Qualitative and quantitative differences of adipose-derived stromal cells from superficial and deep subcutaneous lipoaspirates: a matter of fat

BACKGROUND AIMS

Subcutaneous fat represents a valuable reservoir of adipose-derived stem cells (ASCs) in the stromal vascular fraction (SVF), widely exploited in regenerative medicine applications, being easily harvested through lipoaspiration. The lack of standardized procedures for autologous fat grafting guided research efforts aimed at identifying possible differences related to the harvesting site, which may affect cell isolation yield, cell growth properties and clinical outcomes. Subcutaneous fat features a complex architecture: the superficial fascia separates superficial adipose tissue (SAT) from deep layer tissue (DAT). We aimed to unravel the differences between SAT and DAT, considering morphological structure, SVF composition, and ASC properties.

METHODS

SAT and DAT were collected from female donors and comparatively analyzed to evaluate cellular yield and viability, morphology, immunophenotype and molecular profile. ASCs were isolated in primary culture and used for in vitro differentiation assays. SAT and DAT from cadaver donors were also analyzed through histology and immunohistochemistry to assess morphology and cell localization within the hypoderm.

RESULTS

Liposuctioned SAT contained a higher stromal tissue compound, along with a higher proportion of CD105-positive cells, compared with DAT from the same harvesting site. Also, cells isolated from SAT displayed increased multipotency and stemness features. All differences were mainly evidenced in specimens harvested from the abdominal region. According to our results, SAT features overall increased stem properties.

CONCLUSIONS

Given that subcutaneous adipose tissue is currently exploited as the gold standard source for high-yield isolation of adult stem cells, these results may provide precious hints toward the definition of standardized protocols for microharvesting.

Contribution of chitinase A's C-terminal vacuolar sorting determinant to the study of soluble protein compartmentation

Plant chitinases have been studied for their importance in the defense of crop plants from pathogen attacks and for their peculiar vacuolar sorting determinants. A peculiarity of the sequence of many family 19 chitinases is the presence of a C-terminal extension that seems to be important for their correct recognition by the vacuole sorting machinery. The 7 amino acids long C-terminal vacuolar sorting determinant (CtVSD) of tobacco chitinase A is necessary and sufficient for the transport to the vacuole. This VSD shares no homology with other CtVSDs such as the phaseolin’s tetrapeptide AFVY (AlaPheValTyr) and it is also sorted by different mechanisms. While a receptor for this signal has not yet been convincingly identified, the research using the chitinase CtVSD has been very informative, leading to the observation of phenomena otherwise difficult to observe such as the presence of separate vacuoles in differentiating cells and the existence of a Golgi-independent route to the vacuole. Thanks to these new insights in the endoplasmic reticulum (ER)-to-vacuole transport, GFPChi (Green Fluorescent Protein carrying the chitinase A CtVSD) and other markers based on chitinase signals will continue to help the investigation of vacuolar biogenesis in plants.

Gelatin tannate ameliorates acute colitis in mice by reinforcing mucus layer and modulating gut microbiota composition: Emerging role for 'gut barrier protectors' in IBD?

BACKGROUND

Gelatin tannate, a gelatin powder containing tannic acids, is commonly employed as an intestinal astringent. Neither information nor animal model exist to confirm its efficacy or unravel mechanisms of action.

OBJECTIVE

To evaluate the action of gelatin tannate in murine dextran sodium sulphate (DSS)-induced acute colitis.

METHODS

Mice were exposed to DSS and received gelatin tannate by gavage. At sacrifice, colon histological degree of inflammation was assessed. Stool samples were cultured for microbiological analysis. Colon samples were analysed by two-photon confocal microscopy and atomic force microscopy. Elisa was performed on murine serum to assess lipopolysaccharide and peptidoglycan levels.

RESULTS

Gelatin tannate treatment reduced disease activity, bodyweight loss, and preserved colonic length. It produced a decrease in the amount of enterobacteria and enterococci. At confocal microscopy, intestinal samples from healthy and treated mice displayed similar structure in mucus layer thickness and composition; samples from placebo group had no mucus layer or a thinner stratus. Atomic force microscopy confirmed these findings. Treated mice showed lower blood LPS levels vs. control.

