studies reported higher intimal thickness of the radial artery (RA) wall in patients with a previous history of TRC. In this investigation the aim was to assess the intimal changes of RA using the optical coherence tomography (OCT) intravascular imaging in a serial manner.

Methods and results

100 patients with the diagnosis of non-ST-elevation myocardial infarction (nSTEMI) treated by PCI were enrolled (6 patients were excluded from this analysis because of occluded RA at follow-up [2 patients] and insufficient quality of OCT images [4 patients]). An 54mm long OCT run of the RA was performed immediately after the index PCI and repeated 9 months later. Volumetric analyses of the intimal layer and lumen changes were conducted. Median intimal volume at baseline versus 9 months was 33.9mm³ (19.0; 69.4) versus 39.0mm³ (21.7; 72.6) (p<0.001); and median arterial lumen volume was 356.3mm³ (227.8; 645.3) versus 304.7mm³ (186.1; 582.7) (p<0.001). There was no significant difference in the effect of any clinical factor on the RA volume changes.

Conclusions

OCT volumetric analyses at baseline and 9 months showed a significant increase in the radial artery intimal layer volume and a decrease in lumen volume after transradial PCI. No significant factors affecting this process were identified.

Discriminating between virilizing ovary tumors and ovary hyperthecosis in postmenopausal women: clinical data, hormonal profiles and image studies

BACKGROUND

The presence of virilizing signs associated with high serum androgen levels in postmenopausal women is rare. Virilizing ovarian tumors (VOTs) and ovarian stromal hyperthecosis (OH) are the most common etiologies in virilized postmenopausal women. The differential diagnosis between these two conditions is often difficult.

OBJECTIVE

To evaluate the contribution of clinical features, hormonal profiles and radiological studies to the differential diagnosis of VOT and OH.

DESIGN

A retrospective study.

SETTING

A tertiary center.

MAIN OUTCOME MEASURES

Clinical data, hormonal status (T, E2, LH and FSH), pelvic images (transvaginal sonography and MRI) and anatomopathology were reviewed.

PATIENTS

Thirty-four postmenopausal women with a diagnosis of VOT (13 women) and OH (21 women) were evaluated retrospectively.

RESULTS

Clinical signs of hyperandrogenism were more prevalent in the VOT group than the OH group. Although the VOT group showed higher T and E2 levels and lower gonadotropin levels than the OH group, a great overlap occurred among the hormone levels. A pelvic MRI provided an accurate differentiation of these two conditions.

CONCLUSION

In this group of patients, the main features contributing to the differential diagnosis of VOT and OH were serum levels of testosterone and gonadotropins and the presence of an ovarian nodule identified on the MRI. Although the association of clinical, hormonal and radiological features contributes to the differential diagnosis of these two conditions, histopathological analysis remains the gold standard for the diagnosis of ovarian hyperandrogenism in postmenopausal women.

Human biallelic MFN2 mutations induce mitochondrial dysfunction, upper body adipose hyperplasia, and suppression of leptin expression

MFN2 encodes mitofusin 2, a membrane-bound mediator of mitochondrial membrane fusion and inter-organelle communication. MFN2 mutations cause axonal neuropathy, with associated lipodystrophy only occasionally noted, however homozygosity for the p.Arg707Trp mutation was recently associated with upper body adipose overgrowth. We describe similar massive adipose overgrowth with suppressed leptin expression in four further patients with biallelic MFN2 mutations and at least one p.Arg707Trp allele. Overgrown tissue was composed of normal-sized, UCP1-negative unilocular adipocytes, with mitochondrial network fragmentation, disorganised cristae, and increased autophagosomes. There was strong transcriptional evidence of mitochondrial stress signalling, increased protein synthesis, and suppression of signatures of cell death in affected tissue, whereas mitochondrial morphology and gene expression were normal in skin fibroblasts. These findings suggest that specific MFN2 mutations cause tissue-selective mitochondrial dysfunction with increased adipocyte proliferation and survival, confirm a novel form of excess adiposity with paradoxical suppression of leptin expression, and suggest potential targeted therapies.

Hyperplasia vs hypertrophy in tissue regeneration after extensive liver resection

AIM

To address to what extent hypertrophy and hyperplasia contribute to liver mass restoration after major tissue loss.

METHODS

The ability of the liver to regenerate is remarkable on both clinical and biological grounds. Basic mechanisms underlying this process have been intensively investigated. However, it is still debated to what extent hypertrophy and hyperplasia contribute to liver mass restoration after major tissue loss. We addressed this issue using a genetically tagged system. We were able to follow the fate of single transplanted hepatocytes during the regenerative response elicited by 2/3 partial surgical hepatectomy (PH) in rats. Clusters of transplanted cells were 3D reconstructed and their size distribution was evaluated over time after PH.

RESULTS

Liver size and liver DNA content were largely recovered 10 d post-PH, as expected (e.g., total DNA/liver/100 g b.w. was 6.37 ± 0.21 before PH and returned to 6.10 ± 0.36 10 d after PH). Data indicated that about 2/3 of the original residual hepatocytes entered S-phase in response to PH. Analysis of cluster size distribution at 24, 48, 96 h and 10 d after PH revealed that about half of the remnant hepatocytes completed at least 2 cell cycles. Average size of hepatocytes increased at 24 h (248.50 μm² ± 7.82 μm², P = 0.0015), but returned to control values throughout the regenerative process (up to 10 d post-PH, 197.9 μm² ± 6.44 μm², P = 0.11). A sizeable fraction of the remnant hepatocyte population does not participate actively in tissue mass restoration.

CONCLUSION

Hyperplasia stands as the major mechanism contributing to liver mass restoration after PH, with hypertrophy playing a transient role in the process.

Pulmonary toxicity and global gene expression changes in response to sub-chronic inhalation exposure to crystalline silica in rats

Exposure to crystalline silica results in serious adverse health effects, most notably, silicosis. An understanding of the mechanism(s) underlying silica-induced pulmonary toxicity is critical for the intervention and/or prevention of its adverse health effects. Rats were exposed by inhalation to crystalline silica at a concentration of 15 mg/m³, 6 hr/day, 5 days/week for 3, 6 or 12 weeks. Pulmonary toxicity and global gene expression profiles were determined in lungs at the end of each exposure period. Crystalline silica was visible in lungs of rats especially in the 12-week group. Pulmonary toxicity, as evidenced by an increase in lactate dehydrogenase (LDH) activity and albumin content and accumulation of macrophages and neutrophils in the bronchoalveolar lavage (BAL), was seen in animals depending upon silica exposure duration. The most severe histological changes, noted in the 12-week exposure group, consisted of chronic active inflammation, type II pneumocyte hyperplasia, and fibrosis. Microarray analysis of lung gene expression profiles detected significant differential expression of 38, 77, and 99 genes in rats exposed to silica for 3-, 6-, or 12-weeks, respectively, compared to time-matched controls. Among the significantly differentially expressed genes (SDEG), 32 genes were common in all exposure groups. Bioinformatics analysis of the SDEG identified enrichment of functions, networks and canonical pathways related to inflammation, cancer, oxidative stress, fibrosis, and tissue remodeling in response to silica exposure. Collectively, these results provided insights into the molecular mechanisms underlying pulmonary toxicity following sub-chronic inhalation exposure to crystalline silica in rats.

