Digital quantification of fibrosis in liver biopsy sections: description of a new method by Photoshop software

Adapted clustering method for generic analysis of histological fibrosis staining as an open source tool

Pathological remodeling of the extracellular matrix is a hallmark of cardiovascular disease. Abnormal fibrosis causes cardiac dysfunction by reducing ejection fraction and impairing electrical conductance, leading to arrhythmias. Hence, accurate quantification of fibrosis deposition in histological sections is of extreme importance for preclinical and clinical studies. Current automatic tools do not perform well under variant conditions. Moreover, users do not have the option to evaluate data from staining methods of their choice according to their purpose. To overcome these challenges, we underline a novel machine learning-based tool (FibroSoft) and we show its feasibility in a model of cardiac hypertrophy and heart failure in mice. Our results demonstrate that FibroSoft can identify fibrosis in diseased myocardium and the obtained results are user-independent. In addition, the results acquired using our software strongly correlate to those obtained by Western blot analysis of collagen 1 expression. Additionally, we could show that this method can be used for Masson's Trichrome and Picosirius Red stained histological images. The evaluation of our method also indicates that it can be used for any particular histology segmentation and quantification. In conclusion, our approach provides a powerful example of the feasibility of machine learning strategies to enable automatic analysis of histological images.

E-cadherin deficiency promotes prostate macrophage inflammation and bladder overactivity in aged male mice

Decreased E-cadherin immunostaining is frequently observed in benign prostatic hyperplasia (BPH) and was recently correlated with increased inflammation in aging prostate. Homozygous E-cadherin deletion in the murine prostate results in prostate inflammation and bladder overactivity at 6 months of age. However, this model is limited in that while E-cadherin is significantly reduced in BPH, it is not completely lost; BPH is also strongly associated with advanced age and is infrequent in young men. Here, we examined the functional consequences of aging in male mice with prostate luminal epithelial cell-specific E-cadherin heterozygosity. In control mice, aging alone resulted in an increase in prostate inflammation and changes in bladder voiding function indicative of bladder underactivity. At 24 months of age, mice with prostate-specific Cre-mediated heterozygous deletion of E-cadherin induced at 7 weeks of age developed additional prostatic defects, particularly increased macrophage inflammation and stromal proliferation, and bladder overactivity compared to age-matched control mice, which are similar to BPH/LUTS in that the phenotype is slow-progressing and age-dependent. These findings suggest that decreased E-cadherin may promote macrophage inflammation and fibrosis in the prostate and subsequent bladder overactivity in aging men, promoting the development and progression of BPH/LUTS.

Salivary ZG16B expression loss follows exocrine gland dysfunction related to oral chronic graft-versus-host disease

Chronic graft-versus-host disease (cGVHD) targets include the oral mucosa and salivary glands after allogeneic hematopoietic stem cell transplant (HSCT). Without incisional biopsy, no diagnostic test exists to confirm oral cGVHD. Consequently, therapy is often withheld until severe manifestations develop. This proteomic study examined saliva and human salivary gland for a biomarker profile at first onset of oral cGVHD prior to initiation of topical steroid therapy. Whole saliva collected at onset of biopsy-proven oral GVHD was assessed using liquid chromatography-coupled tandem mass spectrometry with identification of 569 proteins, of which 77 significantly changed in abundance. ZG16B, a secretory lectin protein, was reduced 2-fold in oral cGVHD saliva (p <0.05), and significantly decreased in salivary gland secretory cells affected by cGVHD. Single-cell RNA-seq analysis of healthy MSG localized ZG16B expression to two discrete acinar cell populations. Reduced ZG16B expression may indicate specific cGVHD activity and possibly general salivary gland dysfunction.

SOFTWARE-ASSISTED IMAGE ANALYSIS FOR IDENTIFICATION AND QUANTIFICATION OF HEPATIC SINUSOIDAL DILATATION AND CENTRILOBULAR FIBROSIS

Background:

Heart dysfunction and liver disease often coexist because of systemic disorders. Any cause of right ventricular failure may precipitate hepatic congestion and fibrosis. Digital image technologies have been introduced to pathology diagnosis, allowing an objective quantitative assessment. The quantification of fibrous tissue in liver biopsy sections is extremely important in the classification, diagnosis and grading of chronic liver disease.

Aim:

To create a semi-automatic computerized protocol to quantify any amount of centrilobular fibrosis and sinusoidal dilatation in liver Masson’s Trichrome-stained specimen.

Method:

Once fibrosis had been established, liver samples were collected, histologically processed, stained with Masson’s trichrome, and whole-slide images were captured with an appropriated digital pathology slide scanner. After, a random selection of the regions of interest (ROI’s) was conducted. The data were subjected to software-assisted image analysis (ImageJ^®).

Results:

The analysis of 250 ROI’s allowed to empirically obtain the best application settings to identify the centrilobular fibrosis (CF) and sinusoidal lumen (SL). After the establishment of the colour threshold application settings, an in-house Macro was recorded to set the measurements (fraction area and total area) and calculate the CF and SL ratios by an automatic batch processing.

Conclusion:

Was possible to create a more detailed method that identifies and quantifies the area occupied by fibrous tissue and sinusoidal lumen in Masson’s trichrome-stained livers specimens.

Electrophysiological and Structural Remodeling of the Atria in a Mouse Model of Troponin-I Mutation Linked Hypertrophic Cardiomyopathy: Implications for Atrial Fibrillation

Hypertrophic cardiomyopathy (HCM) is an inherited cardiac disorder affecting one in 500 of the general population. Atrial fibrillation (AF) is the most common arrhythmia in patients with HCM. We sought to characterize the atrial electrophysiological and structural substrate in young and aging Gly203Ser cardiac troponin-I transgenic (HCM) mice. At 30 weeks and 50 weeks of age (n = 6 per strain each group), the left atrium was excised and placed on a multi-electrode array (MEA) for electrophysiological study; subsequent histological analyses and plasma samples were analyzed for biomarkers of extracellular matrix remodeling and cell adhesion and inflammation. Wild-type mice of matched ages were included as controls. Young HCM mice demonstrated significantly shortened atrial action potential duration (APD), increased conduction heterogeneity index (CHI), increased myocyte size, and increased interstitial fibrosis without changes in effective refractory periods (ERP), conduction velocity (CV), inflammatory infiltrates, or circulating markers of extracellular matrix remodeling and inflammation. Aging HCM mice demonstrated aggravated changes in atria electrophysiology and structural remodeling as well as increased circulating matrix metalloproteinases (MMP)-2, MMP-3, and VCAM-1 levels. This model of HCM demonstrates an underlying atrial substrate that progresses with age and may in part be responsible for the greater propensity for AF in HCM.

A cyclic peptide significantly improves thyroid function, thyrotropin-receptor antibodies and orbital mucine /collagen content in a long-term Graves' disease mouse model

BACKGROUND

BALB/c mice which received long-term immunizations of adenovirus (Ad) expressing thyrotropin receptor A-subunits (TSHR) developed stable Graves' disease (GD). TSHR-derived cyclic peptide 19 (P19) was identified as effective therapy in this model.

METHODS

In Ad-TSHR mice, we investigated shorter disease intervals up to 4 months for histological alterations of the orbits, fine tuning of anti-TSHR antibodies (Ab) and free thyroxine (fT4) hormone levels by using novel detection methods in an independent laboratory. Therapy (0.3 mg/kg P19 or vehicle) was given intravenously after the fourth Ad-TSHR immunization (week 11) and continued until week 19.

RESULTS

Thyrotropin binding inhibitory immunoglobulins (TBII, bridge immunoassay), blocking (TBAb) and stimulating (TSAb) TSHR-Ab (both cell-based bioassays) and serum levels of fT4 were significantly elevated at week 11 in Ad-TSHR-immunized mice versus none in control mice. For the first time, TSAb, TBAb, and thyroperoxidase-Ab were detected in 17 of 19, 12/19 and 6/19 Ad-TSHR immunized mice, respectively at week 21. Also, for the first time, this study showed that P19 treatment markedly reduced serum TBII (p < 0.0001), serum fT4 (p = 0.02), and acidic mucins and collagen content in the orbital tissue of Ad-TSHR-immunized mice.

CONCLUSION

P19 significantly improved thyroid function, confirming previous results in an independent second laboratory. A relevant shift of anti-TSHR antibody subpopulations in response to P19 therapy may help explain its immunological effects. Moreover, P19 exerted a beneficial effect on mucine and collagen content of orbital tissue. Hence, P19 offers a potential novel therapeutic approach for GD and associated orbitopathy.