CONCLUSIONS

Gelatin tannate decreased the severity of colitis. Acting as a gut barrier enhancer, it re-establishes gut homeostasis by recovering intestinal permeability and mucus layer integrity in gut mucosa and by modulating microbiota composition.

Large non-functioning parathyroid cysts: our institutional experience of a rare entity and a possible pitfall in thyroid cytology

OBJECTIVE

Large non-functioning parathyroid cysts represent a rare entity with a benign clinical course. They may be misdiagnosed as thyroid cystic neoplasms on fine needle aspiration cytology (FNAC), resulting in inappropriate surgical treatment. We evaluated our institutional experience in the diagnosis of large parathyroid cystic lesions underlining all the differential diagnoses and pitfalls.

METHODS

In the period between 1998 and 2012, we reported the cytology of eight large (>2.5 cm) parathyroid cystic lesions (all female patients) with histological control. The aspirations were performed with a 25-gauge needle with ultrasonographic guidance. The aspirated material was processed with liquid-based cytology (LBC). All the patients had normal serum parathyroid hormone (PTH) and calcium.

RESULTS

The cytological samples showed a fluid watery component without colloid and few or absent epithelial cells. The resulting negativity for thyroglobulin and positivity for PTH, carried out on the cystic fluids, suggested parathyroid lesions rather than either thyroid cystic lesions (including follicular thyroid neoplasm) or cystic malignant lesions. All the patients underwent surgery without complications.

CONCLUSIONS

To the best of our knowledge, this is one of the largest series with cytohistological evaluation of large parathyroid cysts. The incidence of large parathyroid cysts remains controversial as most patients are asymptomatic. FNAC may be performed with conclusive results in the majority of cystic cases. The detection of PTH and calcium on the cystic liquid is likely to achieve a correct cytological diagnosis, allowing adequate treatment and ruling out a more frequent thyroid lesion.

Increased production of gliotoxin is related to the formation of biofilm by Aspergillus fumigatus: an immunological approach

Gliotoxin (GT) belongs to the epipolythiodioxopiperazine class of toxins secreted from certain fungi including Aspergillus fumigatus, which is the most prolific producer of this secondary metabolite. Recently, enhanced amounts of GT were found in in vitro biofilm-grown A. fumigatus mycelium. To further correlate the A. fumigatus biofilm growth phenotype with the enhanced secretion of GT, a polyclonal antibody (pAb) was produced by immunizing mice against GT. By an indirect immunofluorescent assay, pAb was then able to recognize specifically GT onto A. fumigatus Af293 biofilm formed on human pulmonary epithelial cells. Then, treating Af293 biofilms with a compound which reduces the GT disulfide bonds provoked shutdown of the GT-specific immunofluorescence (IF) signals along the hyphae. To explore the potential of GT for diagnostic use, pAb was shown to react with GT on hyphae into Aspergillus culture-positive respiratory tract specimens from patients with probable invasive aspergillosis (IA) and into tissue specimens from the lungs of patients with proven IA. As the presence of fungal hyphae in clinical specimens strongly indicates the in vivo A. fumigatus growth as a biofilm, anti-GT antibodies could be a specific and sensitive diagnostic tool for detecting A. fumigatus biofilm-associated clinical infections.

Cilostazol improves the response to ischemia in diabetic mice by a mechanism dependent on PPARγ

Cilostazol is effective for the treatment of peripheral ischemia. This compound has several beneficial effects on platelet aggregation, serum lipids and endothelial cells, and we recently found that it enhances collateral blood flow in the ischemic hind limbs of mice. Peroxisome proliferator-activated receptor (PPAR)γ, a receptor for thiazolidinediones, plays a role in angiogenesis. The aim of this work was to investigate the underlying molecular mechanisms and effects of cilostazol in a model of peripheral ischemia in diabetic mice. We induced diabetes in mice by streptozotocin (STZ) administration and studied ischemia-induced angiogenesis in the ischemic hind limbs of cilostazol-treated and untreated control mice. We found that perfusion recovery was significantly improved in treated compared with control diabetic mice. Interestingly, we found that the expression of PPARγ is reduced in ischemic tissues of diabetic mice. Furthermore, we discovered that local inhibition of the activity of this nuclear receptor decreased the angiogenic response to cilostazol treatment. Finally, we noted that this phenomenon is dependent on VEGF and modulated by PPARγ. Cilostazol administration enhances collateral blood flow in the ischemic hind limbs of STZ-induced diabetic mice through a PPARγ-dependent mechanism.

