Renal expression of alpha-smooth muscle actin and c-Met in children with Henoch-Schönlein purpura nephritis

Pravastatin attenuates isoprenaline induced cardiac fibrosis in a mouse model

We investigated the effects of pravastatin (PRAVA) on isoprenaline (ISP) induced cardiac fibrosis using four groups of mice: untreated control, PRAVA, ISP, ISP + PRAVA groups. ISP, 20 mg/kg, was administered subcutaneously daily for 14 days. PRAVA, 20 mg/kg, was administered orally daily for 14 days. Mice were sacrificed on day15 and heart and blood samples were collected to investigate cardiac injury markers. The mean body weight for the ISP group on day 15 was decreased significantly compared to day 0; PRAVA increased the mean body weight slightly on day 15 of treatment compared to day 0. The heart:body weight ratio was increased in the ISP group compared to the control group, but the ratio was returned to near control ratio in the PRAVA + ISP group. The serum creatine kinase-myocardial band (CK-MB) level was reduced significantly in the PRAVA + ISP group compared to the ISP group. Serum triglyceride level was decreased significantly in ISP + PRAVA group compared to the ISP group. PRAVA administration significantly reduced tissue collagen I and III levels in the ISP + PRAVA group compared to the ISP group. Lipid oxidation was decreased and reduced glutathione activity was increased in the PRAVA + ISP group compared to the ISP group. IL-6, α-SMA, CTGF, TGF-β and SMAD-3 gene expressions were decreased in the PRAVA + ISP group compared to the ISP group. We found fewer inflammatory cells and less fibrosis in heart tissue in the PRAVA + ISP group compared to the ISP group. PRAVA decreased ISP induced cardiac fibrosis by reducing oxidative stress, collagen deposition and inflammation, as well as by decreasing expression of TGF-β, SMAD-3 and CTGF genes.

Effects and mechanism of Rictor interference in podocyte injury induced by high glucose

Rapamycin-insensitive companion of mTOR (Rictor) is a critical effector of mTOR protein complex 2 (mTORC2). The aim of the present study was to investigate the effect of Rictor in the mTORC2 signaling pathway in high glucose (HG)-induced diabetic podocyte injury by silencing the expression of Rictor. In the present study, mouse podocytes were treated with glucose (150 mM) and mannitol (200 mM), the Rictor gene was silenced using small interfering RNA (siRNA). Apoptosis was detected by flow cytometry, whereas podocyte cytoskeletal protein expression was detected by western blotting (WB) and immunofluorescence staining. The results demonstrated that, compared with that in the control group, the podocyte apoptotic rate was significantly increased in the mannitol group (negative group) and the groups that were treated with glucose (model groups). The podocyte apoptotic rate in the model + Rictor siRNA group was significantly decreased compared with that in the negative, model and the model glucose + siRNA negative control (NC) groups. WB indicated that the protein expression levels of podocalyxin and synaptopodin were reduced in the model and model + siRNA NC groups compared with those in the normal control and negative groups. Additionally, the protein expression levels of α-smooth muscle actin (α-SMA) and P-AKT/AKT were increased in the model and model + siRNA NC groups compared with the those in control and negative groups. Compared with those the model and model + siRNA NC groups, the protein expression levels of podocalyxin and synaptopodin were increased, whilst those of the α-SMA and P-AKT/AKT proteins were decreased, in the model + Rictor siRNA group. Results from immunofluorescence analysis were basically consistent with those of WB. Therefore, results of the present study suggest that silencing of the Rictor gene may reduce the damage to podocytes induced by HG, such that the Rictor/mTORC2 signaling pathway may be involved in the remodeling of podocyte actin cytoskeletal in diabetes.

Immunohistochemical Changes in the Testicular Excurrent Duct System of Healthy, Male Japanese Quail (Coturnix coturnix japonica) Observed at 4, 6-7, 12, and 52 Weeks of Age

The immunolocalization of the cytoskeletal and the extracellular matrix proteins was investigated in the testicular excurrent duct system of healthy Japanese quail at 4, 6−7, 12 and 52 weeks of age. TdT dUTP Nick End Labeling (TUNEL) assay was used to assess apoptotic cell formation. The epithelia of the testicular excurrent duct system in birds of all age groups displayed various immunolabeling intensities and localization of cytokeratin 5 and beta-tubulin, while α-SMA was observed in epithelia only of 4-week-old birds. In all age groups, vimentin immunostaining was observed in the rete testes and efferent ductular epithelia, but not in the epididymal duct unit. The periductal smooth muscle cells of the excurrent duct system displayed variably intense immunopositivity with cytokeratin 5, desmin, fibronectin, α-SMA, and beta-tubulin. Furthermore, beta-tubulin and vimentin immunolabeled endothelial cells and fibroblasts with various intensities, while fibronectin immunostained extracellular matrices surrounding these cells. TUNEL-positive apoptotic cells were observed in the rete testes and efferent ductular epithelia, with increased frequency (p < 0.001) in 52-week-old birds. The study serves as a baseline normal for this region in healthy birds at 4, 6−7, 12, and 52 weeks of age, for comparison in future similar immunohistochemical studies involving environmental toxins affecting this region.