A Promising Mouse Model of Graves' Orbitopathy Induced by Adenovirus Expressing Thyrotropin Receptor A Subunit

Background: Graves' orbitopathy (GO) is the most common and serious manifestation of Graves' disease (GD). It is characterized by orbital inflammation and tissue remodeling. Although several GO models have been reported, most lack a full assessment or mechanistic evaluation. Here, we established a promising mouse model mimicking many aspects of human GO with a frequency of 70% and characterized the key role of T cells in the progression of GO. Methods: An adenovirus expressing the human thyrotropin (TSH) receptor A subunit (Ad-TSHRA) was injected in the muscles of female BALB/C mice nine times to induce GO. At predetermined time points, histological examinations of retrobulbar tissues and thyroid glands were performed to dynamically monitor changes; serum autoantibodies and total thyroxine levels were examined to evaluate thyroid function. Flow cytometry of CD4+ T cell subgroups and RNA sequencing (RNA-Seq) of splenocytes were also performed to explore the underlying mechanism. Results: After nine injections, 7 of 10 mice challenged with Ad-TSHRA developed the orbital changes associated with GO. Seven mice manifested retrobulbar fibrosis, and four mice showed adipogenesis. Exophthalmia, conjunctival redness, and orbital lymphocyte infiltration were also observed in a subset of mice. The orbitopathy was first detected after seven injections and followed the hyperplastic change observed in thyroids after four injections. Flow cytometry revealed increased proportions of Th1 cells and decreased proportions of Th2 cells and regulatory T (Treg) cells in the splenocytes of GO mice. This change in CD4+ T cell subgroups was confirmed by orbital immunohistochemical staining. Genes involved in T cell receptor signaling, proliferation, adhesion, inflammation, and cytotoxicity were upregulated in GO mice according to the RNA-Seq; a trend of upregulation of these GO-specific genes was observed in mice with hyperthyroidism without orbitopathy after four injections. Conclusions: A GO mouse model was successfully established by administering nine injections of Ad-TSHRA. The model was achieved with a frequency of 70% and revealed the importance of T cell immunity. A potential time window from Graves' hyperthyroidism to GO was presented for the first time. Therefore, this model could be used to study the pathogenesis and novel treatments for GO.

Liver Collagen Contents Are Closely Associated with the Severity of Cirrhosis and Posthepatectomy Liver Failure in Patients with Hepatocellular Carcinoma and Child-Pugh Grade A Liver Function

BACKGROUND

Hepatocellular carcinoma (HCC) is usually accompanied by different severities of cirrhosis, which is a risk factor for posthepatectomy liver failure (PHLF). Collagen proportional area (CPA) measurements can quantitatively determine the collagen contents of liver tissue. This study explored the impact of CPA on PHLF, and further investigated the correlation between CPA and a non-invasive method, namely cirrhotic severity scoring (CSS), previously proposed by our team.

METHODS

A total of 224 HCC patients with Child-Pugh grade A liver function undergoing hepatectomy between 2017 and 2019 were retrospectively studied. Quantitative digital image analysis of resected liver tissues was used for the CPA measurement. Risk factors for PHLF were subjected to univariate and multivariate analyses, and the correlation between CPA and CSS was analyzed.

RESULTS

Overall, 28 (12.5%) patients experienced PHLF. Patients with PHLF had higher CPA values than those without PHLF (p < 0.001). Multivariate analysis showed CPA and extent of hepatectomy to be independent risk factors for PHLF. CPA values were divided into four stages based on their quartiles (C1: < 6.6%; C2: 6.6-10.7%; C3: 10.7-18.0%; C4: ≥ 18.0%). The incidence of PHLF increased with increasing CPA stages (p < 0.001). Furthermore, CSS was significantly correlated with CPA (r = 0.720; p < 0.001). The incidence of PHLF also increased with increasing severity of cirrhosis evaluated by CSS (p < 0.001).

CONCLUSIONS

In HCC patients with Child-Pugh grade A liver function, cirrhosis could be staged by liver collagen contents, which significantly influenced PHLF. Furthermore, CSS was useful in the preoperative evaluation of cirrhotic severity.

Serum metabolite profiles are associated with the presence of advanced liver fibrosis in Chinese patients with chronic hepatitis B viral infection

BACKGROUND

Accurate and noninvasive diagnosis and staging of liver fibrosis are essential for effective clinical management of chronic liver disease (CLD). We aimed to identify serum metabolite markers that reliably predict the stage of fibrosis in CLD patients.

METHODS

We quantitatively profiled serum metabolites of participants in 2 independent cohorts. Based on the metabolomics data from cohort 1 (504 HBV associated liver fibrosis patients and 502 normal controls, NC), we selected a panel of 4 predictive metabolite markers. Consequently, we constructed 3 machine learning models with the 4 metabolite markers using random forest (RF), to differentiate CLD patients from normal controls (NC), to differentiate cirrhosis patients from fibrosis patients, and to differentiate advanced fibrosis from early fibrosis, respectively.

RESULTS

The panel of 4 metabolite markers consisted of taurocholate, tyrosine, valine, and linoelaidic acid. The RF models of the metabolite panel demonstrated the strongest stratification ability in cohort 1 to diagnose CLD patients from NC (area under the receiver operating characteristic curve (AUROC) = 0.997 and the precision-recall curve (AUPR) = 0.994), to differentiate fibrosis from cirrhosis (0.941, 0.870), and to stage liver fibrosis (0.918, 0.892). The diagnostic accuracy of the models was further validated in an independent cohort 2 consisting of 300 CLD patients with chronic HBV infection and 90 NC. The AUCs of the models were consistently higher than APRI, FIB-4, and AST/ALT ratio, with both greater sensitivity and specificity.

CONCLUSIONS

Our study showed that this 4-metabolite panel has potential usefulness in clinical assessments of CLD progression in patients with chronic hepatitis B virus infection.

Metabolic Syndrome Is Reduced in C57BL/6J Mice Fed High-Fat Diets Supplemented with Oak Tannins

BACKGROUND

Wine aged in oak barrels will incorporate polyphenols inherent in the staves, suggesting that wine stored in these wooden containers will introduce oak compounds into the human body after consumption.

OBJECTIVE

The purpose of the present study is to test whether consumption of these oak compounds could favorably influence metabolism in mice fed an obesogenic diet.

METHODS

C57BL/6  male mice (n = 8) were fed diets for 10 wk as follows: low-fat (LF), high-fat (HF), and HF containing 0.17% of oak tannin (HF+OT). A second 10-wk study was completed; mice were provided LF, HF, and HF diets supplemented with 7.0% of concentrates made from oaked wine (HF+OWC) or unoaked wine (HF+UWC). Physiological parameters were measured during the feeding trial and serum markers and hepatic gene expression measured from samples obtained at necropsy.

RESULTS

Intake of HF+OT significantly reduced body-weight gain (18.4 ± 1.2 g in HF vs. 13.2 ± 1.4 g in HF+OT, P < 0.05). Serum resistin concentrations were lower in HF+OT mice compared with HF mice (301 ± 10.1 pg/mL in HF+OT vs. 374 ± 10.9 pg/mL in HF; P < 0.05). Hepatic lipid accumulation and expression of glutathione-S-transferase-m2 (Gstm2) and NAD(P)H:quinone oxidoreductase (Nqo1) mRNAs were significantly decreased in HF+OT compared with HF mice (P < 0.05). When compared with HF-fed mice, intake of both OWC and UWC decreased body-weight gain (P < 0.05), with no significant impact on food consumption. Fasting glucose concentrations, serum insulin, and hepatic lipid accumulation were reduced in HF+OWC-fed mice compared with HF+UWC-fed mice (P < 0.05). Furthermore, hepatic glutathione-S-transferase-a1 (Gsta1) mRNA levels were significantly reduced in OWC-supplemented (0.25 ± 0.08) compared with UWC-supplemented (1.71 ± 0.24) mice (P < 0.05).

CONCLUSIONS

In this mouse model of metabolic disease, intake of OTs and a concentrate made from an oaked wine had a potent impact on alleviating HF-induced metabolic syndrome. Thus, intake of OTs, provided passively in oaked wine or as a dietary supplement, may act as an agent to attenuate the markers of metabolic syndrome.

Transgenic interleukin 11 expression causes cross-tissue fibro-inflammation and an inflammatory bowel phenotype in mice

Interleukin 11 (IL11) is a profibrotic cytokine, secreted by myofibroblasts and damaged epithelial cells. Smooth muscle cells (SMCs) also secrete IL11 under pathological conditions and express the IL11 receptor. Here we examined the effects of SMC-specific, conditional expression of murine IL11 in a transgenic mouse (Il11SMC). Within days of transgene activation, Il11SMC mice developed loose stools and progressive bleeding and rectal prolapse, which was associated with a 65% mortality by two weeks. The bowel of Il11SMC mice was inflamed, fibrotic and had a thickened wall, which was accompanied by activation of ERK and STAT3. In other organs, including the heart, lung, liver, kidney and skin there was a phenotypic spectrum of fibro-inflammation, together with consistent ERK activation. To investigate further the importance of stromal-derived IL11 in the inflammatory bowel phenotype we used a second model with fibroblast-specific expression of IL11, the Il11Fib mouse. This additional model largely phenocopied the Il11SMC bowel phenotype. These data show that IL11 secretion from the stromal niche is sufficient to drive inflammatory bowel disease in mice. Given that IL11 expression in colonic stromal cells predicts anti-TNF therapy failure in patients with ulcerative colitis or Crohn's disease, we suggest IL11 as a therapeutic target for inflammatory bowel disease.