Progression from low-grade dysplasia to malignancy in patients with Barrett's esophagus diagnosed by two or more pathologists

AIM

To evaluate annual incidence of low grade dysplasia (LGD) progression to high grade dysplasia (HGD) and/or esophageal adenocarcinoma (EAC) when diagnosis was made by two or more expert pathologists.

METHODS

Studies evaluating the progression of LGD to HGD or EAC were included. The diagnosis of LGD must be made by consensus of two or more expert gastrointestinal pathologists. Articles were searched in Medline, Pubmed, and Embase. Pooled proportions were calculated using fixed and random effects model. Heterogeneity among studies was assessed using the I2 statistic.

RESULTS

Initial search identified 721 reference articles, of which 53 were selected and reviewed. Twelve studies (n = 971) that met the inclusion criteria were included in this analysis. Among the total original LGD diagnoses in the included studies, only 37.49% reached the consensus LGD diagnosis after review by two or more expert pathologists. Total follow up period was 1532 patient-years. In the pooled consensus LGD patients, the annual incidence rate (AIR) of progression to HGD and or EAC was 10.35% (95%CI: 7.56-13.13) and progression to EAC was 5.18% (95%CI: 3.43-6.92). Among the patients down staged from original LGD diagnosis to No-dysplasia Barrett's esophagus, the AIR of progression to HGD and EAC was 0.65% (95%CI: 0.49-0.80). Among the patients down staged to Indefinite for dysplasia, the AIR of progression to HGD and EAC was 1.42% (95%CI: 1.19-1.65). In patients with consensus HGD diagnosis, the AIR of progression to EAC was 28.63% (95%CI: 13.98-43.27).

CONCLUSION

When LGD is diagnosed by consensus agreement of two or more expert pathologists, its progression towards malignancy seems to be at least three times the current estimates, however it could be up to 20 times the current estimates. Biopsies of all Barrett's esophagus patients with LGD should be reviewed by two expert gastroenterology pathologists. Follow-up strict surveillance programs should be in place for these patients.

[Effects of moxibustion on cell proliferative factors in gastric mucosa in rats with precancerous lesions of chronic atrophic gastritis]

OBJECTIVE

To explore the molecular mechanism of moxibustion at stomach meridian acupoints for precancerous lesions of chronic atrophic gastritis (CAG).

METHODS

Fifty male SD rats were randomly divided into a normal group, a model group, a stomach meridian group, a control point group and a vitacoenzyme group, 10 rats in each group. The CAG precancerous lesion model was made in all the groups except the normal group. The rats in the normal group and model group were bundled for 30 min per day; the rats in the stomach meridian group and control point group were bundled and treated with moxibustion at stomach meridian acupoints or control points for 30 min per day; the rats in the vitacoenzyme group were treated with intragastric administration of vitacoenzyme, once per day. All the treatment was given for 20 weeks. The pathological morphological change of gastric mucosa was observed under optical microscope; the expression of epidermal growth factor (EGF), transforming growth factor alpha (TGF-alpha), vascular endothelial growth factor (VEGF), gastric mucosal proliferatig cell nuclear antigen (PCNA), argyrophilic protein of nucleolar organizer regions (Ag-NORs) in gastric mucosal cells were detected by enzyme linked immuno sorbent assay (ELISA).

RESULTS

Compared with the normal group, in the model group the gastric mucosal cells showed dysplasia and the expression of EGF, TGF-alpha, PCNA, VEGF, Ag-NORs in gastric mucosa cells in the model group was increased significantly (all P < 0.05). Compared with the model group, the gastric mucosa lesion gradually recovered and the expression of EGF, TGF-alpha, PCNA, VEGF, Ag-NORs in gastric mucosal cells was gradually decreased in the stomach meridian group, control point group and vitacoenzyme group, in which the stomach meridian group had the most significant effects (all P < 0.05).

CONCLUSION

Moxibustion at stomach meridian acupoints can obviously decrease the expression of cell proliferative factors in gastric mucosa in rats with CAG precancerous lesions, inhibit the gastric mucosal cell dysplasia, and promote the recovery of gastric mucosa.

Germline PRKACA amplification causes variable phenotypes that may depend on the extent of the genomic defect: molecular mechanisms and clinical presentations

OBJECTIVE

We have recently reported five patients with bilateral adrenocortical hyperplasia (BAH) and Cushing's syndrome (CS) caused by constitutive activation of the catalytic subunit of protein kinase A (PRKACA). By doing new in-depth analysis of their cytogenetic abnormality, we attempted a better genotype-phenotype correlation of their PRKACA amplification.

DESIGN

This study is a case series.

METHODS

Molecular cytogenetic, genomic, clinical, and histopathological analyses were performed in five patients with CS.

RESULTS

Reinvestigation of the defects of previously described patients by state-of-the-art molecular cytogenetics showed complex genomic rearrangements in the chromosome 19p13.2p13.12 locus, resulting in copy number gains encompassing the entire PRKACA gene; three patients (one sporadic case and two related cases) were observed with gains consistent with duplications, while two sporadic patients were observed with gains consistent with triplications. Although all five patients presented with ACTH-independent CS, the three sporadic patients had micronodular BAH and underwent bilateral adrenalectomy in early childhood, whereas the two related patients, a mother and a son, presented with macronodular BAH as adults. In at least one patient, PRKACA triplication was associated with a more severe phenotype.

CONCLUSIONS

Constitutional chromosomal PRKACA gene amplification is a recently identified genetic defect associated with CS, a trait that may be inherited in an autosomal dominant manner or occur de novo. Genomic rearrangements can be complex and can result in different copy number states of dosage-sensitive genes, e.g., duplication and triplication. PRKACA amplification can lead to variable phenotypes clinically and pathologically, both micro- and macro-nodular BAH, the latter of which we speculate may depend on the extent of amplification.

[Clinical analysis of Mondini dysplasia with cerebrospinal fluid leakage and preliminary genetic research of it]

OBJECTIVE

To summarize and analyze the clinical characteristics of Mondini dysplasia with cerebrospinal fluid leakage, as well as preliminarily investigate the genetic mechanism of the disease.

METHOD

The clinical data of 2 patients diagnosed as Mondini dysplasia with cerebrospinal fluid leakage treated in our hospital were analyzed. Blood samples of these two patients were obtained to extract DNA. We screened DNA samples for gene SLC26A4 mutations by using polymerase chain reaction and direct sequencing. The sequencing results were analyzed in DNASTAR software.

RESULT

Both patients came to our hospital because of recurrent meningitis, and the fistula were both located in vestibular window. Patients were cured one-time after surgical closure of the leakages with temporalis + temporalis fascia + temporalis through the mastoid approach. No pathogenic mutations of gene SLC26A4 with exome sequencing were found.