Histological and Immunohistochemical Analysis of Peri-Implant Soft and Hard Tissues in Patients with Peri-Implantitis

Currently, researchers are focused on the study of cytokines as predictive biomarkers of peri-implantitis (PI) in order to obtain an early diagnosis and prognosis, and for treatment of the disease. The aim of the study was to characterize the peri-implant soft and hard tissues in patients with a peri-implantitis diagnosis. A descriptive observational study was conducted. Fifteen soft tissue (ST) samples and six peri-implant bone tissue (BT) samples were obtained from 13 patients who were diagnosed with peri-implantitis. All the samples were processed and embedded in paraffin for histological and immunohistochemical analyses. A descriptive and quantitative analysis of mast cells and osteocytes, A proliferation-inducing ligand (APRIL), B-cell activating factor (BAFF), osteonectin (ON), and ∝-smooth muscle actin (∝-SMA) was performed. We observed the presence of mast cells in peri-implant soft tissue in all samples (mean 9.21 number of mast cells) and osteocytes in peri-implant hard tissue in all samples (mean 37.17 number of osteocytes). The expression of APRIL-ST was 32.17% ± 6.39%, and that of APRIL-BT was 7.09% ± 5.94%. The BAFF-ST expression was 17.26 ± 12.90%, and the BAFF-BT was 12.16% ± 6.30%. The mean percentage of ON was 7.93% ± 3.79%, and ∝-SMA was 1.78% ± 3.79%. It was concluded that the expression of APRIL and BAFF suggests their involvement in the bone resorption observed in peri-implantitis. The lower expression of osteonectin in the peri-implant bone tissue can also be associated with a deficiency in the regulation of bone remodeling and the consequent peri-implant bone loss.

Dysregulation of the sensory and regulatory pathways controlling cellular iron metabolism in unilateral obstructive nephropathy

Chronic kidney disease involves disturbances in iron metabolism including anemia caused by insufficient erythropoietin (EPO) production. However, underlying mechanisms responsible for the dysregulation of cellular iron metabolism are incompletely defined. Using the unilateral ureteral obstruction (UUO) model in Irp1+/+ and Irp1-/- mice, we asked if iron regulatory proteins (IRPs), the central regulators of cellular iron metabolism and suppressors of EPO production, contribute to the etiology of anemia in kidney failure. We identified a significant reduction in IRP protein level and RNA binding activity that associates with a loss of the iron uptake protein transferrin receptor 1 (TfR1), increased expression of the iron storage protein subunits H- and L-ferritin, and a low but overall variable level of stainable iron in the obstructed kidney. This reduction in IRP RNA binding activity and ferritin RNA levels suggests the concomitant rise in ferritin expression and iron content in kidney failure is IRP dependent. In contrast, the reduction in the Epo mRNA level in the obstructed kidney was not rescued by genetic ablation of IRP1, suggesting disruption of normal hypoxia-inducible factor (HIF)-2α regulation. Furthermore, reduced expression of some HIF-α target genes in UUO occurred in the face of increased expression of HIF-α proteins and prolyl hydroxylases 2 and 1, the latter of which is not known to be HIF-α mediated. Our results suggest that the IRP system drives changes in cellular iron metabolism that are associated with kidney failure in UUO but that the impact of IRPs on EPO production is overridden by disrupted hypoxia signaling.NEW & NOTEWORTHY This study demonstrates that iron metabolism and hypoxia signaling are dysregulated in unilateral obstructive nephropathy. Expression of iron regulatory proteins (IRPs), central regulators of cellular iron metabolism, and the iron uptake (transferrin receptor 1) and storage (ferritins) proteins they target is strongly altered. This suggests a role of IRPs in previously observed changes in iron metabolism in progressive renal disease. Hypoxia signaling is disrupted and appeared to dominate the action of IRP1 in controlling erythropoietin expression.

Potential Vasculoprotective Effects of Blackcurrant (Ribes nigrum) Extract in Diabetic KK-Ay Mice

Polyphenols are bioactive compounds found naturally in fruits and vegetables; they are widely used in disease prevention and health maintenance. Polyphenol-rich blackcurrant extract (BCE) exerts beneficial effects on vascular health in menopausal model animals. However, the vasculoprotective effects in diabetes mellitus (DM) and atherosclerotic vascular disease secondary to DM are unknown. Therefore, we investigated whether BCE is effective in preventing atherosclerosis using KK-A^y mice as a diabetes model. The mice were divided into three groups and fed a high-fat diet supplemented with 1% BCE (BCE1), 3% BCE (BCE2), or Control for 9 weeks. The mice in the BCE2 group showed a considerable reduction in the disturbance of elastic lamina, foam cell formation, and vascular remodeling compared to those in the BCE1 and Control groups. Immunohistochemical staining indicated that the score of endothelial nitric oxide synthase staining intensity was significantly higher in both BCE2 (2.9) and BCE1 (1.9) compared to that in the Control (1.1). Furthermore, the score for the percentage of alpha-smooth muscle actin was significantly lower in the BCE2 (2.9%) than in the Control (2.1%). Our results suggest that the intake of anthocyanin-rich BCE could have beneficial effects on the blood vessels of diabetic patients.

Blackcurrant (Ribes nigrum L.) Extract Exerts Potential Vasculoprotective Effects in Ovariectomized Rats, Including Prevention of Elastin Degradation and Pathological Vascular Remodeling

Estrogen exerts cardioprotective effects in menopausal women. Phytoestrogens are plant-derived substances exhibiting estrogenic activity that could beneficially affect vascular health. We previously demonstrated that blackcurrant (Ribes nigrum L.) extract (BCE) treatment exerted beneficial effects on vascular health via phytoestrogenic activity in ovariectomized (OVX) rats, which are widely used as menopausal animal models. Here, we examined whether BCE treatment reduced elastin degradation and prevented pathological vascular remodeling in OVX rats fed a regular diet (OVX Control) or a 3% BCE-supplemented diet (OVX BCE), compared with sham surgery rats fed a regular diet (Sham) for 3 months. The results indicated a lower staining intensity of elastic fibers, greater elastin fragmentation, and higher α-smooth muscle actin protein expression in OVX Control rats than in OVX BCE and Sham rats. Pathological vascular remodeling was only observed in OVX Control rats. Additionally, we investigated matrix metalloproteinase (MMP)-12 mRNA expression levels to elucidate the mechanism underlying elastin degradation, revealing significantly upregulated MMP-12 mRNA expression in OVX Control rats compared with that in Sham and OVX BCE rats. Together, we identify BCE as exerting a vascular protective effect through reduced MMP-12 expression and vascular smooth muscle cell proliferation. To our knowledge, this is the first report indicating that BCE might protect against elastin degradation and pathological vascular remodeling during menopause.