The Homeodomain Transcription Factor NKX3.1 Modulates Bladder Outlet Obstruction Induced Fibrosis in Mice

Fibrosis is an irreversible remodeling process characterized by the deposition of collagen in the extracellular matrix of various organs through a variety of pathologies in children, leading to the stiffening of healthy tissues and organ dysfunction. Despite the prevalence of fibrotic disease in children, large gaps exist in our understanding of the mechanisms that lead to fibrosis, and there are currently no therapies to treat or reverse it. We previously observed that castration significantly reduces fibrosis in the bladders of male mice that have been partially obstructed. Here, we investigated if the expression of androgen response genes were altered in mouse bladders after partial bladder outlet obstruction (PO). Using a QPCR microarray and QRTPCR we found that PO was sufficient to increase expression of the androgen response gene Nkx3.1. Consistent with this was an increase in the expression of NKX3.1 protein. Immunofluorescent antibody localization demonstrated nuclear NKX3.1 in most bladder cells after PO. We tested if genetic deletion of Nkx3.1 alters remodeling of the bladder wall after PO. After PO, Nkx3.1 ^KO/KO bladders underwent remodeling, demonstrating smaller bladder area, thickness, and bladder: body weight ratios than obstructed, wild type controls. Remarkably, Nkx3.1 ^KO/KO specifically affected histological parameters of fibrosis, including reduced collagen to muscle ratio. Loss of Nkx3.1 altered collagen and smooth muscle cytoskeletal gene expression following PO which supported our histologic findings. Together these findings indicated that after PO, Nkx3.1 expression is induced in the bladder and that it mediates important pathways that lead to tissue fibrosis. As Nkx3.1 is an androgen response gene, our data suggest a possible mechanism by which fibrosis is mediated in male mice and opens the possibility of a molecular pathway mediated by NKX3.1 that could explain sexual dimorphism in bladder fibrosis.

Comparative study of amlodipine vs. cilnidipine for the prevention of hepatic ischemia-reperfusion injury in rat model

Ca²⁺ signaling plays crucial role in ischemia and reperfusion (I/R) injury. Although blockade of L-type Ca²⁺ channels by amlodipine (AML) has been shown to suppress hepatic I/R injury in several animal models, information is still needed regarding the hepatoprotective effects of the dual L/N-type Ca²⁺ channel blockers, cilnidipine (CIL). We examined the effect of pretreatment with AML or CIL (100 μg/kg i.p.) 45 min before induction of 60 min of liver ischemia followed by reperfusion, on oxidative stress markers, liver enzymes, serum tumor necrosis factor-α, interleukin-1β, apoptosis markers, and nuclear factor KB after 6 and 24 h of hepatic reperfusion. Both drugs significantly ameliorated biochemical and histological markers of hepatic I/R injury, but protection with CIL was more significant at the 6-h time point where protection with AML outlasted that of CIL. Both drugs offered significant protection against hepatic I/R damage, but the protection with CIL seemed more potent but of shorter duration than that observed with AML possibly due to the shorter half-life of CIL.

HCaRG/COMMD5 inhibits ErbB receptor-driven renal cell carcinoma

Hypertension-related, calcium-regulated gene (HCaRG/COMMD5) is highly expressed in renal proximal tubules, where it contributes to the control of cell proliferation and differentiation. HCaRG accelerates tubular repair by facilitating re-differentiation of injured proximal tubular epithelial cells, thus improving mouse survival after acute kidney injury. Sustained hyper-proliferation and de-differentiation are important hallmarks of tumor progression. Here, we demonstrate that cancer cells overexpressing HCaRG maintain a more differentiated phenotype, while several of them undergo autophagic cell death. Its overexpression in mouse renal cell carcinomas led to smaller tumor size with less tumor vascularization in a homograft tumor model. Mechanistically, HCaRG promotes de-phosphorylation of the proto-oncogene erythroblastosis oncogene B (ErbB)2/HER2 and epigenetic gene silencing of epidermal growth factor receptor and ErbB3 via promoter methylation. Extracellular signal-regulated kinase, AKT and mammalian target of rapamycin which mediate ErbB-dowstream signaling pathways are inactivated by HCaRG expression. In addition, HCaRG is underexpressed in human renal cell carcinomas and more expressed in normal tissue adjacent to renal cell carcinomas of patients with favorable prognosis. Taken together, our data suggest a role for HCaRG in the inhibition of tumor progression as a natural inhibitor of the ErbB signals in cancer and as a potential prognostic marker for renal cell carcinomas.

Cyclic Peptides for Effective Treatment in a Long-Term Model of Graves Disease and Orbitopathy in Female Mice

A model for human Graves disease in mice was used to compare several treatment approaches. The mice received regular adenovirus (Ad) thyroid-stimulating hormone receptor (TSHR) A subunit immunizations (injections every 4 weeks). The generation of anti-TSHR antibodies, enlarged thyroid sizes (goiter), elevated serum thyroxine levels, retro-orbital fibrosis, and cardiac involvement (tachycardia and hypertrophy) were consistently observed over 9 months. Treatment of established disease in these mice using cyclic peptides that mimic one of the cylindrical loops of the TSHR leucine-rich repeat domain improved or cured all investigated parameters after six consecutive monthly injections. The first significant beneficial effects were observed 3 to 4 months after starting these therapies. In immunologically naïve mice, administration of any of the cyclic peptides did not induce any immune response. In contrast, monthly injections of the full antigenic TSHR A domain as fusion protein with immunoglobulin G crystallizable fragment induced clinical signs of allergy in Ad-TSHR-immunized mice and anti-TSHR antibodies in naïve control mice. In conclusion, cyclic peptides resolved many clinical findings in a mouse model of established Graves disease and orbitopathy. In contrast to blocking TSHR by allosteric modulation, the approach does not incur a direct receptor antagonism, which might offer a favorable side effect profile.

Lysophosphatidic acid-induced RhoA signaling and prolonged macrophage infiltration worsens fibrosis and fatty infiltration following rotator cuff tears

Previous studies have suggested that macrophage-mediated chronic inflammation is involved in the development of rotator cuff muscle atrophy and degeneration following massive tendon tears. Increased RhoA signaling has been reported in chronic muscle degeneration, such as muscular dystrophy. However, the role of RhoA signaling in macrophage infiltration and rotator muscle degeneration remains unknown. Using a previously established rat model of massive rotator cuff tears, we found RhoA signaling is upregulated in rotator cuff muscle following a massive tendon-nerve injury. This increase in RhoA expression is greatly potentiated by the administration of a potent RhoA activator, lysophosphatidic acid (LPA), and is accompanied by increased TNFα and TGF-β1 expression in rotator cuff muscle. Boosting RhoA signaling with LPA significantly worsened rotator cuff muscle atrophy, fibrosis, and fatty infiltration, accompanied with massive monocytic infiltration of rotator cuff muscles. Co-staining of RhoA and the tissue macrophage marker CD68 showed that CD68+ tissue macrophages are the dominant cell source of increased RhoA signaling in rotator cuff muscles after tendon tears. Taken together, our findings suggest that LPA-mediated RhoA signaling in injured muscle worsens the outcomes of atrophy, fibrosis, and fatty infiltration by increasing macrophage infiltraion in rotator cuff muscle. Clinically, inhibiting RhoA signaling may represent a future direction for developing new treatments to improve muscle quality following massive rotator cuff tears. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1539-1547, 2017.

Review of Mouse Models of Graves' Disease and Orbitopathy-Novel Treatment by Induction of Tolerance

Various approaches have been used to model human Graves' disease in mice, including transfected fibroblasts, and plasmid or adenoviral immunisations with the extracellular A subunit of the human thyrotropin receptor (TSHR). Some of these models were only observed for a short time period or were self-limiting. A long-term model for human Graves' disease was established in mice using continuing immunisations (4-weekly injections) with recombinant adenovirus expressing TSHR. Generation of TSHR binding cAMP-stimulatory antibodies, thyroid enlargement and alterations, elevated serum thyroxin levels, tachycardia and cardiac hypertrophy were maintained for at least 9 months in all Ad-TSHR-immunised mice. Here, we show that these mice suffer from orbitopathy, which was detected by serial orbital sectioning and histomorphometry. Attempts to treat established Graves' disease in preclinical mouse model studies have included small molecule allosteric antagonists and specific antagonist antibodies which were isolated from hypothyroid patients. In addition, novel peptides have been conceived which mimic the cylindrical loops of the TSHR leucine-rich repeat domain, in order to re-establish tolerance toward the antigen. Here, we show preliminary results that one set of these peptides improves or even cures all signs and symptoms of Graves' disease in mice after six consecutive monthly injections. First beneficial effects were observed 3-4 months after starting these therapies. In immunologically naïve mice, administration of the peptides did not induce any immune response.

Consumption of a single serving of red raspberries per day reduces metabolic syndrome parameters in high-fat fed mice

Intake of one daily serving of raspberry ameliorates the symptoms of metabolic syndrome in a high fat diet fed C57BL/6J mouse model.