CONCLUSION

Mondini dysplasia with cerebrospinal fluid leakage should be considered in patients with recurrent meningitis and hearing disorder. Temporal bone HRCT is helpful to the diagnosis. Surgical closure is an effective therapeutic method and may prevent recurrent meningitis. The molecular mechanism of simple Mondini dysplasia needs further study.

Nodular extramammary Paget disease with fibroepitheliomatous hyperplasia

Extramammary Paget disease (EMPD) is a rare skin condition usually found in the anogenital region. Histologically, EMPD may be associated with varying degrees of epidermal hyperplasia classified as squamous, papillomatous, or fibroepitheliomatous. We report a case of EMPD in a 90-year-old man who presented with well-demarcated plaques and a nodule in the pubic area with fibroepitheliomatous hyperplasia.

TGF-β/Smad3 inhibit vascular smooth muscle cell apoptosis through an autocrine signaling mechanism involving VEGF-A

We have previously shown that in the presence of elevated Smad3, transforming growth factor-β (TGF-β) transforms from an inhibitor to a stimulant of vascular smooth muscle cell (SMC) proliferation and intimal hyperplasia (IH). Here we identify a novel mechanism through which TGF-β/Smad3 also exacerbates IH by inhibiting SMC apoptosis. We found that TGF-β treatment led to inhibition of apoptosis in rat SMCs following viral expression of Smad3. Conditioned media from these cells when applied to naive SMCs recapitulated this effect, suggesting an autocrine pathway through a secreted factor. Gene array of TGF-β/Smad3-treated cells revealed enhanced expression of vascular endothelial growth factor (VEGF), a known inhibitor of endothelial cell apoptosis. We then evaluated whether VEGF is the secreted mediator responsible for TGF-β/Smad3 inhibition of SMC apoptosis. In TGF-β/Smad3-treated cells, VEGF mRNA and protein as well as VEGF secretion were increased. Moreover, recombinant VEGF-A inhibited SMC apoptosis and a VEGF-A-neutralizing antibody reversed the inhibitory effect of conditioned media on SMC apoptosis. Stimulation of SMCs with TGF-β led to the formation of a complex of Smad3 and hypoxia-inducible factor-1α (HIF-1α) that in turn activated the VEGF-A promoter and transcription. In rat carotid arteries following arterial injury, Smad3 and VEGF-A expression were upregulated. Moreover, Smad3 gene transfer further enhanced VEGF expression as well as inhibited SMC apoptosis. Finally, blocking either the VEGF receptor or Smad3 signaling in injured carotid arteries abrogated the inhibitory effect of Smad3 on vascular SMC apoptosis. Taken together, our study reveals that following angioplasty, elevation of both TGF-β and Smad3 leads to SMC secretion of VEGF-A that functions as an autocrine inhibitor of SMC apoptosis. This novel pathway provides further insights into the role of TGF-β in the development of IH.

Progesterone as a morphological regulatory factor of the male and female gerbil prostate

Testosterone (T) and oestrogen are the main active steroid hormones in the male and female reproductive system respectively. In female rodents progesterone (P4), together with testosterone and oestrogen, has an essential role in the regulation of the oestrous cycle, which influences the prostate physiology through their oscillations. In this work we investigated how the male and female prostate gland of Mongolian gerbils responds to surgical castration at the start of puberty and what are the effects of T, oestradiol (E2) and P4 replacement, using both quantitative and qualitative methods. We also examined the location of the main steroid receptors present in the prostate. In the castrated animals of both sexes an intense glandular regression, along with disorganization of the stromal compartment, and abundant hyperplasia was observed. The replacement of P4 secured a mild recovery of the glandular morphology, inducing the growth of secretory cells and restoring the androgen receptor (AR) cells. The administration of P4 and E2 eliminated epithelial hyperplasia and intensified gland hypertrophy, favouring the emergence of prostatic intraepithelial neoplasia (PIN). In animals treated with T and P4, even though there are some inflammatory foci and other lesions, the prostate gland revealed morphology closer to that of control animals. In summary, through the administration of P4, we could demonstrate that this hormone has anabolic characteristics, promoting hyperplasia and hypertrophy, mainly in the epithelial compartment. When combined with E2 and T, there is an accentuation of glandular hypertrophy that interrupts the development of hyperplasia and ensures the presence of a less dysplastic glandular morphology.

Long-term cardio- and cerebrovascular events in patients with primary aldosteronism

BACKGROUND

Aldosterone plays a detrimental role on the cardiovascular system and PA patients display a higher risk of events compared with EH.

OBJECTIVES

The objectives of the study were to compare cardio- and cerebrovascular events in patients with primary aldosteronism (PA) and matched essential hypertension (EH).

METHODS

We retrospectively compared the percentage of patients experiencing events at baseline and during a median follow-up of 12 years in 270 PA patients case-control matched 1:3 with EH patients and in PA subtypes [aldosterone-producing adenoma (n = 57); bilateral adrenal hyperplasia (n = 213)] vs matched EH.

RESULTS

A significantly higher number of PA patients experienced cardiovascular events over the entire period of the study (22.6% vs 12.7%, P < .001). At the diagnosis of PA, a higher number of patients had experienced total events (14.1% vs 8.4% EH, P = .007); furthermore, during the follow-up period, PA patients had a higher rate of events (8.5% vs 4.3% EH, P = .008). In particular, stroke and arrhythmias were more frequent in PA patients. During the follow-up, a higher percentage of PA patients developed type 2 diabetes. Parameters that were independently associated with the occurrence of all events were age, duration of hypertension, systolic blood pressure, presence of diabetes mellitus, and PA diagnosis. After division into PA subtypes, patients with either aldosterone-producing adenoma or bilateral adrenal hyperplasia displayed a higher rate of events compared with the matched EH patients.

CONCLUSIONS

This study demonstrates in a large population of patients the pathogenetic role of aldosterone excess in the cardiovascular system and thus the importance of early diagnosis and targeted PA treatment.

Efficient tumorigenesis by mutation-induced failure to terminate microRNA-mediated adaptive hyperplasia

Seven current contending cancer theories consider different sets of critical events as sufficient for tumorigenesis. These theories, most recently the microRNA dysregulation (MRD) theory, have overlapping attributes and extensive empirical support, but also some discrepancies, and some do not address both benign and malignant tumorigenesis. By definition, the most efficient tumorigenic pathways will dominate under conditions that selectively activate those pathways. The MRD theory provides a mechanistic basis to combine elements of the current theories into a new hypothesis that: (i) tumors arise most efficiently under stress that induces and sustains either protective or regenerative states of adaptive hyperplasia (AH) that normally are epigenetically maintained unless terminated; and (ii) if dysregulated by a somatic mutation that prevents normal termination, these two AH states can generate benign and malignant tumors, respectively. This hypothesis, but not multistage cancer theory, predicts that key participating AH-stem-cell populations expand markedly when triggered by stress, particularly chronic metabolic or oxidative stress, mechanical irritation, toxic exposure, wounding, inflammation, and/or infection. This hypothesis predicts that microRNA expression patterns in benign vs. malignant tumor tissue will correlate best with those governing protective vs. regenerative AH in that tissue, and that tumors arise most efficiently inmutagen-exposed stem cells that either happen to be in, or incidentally later become recruited into, an AH state.