Multiomics of World Trade Center Particulate Matter-induced Persistent Airway Hyperreactivity. Role of Receptor for Advanced Glycation End Products

Pulmonary disease after World Trade Center particulate matter (WTC-PM) exposure is associated with dyslipidemia and the receptor for advanced glycation end products (RAGE); however, the mechanisms are not well understood. We used a murine model and a multiomics assessment to understand the role of RAGE in the pulmonary long-term effects of a single high-intensity exposure to WTC-PM. After 1 month, WTC-PM-exposed wild-type (WT) mice had airway hyperreactivity, whereas RAGE-deficient (Ager^-/-) mice were protected. PM-exposed WT mice also had histologic evidence of airspace disease, whereas Ager^-/- mice remained unchanged. Inflammatory mediators such as G-CSF (granulocyte colony-stimulating factor), IP-10 (IFN-γ-induced protein 10), and KC (keratinocyte chemoattractant) were differentially expressed after WTC-PM exposure. WTC-PM induced α-SMA, DIAPH1 (protein diaphanous homolog 1), RAGE, and significant lung collagen deposition in WT compared with Ager^-/- mice. Compared with WT mice with PM exposure, relative expression of phosphorylated to total CREB (cAMP response element-binding protein) and JNK (c-Jun N-terminal kinase) was significantly increased in the lung of PM-exposed Ager^-/- mice, whereas Akt (protein kinase B) was decreased. Random forests of the refined lung metabolomic profile classified subjects with 92% accuracy; principal component analysis captured 86.7% of the variance in three components and demonstrated prominent subpathway involvement, including known mediators of lung disease such as vitamin B₆ metabolites, sphingolipids, fatty acids, and phosphatidylcholines. Treatment with a partial RAGE antagonist, pioglitazone, yielded similar fold-change expression of metabolites (N₆-carboxymethyllysine, 1-methylnicotinamide, N¹+N⁸-acetylspermidine, and succinylcarnitine [C4-DC]) between WT and Ager^-/- mice exposed to WTC-PM. RAGE can mediate WTC-PM-induced airway hyperreactivity and warrants further investigation.

Multisystemic manifestations of IgA vasculitis

Immunoglobulin A vasculitis (IgAV), also known as Henoch-Schönlein Purpura, is one of the most common kind of systemic vasculitis in children, and due to the involvement of small blood vessels throughout the body, this disease can cause a variety of symptoms in different organs. Our aim was to review the data on various systemic manifestations of IgAV. A research of the literature was performed in PubMed database, utilizing the MeSH terms "IgA vasculitis" and "Henoch Schönlein Purpura". According to the predetermined structure of the manuscript, we extracted and sorted out the relevant data. Clinically, almost all the patients will present with palpable skin purpura, together with arthritis, gastrointestinal tract involvement, or kidney damage. Other rare systemic manifestations include neurological symptoms, scrotal involvement, and cardiopulmonary disease. When uncommon complications occur, patients may be misdiagnosed as other diseases, thus delaying treatment. Although the course of IgAV is mostly self-limited, misdiagnosis can also lead to a poor prognosis. A comprehensive awareness to the clinical manifestations of IgAV is the necessary prerequisite for its timely diagnosis. Prompt diagnosis and adequate treatment are essential for optimal results.

Oxidative stress enhanced the transforming growth factor-β2-induced epithelial-mesenchymal transition through chemokine ligand 1 on ARPE-19 cell

Fibroblast-like transformation of retinal pigment epithelial (RPE) cells is a pathological feature of proliferative vitreoretinopathy (PVR) that may cause blindness. The effect of oxidative stress alone or together with transforming growth factor-beta 2 (TGF-β2) on epithelial-mesenchymal transformation (EMT) is not fully understood in RPE. TGF-β2 induced the upregulation EMT markers including α-smooth muscle actin (α-SMA), Snail, and Slug and downregulation of E-cadherin (E-cad) in ARPE-19 cells. Hydrogen peroxide (H₂O₂) not only upregulated α-SMA but also enhanced the effect of TGF-β2 on the expression of Snail and Slug. The CXCL family of cytokines could be the mediators of EMT induced by H₂O₂ and TGF-β2. H₂O₂ induced CXCL1, that upregulated α-SMA and fibronectin. Both SB225002, an inhibitor of CXCR2, and antioxidant N-acetylcysteine suppressed the TGF-β2-induced EMT in ARPE-19 cells. Taken together, the results suggest that oxidative stress enhanced TGF-β2-induced EMT through the possible autocrine effect of CXCL1 on CXCR2 in ARPE-19 cells.

Prediction of renal outcome in Henoch-Schönlein nephritis based on biopsy findings

BACKGROUND

In Henoch-Schönlein nephritis (HSN), a risk factor for unfavorable outcome is prolonged proteinuria, but the value of renal biopsies in prognosis assessment is debatable.

METHODS

We evaluated serial renal biopsies from 26 HSN patients. Follow-up biopsy occurred at median 2.1 years after diagnostic biopsy. Patients formed two groups at the follow-up biopsy: patients without proteinuria (group I; n = 11) and with proteinuria (group II; n = 15). Biopsies underwent evaluation according to three classifications: International Study of Kidney Disease in Children (ISKDC), Oxford (MEST-C), and semiquantitative classification (SQC) including an activity and chronicity score. Analysis also included expression of pro-fibrotic (alpha-smooth muscle actin and vimentin) and inflammatory (P-selectin glycoprotein ligand-1) molecules in the diagnostic biopsy specimens. Definition of unfavorable outcome was active renal disease or reduced renal function at last follow-up.

RESULTS

Between the biopsies, SQC chronicity score increased in 22 (85%) patients, whereas activity score and ISKDC grade decreased in 21 (81%) and 17 (65%), respectively. Of the MEST-C parameters, endocapillary proliferation (from 83 to 13%; p < 0.001) and crescents (from 63 to 25%; p = 0.022) showed significant reduction, and segmental glomerulosclerosis (from 38 to 79%; p = 0.006) significant increment. These changes occurred similarly in groups I and II. Expression of the pro-fibrotic and inflammatory molecules showed no clinically significant differences between groups I and II. None in group I and five (33%) patients in group II had unfavorable outcome (p = 0.053).