Locally injected Infliximab ameliorates murine DSS colitis: differences in serum and intestinal levels of drug between healthy and colitic mice

BACKGROUND

Infliximab is effective in human and murine IBD, but its pharmacodynamic is still poorly known. The aim of this study was to assess the affinity of infliximab to murine TNF-α, its role in murine colitis when administered intra-rectally and its levels in the blood, gut mucosa and stool of healthy and sick mice.

METHODS

An ELISA kit was built in order to assess the affinity of infliximab to human or murine-TNF-α. Human IgG were used as controls. DSS model of colitis on C57BL/6 mice was used to assess clinical efficacy of infliximab administered intravenously or by enema. Stool, serum and colon samples were collected to assess infliximab levels and histology for Rachmilewitz score.

RESULTS

Infliximab showed a good affinity both for human-TNF-α and murine-TNF-α. In DSS colitic mice infliximab ameliorated the severity of colitis, regardless of the administration route. In comparison with colitic mice, healthy mice displayed higher serum and mucosal infliximab levels, while detectable levels of infliximab were found in faeces, particularly in colitic mice.

CONCLUSION

Our data support murine models to study infliximab pharmacokinetics and dynamics. Measurable levels of infliximab can be found at different concentrations in blood, intestinal mucosa and stool from healthy and sick mice, thus infliximab pharmacokinetics could have a major impact in human IBD.

Two glycosylated vacuolar GFPs are new markers for ER-to-vacuole sorting

Vacuolar Sorting Determinants (VSDs) have been extensively studied in plants but the mechanisms for the accumulation of storage proteins in somatic tissues are not yet fully understood. In this work we used two mutated versions of well-documented vacuolar fluorescent reporters, a GFP fusion in frame with the C-terminal VSD of tobacco chitinase (GFPChi) and an N-terminal fusion in frame with the sequence-specific VSD of the barley cysteine protease aleurain (AleuGFP). The GFP sequence was mutated to present an N-glycosylation site at the amino-acid position 133. The reporters were transiently expressed in Nicotiana tabacum protoplasts and agroinfiltrated in Nicotiana benthamiana leaves and their distribution was identical to that of the non-glycosylated versions. With the glycosylated GFPs we could highlight a differential ENDO-H sensitivity and therefore differential glycan modifications. This finding suggests two different and independent routes to the vacuole for the two reporters. BFA also had a differential effect on the two markers and further, inhibition of COPII trafficking by a specific dominant-negative mutant (NtSar1h74l) confirmed that GFPChi transport from the ER to the vacuole is not fully dependent on the Golgi apparatus.

US-guided application of Nd:YAG laser in porcine pancreatic tissue: an ex vivo study and numerical simulation

BACKGROUND

Laser ablation (LA) with a neodymium-doped yttrium aluminum garnet (Nd:YAG) laser is a minimally invasive approach able to achieve a high rate of complete tissue necrosis. In a previous study we described the feasibility of EUS-guided Nd:YAG pancreas LA performed in vivo in a porcine model.

OBJECTIVE

To establish the best laser setting of Nd:YAG lasers for pancreatic tissue ablation. A secondary aim was to investigate the prediction capability of a mathematical model on ablation volume.

DESIGN

Ex vivo animal study.

SETTING

Hospital animal laboratory.

SUBJECTS

Explanted pancreatic glands from 60 healthy farm pigs.

INTERVENTION

Laser output powers (OP) of 1.5, 3, 6, 10, 15, and 20 W were supplied. Ten trials for each OP were performed under US guidance on ex vivo healthy porcine pancreatic tissue.

MAIN OUTCOME MEASUREMENTS

Ablation volume (Va) and central carbonization volume (Vc) were measured on histologic specimens as the sum of the lesion areas multiplied by the thickness of each slide. The theoretical model of the laser-tissue interaction was based on the Pennes equation.

RESULTS

A circumscribed ablation zone was observed in all histologic specimens. Va values grow with the increase of the OP up to 10 W and reach a plateau between 10 and 20 W. The trend of Vc values rises constantly until 20 W. The theoretical model shows a good agreement with experimental Va and Vc for OP between 1.5 and 10 W.

LIMITATIONS

Ex vivo study.