Effects of high glucose on AVP-induced hyperplasia, hypertrophy, and type IV collagen synthesis in cultured rat mesangial cells

INTRODUCTION

Hyperglycemia is a principal characteristic of diabetes and influences many cellular functions. Diabetic nephropathy is characterized by glomerular mesangial expansion which could result from increased mesangial cell extracellular matrix synthesis induced by hyperglycemia.

METHODS

To investigate whether the physiological functions of mesangial cells are altered in a diabetic environment, we evaluated the effect of high extracellular glucose concentration on thymidine/leucine incorporation, hyperplasia/hypertrophy, and type IV collagen synthesis, induced by vasopressin (AVP), in cultured rat mesangial cells.

RESULTS

The exposure of mesangial cells to a high glucose concentration (30 mM) significantly reduced AVP-induced thymidine incorporation and hyperplasia compared with normal glucose (10 mM). By contrast, treatment of mesangial cells with AVP in the presence of high extracellular glucose significantly increased leucine incorporation, hypertrophy, and type IV collagen synthesis compared with those at normal glucose levels. The administration of staurosporine, a protein kinase C inhibitor, reversed these effects of high-glucose conditions. Furthermore, the nonpeptide AVP V(1A) receptor-selective antagonists potently inhibited these AVP-induced physiological responses in mesangial cells cultured in high-glucose conditions.

CONCLUSIONS

These results demonstrate that high glucose suppresses mesangial cell proliferation but enhances hypertrophy and type IV collagen synthesis induced by AVP. This increased mesangial cell hypertrophy and extracellular matrix synthesis may play a crucial role in the glomerular mesangial expansion common to diabetic nephropathy.

Parathyroid carcinoma arising from four-gland hyperplasia

OBJECTIVE

To report the use of immunohistochemical staining for parafibromin, APC, and galectin-3 to evaluate the malignant potential of a resected parathyroid specimen in a patient initially presenting with primary hyperparathyroidism attributable to 4-gland hyperplasia, who subsequently developed metastatic parathyroid carcinoma.

METHODS

We describe a patient with primary hyperparathyroidism who underwent a 3-gland resection of hypercellular parathyroid glands, with postoperative normalization of her serum calcium and parathyroid hormone levels. She returned 4 years later with recurrent hypercalcemia and underwent partial resection of her remaining hypercellular parathyroid gland, without improvement of her hypercalcemia. Selective venous sampling localized the source as draining into her azygos vein, and metastatic parathyroid carcinoma was ultimately diagnosed.

RESULTS

Immunohistochemical staining for parafibromin, APC, and galectin-3 suggested the malignant potential of the atypical adenoma removed during the patient's original operation, which is believed to be the source of her metastatic disease. Access to this information by the treating surgeon may have prompted a more extensive en bloc resection or more vigilant follow-up that could have altered the patient's clinical course.

CONCLUSION

Immunohistochemical staining for parafibromin, APC, and galectin-3 can be used to help distinguish the source of metastatic disease in patients with parathyroid carcinoma. Selective venous sampling may help localize metastatic parathyroid carcinoma when the source is otherwise not apparent.

Expression of P-450(c11beta) in adrenal aldosterone-producing adenomas and nodular hyperplasia tissues

BACKGROUND

Our previous study suggests that decreased P-450(c17alpha) expression correlated with the overproduction of aldosterone in APA and nodular hyperplasia in patients with primary aldosteronism. This study was performed to further investigate if P-450(c11beta) contributes to the overproduction of aldosterone in APA and nodular hyperplasia tissues.

METHODS

Total RNA and protein were extracted from 7 cases of APA tissue, 3 nodular hyperplasia tissues, 7 normal adrenal glands. P-450(c11beta) mRNA was examined by dot blot and confirmed by Northern blot analysis and by realtime PCR. Protein expression level of P-450(c11beta) was also investigated by immunohistochemical staining and confirmed by Western blot.

RESULTS

The relative expression level of P-450(c11beta) mRNA to beta-actin in APA, nodular hyperplasia and the normal adrenal gland group are 47 +/- 22%, 55 +/- 13%, 64 +/- 16% respectively by dot blot and are 94 +/- 18%, 101 +/- 20%, 112 +/- 62% respectively by Northern blot. These results are further confirmed by realtime PCR. This result was also supported by the relative protein expression level of P-450(c11beta) to beta-actin which are 118 +/- 15%, 107 +/- 32%, 108 +/- 22% respectively evaluated by Western blot. There was no significant difference in protein expression level of P-450(c11beta) among the normal adrenal gland tissues, APA and adrenal nodular hyperplasia tissue, either (P > 0.05).

CONCLUSIONS

These results suggest that P-450(c11beta) is not a key contributor to the overproduction of aldosterone in APA and nodular hyperplasia and can not be considered as a potential marker to differentiate between them in patients with primary aldosteronism.

A rare case of ACTH-independent macronodular adrenal hyperplasia associated with aldosterone-producing adenoma

A 52-year-old man was evaluated for incidentally discovered bilateral adrenal masses. He had drug-resistant hypertension but lacked Cushingoid features. Endocrinological tests revealed autonomous secretion of cortisol and aldosterone with suppressed plasma ACTH and renin activity. A selective adrenal venous sampling demonstrated aldosterone hypersecretion from the left adrenal vein. The clinical diagnosis of subclinical Cushing's syndrome due to ACTH-independent macronodular adrenal hyperplasia (AIMAH) associated with primary aldosteronism was made, and he underwent left adrenalectomy; the resected adrenal lesion was consistent with the pathological diagnosis of AIMAH coexistent with aldosterone-producing adenoma (APA). This is a very rare case of AIMAH with concomitant unilateral APA, whose hypertension improved after surgery.

Cyclin D2 is essential for the compensatory beta-cell hyperplastic response to insulin resistance in rodents

OBJECTIVE

A major determinant of the progression from insulin resistance to the development of overt type 2 diabetes is a failure to mount an appropriate compensatory beta-cell hyperplastic response to maintain normoglycemia. We undertook the present study to directly explore the significance of the cell cycle protein cyclin D2 in the expansion of beta-cell mass in two different models of insulin resistance.

RESEARCH DESIGN AND METHODS

We created compound knockouts by crossing mice deficient in cyclin D2 (D2KO) with either the insulin receptor substrate 1 knockout (IRS1KO) mice or the insulin receptor liver-specific knockout mice (LIRKO), neither of which develops overt diabetes on its own because of robust compensatory beta-cell hyperplasia. We phenotyped the double knockouts and used RT-qPCR and immunohistochemistry to examine beta-cell mass.