CONCLUSIONS

Our results suggest that follow-up biopsies provide limited additional information to clinical symptoms in HSN outcome prediction.

Ultrastructural characterization of cells in the tibial stump of ruptured human anterior cruciate ligament, their changes and significance with duration of injury

Fibroblasts and myofibroblasts have been known to be present in both ruptured and intact human anterior cruciate ligament (ACL), and although their relevant histology and immunochemistry have been studied in the past, ultrastructural features of these cells are largely lacking. Therefore, we aim to characterise the ultrastructural details of these cells with the help of transmission electron microscopy (TEM) and to study the changes and their significance with duration of injury. Samples from 60 ruptured human ACL undergoing surgery were obtained and categorised according to duration of injury and observed under TEM with main focus on the following ultrastructural features: cellular morphology, presence of rough endoplasmic reticulum, Golgi apparatus, lamina, myofilaments, and presence of myofibroblasts. These features were further correlated with the duration of injury and association, if any, determined using appropriate statistical analysis. A total of 54 male and 6 female patients with mean duration of the injury of 23.01 ± 26.09 weeks (2-108 weeks) were included in the study and categorised into five groups based on duration of injury as follows: I (< 6 weeks), II (7-12 weeks), III (13-20 weeks), IV (21-50 weeks) and V (> 50 weeks). There was a significant association between the above-mentioned ultrastructural features and the duration of injury (p < 0.05) except for the presence of ovoid fibroblast cells (p = 0.53). Furthermore, number of myofibroblasts and cells with Golgi apparatus and rough endoplasmic reticulum was seen to peak at 13-20 weeks following injury. We describe ultrastructural features of fibroblast of different morphology along with myofibroblasts in the ligaments following injury, the changes in which might have a potential bearing on ligament healing.

Antimicrobial activity and acetylcholinestrase inhibition of novel synthesized pyrimidine derivatives versus Candida albicans trafficking to brain and kidney

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The current study interested by treatment of Candida albicans in case of invading the fungi into brain and kidney.

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Investigating novel synthesized compounds as antifungal agents then determining their efficiency and safety margin.

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Assessment molecular biochemical parameters specific for inflammation.

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Comparing their antifungal effect to Diflucan in case of invading the fungi to kidney and brain tissue.

The expedient fungi Candida albicans (C. albicans) is able to thrive in many host niches including blood stream, skin, mucosal surfaces, and different body organs. Herein, the assessment of novel synthesized pyrimidine derivatives as anti fungal agent was investigated. Female albino mice were injected intraperitoneally by C. albicans (1.5 × 10⁶ CFU). infected Mice then subjected to treatment with two different doses which was low (50 mg/kg) and high one (200 mg/kg) of diflucan in addition to the newly synthestic compounds (2-(4- (Pyridine- 2- yl) aminosulfonyle phenylamino) - 6 -(naphthalene-2- yl)-4-(pyridine-2- yl) n - 3 carbonitril) and (2-(4-(Pyrimidine-2- yl) aminosulfonyle phenylamino)- 6 -(naphthalene-2- yl)- 4 -(pyridine-2- yl) pyridine-3- carbonitril) donated as (C1 & C2, respectively). Three weeks later gene expression of renal alpha smooth muscle actin (α-SMA) and of cyclooxygenase-2 (COX-2) protein expression were assessed as well as serum malondialdehyde (MDA) and total antioxidant capacity in both kidney and brain tissues. Furthermore, acetylcholinestrase activity was assessed. Candida albicans significantly elevated serum MDA. On the other hand, C. albicans injection revealed a significantly reduction in total antioxidant capacity in kidney as well as in brain tissue. Furthermore, acetylcholine assessment declared a significant elevation. All biochemical parametersۥ upset were modulated upon new synthesized compounds treatment. Molecular analyses declared a significant down - regulation in renal α -smooth muscle actin gene expression in addition to, a significant down- regulation in COX-2 protein expression. From data recorded, it could be concluded that, C2 in a dose 200 mg ∕kg noticeably declared a significant effect comparing with the other treated groups revealing its promising effect as anti-fungal agent.

Role of mTOR signaling in the regulation of high glucose-induced podocyte injury

Podocyte injury, which promotes progressive nephropathy, is considered a key factor in the progression of diabetic nephropathy. The mammalian target of rapamycin (mTOR) signaling cascade controls cell growth, survival and metabolism. The present study investigated the role of mTOR signaling in regulating high glucose (HG)-induced podocyte injury. MTT assay and flow cytometry assay results indicated that HG significantly increased podocyte viability and apoptosis. HG effects on podocytes were suppressed by mTOR complex 1 (mTORC1) inhibitor, rapamycin, and further suppressed by dual mTORC1 and mTORC2 inhibitor, KU0063794, when compared with podocytes that received mannitol treatment. In addition, western blot analysis revealed that the expression levels of Thr-389-phosphorylated p70S6 kinase (p-p70S6K) and phosphorylated Akt (p-Akt) were significantly increased by HG when compared with mannitol treatment. Notably, rapamycin significantly inhibited HG-induced p-p70S6K expression, but did not significantly impact p-Akt expression. However, KU0063794 significantly inhibited the HG-induced p-p70S6K and p-Akt expression levels. Furthermore, the expression of ezrin was significantly reduced by HG when compared with mannitol treatment; however, α-smooth muscle actin (α-SMA) expression was significantly increased. Immunofluorescence analysis on ezrin and α-SMA supported the results of western blot analysis. KU0063794, but not rapamycin, suppressed the effect of HG on the expression levels of ezrin and α-SMA. Thus, it was suggested that the increased activation of mTOR signaling mediated HG-induced podocyte injury. In addition, the present findings suggest that the mTORC1 and mTORC2 signaling pathways may be responsible for the cell viability and apoptosis, and that the mTORC2 pathway could be primarily responsible for the regulation of cytoskeleton-associated proteins.