CaMKIIδ meditates phenylephrine induced cardiomyocyte hypertrophy through store-operated Ca2+ entry

Evidence suggests that store-operated Ca2+ entry (SOCE) is involved in the hypertrophy of cardiomyocytes. The signaling mechanisms of SOCE contributing to cardiac hypertrophy following phenylephrine (PE) stimulation are not fully understood. Ca²⁺/calmodulin-dependent protein kinase II δ (CaMKIIδ) plays an important role in regulating intracellular Ca²⁺ hemostasis and function in the cardimyocytes. This study is aimed to determine the role of CaMKIIδ in regulating the PE-induced myocardial hypertrophy and the associated molecular signaling mechanisms. We used primary cultures of neonatal cardimyocytes isolated from the left ventricle of Sprague Dawley rats to investigate the effects of CaMKIIδ on myocardial hypertrophy and intracellular Ca²⁺ mobilization. We found that the expression of CaMKIIδ was enhanced in PE-induced hypertrophic cardiomyocytes. CaMKIIδ siRNA, CaMKII inhibitor KN93, and SOCE blocker BTP2 attenuated the increase in the expression of CaMKIIδ and normalized the hypertrophic markers, atrial natriuretic peptide and brain natriuretic peptide, and size of cardiomyocytes induced by PE stimulation. The protein level of stromal interaction molecule 1 and Orai1, the essential components of the SOCE, is also enhanced in hypertrophic cardiomyocytes, which were normalized by CaMKIIδ siRNA and KN93 treatment. Hypertrophic cardiomyocytes showed an increase in the peak of Ca²⁺ transient following store depletion, which was inhibited by SOCE blocker BTP2, CaMKIIδ siRNA, and KN93. The Ca²⁺ currents through Ca²⁺ release-activated Ca²⁺ channels were increased in PE-treated cardiomyocytes and were attenuated by CaMKIIδ siRNA and KN93. These data indicate that PE-induced myocardial hypertrophy requires a complex signaling pathway that involves activation of both CaMKIIδ and SOCE. In conclusion, these studies reveal that up-regulation of CaMKIIδ may contribute to the PE-induced myocardial hypertrophy through the activation of SOCE expressed in the cardiomyocytes.

The pro-fibrotic role of dipeptidyl peptidase 4 in carbon tetrachloride-induced experimental liver injury

Liver fibrosis is a progressive pathological process involving inflammation and extracellular matrix deposition. Dipeptidyl peptidase 4 (DPP4), also known as CD26, is a cell surface glycoprotein and serine protease. DPP4 binds to fibronectin, can inactivate specific chemokines, incretin hormone and neuropeptides, and influences cell adhesion and migration. Such properties suggest a pro-fibrotic role for this peptidase but this hypothesis needs in vivo examination. Experimental liver injury was induced with carbon tetrachloride (CCl₄) in DPP4 gene knockout (gko) mice. DPP4 gko had less liver fibrosis and inflammation and fewer B cell clusters than wild type mice in the fibrosis model. DPP4 inhibitor-treated mice also developed less liver fibrosis. DNA microarray and PCR showed that many immunoglobulin (Ig) genes and some metabolism-associated transcripts were differentially expressed in the gko strain compared with wild type. CCl₄-treated DPP4 gko livers had more IgM⁺ and IgG⁺ intrahepatic lymphocytes, and fewer CD4⁺, IgD⁺ and CD21⁺ intrahepatic lymphocytes. These data suggest that DPP4 is pro-fibrotic in CCl₄-induced liver fibrosis and that the mechanisms of DPP4 pro-fibrotic action include energy metabolism, B cells, NK cells and CD4⁺ cells.

Comparison of collagen proportionate areas in liver fibrosis quantification between chronic hepatitis B and C

Few studies have compared the distinct hepatic collagen morphometrics of chronic hepatitis B (CHB) and chronic hepatitis C (CHC). This study compared the discrepancies between CHB and CHC in liver fibrosis (F) quantification by using the collagen proportionate area (CPA) and liver stiffness (LS) measured with shear wave velocity (SWV).This study enrolled 274 eligible consecutive patients diagnosed with CHB (n = 137) or CHC (n = 137). Their ages ranged from 20 to 80 years (median = 50). In total, 154 patients (56.2%) were male. Participant LS was measured by using acoustic radiation force impulse elastography preceding an immediate percutaneous liver biopsy. The total proportion of the collagen stained with picrosirius red to the total tissue area was expressed as the CPA percentage, which was stratified into portal-bridging (PB) and perisinusoidal (PS) proportionate areas (PAs).Based on the METAVIR F staging system, 36 (26.3%), 36 (26.3%), 28 (20.4%), and 37 (27.0%) participants in the CHB group and 34 (24.8%), 45 (32.9%), 34 (24.8%), and 24 (17.5%) participants in the CHC group were staged as F1, F2, F3, and F4, respectively. Both the total CPAs and PBPAs were significantly (P < 0.05) higher in the CHC group than in the CHB group within all F-stratified subgroups. The SWVs were significantly (P < 0.05) higher in the CHC group than in the CHB group only within the F2, F3, and F4 subgroups. However, the PSPAs did not differ significantly between the CHC and CHB groups within all subgroups. Multiple regression analysis revealed that viral hepatitis etiology (P < 0.001), METAVIR F stages (P < 0.001), and platelet count (P = 0.007) were independent factors correlated with the CPA (R = 0.543, P < 0.001).In conclusion, both the F stage-stratified CPAs and SWVs tended to be higher in cases of CHC than in those of CHB. The type of viral hepatitis significantly affected both the CPA and SWV values. The PBPAs were more closely correlated with F stages and SWV than were the PSPAs.

Elastin Fiber Accumulation in Liver Correlates with the Development of Hepatocellular Carcinoma

Background & Aims

The fibrosis stage, which is evaluated by the distribution pattern of collagen fibers, is a major predictor for the development of hepatocellular carcinoma (HCC) for patients with hepatitis C. Meanwhile, the role of elastin fibers has not yet been elucidated. The present study was conducted to determine the significance of quantifying both collagen and elastin fibers.

Methods

We enrolled 189 consecutive patients with hepatitis C and advanced fibrosis. Using Elastica van Gieson-stained whole-slide images of pretreatment liver biopsies, collagen and elastin fibers were evaluated pixel by pixel (0.46 μm/pixel) using an automated computational method. Consequently, fiber amount and cumulative incidences of HCC within 3 years were analyzed.

Results

There was a significant correlation between collagen and elastin fibers, whereas variation in elastin fiber was greater than in collagen fiber. Both collagen fiber (p = 0.008) and elastin fiber (p < 0.001) were significantly correlated with F stage. In total, 30 patients developed HCC during follow-up. Patients who have higher elastin fiber (p = 0.002) in addition to higher collagen fiber (p = 0.05) showed significantly higher incidences of HCC. With regard to elastin fiber, this difference remained significant in F3 patients. Furthermore, for patients with a higher collagen fiber amount, higher elastin was a significant predictor for HCC development (p = 0.02).

Conclusions

Computational analysis is a novel technique for quantification of fibers with the added value of conventional staging. Elastin fiber is a predictor for the development of HCC independently of collagen fiber and F stage.

Head-to-Head Comparison between Collagen Proportionate Area and Acoustic Radiation Force Impulse Elastography in Liver Fibrosis Quantification in Chronic Hepatitis C

BACKGROUND

The aim of this study was to compare the diagnostic performances of the collagen proportionate area (CPA) and liver stiffness measurement (LSM) for liver fibrosis quantification in chronic hepatitis C (CHC).

METHODS

A total of 137 eligible consecutive Taiwanese patients (74 women and 63 men; age 21-80 years; median age 54 years), with CHC underwent LSM by using acoustic radiation force impulse (ARFI) elastography and an immediate percutaneous liver biopsy for METAVIR scoring. Liver tissue sections were stained using picrosirius red. Areas of the stained collagen and the tissue parenchyma were calculated in pixels. The ratio between the two areas was expressed as a CPA percentage. The result of LSM was presented as shear wave velocity (SWV).

RESULTS

METAVIR fibrosis (F) stages were dichotomized using the CPA (%) and SWV (m/s), and the optimal cut-off values were 7.47 and 1.59 for F1 versus F2-4; 12.56 and 1.73 for F1, 2 versus F3, 4; 15.32 and 1.96 for F1-3 versus F4. To dichotomize F1 versus F2-4, the areas under receiver operating characteristic curves for the CPA was 0.9349 (95% confidence interval: 0.8943-0.9755) and for SWV was 0.8434 (0.7762-0.9105) (CPA versus SWV, P = 0.0063). For F1, 2 versus F3, 4, the CPA was 0.9436 (0.9091-0.9781); SWV was 0.8997 (0.8444-0.9551) (P = 0.1587). For F1-3 versus F4, the CPA was 0.8647 (0.7944-0.9349); SWV was 0.9036 (0.8499-0.9573) (P = 0.2585). The CPA could be predicted in a linear regression formula by using SWV and platelet count (R2 = 0.524).