RESULTS

Both compound knockouts, D2KO/LIRKO and D2KO/IRS1KO, exhibited insulin resistance and hyperinsulinemia and an absence of compensatory beta-cell hyperplasia. However, the diabetic D2KO/LIRKO group rapidly succumbed early compared with a relatively normal lifespan in the glucose-intolerant D2KO/IRS1KO mice.

CONCLUSIONS

This study provides direct genetic evidence that cyclin D2 is essential for the expansion of beta-cell mass in response to a spectrum of insulin resistance and points to the cell-cycle protein as a potential therapeutic target that can be harnessed for preventing and curing type 2 diabetes.

[Comparative observation on acupoint catgut embedding and electroacupuncture in treatment of hyperplasia of mammary glands]

OBJECTIVE

To observe the effect difference between the catgut embedding method and electroacupuncture in treatment of hyperplasia of mammary glands.

METHODS

Eighty-six cases were divided into a catgut embedding group and an electroacupuncture group according to their treatment order, including 43 cases in each group. Both groups were treated with such points as Danzhong (CV 17), Qihai (CV 6), Jianjing (GB 21), Qihu (ST 13) etc. The treatment in the catgut embedding group was carried out every 1-2 weeks and 8 times as a course of treatment; the treatment in the electroacupuncture group was carried out every other day, 24 times as a course of treatment; the effects were analyzed respectively at the end of the first course and 3 months after the end of the second course of treatment.

RESULTS

The total effective rate was 69.8% (30/43) in the catgut embedding group and 88.4% (38/43) in the electroacupuncture group after the first course of treatment, there was significant difference between the two groups (P<0.05); the cured-markedly effective rate of catgut embedding group was 87.8% (36/41) compared with 69.7% (23/33) in the electroacupuncture group after the two courses of treatment, which was significant difference (P<0.01).

CONCLUSION

Both the catgut embedding and electroacupuncture therapies have good clinical effects in treatment of hyperplasia of mammary glands. The therapeutic effect is better in the electroacupuncture group after the first therapeutic course while that of acupoint catgut embedding is better after two therapeutic courses.

Soluble epoxide hydrolase inhibition modulates vascular remodeling

The soluble epoxide hydrolase enzyme (SEH) and vascular remodeling are associated with cardiovascular disease. Although inhibition of SEH prevents smooth muscle cell proliferation in vitro, the effects of SEH inhibition on vascular remodeling in vivo and mechanisms of these effects remain unclear. Herein we determined the effects of SEH antagonism in an endothelium intact model of vascular remodeling induced by flow reduction and an endothelium denuded model of vascular injury. We demonstrated that chronic treatment of spontaneously hypertensive stroke-prone rats with 12-(3-adamantan-1-yl-ureido) dodecanoic acid, an inhibitor of SEH, improved the increment of inward remodeling induced by common carotid ligation to a level that was comparable with normotensive Wistar Kyoto rats. Similarly, mice with deletion of the gene responsible for the production of the SEH enzyme (Ephx2(-/-)) demonstrated enhanced inward vascular remodeling induced by carotid ligation. However, the hyperplastic response induced by vascular injury that denudes the endothelium was unabated by SEH inhibition or Ephx2 gene deletion. These results suggest that SEH inhibition or Ephx2 gene deletion antagonizes neointimal formation in vivo by mechanisms that are endothelium dependent. Thus SEH inhibition may have therapeutic potential for flow-induced remodeling and neointimal formation.

Adipocyte turnover: relevance to human adipose tissue morphology

OBJECTIVE

Adipose tissue may contain few large adipocytes (hypertrophy) or many small adipocytes (hyperplasia). We investigated factors of putative importance for adipose tissue morphology.

RESEARCH DESIGN AND METHODS

Subcutaneous adipocyte size and total fat mass were compared in 764 subjects with BMI 18-60 kg/m(2). A morphology value was defined as the difference between the measured adipocyte volume and the expected volume given by a curved-line fit for a given body fat mass and was related to insulin values. In 35 subjects, in vivo adipocyte turnover was measured by exploiting incorporation of atmospheric (14)C into DNA.

RESULTS

Occurrence of hyperplasia (negative morphology value) or hypertrophy (positive morphology value) was independent of sex and body weight but correlated with fasting plasma insulin levels and insulin sensitivity, independent of adipocyte volume (beta-coefficient = 0.3, P < 0.0001). Total adipocyte number and morphology were negatively related (r = -0.66); i.e., the total adipocyte number was greatest in pronounced hyperplasia and smallest in pronounced hypertrophy. The absolute number of new adipocytes generated each year was 70% lower (P < 0.001) in hypertrophy than in hyperplasia, and individual values for adipocyte generation and morphology were strongly related (r = 0.7, P < 0.001). The relative death rate (approximately 10% per year) or mean age of adipocytes (approximately 10 years) was not correlated with morphology.

CONCLUSIONS

Adipose tissue morphology correlates with insulin measures and is linked to the total adipocyte number independently of sex and body fat level. Low generation rates of adipocytes associate with adipose tissue hypertrophy, whereas high generation rates associate with adipose hyperplasia.

Genetic and biochemical pathways of beta-cell failure in type 2 diabetes

We review mechanisms of beta-cell failure in type 2 diabetes. A wealth of information indicates that it is caused by impaired insulin secretion and decreased beta-cell mass. Interestingly, there appears to be a link between these two mechanisms. The earliest reaction to peripheral insulin resistance is an increase in insulin production, owing primarily to increased secretion, and to a lesser extent to decreased clearance. Experimental animal models indicate that hyperinsulinaemia promotes an increase in beta-cell mass, largely via increased beta-cell replication. In contrast, following the onset of overt diabetes, there is a slowly progressive loss of beta-cell function and mass, both in animal models and in diabetic humans. It is of great interest that most diabetes-associated genes identified in genome-wide association studies appear to be enriched in the beta-cell and to have the potential to regulate mass and/or function. Here, we review evidence derived from experimental animal models to unravel the mechanisms underlying beta-cell dysfunction. We focus primarily on signalling pathways, as opposed to nutrient sensing, and specifically on the notion that insulin and growth factor signalling via Foxo1 in pancreatic beta-cells links insulin secretion with cellular proliferation and survival.

Advances and new frontiers in the pathophysiology of venous neointimal hyperplasia and dialysis access stenosis

Hemodialysis vascular access dysfunction is a major cause of morbidity and mortality in hemodialysis patients. The most common cause of this vascular access dysfunction is venous stenosis as a result of venous neointimal hyperplasia within the perianastomotic region (arteriovenous fistula) or at the graft-vein anastomosis (polytetrafluoroethylene, or PTFE, grafts). There have been few effective treatments to date for venous neointimal hyperplasia, in part, because of the poor understanding of the pathogenesis of venous neointimal hyperplasia. Therefore, this article will (1) describe the pathology of hemodialysis access stenosis in arteriovenous fistulas and grafts, (2) review and describe both current and novel concepts in the pathogenesis of neointimal hyperplasia formation, (3) discuss current and future novel therapies for treating venous neointimal hyperplasia, and (4) suggest future research areas in the field of hemodialysis vascular access dysfunction.