Digitally Tunable Microfluidic Bioprinting of Multilayered Cannular Tissues

Despite advances in the bioprinting technology, biofabrication of circumferentially multilayered tubular tissues or organs with cellular heterogeneity, such as blood vessels, trachea, intestine, colon, ureter, and urethra, remains a challenge. Herein, a promising multichannel coaxial extrusion system (MCCES) for microfluidic bioprinting of circumferentially multilayered tubular tissues in a single step, using customized bioinks constituting gelatin methacryloyl, alginate, and eight-arm poly(ethylene glycol) acrylate with a tripentaerythritol core, is presented. These perfusable cannular constructs can be continuously tuned up from monolayer to triple layers at regular intervals across the length of a bioprinted tube. Using customized bioink and MCCES, bioprinting of several tubular tissue constructs using relevant cell types with adequate biofunctionality including cell viability, proliferation, and differentiation is demonstrated. Specifically, cannular urothelial tissue constructs are bioprinted, using human urothelial cells and human bladder smooth muscle cells, as well as vascular tissue constructs, using human umbilical vein endothelial cells and human smooth muscle cells. These bioprinted cannular tissues can be actively perfused with fluids and nutrients to promote growth and proliferation of the embedded cell types. The fabrication of such tunable and perfusable circumferentially multilayered tissues represents a fundamental step toward creating human cannular tissues.

Direct 3D bioprinting of perfusable vascular constructs using a blend bioink

Despite the significant technological advancement in tissue engineering, challenges still exist towards the development of complex and fully functional tissue constructs that mimic their natural counterparts. To address these challenges, bioprinting has emerged as an enabling technology to create highly organized three-dimensional (3D) vascular networks within engineered tissue constructs to promote the transport of oxygen, nutrients, and waste products, which can hardly be realized using conventional microfabrication techniques. Here, we report the development of a versatile 3D bioprinting strategy that employs biomimetic biomaterials and an advanced extrusion system to deposit perfusable vascular structures with highly ordered arrangements in a single-step process. In particular, a specially designed cell-responsive bioink consisting of gelatin methacryloyl (GelMA), sodium alginate, and 4-arm poly(ethylene glycol)-tetra-acrylate (PEGTA) was used in combination with a multilayered coaxial extrusion system to achieve direct 3D bioprinting. This blend bioink could be first ionically crosslinked by calcium ions followed by covalent photocrosslinking of GelMA and PEGTA to form stable constructs. The rheological properties of the bioink and the mechanical strengths of the resulting constructs were tuned by the introduction of PEGTA, which facilitated the precise deposition of complex multilayered 3D perfusable hollow tubes. This blend bioink also displayed favorable biological characteristics that supported the spreading and proliferation of encapsulated endothelial and stem cells in the bioprinted constructs, leading to the formation of biologically relevant, highly organized, perfusable vessels. These characteristics make this novel 3D bioprinting technique superior to conventional microfabrication or sacrificial templating approaches for fabrication of the perfusable vasculature. We envision that our advanced bioprinting technology and bioink formulation may also have significant potentials in engineering large-scale vascularized tissue constructs towards applications in organ transplantation and repair.

Microvesicles from brain-extract-treated mesenchymal stem cells improve neurological functions in a rat model of ischemic stroke

Transplantation of mesenchymal stem cells (MSCs) was reported to improve functional outcomes in a rat model of ischemic stroke, and subsequent studies suggest that MSC-derived microvesicles (MVs) can replace the beneficial effects of MSCs. Here, we evaluated three different MSC-derived MVs, including MVs from untreated MSCs (MSC-MVs), MVs from MSCs treated with normal rat brain extract (NBE-MSC-MVs), and MVs from MSCs treated with stroke-injured rat brain extract (SBE-MSC-MVs), and tested their effects on ischemic brain injury induced by permanent middle cerebral artery occlusion (pMCAO) in rats. NBE-MSC-MVs and SBE-MSC-MVs had significantly greater efficacy than MSC-MVs for ameliorating ischemic brain injury with improved functional recovery. We found similar profiles of key signalling proteins in NBE-MSC-MVs and SBE-MSC-MVs, which account for their similar therapeutic efficacies. Immunohistochemical analyses suggest that brain-extract—treated MSC-MVs reduce inflammation, enhance angiogenesis, and increase endogenous neurogenesis in the rat brain. We performed mass spectrometry proteomic analyses and found that the total proteomes of brain-extract—treated MSC-MVs are highly enriched for known vesicular proteins. Notably, MSC-MV proteins upregulated by brain extracts tend to be modular for tissue repair pathways. We suggest that MSC-MV proteins stimulated by the brain microenvironment are paracrine effectors that enhance MSC therapy for stroke injury.

Tributyltin chloride induces renal dysfunction by inflammation and oxidative stress in female rats

Tributyltin chloride (TBT) is an organometallic pollutant that is used as a biocide in antifouling paints. TBT induces several toxic and endocrine-disrupting effects. However, studies evaluating the effects of TBT on renal function are rare. This study demonstrates that TBT exposure is responsible for improper renal function as well as the development of abnormal morphophysiology in mammalian kidneys. Female rats were treated with TBT, and their renal morphophysiology was assessed. Morphophysiological abnormalities such as decreased glomerular filtration rate and increased proteinuria levels were observed in TBT rats. In addition, increases in inflammation, collagen deposition and α-smooth muscle actin (α-SMA) protein expression were observed in TBT kidneys. A disrupted cellular redox balance and apoptosis in kidney tissue were also observed in TBT rats. TBT rats demonstrated reduced serum estrogen levels and estrogen receptor-α (ERα) protein expression in renal cortex. Together, these data provide in vivo evidence that TBT is toxic to normal renal function and that these effects may be associated with renal histopathology complications, such as inflammation and fibrosis.