CONCLUSIONS

The CPA and ARFI elastography are promising tools for liver fibrosis evaluation. The CPA was superior to ARFI elastography in the diagnosis of significant fibrosis (≥ F2). The CPA may be independent of severe necroinflammation, which may augment liver stiffness.

Head-to-Head Comparison between Collagen Proportionate Area and Acoustic Radiation Force Impulse Elastography in Liver Fibrosis Quantification in Chronic Hepatitis C

BACKGROUND

The aim of this study was to compare the diagnostic performances of the collagen proportionate area (CPA) and liver stiffness measurement (LSM) for liver fibrosis quantification in chronic hepatitis C (CHC).

METHODS

A total of 137 eligible consecutive Taiwanese patients (74 women and 63 men; age 21-80 years; median age 54 years), with CHC underwent LSM by using acoustic radiation force impulse (ARFI) elastography and an immediate percutaneous liver biopsy for METAVIR scoring. Liver tissue sections were stained using picrosirius red. Areas of the stained collagen and the tissue parenchyma were calculated in pixels. The ratio between the two areas was expressed as a CPA percentage. The result of LSM was presented as shear wave velocity (SWV).

RESULTS

METAVIR fibrosis (F) stages were dichotomized using the CPA (%) and SWV (m/s), and the optimal cut-off values were 7.47 and 1.59 for F1 versus F2-4; 12.56 and 1.73 for F1, 2 versus F3, 4; 15.32 and 1.96 for F1-3 versus F4. To dichotomize F1 versus F2-4, the areas under receiver operating characteristic curves for the CPA was 0.9349 (95% confidence interval: 0.8943-0.9755) and for SWV was 0.8434 (0.7762-0.9105) (CPA versus SWV, P = 0.0063). For F1, 2 versus F3, 4, the CPA was 0.9436 (0.9091-0.9781); SWV was 0.8997 (0.8444-0.9551) (P = 0.1587). For F1-3 versus F4, the CPA was 0.8647 (0.7944-0.9349); SWV was 0.9036 (0.8499-0.9573) (P = 0.2585). The CPA could be predicted in a linear regression formula by using SWV and platelet count (R2 = 0.524).

CONCLUSIONS

The CPA and ARFI elastography are promising tools for liver fibrosis evaluation. The CPA was superior to ARFI elastography in the diagnosis of significant fibrosis (≥ F2). The CPA may be independent of severe necroinflammation, which may augment liver stiffness.

Evaluation of Histological and non-Invasive Methods for the Detection of Liver Fibrosis: The Values of Histological and Digital Morphometric Analysis, Liver Stiffness Measurement and APRI Score

Prognosis and treatment of liver diseases mainly depend on the precise evaluation of the fibrosis. Comparisons were made between the results of Metavir fibrosis scores and digital morphometric analyses (DMA), liver stiffness (LS) values and aminotransferase-platelet ratio (APRI) scores, respectively. Liver biopsy specimens stained with Sirius red and analysed by morphometry, LS and APRI measurements were taken from 96 patients with chronic liver diseases (56 cases of viral hepatitis, 22 cases of autoimmune- and 18 of mixed origin). The strongest correlation was observed between Metavir score and DMA (r = 0.75 p < 0.05), followed in decreasing order by LS and Metavir (r = 0.61), LS and DMA (r = 0.47) LS and APRI (r = 0.35) and Metavir and APRI (r = 0.24), respectively. DMA is a helpful additional tool for the histopathological evaluation of fibrosis, even when the sample size is small and especially in case of advanced fibrosis. The non-invasive methods showed good correlation with the histopathological methods; LS proved to be more accurate than APRI. The stronger correlation between LS values and Metavir scores, as well as the results of DMA in case of appropriate sample size were remarkable.

Expression and function of Kv1.1 potassium channels in human atria from patients with atrial fibrillation

Voltage-gated Kv1.1 channels encoded by the Kcna1 gene are traditionally regarded as being neural-specific with no known expression or intrinsic functional role in the heart. However, recent studies in mice reveal low-level Kv1.1 expression in heart and cardiac abnormalities associated with Kv1.1-deficiency suggesting that the channel may have a previously unrecognized cardiac role. Therefore, this study tests the hypothesis that Kv1.1 channels are associated with arrhythmogenesis and contribute to intrinsic cardiac function. In intra-atrial burst pacing experiments, Kcna1-null mice exhibited increased susceptibility to atrial fibrillation (AF). The atria of Kcna1-null mice showed minimal Kv1 family ion channel remodeling and fibrosis as measured by qRT-PCR and Masson's trichrome histology, respectively. Using RT-PCR, immunocytochemistry, and immunoblotting, KCNA1 mRNA and protein were detected in isolated mouse cardiomyocytes and human atria for the first time. Patients with chronic AF (cAF) showed no changes in KCNA1 mRNA levels relative to controls; however, they exhibited increases in atrial Kv1.1 protein levels, not seen in paroxysmal AF patients. Patch-clamp recordings of isolated human atrial myocytes revealed significant dendrotoxin-K (DTX-K)-sensitive outward current components that were significantly increased in cAF patients, reflecting a contribution by Kv1.1 channels. The concomitant increases in Kv1.1 protein and DTX-K-sensitive currents in atria of cAF patients suggest that the channel contributes to the pathological mechanisms of persistent AF. These findings provide evidence of an intrinsic cardiac role of Kv1.1 channels and indicate that they may contribute to atrial repolarization and AF susceptibility.

Micro-CT and histological analysis of Ti6Al7Nb custom made implants with hydroxyapatite and SiO2-TiO2 coatings in a rabbit model

Background and aim

Bone defect reconstruction in the maxillofacial area comes as a necessity after traumatic, oncological or congenital pathology. Custom made implant manufacturing, such as selective laser melting (SLM), is very helpful when bone reconstruction is needed. In the present study we assessed the osseointegration of custom made implants made of Ti₆Al₇Nb with two different coatings: SiO₂-TiO₂ and hydroxyapatite, by comparing the bone mineral density (BMD) measured on micro-CT and the histological mineralized bone surrounding the implants.

Methods

Custom made – cylindrical type – implants were produced by selective laser melting, coated with SiO₂-TiO₂ and hydroxyapatite and implanted in the rabbit femur. The animals (divided into 3 groups) were sacrificed at 1, 3 and 6 months and the implants were removed together with the surrounding bone. Bone mineral density and histological examination of the bone-implant surface was performed for each group.

Results

BMD and histological examination of the samples determined the quantity of mineralized bone at the implant site, showing a good percentage of mineralized bone for the coated implants at 1, 3 and 6 months. The measurements for the implants without coating showed a significant lower quantity of mineralized bone at 3 months compared with the implants with coating, and a good quantity of mineralized bone at 6 months, showing a process of demineralization followed by remineralization in the last month. The measurements of BMD showed similar results with the histological examination.

Conclusions

The use of micro-CT and the measurement of BMD are a reliable, minimally invasive and a quick method of osseointegration assessment.

Rat rotator cuff muscle responds differently from hindlimb muscle to a combined tendon-nerve injury

Rotator cuff tears (RCTs) are among the most common musculoskeletal injuries seen by orthopaedic surgeons. Clinically, massive cuff tears lead to unique pathophysiological changes in rotator cuff muscle, including atrophy, and massive fatty infiltration, which are rarely seen in other skeletal muscles. Studies in a rodent model for RCT have demonstrated that these histologic findings are accompanied by activation of the Akt/mammalian target of rapamycin (mTOR) and transforming growth factor-β (TGF-β) pathways following combined tendon-nerve injury. The purpose of this study was to compare the histologic and molecular features of rotator cuff muscle and gastrocnemius muscle--a major hindlimb muscle, following combined tendon-nerve injury. Six weeks after injury, the rat gastrocnemius did not exhibit notable fatty infiltration compared to the rotator cuff. Likewise, the adipogenic markers SREBP-1 and PPARγ as well as the TGF-β canonical pathway were upregulated in the rotator cuff, but not the gastrocnemius. Our study suggests that the rat rotator cuff and hindlimb muscles differ significantly in their response to a combined tendon-nerve injury. Clinically, these findings highlight the unique response of the rotator cuff to injury, and may begin to explain the poor outcomes of massive RCTs compared to other muscle-tendon injuries.

Sirtuin 1 ablation in endothelial cells is associated with impaired angiogenesis and diastolic dysfunction

Discordant myocardial growth and angiogenesis can explain left ventricular (LV) hypertrophy progressing toward heart failure with aging. Sirtuin 1 expression declines with age; therefore we explored the role played by angiogenesis and Sirtuin 1 in the development of cardiomyopathy. We compared the cardiac function of 10- to 15-wk-old (wo), 30-40 wo, and 61-70 wo endothelial Sirtuin 1-deleted (Sirt1(endo-/-)) mice and their corresponding knockout controls (Sirt1(Flox/Flox)). After 30-40 wk, Sirt1(endo-/-) animals exhibited diastolic dysfunction (DD), decreased mRNA expression of Serca2a in the LV, and decreased capillary density compared with control animals despite a similar VEGFa mRNA expression. However, LV fibrosis and hypoxia-inducible factor (HIF)1α expression were not different. The creation of a transverse aortic constriction (TAC) provoked more severe DD and LV fibrosis in Sirt1(endo-/-) compared with control TAC animals. Although the VEGFa mRNA expression was not different and the protein expression of HIF1α was higher in the Sirt1(endo-/-) TAC animals, capillary density remained reduced. In cultured endothelial cells administration of Sirtuin 1 inhibitor decreased mRNA expression of VEGF receptors FLT 1 and FLK 1. Ex vivo capillary sprouting from aortic explants showed impaired angiogenic response to VEGF in the Sirt1(endo-/-) mice. In conclusion, the data demonstrate 1) a defect in angiogenesis preceding development of DD; 2) dispensability of endothelial Sirtuin 1 under unstressed conditions and during normal aging; and 3) impaired angiogenic adaptation and aggravated DD in Sirt1(endo-/-) mice challenged with LV overload.