Hypertrophy and/or Hyperplasia: Dynamics of Adipose Tissue Growth

Adipose tissue grows by two mechanisms: hyperplasia (cell number increase) and hypertrophy (cell size increase). Genetics and diet affect the relative contributions of these two mechanisms to the growth of adipose tissue in obesity. In this study, the size distributions of epididymal adipose cells from two mouse strains, obesity-resistant FVB/N and obesity-prone C57BL/6, were measured after 2, 4, and 12 weeks under regular and high-fat feeding conditions. The total cell number in the epididymal fat pad was estimated from the fat pad mass and the normalized cell-size distribution. The cell number and volume-weighted mean cell size increase as a function of fat pad mass. To address adipose tissue growth precisely, we developed a mathematical model describing the evolution of the adipose cell-size distributions as a function of the increasing fat pad mass, instead of the increasing chronological time. Our model describes the recruitment of new adipose cells and their subsequent development in different strains, and with different diet regimens, with common mechanisms, but with diet- and genetics-dependent model parameters. Compared to the FVB/N strain, the C57BL/6 strain has greater recruitment of small adipose cells. Hyperplasia is enhanced by high-fat diet in a strain-dependent way, suggesting a synergistic interaction between genetics and diet. Moreover, high-fat feeding increases the rate of adipose cell size growth, independent of strain, reflecting the increase in calories requiring storage. Additionally, high-fat diet leads to a dramatic spreading of the size distribution of adipose cells in both strains; this implies an increase in size fluctuations of adipose cells through lipid turnover.

Adrenal hyperplasia and tumours in mice in connection with aberrant pituitary-gonadal function

Gonadectomy induces in certain inbred stains of mice adrenal hyperplasia and tumorigenesis, originating from the putative subcapsular stem/progenitor cell layer. This response is apparently triggered by the elevated post-gonadectomy levels of luteinising hormone (LH), followed by ectopic upregulation of adrenal LH/chorionic gonadotrophin (CG) receptors (Lhcgr). The clear strain dependence of this adrenal response to gonadectomy prompted us to study its genetic basis. Tumorigenic DBA/2J and non-tumorigenic C57BL/6J mice, as well as their F2 and backcrosses, were studied by whole genome linkage analysis. Gonadectomy induced similar upregulation of adrenal Lhcgr in both parental strains and their crosses, irrespective of the tumour status, indicating that ectopic expression of this receptor is not the immediate cause of tumours. Linkage analysis revealed one major significant quantitative trait locus (QTL) for the tumorigenesis on chromosome 8, modulated by epistasis with another QTL on chromosome 18. Hence, post-gonadectomy adrenal tumorigenesis in DBA/2J mice is a dominant trait, not a direct consequence of adrenal Lhcgr expression, and is driven by a complex genetic architecture. A promising candidate gene in the tumorigenesis linkage region is Sfrp1 (secreted frizzled-related protein 1), a tumour suppressor gene, which was down-regulated in the neoplastic tissue. Our findings may have relevance to the human pathogenesis of macronodular adrenal hyperplasia and postmenopausal adrenocortical tumours. A distinctly different adrenal response was observed in TG mice overexpressing LH or CG, or a constitutively activated form of the follicle-stimulating hormone receptor (Fshr). These mice developed perimedullary hyperlasia of foamy multinucleated cells, reminding of macrophages and filled with lipofuscin. Similar response was observed in TG mice overexpressing aromatase (CYP19). The cause of this response is not related to direct LH/CG action, but merely to adrenal response to chronically elevated oestrogen levels. This phenotype is reminiscent of the rare 'black adenomas' of the human adrenal cortex.

Crucial role of insulin receptor substrate-2 in compensatory beta-cell hyperplasia in response to high fat diet-induced insulin resistance

In type 2 diabetes, there is a defect in the regulation of functional beta-cell mass to overcome high-fat (HF) diet-induced insulin resistance. Many signals and pathways have been implicated in beta-cell function, proliferation and apoptosis. The co-ordinated regulation of functional beta-cell mass by insulin signalling and glucose metabolism under HF diet-induced insulin-resistant conditions is discussed in this article. Insulin receptor substrate (IRS)-2 is one of the two major substrates for the insulin signalling. Interestingly, IRS-2 is involved in the regulation of beta-cell proliferation, as has been demonstrated using knockout mice models. On the other hand, in an animal model for human type 2 diabetes with impaired insulin secretion because of insufficiency of glucose metabolism, decreased beta-cell proliferation was observed in mice with beta-cell-specific glucokinase haploinsufficiency (Gck(+/) (-)) fed a HF diet without upregulation of IRS-2 in beta-cells, which was reversed by overexpression of IRS-2 in beta-cells. As to the mechanism underlying the upregulation of IRS-2 in beta-cells, glucose metabolism plays an important role independently of insulin, and phosphorylation of cAMP response element-binding protein triggered by calcium-dependent signalling is the critical pathway. Downstream from insulin signalling via IRS-2 in beta-cells, a reduction in FoxO1 nuclear exclusion contributes to the insufficient proliferative response of beta-cells to insulin resistance. These findings suggest that IRS-2 is critical for beta-cell hyperplasia in response to HF diet-induced insulin resistance.

Unraveling the molecular basis of micronodular adrenal hyperplasia

PURPOSE OF REVIEW

The present review discusses the molecular basis of micronodular adrenal hyperplasia. It focuses on the role of genetic defects in cyclic-AMP (cAMP) signaling-related molecules, namely PRKAR1A, GNAS, PDE11A, and PDE8B in the predisposition to tumor formation. This review also discusses the involvement of cAMP signaling and related pathways and their impact on the adrenocortical tumor formation.

RECENT FINDINGS

Molecular abnormalities in the phosphodiesterases family are the most recently discovered genetic abnormalities that predispose individuals to various adrenocortical tumors. In contrast to GNAS and PRKAR1A, defects in phosphodiesterases are associated more frequently with incomplete penetrance.

SUMMARY

Recent findings indicate the importance of cAMP signaling for normal adrenocortical functioning and the sensitivity of the adrenal gland to subtle alterations in cAMP levels. The identification of low-penetrance mutations in more than one phosphodiesterase in patients with adrenocortical hyperplasia is suggestive for a complementary role of the different phosphodiesterases in adrenal gland abnormalities and possible involvement of other members of this pathway in adrenocortical tumor defects.

Tumor necrosis factor receptor-2 signaling attenuates vein graft neointima formation by promoting endothelial recovery

OBJECTIVE

Inflammation appears intricately linked to vein graft arterialization. We have previously shown that tumor necrosis factor (TNF) receptor-1 (TNFR1, p55) signaling augments vein graft neointimal hyperplasia (NH) and remodeling through its effects on vascular smooth muscle cells (SMCs). In this study we examined the role of TNFR2 (p75) signaling in vein graft arterialization.