CONCLUSION

Volumes recorded suggest that the best laser OP could be the lowest one to obtain similar Va with smaller Vc in order to avoid the risk of thermal injury to the surrounding tissue. The good agreement between the two models demonstrates the prediction capability of the theoretical model on laser-induced ablation volume in an ex vivo animal model and supports its potential use for estimating the ablation size at different laser OPs.

Angiogenic impairment of the vascular endothelium: a novel mechanism and potential therapeutic target in muscular dystrophy

OBJECTIVE

Dystrophin, the missing or defective protein in Duchenne muscular dystrophy, is expressed not only in muscle cells but also in vascular endothelial cells (ECs). In this study, we assessed the effects of dystrophin deficiency on the angiogenic capacities of ECs.

APPROACH AND RESULTS

We isolated vascular ECs from mdx mice, the murine equivalent of Duchenne muscular dystrophy in humans, and wild-type controls, and we found that mdx-derived ECs have impaired angiogenic properties, in terms of migration, proliferation, and tube formation. They also undergo increased apoptosis in vitro compared with wild-type cells and have increased senescence-associated β-galactosidase activity. Mdx-derived ECs also display reduced ability to support myoblast proliferation when cocultured with satellite cell-derived primary myoblasts. These endothelial defects are mirrored by systemic impairment of angiogenesis in vivo, both on induction of ischemia, stimulation with growth factors in the corneal model and matrigel plug assays, and tumor growth. We also found that dystrophin forms a complex with endothelial NO synthase and caveolin-1 in ECs, and that NO production and cGMP formation are compromised in ECs isolated from mdx mice. Interestingly, treatment with aspirin enhances production of both cGMP and NO in dystrophic ECs, whereas low-dose aspirin improves the dystrophic phenotype of mdx mice in vivo, in terms of resistance to physical exercise, muscle fiber permeability, and capillary density.

CONCLUSIONS

These findings demonstrate that impaired angiogenesis is a novel player and potential therapeutic target in Duchenne muscular dystrophy.

AtSYP51/52 functions diverge in the post-Golgi traffic and differently affect vacuolar sorting

Plant sensitive factor attachment protein receptors (SNAREs) encoded by genes of the same sub-family are generally considered as redundant in promoting vesicle-associated membrane fusion events. Nonetheless, the application of innovative experimental approaches highlighted that members of the same gene sub-family often have different functional specificities. In this work, two closely related Qc-SNAREs--the AtSYP51 and the AtSYP52--are compared in their ability to influence different secretory pathways. Their role in the vesicle sorting to the central vacuole has been revised and they were found to have a novel inhibitory function. When transiently overexpressed, the SYP51 and the SYP52 distributed between the TGN and the tonoplast. Our data demonstrate that these SYPs (syntaxin of plants) act as t-SNARE when present on the membrane of TGN/PVC, whereas they behave as inhibitory or interfering SNAREs (i-SNAREs) when they accumulate on the tonoplast. Moreover, the performed functional analysis indicated that the AtSYP51 and the AtSYP52 roles differ in the traffic to the vacuole. The findings are a novel contribution to the functional characterization of plant SNAREs that reveals additional non-fusogenic roles.

Haemophagocytic syndrome associated with mucormycosis infection

Several clinical forms of mucormycosis are recognized. The tendency of mucoraceous zygomycetes to invade the blood vessels often produces a disseminated infection. A case of disseminate mucormycosis complicated by a haemophagocytic syndrome (HS) in a 32-year-old Caucasian male is reported in this article. Few cases of infection-associated HS (IAHS), involving infections caused by fungi, have been reported. In all the recorded cases, the fungal infection coexists with malignant lymphoma, immunodeficiency and a long-term steroid therapy for renal transplant or Crohn's disease. This is the second described case of the HS due to mucormycosis.

Increased expression of CD133 and reduced dystroglycan expression are strong predictors of poor outcome in colon cancer patients

Background

Expression levels of CD133, a cancer stem cell marker, and of the α-subunit of the dystroglycan (α-DG) complex, have been previously reported to be altered in colorectal cancers.

Methods

Expression levels of CD133 and α-DG were assessed by immunohistochemistry in a series of colon cancers and their prognostic significance was evaluated.