Alpha-Smooth Muscle Actin mRNA and Protein Are Increased in Isolated Brain Vessel Extracts of Alzheimer Mice

Alzheimer's disease (AD) is a severe neurodegenerative disorder of the brain, characterized by extracellular beta-amyloid (Aβ) plaques, intracellular tau pathology, neurodegeneration and inflammation. There is clear evidence that the blood-brain barrier is damaged in AD and that vessel function is impaired. Alpha-smooth muscle actin (αSMA) is a prominent protein expressed on brain vessels, especially in cells located closer to the arteriole end of the capillaries, which possibly influences the blood vessel contraction. The aim of the present study was to observe αSMA protein and mRNA expression in isolated brain vessel extracts and cortex in an Alzheimer mouse model with strong Aβ plaque deposition. Our data revealed a prominent expression of αSMA protein in isolated brain vessel extracts of AD mice by Western blot analysis. Immunostaining showed that these vessels were associated with Aβ plaques. Quantitative real-time PCR analysis confirmed this increase at the mRNA expression level and showed a significant increase of transforming growth factor beta-1 mRNA expression in AD mice. In situ hybridization demonstrated a strong expression pattern of αSMA mRNA in the whole cortex and hippocampus. In conclusion, our data provide evidence that αSMA protein and mRNA are enhanced in vessels in an AD mouse model, possibly counteracting vessel malfunction in AD.

Changes in keratins and alpha-smooth muscle actin during three-dimensional reconstitution of eccrine sweat glands

We have examined the changes of keratins and alpha-SMA at various time points in order to investigate the development and differentiation of eccrine sweat gland cells during the course of three-dimensional (3D) reconstitution. Mixtures of eccrine sweat gland cells and Matrigel were injected subcutaneously into the inguinal regions of nude mice. At 1, 2, 4, 6, 8, 14, 21, 28, 35, and 42 days post-implantation, Matrigel plugs were removed and immunostained. We found that during 3D reconstitution, keratin and alpha-SMA expression changed in a time-dependent manner. At day 1, all cells stained positively for keratin isoforms K5, K14, and K15, with the staining intensity of K15 being weak and K5 and K14 being strong, but none of the cells displayed K7, K8, or alpha-SMA. As time progressed, spheroid-like structures formed with the inner layer acquiring K7 and K8, but losing K5 and K14 expression, and the outer layer acquiring alpha-SMA expression, but losing K15 expression. K8 expression was first noted at day 14, and K7 and alpha-SMA at day 21. The loss of K15 expression was first noted at day 14, K14 at day 21, and K5 at day 28. At 28, 35, and 42 days, the spheroid-like structures could be distinguished, by immunohistochemistry, as having secretory coil-like and coiled duct-like structures. We conclude that the changes in expression of keratins and alpha-SMA in 3D-reconstituted eccrine sweat glands are similar to those of native eccrine sweat glands, indicating that the 3D reconstitution of sweat glands provides an excellent model for studying the development, cytodifferentiation, and regulation of eccrine sweat glands.

Post-Natal Inhibition of NF-κB Activation Prevents Renal Damage Caused by Prenatal LPS Exposure

Prenatal exposure to an inflammatory stimulus has been shown to cause renal damage in offspring. Our present study explored the role of intra-renal NF-κB activation in the development of progressive renal fibrosis in offspring that underwent prenatal exposure to an inflammatory stimulus. Time-dated pregnant rats were treated with saline (control group) or 0.79 mg/kg lipopolysaccharide (LPS) through intra-peritoneal injection on gestational day 8, 10 and 12. At the age of 7 weeks, offspring from control or LPS group were treated with either tap water (Con+Ve or LPS+Ve group) or pyrollidine dithiocarbamate (PDTC, 120mg/L), a NF-κB inhibitor, via drinking water starting (Con+PDTC or LPS+PDTC group), respectively, till the age of 20 or 68 weeks. The gross structure of kidney was assessed by hematoxylin-eosin, periodic acid–Schiff staining and Sirius red staining. The expression levels of TNF-α, IL-6, α-smooth muscle actin (α-SMA) and renin-angiotensin system (RAS) genes were determined by real time polymerase chain reaction and/or immunohistochemical staining. Our data showed that post-natal persistent PDTC administration efficiently repressed intra-renal NF-κB activation, TNF-α and IL-6 expression. Post-natal PDTC also prevented intra-renal glycogen deposition and collagenous fiber generation as evident by the reduced expression of collagen III and interstitial α-SMA in offspring of prenatal LPS exposure. Furthermore, post-natal PDTC administration reversed the intra-renal renin-angiotensin system (RAS) over-activity in offspring of prenatal LPS exposure. In conclusion, prenatal inflammatory exposure results in offspring’s intra-renal NF-κB activation along with inflammation which cross-talked with excessive RAS activation that caused exacerbation of renal fibrosis and dysfunction in the offspring. Thus, early life prevention of NF-κB activation may be a potential preventive strategy for chronic renal inflammation and progressive renal damage.

BrdU-label-retaining cells in rat eccrine sweat glands over time

Cell proliferation and turnover are fueled by stem cells. In a previous study, we demonstrated that rat eccrine sweat glands contained abundant bromodeoxyuridine (BrdU)-label-retaining cells (LRCs). However, morphological observations showed that eccrine sweat glands usually show little or no signs of homeostatic change. In this study, we account for why the homeostatic change is rare in eccrine sweat glands based on cytokinetic changes in BrdU-LRC turnover, and also determine the BrdU-labeled cell type. Thirty-six newborn SD rats, were injected intraperitoneally with 50mg/kg BrdU twice daily at a 2h interval for 4 consecutive days. After a chase period of 4, 6, 8, 12, 24 and 32 weeks, rats were euthanized, and the hind footpads were removed and processed for BrdU immunostaining, and BrdU/α-SMA and BrdU/K14 double-immunostaining. BrdU-LRCs were observed in the ducts, secretory coils and mesenchymal cells at all survival time points. The percentage of BrdU(+) cells in rat eccrine sweat glands averaged 4.2±1.2% after 4 weeks of chase, increased slightly by the 6th week, averaging 4.4±0.9%, and peaked at 8 weeks, averaging 5.3±1.0%. Subsequently, the average percentage of BrdU(+) cells declined to 3.2±0.8% by the 32nd week. There was no difference in the percentage of BrdU-LRCs among the different survival time points except that a significant difference in the percentage of BrdU-LRCs detected at 24 weeks versus 8 weeks, and 32 weeks versus 8 weeks, was observed. We concluded that the BrdU-LRCs turnover is slow in eccrine sweat glands.