METHODS AND RESULTS

Inferior vena cava-to-carotid artery interposition grafting was performed between p75-/- and congenic (C57B1/6J) wild-type (WT) mice. Six weeks postoperatively, neointimal and medial dimensions were greater in p75-/- grafts placed into p75-/- recipients (by 42% or 60%, respectively; P<0.05), when compared with WT veins grafted into WT recipients. Relative to WT vein grafts, p75 deficiency augmented early (2-week-old) graft vascular cell adhesion molecule (VCAM)-1 expression (by 2.4-fold, P<0.05), increased endothelial cell apoptosis (2-fold), and delayed graft re-endothelialization. Both cellular proliferation in early, and collagen I content of mature (6-week-old) vein grafts were increased (by 70% and 50%, respectively) in p75-/- grafts. P75 deficiency augmented TNF-induced apoptosis of cultured endothelial cells, but did not affect TNF-stimulated SMC proliferation or migration induced by co-cultured macrophages.

CONCLUSIONS

TNF signaling via p75 reduces vein graft neointimal hyperplasia through mechanisms involving reduction of adhesion molecule expression and endothelial cell apoptosis.

Antipsoriatic effects of avarol-3'-thiosalicylate are mediated by inhibition of TNF-alpha generation and NF-kappaB activation in mouse skin

BACKGROUND AND PURPOSE

Avarol is a marine sesquiterpenoid hydroquinone with anti-inflammatory and antipsoriatic properties. The aim of this study was to evaluate the in vitro and in vivo pharmacological behaviour of the derivative avarol-3'-thiosalicylate (TA) on some inflammatory parameters related to the pathogenesis of psoriasis.

EXPERIMENTAL APPROACH

Human neutrophils and monocytes as well as the human keratinocyte cell line HaCaT were used to study the effect of TA on oxidative stress, the arachidonic acid pathway, tumour necrosis factor-alpha (TNF-alpha) release and nuclear factor-kappaB (NF-kappaB) activation. All these parameters were also determined in vivo using the zymosan induced mouse air pouch model and the 12-O-tetradecanoylphorbol-13-acetate (TPA) induced mouse epidermal hyperplasia model.

KEY RESULTS

TA showed antioxidant properties in human neutrophils and in the hypoxanthine/xanthine oxidase assay. This compound reduced, in a concentration-dependent manner, leukotriene B(4), prostaglandin E(2) and TNF-alpha production in activated leukocytes. Oral and intrapouch administration of TA in the mouse air pouch model produced a dose-dependent reduction of all these inflammatory mediators. TA also inhibited secretory phospholipase A(2) activity and NF-kappaB DNA-binding in HaCaT keratinocytes. In TPA-induced mouse epidermal hyperplasia, topical administration of TA reduced oedema, leukocyte infiltration, eicosanoid levels and TNF-alpha in skin. In addition, interleukin (IL)-1beta and IL-2 production were also inhibited. Finally, TA was also capable of suppressing NF-kappaB nuclear translocation in vivo.

CONCLUSIONS AND IMPLICATIONS

TA inhibited several key biomarkers up-regulated in the inflammatory response of psoriatic skin and this compound could be a promising antipsoriatic agent.

The role of Smad3-dependent TGF-beta signal in vascular response to injury

Transforming growth factor (TGF)-beta is a multifunctional cytokine involved in the regulation of proliferation, differentiation, migration, and survival of many different cell types. The role of TGF-beta in atherosclerosis has been intensively studied, but the precise function of the downstream signals in this disease entity remains unclear. We recently discovered that mice lacking Smad3, a major downstream mediator of TGF-beta, show enhanced neointimal hyperplasia with decreased matrix deposition in response to vascular injury. This review summarizes the current view on involvement of TGF-beta in atherosclerotic vascular disease and discusses the role of Smad3-dependent TGF-beta signal in vascular response to injury.

SPDEF regulates goblet cell hyperplasia in the airway epithelium

Goblet cell hyperplasia and mucous hypersecretion contribute to the pathogenesis of chronic pulmonary diseases including cystic fibrosis, asthma, and chronic obstructive pulmonary disease. In the present work, mouse SAM pointed domain-containing ETS transcription factor (SPDEF) mRNA and protein were detected in subsets of epithelial cells lining the trachea, bronchi, and tracheal glands. SPDEF interacted with the C-terminal domain of thyroid transcription factor 1, activating transcription of genes expressed selectively in airway epithelial cells, including Sftpa, Scgb1a1, Foxj1, and Sox17. Expression of Spdef in the respiratory epithelium of adult transgenic mice caused goblet cell hyperplasia, inducing both acidic and neutral mucins in vivo, and stainined for both acidic and neutral mucins in vivo. SPDEF expression was increased at sites of goblet cell hyperplasia caused by IL-13 and dust mite allergen in a process that was dependent upon STAT-6. SPDEF was induced following intratracheal allergen exposure and after Th2 cytokine stimulation and was sufficient to cause goblet cell differentiation of Clara cells in vivo.

Papillary endothelial hyperplasia of the orbit: report of a case highlighting a pitfall on fine needle aspiration biopsy

BACKGROUND

Papillary endothelial hyperplasia (PEH) is an unusual form of thrombus organization that occurs predominantly in the extremities, including the head and neck. However, it is rare in the orbit/ocular region. Although the histologic features of PEH have been well described, the cytologic diagnosis remains difficult.

CASE

A 63-year-old man presented with a left intraorbital mass that was increasing in size and associated with paresthesia and a recent history of excision of squamous cell carcinomas (SCC) from his left cheek. Fine needle aspiration biopsy (FNAB) yielded very limited material, predominantly blood. However, 1 Papanicolaou-stained slide showed groups of atypical cells with scanty but dense cytoplasm and large, hyperchromatic nuclei with prominent nucleoli. SCC was favored, and excision was performed. Histology showed PEH within an assumed cystic lymphangioma, associated with inflammatory and fibrotic change in the compressed supraorbital nerve.

CONCLUSION

To our knowledge this is the third report on the cytology of PEH and the first report of FNAB in PEH of the orbit. The case was also unusual as it was the second metachronous PEH in the patient.

Novel model of inflammatory neointima formation reveals a potential role of myeloperoxidase in neointimal hyperplasia

Atherosclerosis, which is characterized by neointima formation, is an inflammatory disease. However, there is no inflammatory product-elicited neointimal model to support the causal role of inflammation in atherogenesis. We reported previously that leukocyte-derived MPO induces vascular injury responses such as endothelial dysfunction. We now test the role of MPO in inflammatory neointima formation. We infused temporarily isolated rat common carotid arteries with MPO (200 nM) and incubated for 1 h. We found that although MPO itself did not induce any neointima formation 2 wk after treatment, in the presence of its substrate, hydrogen peroxide, MPO was able to elicit neointimal hyperplasia. We further confirmed that MPO-induced neointimal hyperplasia is mediated by its product, hypochlorous acid (HOCl). HOCl elicited apoptosis both in intima and media followed by vascular proliferative response and resulted in neointima formation with a heterogeneous cell population. Both histological and functional features of HOCl-treated vessels are similar to those in atherosclerotic lesions. To our knowledge, this is the first direct in vivo demonstration of neointimal formation induced by a product of the inflammatory cascade. The results suggest that MPO may be a mediator for pathological neointima growth. This novel neointimal model could be useful for studying inflammation and atherosclerosis.