Results

Scattered cells positive for CD133 were rarely detected at the bases of the crypts in normal colonic mucosa while in cancer cells the median percentage of positive cells was 5% (range 0–80). A significant correlation was observed with pT parameter and tumor stage but not with tumor grade and N status. Recurrence and death from disease were significantly more frequent in CD133-high expressing tumors and Kaplan-Meier curves showed a significant separation between high vs low expressor groups for both disease-free (p = 0.002) and overall (p = 0.008) survival.

Expression of α-DG was reduced in a significant fraction of tumors but low α-DG staining did not correlate with any of the classical clinical-pathological parameters. Recurrence and death from the disease were significantly more frequent in α-DG-low expressing tumors and Kaplan-Meier curves showed a significant separation between high vs low expressor tumors for both disease-free (p = 0.02) and overall (p = 0.02) survival. Increased expression of CD133, but not loss of α-DG, confirmed to be an independent prognostic parameters at a multivariate analysis associated with an increased risk of recurrence (RR = 2.4; p = 0.002) and death (RR = 2.3; p = 0.003).

Conclusions

Loss of α-DG and increased CD133 expression are frequent events in human colon cancer and evaluation of CD133 expression could help to identify high-risk colon cancer patients.

Application of liquid-based cytology to fine-needle aspiration biopsies of the thyroid gland

Fine-needle aspiration biopsy is regarded as an important tool for diagnosing thyroid lesions because of its simplicity, safety, and cost-effectiveness. Its role in correctly characterizing the group of indeterminate lesions or follicular-patterned neoplasms (FN) might be more decisive. Liquid-based cytology (LBC) is a technique based on the use of a semi-automated device that has gained popularity as a method of collecting and processing both gynecologic and non-gynecologic cytologic specimens. It achieves a diagnostic sensitivity as accurate as conventional preparations especially for its excellent cell preservation and for the lack of background which decrease the amount of inadequate diagnoses. Moreover, the cellular material which has been stored in the preservative solution could be effectively used for the application of immunocytochemical and molecular techniques especially for the Follicular proliferations. In many cases the cytologic features are similar in both methods but the colloid film and the lymphocytic component are more easily evaluated on direct smears whereas nuclear details and colloid globules are better evaluated in LBC slides. The LBC-processed biopsies represent a valid alternative to conventional cytology. The possibility of applying special techniques enhance the efficacy of the cytological diagnosis of thyroid lesions.

An Acephalus Acardius Amorphous Fetus in a Monochorionic Pregnancy With Sex Discrepancy

Acephalus acardia is among the most severe malformations described in fetuses, with an incidence of about 1 in 35,000 births and is due to twin-to-twin transfusion syndrome, frequently occurring in monochorionic twin pregnancies. The severity of the syndrome depends upon the type of the anastomoses arising between the vascular networks of the two fetuses, usually configuring the ‘twin reverse arterial perfusion syndrome’. No clear and univocal etiological explanation is known, though few cases with chromosomal abnormalities have been reported so far. In some cases the fusion of two or more separate placentae of dizygotic fetuses occurs, leading to monochorionic twinning. Few cases of acardius amorphous with complete autoptical examination have been described so far. We report a case of acephalus acardius amorphus fetus, showing features of extremely severe sistemic immaturity with very few structured organs. Defined external and autoptic examinations have been performed on the dismorphic twin, along with the histological examination of tissue samples. Kariotype analysis showed sex discrepancy between the twins, as a normal female kariotype had been detected in the acephalus acardius while the living co-twin was a normal healthy male. The analysis of the placenta showed the vascular anomalies leading to the twin-to-twin transfusion syndrome.

Aggressive large B-cell lymphoma in a systemic lupus erythematosus patient with chronic active Epstein-Barr virus infection: a case report

A link between Epstein-Barr Virus (EBV) infection, systemic lupus erythematosus (SLE) and non-Hodgkin's lymphoma (NHL) has been recently reported in literature. Here we report a case of diffuse large B-cell lymphoma (DLBCL) with a particularly aggressive clinical course in an SLE patient with EBV infection. A 49-year-old woman with a long history of SLE was admitted to the Department of Experimental and Clinical Medicine and dramatically died a few hours later. The autopsy described no evidence of active lymphoproliferative disorder. Instead, histological examination demonstrated an atypical lymphocitic proliferation in lymph node, kidneys, pericardium and uterus. Immunoistochemically, the lymphomatous cells were positive with CD19, CD20, CD22 and CD79a, which was consistent with a DLBCL. The cells were also reactive to EBV markers, indicating the possible role of previous EBV infection in DLBCL pathogenesis.