Aspidin PB, a novel natural anti-fibrotic compound, inhibited fibrogenesis in TGF-β1-stimulated keloid fibroblasts via PI-3K/Akt and Smad signaling pathways

Keloid is an overgrowth of scar tissue that develops around a wound. The mechanisms of keloid formation and development still remain unknown, and no effective treatment is available. Searching for active natural resources may develop better prevention and treatment approaches for keloids. Aspidin PB is a natural resource with lower toxicity. We explored its effect on the regulation of TGF-β1-induced expression of type I collagen, CTGF, and α-SMA in keloid fibroblasts (KFs). Western blotting was used to detect the expression levels of type I collagen, CTGF, α-SMA, PI-3K/Akt and Smad-dependent and Smad-independent signaling pathway. The effect of aspidin PB on cell viability in human keloid fibroblasts was measured by MTT (3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide). The percentage of the apoptotic cells was studied by flow cytometry. Based on our results, we revealed that aspidin PB inhibited the production of type I collagen, CTGF, and α-SMA in TGF-β1-induced KFs by blocking PI-3K/Akt signaling pathway. The TGF-β1-mediated phosphorylated levels of Smad2/3 were inhibited by aspidin PB pretreatment. Conclusively, our study suggests that aspidin PB has an inhibitory effect on fibrogenesis in TGF-β1-induced KFs. Our findings imply that aspidin PB has a therapeutic potential to intervene and prevent keloids and other fibrotic diseases.

Combination of keratins and alpha-smooth muscle actin distinguishes secretory coils from ducts of eccrine sweat glands

Eccrine sweat glands are comprised of secretory coils and ducts, which are distinct in morphology and function. To better understand the roles of the two parts in development, homeostasis, wound repair and regeneration of eccrine sweat glands, we must distinguish between them. In this study, the localization of keratins and alpha-SMA in human eccrine sweat glands was examined by immunofluorescence staining. Based on the differential localization of keratins and alpha-SMA in different cell types, four pairs of antibodies (K5/K7, K5/alpha-SMA, K14/K7 and K14/alpha-SMA) were used to differentiate secretory coils from ducts by double-immunofluorescence staining. Immunofluorescence staining showed that myoepithelial cells of secretory coils expressed K5, K14 and alpha-SMA, whereas secretory cells of secretory coils expressed K7, K8, K15, K18 and K19. Ductal cells expressed K5, K8, K14 and K19. Double-staining showed that the secretory coils were K5(+)/K7(+), K5(+)/alpha-SMA(+), K14(+)/K7(+) and K14(+)/alpha-SMA(+), whereas ducts were K5(+)/K7(-), K5(+)/alpha-SMA(-), K14(+)/K7(-) and K14(+)/alpha-SMA(-). In conclusion, by combining use of keratins and alpha-SMA antibodies, secretory coils can be easily differentiated from ducts in morphology.

Henoch-Schönlein purpura nephritis in children: incidence, pathogenesis and management

BACKGROUND

Henoch-Schönlein purpura (HSP) is one of the most common vasculitides in children. It is manifested by skin purpura, arthritis, abdominal pain, renal involvement, etc. Typically, HSP is considered to be self-limiting, although renal involvement (HSP purpura nephritis, HSPN) is the principal cause of morbidity from this disease. For this reason, it is important to clarify the mechanism of onset and clinical manifestations of HSPN and to ascertain the most appropriate treatment for HSPN. In this article, we review the updated pathophysiology and treatment strategies for HSPN.

DATA SOURCES

We searched databases including PubMed, Elsevier and Wanfang for the following key words: Henoch-Schönlein purpura, nephritis, mechanism and treatment, and we selected those publications written in English that we judged to be relevant to the topic of this review.

RESULTS

Based on the data present in the literature, we reviewed the following topics: 1) the possible pathogenesis of HSPN: several studies suggest that immunoglobulin A immune complexes deposit in the mesangium and induce renal injury; 2) multiple-drug treatment for HSPN: although there have been few evidence-based treatment strategies for HSPN, several studies have suggested that immunosuppressive drugs and multiple drug combination therapy were effective in ameliorating proteinuria and histological severity.

CONCLUSIONS

HSPN is a severe disease of childhood. To better understand this disease, detailed investigations into the pathogenesis of HSPN and prospective randomized controlled treatment studies on children with severe HSPN are needed.

Henoch-Schönlein purpura nephritis in childhood: pathogenesis, prognostic factors and treatment

Henoch-Schönlein purpura (HSP) is a systemic disorder characterized by leukocytoclastic vasculitis involving the capillaries and the deposition of IgA immune complexes. Renal involvement is the principal cause of morbidity and mortality in children with HSP. Thus, it is important to clarify the onset mechanism as well as the prognostic factors of Henoch-Schönlein purpura nephritis (HSPN) and to identify the most appropriate treatment. We herein review the pathogenesis, the prognostic factors and treatment of HSPN. As to the pathogenesis, several studies suggest that galactose-deficient IgA1 (Gd-IgA1) is recognized by anti-glycan antibodies, leading to the formation of circulating immune complexes and their mesangial deposition, thereby inducing renal injury. With regard to the prognostic factors, a number of factors have been suggested including nephrotic syndrome, decreased factor XIII activity, hypertension, severe renal injury, high renal accumulation of activated macrophage, alpha-smooth muscle actin, and high serum myeloid-related protein levels. For the treatment of severe HSPN, aggressive therapies including multiple drug combination therapy and plasmapheresis have been shown to be effective in ameliorating proteinuria and histological severity. Nevertheless, detailed investigation into the pathogenesis of HSPN and double-blind randomized control studies on children with HSPN are still necessary.