Changes to signal peptide and the level of transforming growth factor- β1 due to T869C polymorphism of TGF β1 associated with lupus renal fibrosis

Lupus Nephritis (LN) is a serious manifestation of lupus that can lead to End Stage Renal Disease (ESRD). Fibrosis is the main feature of ESRD, and it is likely influenced by Transforming Growth Factor Beta1 (TGFβ1). The T869C gene polymorphism of TGFβ1 is assumed to change the signal peptide, that has potential to interfere the urine production and renal protein expression of TGFβ1. The influence of T869C gene polymorphism on TGFβ1 production and renal fibrosis was evaluated in this study. Subjects were 45 patients LN with renal fibrosis and 45 participants without renal fibrosis as control, that were recruited from 2011 to 2013.Their urinary TGFβ1 levels and TGFβ1 gene polymorphisms were examined. All lupus patients underwent renal biopsy to assess their protein expression of TGFβ1 in the renal tissue by immunohistochemistry and their renal fibrosis by morphometry and chronicity index. Changes in the signal peptide interaction with Signal Recognition Particle (SRP) and translocon of endoplasmic reticulum were analyzed by Bioinformatics. Levels of urinary and protein expression of TGFβ1 increased in the LN with renal fibrosis group. There were significant differences in levels of urinary TGFβ1 in T, C allele and TT, TC, CC genotypes between case and control groups. Furthermore, patients with C allele are 3.86 times more at risk of renal fibrosis than T allele. The C allele encodes proline, which stabilizes the interaction of the TGFβ1 signal peptide with SRP and translocon, resulting in elevation of TGFβ1 secretion. Our results indicated that T869C gene polymorphism of TGFβ1 changes the signal peptide, that contributes to the production of urinary TGFβ1 and affects renal fibrosis in lupus nephritis.

Quantification of myocardial fibrosis by digital image analysis and interactive stereology

BACKGROUND

Cardiac fibrosis disrupts the normal myocardial structure and has a direct impact on heart function and survival. Despite already available digital methods, the pathologist's visual score is still widely considered as ground truth and used as a primary method in histomorphometric evaluations. The aim of this study was to compare the accuracy of digital image analysis tools and the pathologist's visual scoring for evaluating fibrosis in human myocardial biopsies, based on reference data obtained by point counting performed on the same images.

METHODS

Endomyocardial biopsy material from 38 patients diagnosed with inflammatory dilated cardiomyopathy was used. The extent of total cardiac fibrosis was assessed by image analysis on Masson's trichrome-stained tissue specimens using automated Colocalization and Genie software, by Stereology grid count and manually by Pathologist's visual score.

RESULTS

A total of 116 slides were analyzed. The mean results obtained by the Colocalization software (13.72 ± 12.24%) were closest to the reference value of stereology (RVS), while the Genie software and Pathologist score gave a slight underestimation. RVS values correlated strongly with values obtained using the Colocalization and Genie (r>0.9, p<0.001) software as well as the pathologist visual score. Differences in fibrosis quantification by Colocalization and RVS were statistically insignificant. However, significant bias was found in the results obtained by using Genie versus RVS and pathologist score versus RVS with mean difference values of: -1.61% and 2.24%. Bland-Altman plots showed a bidirectional bias dependent on the magnitude of the measurement: Colocalization software overestimated the area fraction of fibrosis in the lower end, and underestimated in the higher end of the RVS values. Meanwhile, Genie software as well as the pathologist score showed more uniform results throughout the values, with a slight underestimation in the mid-range for both.

CONCLUSION

Both applied digital image analysis methods revealed almost perfect correlation with the criterion standard obtained by stereology grid count and, in terms of accuracy, outperformed the pathologist's visual score. Genie algorithm proved to be the method of choice with the only drawback of a slight underestimation bias, which is considered acceptable for both clinical and research evaluations.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/9857909611227193.

El-Aziz LF, Abdel kawy HS, AbdEl-Samad AA, El-Kharashi OA. Hepatoprotective effects of early pentoxifylline administration on hepatic injury induced by concanavalin A in rat

Tumor necrosis factor alpha (TNF-α) plays an important role in the pathogensis of hepatitis C virus (HCV) infection induced liver injury. This study aimed to evaluate the effects of TNF-α inhibition with pentoxifylline (PTX) on concanavalin A (Con A)-induced hepatic injury in rats. The rats were distributed among 3 groups: (i) control group (1 mL saline·week–1 by intravenous injection (i.v.)); (ii) Con A treatment group (20 mg Con A·(kg body mass)–1·week–1, i.v.), and (iii) rats treated with Con A and with PTX (200 mg PTX·(kg body mass)–1·day–1, per oral) group. Blood samples and livers were collected at the end of weeks 1, 2, 4, and 8 of Con A treatment. Portal pressure (PP) was measured at the end of week 8. The administration of PTX was found to confer significant protection against the injurious effects of Con A on the liver, by reducing serum levels of aspartate aminotransferase, alanine aminotransferase, hepatic TNF-α, and malondialdehyde. Histopathological examination revealed that treatment with PTX significantly suppressed early inflammation, reduced alpha smooth muscle actin, and the apoptosis of hepatocytes induced by Con A. Moreover, PTX significantly (P < 0.05) reduced PP, and quantitative analyses of the area of fibrosis induced by treatment with Con A showed a significant reduction at the end of week 8. We conclude that rats treated with PTX revealed a more or less normal hepatocyte architecture as well as marked improvement in fibrosis and PP.

An inexpensive and worldwide available digital image analysis technique for histological fibrosis quantification in chronic hepatitis C

Hepatic fibrosis staging is based on semiquantitative scores. Digital imaging analysis (DIA) appears more accurate because fibrosis is quantified in a continuous scale. However, high cost, lack of standardization and worldwide unavailability restrict its use in clinical practice. We developed an inexpensive and widely available DIA technique for fibrosis quantification in hepatitis C, and here, we evaluate its reproducibility and correlation with semiquantitative scores, and determine the fibrosis percentage associated with septal fibrosis and cirrhosis. 282 needle biopsies staged by Ishak and METAVIR scores were included. Images of trichrome-stained sections were captured and processed using Adobe(®) Photoshop(®) CS3 and Adobe(®) Bridge(®) softwares. The percentage of fibrosis (fibrosis index) was determined by the ratio between the fibrosis area and the total sample area, expressed in pixels calculated in an automated way. An excellent correlation between DIA fibrosis index and Ishak and METAVIR scores was observed (Spearman's r = 0.95 and 0.92; P < 0.001, respectively). Excellent intra-observer reproducibility was observed in a randomly chosen subset of 39 biopsies with an intraclass correlation index of 0.99 (95% CI, 0.95-0.99). The best cut-offs associated with septal fibrosis and cirrhosis were 6% (AUROC 0.97, 95% CI, 0.95-0.99) and 27% (AUROC 1.0, 95% CI, 0.99-1), respectively. This new DIA technique had high correlation with semiquantitative scores in hepatitis C. This method is reproducible, inexpensive and available worldwide allowing its use in clinical practice. The incorporation of DIA technique provides a more complete evaluation of fibrosis adding the quantification to architectural patterns.

Taxifolin prevents diabetic cardiomyopathy in vivo and in vitro by inhibition of oxidative stress and cell apoptosis

Diabetic cardiomyopathy has been increasingly recognized as an important cause of heart failure in diabetic patients. Excessive oxidative stress has been suggested to play a critical role in the development of diabetic cardiomyopathy. The objective of this study was to investigate the potential protective effects and mechanisms of taxifolin on cardiac function of streptozotocin-induced diabetic mice and on hyperglycemia-induced apoptosis of H9c2 cardiac myoblasts. In vivo study revealed that taxifolin improved diastolic dysfunction, ameliorated myocardium structure abnormality, inhibited myocyte apoptosis and enhanced endogenous antioxidant enzymes activities. Interestingly, taxifolin reduced angiotensin II level in myocardium, inhibited NADPH oxidase activity, and increased JAK/STAT3 activation. In vitro investigation demonstrated that taxifolin inhibited 33 mM glucoseinduced H9c2 cells apoptosis by decreasing intracellular ROS level. It also inhibited caspase-3 and caspase-9 activation, restored mitochondrial membrane potential, and regulated the expression of proteins related to the intrinsic pathway of apoptosis, thus inhibiting the release of cytochrome c from mitochondria into the cytoplasm. In conclusion, taxifolin exerted cardioprotective effects against diabetic cardiomyopathy by inhibiting oxidative stress and cardiac myocyte apoptosis and might be a potential agent in the treatment of diabetic cardiomyopathy.