Inactivity induces increases in abdominal fat

Previously, inducing inactivity for 53 h after 21 days of voluntary running resulted in a 25 and 48% increase in epididymal and omental fat pad weights, respectively, while rats continued to eat more than a group that never had access to a running wheel (J Physiol 565: 911-925, 2005). We wanted to test the hypothesis that inactivity, independent of excessive caloric intake, could induce an increase in fat pad mass. Twenty-one-day-old rats were given access to voluntary running wheels for 42-43 days so that they were running approximately 9 km/day in the last week of running, after which wheels were locked for 5, 53, or 173 h (WL5, WL53, WL173) before the rats were killed. During the 53 and 173 h of inactivity, one group of animals was pair fed (PF) to match sedentary controls, whereas the other continued to eat ad libitum (AL). Epididymal and retroperitoneal fat masses were significantly increased in the WL173-PF vs. the WL5 group, whereas epididymal, perirenal, and retroperitoneal fat masses were all significantly increased in the WL173-AL group compared with the WL5 group. Additionally, hyperplasia, and not hypertrophy, of the epididymal fat mass was responsible for the increase at WL173-AL as demonstrated by a significant increase in cell number vs. WL5, with no change in cell diameter or volume. Thus two important findings have been elucidated: 1) increases in measured abdominal fat masses occur in both AL and PF groups at WL173, and 2) adipocyte expansion via hyperplasia occurred with an ad libitum diet following cessation of voluntary running.

Diffuse idiopathic pulmonary neuroendocrine cell hyperplasia: an under-recognised spectrum of disease

AIMS AND METHODS

A review was undertaken of 19 patients diagnosed with diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) between 1992 and 2006.

RESULTS

Most patients were women (n = 15) and non-smokers (n = 16). Clinical presentation was either with symptomatic pulmonary disease (group 1; n = 9) or as an incidental finding during investigation for another disorder, most frequently malignant disease (group 2; n = 10). In group 1, cough and dyspnoea were the most frequent symptoms, with an average duration of 8.6 years before diagnosis. Both groups showed mainly stable disease without treatment, although one patient progressed to severe airflow obstruction and one was diagnosed at single lung transplantation. Mosaicism with nodule(s) was the typical pattern of DIPNECH on high-resolution computed tomography, but one case had normal imaging despite airflow obstruction. Lung function tests showed obstructive (n = 8), mixed (n = 3) or normal (n = 5, all group 2) physiology. Two patients underwent a bronchoalveolar lavage and showed a lymphocytosis (30%) with mild chronic bronchiolitis being seen in all biopsies. Tumourlets and associated typical carcinoids (n = 9) showed weak positivity for thyroid transcription factor-1. Three patients had atypical carcinoids, one with multiple endocrine neoplasia type 1 syndrome.

CONCLUSIONS

DIPNECH is being increasingly recognised, probably because of an increase in the usage and accuracy of investigative imaging and increased awareness of the entity. Most cases remain stable over many years independent of the mode of presentation, although a few patients progress to severe airflow obstruction.

A new RXR agonist, HX630, suppresses intimal hyperplasia in a mouse blood flow cessation model

The nuclear receptor retinoid X receptor (RXR) forms heterodimers with other nuclear receptors and exerts anti-inflammatory effects. RXR is implicated in the progression of arteriosclerosis; however, the effects of selective RXR activation on smooth muscle cell (SMC) proliferation are unknown. We synthesized a novel RXR agonist, HX630, and examined its effect on vascular SMC (VSMC) proliferation. Male C57BL/6 mice (n=15) were subjected to ligation of the left carotid artery and fed 5 or 10 mg/kg/day HX630 for 4 weeks. HX630-fed mice showed significantly suppressed intimal hyperplasia progression compared to that in control mice (0.286+/-0.093 vs. 1.022+/-0.134 intima/media ratio, P<0.05). Immunohistochemistry of the carotid artery showed that HX630 suppressed cytokine and adhesion molecule staining in lesions undergoing intimal thickening. Interleukin (IL)-1beta-induced VSMC proliferation was inhibited by HX630 and the expression of IL-6 mRNA and protein in VSMCs was suppressed. The RXR agonist HX630 exerts antiproliferative effects in VSMCs in vivo and in vitro. Thus, the RXR may serve as a therapeutic target for vascular injury and intimal thickening.

Differential immune responses and pulmonary pathophysiology are induced by two different strains of respiratory syncytial virus

In this study we performed comparisons of pulmonary responses between two different respiratory syncytial virus (RSV) antigenic subgroup A strains, A2 and Line 19. Line 19 strain induced significant dose-responsive airway hyperreactivity (AHR) in BALB/c mice at days 6 and 9 after infection, whereas the A2 strain induced no AHR at any dose. Histological examination indicated that A2 induced no goblet cell hyper/metaplasia, whereas the Line 19 induced goblet cell expansion and significant increases in gob5 and MUC5AC mRNA and protein levels in vivo. When examining cytokine responses, A2 strain induced significant interleukin (IL)-10 expression, whereas Line 19 strain induced significant IL-13 expression. When IL-13-/- mice were infected with Line 19 RSV, the AHR responses were abrogated along with gob5 gene expression. There was little difference in viral titer throughout the infection between the line 19- and A2-infected mice. However, the A2 strain grew to significantly higher titers than the Line 19 strain in HEp-2 cells in vitro. Thus, RSV Line 19-induced airway dysfunction does not correlate with viral load in vivo. These data demonstrate that different RSV strains of the same antigenic subgroup can elicit differential immune responses that impact the phenotypic expression of RSV-induced illness.

Blimp1 defines a progenitor population that governs cellular input to the sebaceous gland

Epidermal lineage commitment occurs when multipotent stem cells are specified to three lineages: the epidermis, the hair follicle, and the sebaceous gland (SG). How and when a lineage becomes specified remains unknown. Here, we report the existence of a population of unipotent progenitor cells that reside in the SG and express the transcriptional repressor Blimp1. Using cell-culture studies and genetic lineage tracing, we demonstrate that Blimp1-expressing cells are upstream from other cells of the SG lineage. Blimp1 appears to govern cellular input into the gland since its loss leads to elevated c-myc expression, augmented cell proliferation, and SG hyperplasia. Finally, BrdU labeling experiments demonstrate that the SG defects associated with loss of Blimp1 lead to enhanced bulge stem cell activity, suggesting that when normal SG homeostasis is perturbed, multipotent stem cells in the bulge can be mobilized to correct this imbalance.