Differential CD133 expression pattern during mouse colon tumorigenesis

BACKGROUND/AIM

The cancer stem cell model suggests that only a rare subpopulation, known as cancer stem cells (CSC) are responsible for tumor initiation. CSC from several human carcinomas are characterized by specific cell surface markers, such as CD133. The CD133 role in colon tumorigenesis remains controversial.

MATERIALS AND METHODS

CD133 was evaluated by immunohistochemistry in a mouse model of colitis-related colon tumorigenesis induced by a combined treatment with azoxymethane (AOM) and dextran sodium sulphate (DSS).

RESULTS

In normal tissue rare scattered positive cells were detectable at the bottom of the crypts. The percentage of positive cells significantly increased in dysplastic lesions and appeared to progressively decrease in the passage from dysplasia to adenoma and then to cancer, although always remaining greater in number than in the normal tissue.

CONCLUSION

An increased CD133 expression occurs at early stages of colon tumorigenesis in the mouse. CD133-expressing cells might play an important role from the earlier phase and throughout the entire process of colon cancer development.

Assessment of the genetic effects of polymorphisms in the osteoprotegerin gene, TNFRSF11B, on serum osteoprotegerin levels and carotid plaque vulnerability

BACKGROUND AND PURPOSE

Osteoprotegerin (OPG) is a secretory glycoprotein which belongs to the tumor necrosis factor receptor family. Various mechanisms have been suggested by which calcification might alter atherosclerotic plaque stability, but the significance of this intimal calcification is controversial. High concentrations of OPG have been associated with the presence of vascular and cardiovascular diseases. This study was designed to assess the association between gene polymorphisms of the OPG gene (TNFRSF11B), the serum OPG level, and plaque stability in patients with carotid atherosclerosis.

METHODS

We studied 177 patients with internal carotid artery stenosis who underwent carotid endarterectomy and also 303 controls. Carotid endarterectomy samples removed from patients were assessed by immunohistochemistry. Concentrations of OPG were measured and gene polymorphisms were examined by polymerase chain reaction and restriction enzyme analysis and were compared, initially between patients with carotid atherosclerosis and controls, and subsequently between stable and unstable carotid plaques.

RESULTS

We found that the GG genotype of the T245G polymorphism, the CC genotype of the T950C polymorphism, and the CC genotype of the G1181C polymorphism were significantly higher in patients with carotid plaque than in controls (21.5% versus 10.9% , P<0.01; 15.8% versus 7.6%, P<0.01; and 20.3% versus 10.9%, P<0.01, respectively) and that these polymorphisms were associated with high serum OPG levels (4.02 [3.07] versus 2.94 [1.81] pmol/L; P<0.01), which were significantly higher in patients with unstable atherosclerotic plaques (5.86 [4.02] versus 3.53 [1.87] pmol/L; P<0.01).

CONCLUSIONS

The TNFRSF11B gene polymorphisms studied are associated with high serum OPG levels and might be potential markers for plaque instability.

High-mobility group box-1 protein promotes angiogenesis after peripheral ischemia in diabetic mice through a VEGF-dependent mechanism

OBJECTIVE

High-mobility group box-1 (HMGB1) protein is a nuclear DNA-binding protein released from necrotic cells, inducing inflammatory responses and promoting tissue repair and angiogenesis. Diabetic human and mouse tissues contain lower levels of HMGB1 than their normoglycemic counterparts. Deficient angiogenesis after ischemia contributes to worse outcomes of peripheral arterial disease in patients with diabetes. To test the hypothesis that HMGB1 enhances ischemia-induced angiogenesis in diabetes, we administered HMGB1 protein in a mouse hind limb ischemia model using diabetic mice.

RESEARCH DESIGN AND METHODS

After the induction of diabetes by streptozotocin, we studied ischemia-induced neovascularization in the ischemic hind limb of normoglycemic, diabetic, and HMGB1-treated diabetic mice.

RESULTS

We found that the perfusion recovery was significantly attenuated in diabetic mice compared with normoglycemic control mice. Interestingly, HMGB1 protein expression was lower in the ischemic tissue of diabetic mice than in normoglycemic mice. Furthermore, we observed that HMGB1 administration restored the blood flow recovery and capillary density in the ischemic muscle of diabetic mice, that this process was associated with the increased expression of vascular endothelial growth factor (VEGF), and that HMGB1-induced angiogenesis was significantly reduced by inhibiting VEGF activity.