Correlation of MR elastography with morphometric quantification of liver fibrosis (Fibro-C-Index) in chronic hepatitis B

PURPOSE

We evaluated the correlation of MR Elastography (MRE) with morphometric assessment of liver fibrosis in chronic hepatitis B (CHB).

METHODS

Thirty-two patients with CHB underwent both MRE and a liver biopsy within a 6-month interval. MRE was performed using standard MRE sequence on a 1.5 Tesla clinical scanner. The liver stiffness (LS) was measured on automatically generated stiffness maps. Morphometric quantification of fibrosis of liver biopsies was performed using a semi-automated image analysis program and expressed as percentage area (Fibro-C-Index). Correlations between MRE, Fibro-C-Index, and histologic fibrosis stages were evaluated. Receiver operating curve (ROC) analysis of MRE and Fibro-C-index for differentiating fibrosis (≥F1), significant fibrosis (≥F2), advanced fibrosis (≥F3), and cirrhosis (F4) was performed.

RESULTS

MRE showed excellent correlation with both Fibro-C-Index (r = 0.78, 95% confidence interval [CI], 0.59-0.88, P < 0.001) and histologic staging (rho = 0.87, 95% CI, 0.72-0.94, P < 0.0001). Significant differences in MRE (P = 0.0001) and Fibro-C-Index (P = 0.003) among different stages of liver fibrosis was found. MRE and Fibro-C-Index had similar accuracies for differentiating fibrosis stages: ≥F1 (0.87 versus 0.81, P = 0.6), ≥F2 (0.95 versus 0.94, P = 0.78), ≥F3 (0.98 versus 0.96, P = 0.76), and F4 (1.00 versus 0.92, P = 0.10).

CONCLUSION

MRE is an excellent noninvasive indicator of liver fibrosis burden in CHB.

Quantifying the interfibrillar spacing and fibrillar orientation of the aortic extracellular matrix using histology image processing: toward multiscale modeling

An essential part of understanding tissue microstructural mechanics is to establish quantitative measures of the morphological changes. Given the complex, highly localized, and interactive architecture of the extracellular matrix, developing techniques to reproducibly quantify the induced microstructural changes has been found to be challenging. In this paper, a new method for quantifying the changes in the fibrillar organization is developed using histology images. A combinatorial frequency-spatial image processing approach was developed based on the Fourier and Hough transformations of histology images to measure interfibrillar spacing and fibrillar orientation, respectively. The method was separately applied to the inner and outer wall thickness of native- and elastin-isolated aortic tissues under different loading states. Results from both methods were interpreted in a complementary manner to obtain a more complete understanding of morphological changes due to tissue deformations at the microscale. The observations were consistent in quantifying the observed morphological changes during tissue deformations and in explaining such changes in terms of tissue-scale phenomena. The findings of this study could pave the way for more rigorous modeling of structure-property relationships in soft tissues, with implications extendable to cardiovascular constitutive modeling and tissue engineering.

Gαi2 signaling: friend or foe in cardiac injury and heart failure?

Receptors coupled to G proteins have many effects on the heart. Enhanced signaling by Gα(s) and Gα(q) leads to cardiac injury and heart failure, while Gα(i2) signaling in cardiac myocytes can protect against ischemic injury and β-adrenergic-induced heart failure. We asked whether enhanced Gα(i2) signaling in mice could protect against heart failure using a point mutation in Gα(i2) (G184S), which prevents negative regulation by regulators of G protein signaling. Contrary to our expectation, it worsened effects of a genetic dilated cardiomyopathy (DCM) and catecholamine-induced cardiac injury. Gα (i2) (G184S/+) /DCM double heterozygote mice (TG9(+)Gα (i2) (G184S/+)) had substantially decreased survival compared to DCM animals. Furthermore, heart weight/body weight ratios (HW/BW) were significantly greater in TG9(+)Gα (i2) (G184S/+) mice as was expression of natriuretic peptide genes. Catecholamine injury in Gα (i2) (G184S/G184S) mutant mice produced markedly increased isoproterenol-induced fibrosis and collagen III gene expression vs WT mice. Cardiac fibroblasts from Gα (i2) (G184S/G184S) mice also showed a serum-dependent increase in proliferation and ERK phosphorylation, which were blocked by pertussis toxin and a mitogen-activated protein/extracellular signal-regulated kinase kinase inhibitor. Gα(i2) signaling in cardiac myocytes protects against ischemic injury but enhancing Gα(i2) signaling overall may have detrimental effects in heart failure, perhaps through actions on cardiac fibroblasts.

Ischemia-reperfusion injury leads to distinct temporal cardiac remodeling in normal versus diabetic mice

Diabetes is associated with higher incidence of myocardial infarction (MI) and increased propensity for subsequent events post-MI. Here we conducted a temporal analysis of the influence of diabetes on cardiac dysfunction and remodeling after ischemia reperfusion (IR) injury in mice. Diabetes was induced using streptozotocin and IR performed by ligating the left anterior descending coronary artery for 30 min followed by reperfusion for up to 42 days. We first evaluated changes in cardiac function using echocardiography after 24 hours reperfusion and observed IR injury significantly decreased the systolic function, such as ejection fraction, fractional shortening and end systolic left ventricular volume (LVESV) in both control and diabetic mice. The longitudinal systolic and diastolic strain rate were altered after IR, but there were no significant differences between diabetic mice and controls. However, a reduced ability to metabolize glucose was observed in the diabetic animals as determined by PET-CT scanning using 2-deoxy-2-(¹⁸F)fluoro-D-glucose. Interestingly, after 24 hours reperfusion diabetic mice showed a reduced infarct size and less apoptosis indicated by TUNEL analysis in heart sections. This may be explained by increased levels of autophagy detected in diabetic mice hearts. Similar increases in IR-induced macrophage infiltration detected by CD68 staining indicated no change in inflammation between control and diabetic mice. Over time, control mice subjected to IR developed mild left ventricular dilation whereas diabetic mice exhibited a decrease in both end diastolic left ventricular volume and LVESV with a decreased intraventricular space and thicker left ventricular wall, indicating concentric hypertrophy. This was associated with marked increases in fibrosis, indicted by Masson trichrome staining, of heart sections in diabetic IR group. In summary, we demonstrate that diabetes principally influences distinct IR-induced chronic changes in cardiac function and remodeling, while a smaller infarct size and elevated levels of autophagy with similar cardiac function are observed in acute phase.

The use of design-based stereology to evaluate volumes and numbers in the liver: a review with practical guidelines

Stereology offers a number of tools for the analysis of sections in microscopy (which usually provide only two-dimensional information) for the purpose of estimating geometric quantities, such as volume, surface area, length or number of particles (cells or other structures). The use of these tools enables recovery of the three-dimensional information that is inherent in biological tissues. This review uses the liver as a paradigm for summarizing the most commonly used state-of-the-art methods for quantitation in design-based stereology. Because it is often relevant to distinguish hyperplasia and hypertrophy in liver responses, we also focus on potential pitfalls in the sampling and processing of liver specimens for stereological purposes, and assess the existing methods for volume and number estimation. With respect to volume, we considered whole liver volume (V), volume density (V(V)) and so-called local volumes, including the number-weighted volume (V(N)) and the volume-weighted volume (V(V)). For number, we considered the total number (N) and the numerical density (N(V)). If correctly applied, current stereological methods guarantee that no bias is introduced in the estimates, which will be therefore accurate; additionally, methods can be tuned for obtaining precise quantitative estimates that can reveal subtle changes in the volume or number of selected hepatic cells. These methods have already detailed the effects of some substances and specific diets on the liver, and should be routinely included in the toolbox of liver research.

Histomorphometry of the ligaments using a generic-purpose image processing software, a new strategy for semi-automatized measurements

Gold chloride technique can be combined with Adobe Photoshop® software to yield a quantitative assessment of the different areas in heterogeneous structures as are ligament. A semi-automatized method based on the sum of two- and three-dimensional morphological criteria upon colorimetric criteria allows the identification and measurement of the area occupied by a structure of interest. It also allows the quantification of color intensity to differentiate structures with similar staining avidity, like vessels and nerves. This computer-assisted, semiquantitative procedure for computerized morphometry is relatively simple to perform. The accuracy, efficiency, and reproducibility of this method based on a commercially available imaging program were considered adequate when tested on the anterior cruciate ligament of the cat. Image normalization by trained observers using a commercially available software package designed for photography, applied to a sample randomly chosen, has provided the means of making reproducible measurements of heterogeneous structures.

Collagen proportionate area of liver tissue determined by digital image analysis in patients with HBV-related decompensated cirrhosis

BACKGROUND

The accurate assessment of the degree of hepatic fibrosis plays a critical role in guiding the diagnosis, treatment and prognostic assessment of chronic liver diseases. Liver biopsy is currently the most reliable method to evaluate the severity of hepatic fibrosis. However, liver biopsy is an invasive procedure associated with morbidity and mortality, and has several limitations in patients with decompensated cirrhosis. There is no report on the collagen proportionate area (CPA) of liver tissue in the decompensated stage of cirrhosis. This study aimed to determine the CPA of resected liver tissue samples from patients with HBV-related decompensated cirrhosis using digital image analysis, and to analyze the relationship between the CPA and liver functional reserve.

METHODS

Fifty-three resected liver tissue samples from liver transplant patients with chronic hepatitis B-induced decompensated cirrhosis were stained with Masson's trichrome, and the CPA in these samples was quantitatively determined using digital image analysis. The values of relevant liver function just before liver transplantation, the CPA in liver tissue, and their correlation were analyzed.

RESULTS

The mean CPA at the decompensated stage of cirrhosis was 35.93+/-14.42% (11.24%-63.41%). The correlation coefficients of the CPA with a model for end-stage liver disease score, serum total bilirubin and international standard ratio of prothrombin B were 0.553, 0.519 and 0.533, respectively (P<0.001). With increasing CPA values, the three indices reflecting liver functional reserve also changed significantly.

CONCLUSIONS

The degree of fibrosis may be correlated with the functional reserve. With the advancement of fibrosis, the liver functional reserve is attenuated accordingly.

Spontaneous repopulation of β-catenin null livers with β-catenin-positive hepatocytes after chronic murine liver injury

Prolonged exposure of mice to diet containing 0.1% 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) results in hepatobiliary injury, atypical ductular proliferation, oval cell appearance, and limited fibrosis. Previously, we reported that short-term ingestion of DDC diet by hepatocyte-specific β-catenin conditional knockout (KO) mice led to fewer A6-positive oval cells than wildtype (WT) littermates. To examine the role of β-catenin in chronic hepatic injury and repair, we exposed WT and KO mice to DDC for 80 and 150 days. Paradoxically, long-term DDC exposure led to significantly more A6-positive cells, indicating greater atypical ductular proliferation in KO, which coincided with increased fibrosis and cholestasis. Surprisingly, at 80 and 150 days in KO we observed a significant amelioration of hepatocyte injury. This coincided with extensive repopulation of β-catenin null livers with β-catenin-positive hepatocytes at 150 days, which was preceded by appearance of β-catenin-positive hepatocyte clusters at 80 days and a few β-catenin-positive hepatocytes at earlier times. Intriguingly, occasional β-catenin-positive hepatocytes that were negative for progenitor markers were also observed at baseline in the KO livers, suggesting spontaneous escape from cre-mediated recombination. These cells with hepatocyte morphology expressed mature hepatocyte markers but lacked markers of hepatic progenitors. The gradual repopulation of KO livers with β-catenin-positive hepatocytes occurred only following DDC injury and coincided with a progressive loss of hepatic cre-recombinase expression. A few β-catenin-positive cholangiocytes were observed albeit only after long-term DDC exposure and trailed the appearance of β-catenin-positive hepatocytes.

CONCLUSION

In a chronic liver injury model, β-catenin-positive hepatocytes exhibit growth and survival advantages and repopulate KO livers, eventually limiting hepatic injury and dysfunction despite increased fibrosis and intrahepatic cholestasis.

Effects of interventions on intra- and interobserver agreement on interpretation of nonalcoholic fatty liver disease histology

Accurate and reproducible interpretation of nonalcoholic fatty liver disease (NAFLD) histology has significant clinical and research-related implications. We evaluated the impact of 2 interventions ([1] review of illustrative histologic images of NAFLD with the study pathologists; [2] use of a scoring sheet with written diagnostic criteria for different NAFLD phenotypes) on intra- and interobserver agreement on interpretation of NAFLD histology. Before and after the interventions, 2 pathologists twice read 65 liver biopsies done for evaluation of suspected NAFLD. The intra- and interobserver agreement was highest on assessment of steatosis and fibrosis. The interventions significantly improved the intraobserver agreement only on assessment of hepatocellular ballooning. The interobserver agreement was only fair on assessment of lobular inflammation, ballooning, and diagnostic classification and did not improve after the interventions. Methods to improve interobserver agreement on assessment of lobular inflammation and ballooning are needed and would likely increase pathologists' agreement on NAFLD diagnostic classification.

The anti-fibrotic effect of mycophenolic acid-induced neutral endopeptidase

Mycophenolic acid (MPA) appears to have anti-fibrotic effects, but the molecular mechanisms underlying this are unknown. We prospectively studied 35 stable kidney transplant recipients maintained on cyclosporine and azathioprine. We converted 20 patients from azathioprine to enteric-coated mycophenolate sodium (EC-MPS) and continued the remaining 15 patients on azathioprine. Exploratory mRNA expression profiling, performed on five randomly selected EC-MPS patients, revealed significant upregulation of neutral endopeptidase (NEP), which is an enzyme that degrades angiotensin II. We confirmed these microarray data by measuring levels of NEP expression in all subjects; in addition, we found that NEP gene expression correlated inversely with proteinuria. In an additional 33 patients, glomerular and tubular NEP protein levels from renal graft biopsies were significantly higher among the 13 patients receiving cyclosporine + EC-MPS than among the 12 patients receiving cyclosporine + azathioprine or 8 patients receiving cyclosporine alone. Glomerular NEP expression inversely correlated with glomerulosclerosis and proteinuria, and tubular NEP expression inversely correlated with interstitial fibrosis. Incubation of human proximal tubular cells with MPA increased NEP gene expression in a dose- and time-dependent manner. Moreover, MPA reduced angiotensin II-induced expression of the profibrotic factor plasminogen activator inhibitor-1, and a specific NEP inhibitor completely reversed this effect. Taken together, our data suggest that MPA directly induces expression of neutral endopeptidase, which may reduce proteinuria and slow the progression of renal damage in kidney transplant recipients.

Immunohistochemical characterization of glomerular and tubulointerstitial infiltrates in renal transplant patients with chronic allograft dysfunction

BACKGROUND

The term chronic allograft nephropathy (CAN) was deleted in the Eighth Banff Classification and two new categories were introduced: chronic T-cell-mediated rejection (CTMR) and chronic active humoral rejection (CAHR). The aim of this study was to revise our CAN cases diagnosed in the last 4 years, analyse allograft survival rates and identify types of infiltrating cells in the different settings.

METHODS

Seventy-nine patients with biopsy-proven CAN were examined and classified into four groups according to the Banff 2005 criteria: CTMR, CAHR, chronic calcineurin inhibitor toxicity (CNITOX) and interstitial fibrosis and tubular atrophy not otherwise specified (NOS). CD4, CD8, CD20, CD68, CD103, Foxp3 and IL-17 protein expression and C4d deposits were investigated.

RESULTS

We diagnosed 20 CTMR, 13 CAHR, 28 CNITOX, and 18 NOS. Death-censored graft survival at 4 years from renal biopsy was worse in CAHR compared with the other types of chronic injury. Glomerular CD8(+) cells were increased in CTMR vs CNITOX and NOS. Interstitial CD4(+) and CD8(+) cells were increased in CTMR vs CNITOX. CD68(+) cells in glomerular and peritubular capillaries were higher in CAHR vs CNITOX, CTMR and NOS. CD103(+) cells were higher in cases with tubulitis than in those without. T regulatory and T helper 17 cells were rarely observed in the different settings.

CONCLUSIONS

Graft survival was worse in patients with CAHR. The presence of any grade transplant glomerulopathy and chronic allograft vasculopathy are poorer prognostic factors. Infiltrating CD8(+), CD103(+) and CD4(+) cells may help to differentiate CTMR from other types of chronic injury, thus improving diagnostic/prognostic features of biopsy in patients with chronic allograft dysfunction.

Development and evaluation of an open source Delphi-based software for morphometric quantification of liver fibrosis

Background

Computer-based morphometry can minimize subjectivity in the assessment of liver fibrosis. An image processing program was developed with Delphi for the quantification of fibrosis in liver tissue samples stained with Sirius Red. Bile duct ligated and sham operated wild type C57BL/6 mice served as a model of time-dependent induction of liver fibrosis. Formation of fibrosis was determined with the developed software at day 0, 3, 7, 10, 14, 20, 30 and 60. The results were compared to a semi-quantitative scoring system.

Results

Quantitative accumulation of collagen fibres was observed from day 3 to day 14, with a slight further increase thereafter. During ongoing fibrogenesis, there was a significant elevation of alanine aminotransferase (ALT), aspartate transaminase (AST) and bilirubin. The results from our computer-based morphometric analysis were highly correlated with the results that were obtained in a standardized pathology semi-quantitative scoring system (R ² = 0.89, n = 38).

Conclusions

Using our Delphi-based image analysing software, the morphometric assessment of fibrosis is as precise as semi-quantitative scoring by an experienced pathologist. This program can be a valuable tool in any kind of experimental or clinical setting for standardized quantitative assessment of fibrosis.