CONCLUSIONS

The results of this study show that endogenous HMGB1 is crucial for ischemia-induced angiogenesis in diabetic mice and that HMGB1 protein administration enhances collateral blood flow in the ischemic hind limbs of diabetic mice through a VEGF-dependent mechanism.

Pioglitazone enhances collateral blood flow in ischemic hindlimb of diabetic mice through an Akt-dependent VEGF-mediated mechanism, regardless of PPARgamma stimulation

Background

Type 2 diabetes mellitus (T2DM) is commonly associated with both microvascular and macrovascular complications and a strong correlation exists between glycaemic control and the incidence and progression of vascular complications. Pioglitazone, a Peroxisome proliferator-activated receptor-γ (PPARγ) ligand indicated for therapy of type T2DM, induces vascular effects that seem to occur independently of glucose lowering.

Methods

By using a hindlimb ischemia murine model, in this study we have found that pioglitazone restores the blood flow recovery and capillary density in ischemic muscle of diabetic mice and that this process is associated with increased expression of Vascular Endothelial Growth Factor (VEGF). Importantly, these beneficial effects are abrogated when endogenous Akt is inhibited; furthermore, the direct activation of PPARγ, with its selective agonist GW1929, does not restore blood flow recovery and capillary density. Finally, an important collateral vessel growth is obtained with combined treatment with pioglitazone and selective PPARγ inhibitor GW9662.

Conclusion

These data demonstrate that Akt-VEGF pathway is essential for ischemia-induced angiogenic effect of pioglitazone and that pioglitazone exerts this effect via a PPARγ independent manner.

Hypoplastic coronary artery disease causing sudden death. Report of two cases and review of the literature

Congenital coronary anomalies represent a condition often unrecognized in the living and in the dead. Investigating this condition is relevant for both clinicians and pathologists in order to identify potentially unrecognized coronary causes of sudden death. Hypoplastic coronary artery disease (HCAD) is a rare congenital abnormality reported to be associated with sudden death. We report two additional cases of previously apparently healthy people who died suddenly and were found to have HCAD at postmortem evaluation. The clinicopathologic findings are discussed along with a review of the literature.

VEGF-A links angiogenesis and inflammation in inflammatory bowel disease pathogenesis

BACKGROUND & AIMS

Vascular endothelial growth factor A (VEGF-A) mediates angiogenesis and might also have a role in inflammation and immunity. We examined whether VEGF-A signaling has a role in inflammatory bowel disease (IBD).

METHODS

Expression levels of VEGF-A, and its receptors VEGFR-1 and VEGFR-2, were examined in samples from patients with IBD and compared with those of controls. The capacity of VEGF-A to induce angiogenesis was tested in human intestinal microvascular endothelial cells using cell-migration and matrigel tubule-formation assays. Levels of vascular cellular adhesion molecule-1 and intercellular adhesion molecule were measured by flow cytometry to determine induction of inflammation; neutrophil adhesion was also assayed. Expression patterns were determined in tissues from mice with dextran sulfate sodium (DSS)-induced colitis; the effects of VEGF-A overexpression and blockade were assessed in these mice by adenoviral transfer of VEGF-A and soluble VEGFR-1. Intestinal angiogenesis was measured by quantitative CD31 staining and leukocyte adhesion in vivo by intravital microscopy.

RESULTS

Levels of VEGF-A and VEGFR-2 increased in samples from patients with IBD and colitic mice. VEGF-A induced angiogenesis of human intestinal microvascular endothelial cells in vitro as well as an inflammatory phenotype and adherence of neutrophils to intestinal endothelium. Overexpression of VEGF-A in mice with DSS-induced colitis worsened their condition, whereas overexpression of soluble VEGFR-1 had the opposite effect. Furthermore, overexpression of VEGF-A increased mucosal angiogenesis and stimulated leukocyte adhesion in vivo.

CONCLUSIONS

VEGF-A appears to be a novel mediator of IBD by promoting intestinal angiogenesis and inflammation. Agents that block VEGF-A signaling might reduce intestinal inflammation in patients with IBD.