Serum levels of alpha-smooth muscle actin and c-Met as biomarkers of the degree of severity of Henoch-Schonlein purpura nephritis

Approximately 40% of patients with Henoch-Schonlein purpura (HSP) develop Henoch-Schonlein purpura nephritis (HSPN) after 4 to 6 weeks of subcutaneous hemorrhaging. Immunoglobulin-A nephropathy (IgAN) and HSPN have numerous similarities, which can cause difficulty in correctly diagnosing the disorder during a differential diagnosis. The pathogenesis of the 2 diseases is not clear. We enrolled 137 patients with HSPN, 107 patients with IgAN, and 28 healthy (control) patients in our study. The levels of alpha-smooth muscle actin (α-SMA), c-Met, and Gal-deficient IgA1 (Gd-IgA1) in the 3 patient groups were determined and compared. The α-SMA, c-Met, and Gd-IgA1 levels and the clinical data from the patients with HSPN were analyzed for any correlations. The α-SMA and c-Met levels of the HSPN group were significantly higher than those of the IgAN and healthy control groups (P < 0.01). The Gd-IgA1 levels of the HSPN and IgAN groups were significantly different from the Gd-IgA1 level of the healthy control group (P < 0.01). The α-SMA levels of the HSPN group were positively correlated with blood urea nitrogen levels, serum creatinine levels, hematuria index, and proteinuria levels (P < 0.01). The c-Met levels of the HSPN group were positively correlated with the blood urea nitrogen and serum creatinine levels (P < 0.01). There were no significant differences among the α-SMA, c-Met, and Gd-IgA1 levels or the clinical data for the child and adult patients with HSPN. The serum levels of α-SMA and c-Met in patients with HSPN may be associated with the degree of disease severity. Gd-IgA1 is involved in the common immunologic pathogenesis of HSPN and IgAN.

Urinary excretion and renal production of hepatocyte growth factor in children with Henoch-Schönlein purpura

This study measured urinary excretion and renal levels of hepatocyte growth factor (HGF) in children with Henoch-Schönlein purpura (HSP), examining the relationship between HGF, proteinuria and renal pathological changes. Seventy-eight patients with HSP aged 6 - 18 years were divided into three groups, based on urinary albumin excretion rate. Urinary HGF concentration was measured by enzyme-linked immunosorbent assay. Renal biopsies were performed in 22 patients; renal levels of HGF protein were determined immunohistochemically. Compared with controls, urinary HGF was significantly increased in patients with normoalbuminuria and microalbuminuria, especially in those with microalbuminuria; no differences were observed between patients with macroalbuminuria and controls. Little or no HGF was present in normal kidney, but HGF was present in renal tissue in all HSP patients, particularly those with microalbuminuria. Urinary HGF was strongly correlated with the presence of renal HGF. These results suggest that HGF is associated with proteinuria and renal pathological changes in children with HSP. The detection of urinary HGF in children with HSP may be a non-invasive, effective, method for early diagnosis of renal injury.

Beneficial effect of all-trans retinoic acid (ATRA) on glomerulosclerosis rats via the down-regulation of the expression of alpha-smooth muscle actin: a comparative study between ATRA and benazepril

Although ATRA is a potent renoprotective agent, relatively little is known regarding the mechanisms of its action. The present study was designed to further elucidate the mechanisms of ATRA's action to GS rats and compare that with the beneficial effect of benazepril. Male SD rats weighting 160 to 200g were used in this study. GS was induced by unilateral nephrectomy and intravenous injection of adriamycin (6mg/kg). They were divided randomly 20 ones per group into GS group, GS treated with ATRA (20mg/kg/day) group, and GS treated with benazepril (10mg/kg/day) group. The other 20 ones were taken as sham-operation group, injected normal saline into caudal vein. 12weeks later, all rats were subjected to sacrifice. As expected, the GS group exhibited significant lower serum TP and Alb, and higher BUN, Cr and proteinuria than those of the sham group. Administration of ATRA or benazepril did ameliorate these above disorders of biochemical parameters in GS rats. Extensive renal damage was observed in the GS group, such as mononuclear infiltration, mesangial proliferation, focal segment glomerular sclerosis, and tubulointerstitial fibrosis. The pathological changes in both ATRA and benazepril group were alleviated remarkably. Semiquantitative GSI was used to evaluate the degree of GS in all groups. GSI was significantly higher in the GS group than in sham group. GSI decreased from 21.9+/-6.7 in the GS group to 6.9+/-2.8 in the ATRA group and 7.0+/-2.7 in benazepril group respectively. However, no significant difference in GSI between rats treated with ATRA and rats treated with benazepril was found. RT-PCR analysis revealed the renal expression of alpha-SMA mRNA was induced substantially in GS group as compared to sham group, which could be offset completely by ATRA or benazepril administration. However, expression level of alpha-SMA mRNA in GS rats treated with ATRA was identical to that in GS rats treated with benazepril. We also examined immunohistochemical staining for renal alpha-SMA, TGF-beta1, Col IV, and FN in this model. Weak staining was observed in some glomerulus, mesangial cells, and tubular interstitium of sham rats. Staining was markedly enhanced in the majority of glomerulus, mesangial cells, and tubular interstitium of untreated GS rats. Compared with untreated GS animals, intensity and extent of staining for renal alpha-SMA, TGF-beta1, Col IV, and FN were markedly reduced in glomerulus, mesangial cells, and tubular interstitium of GS rats treated with either ATRA or benazepril. However, no significant differences existed between ATRA and benazepril with respect to the glomerular and tubulointerstitial staining scores. Interestingly, our data documented some differences of therapeutic capacities between ATRA and benazepril. In comparison with benazepril, ATRA exerted no improvement in hypoproteinemia, but more significant decrease in serum Cr level in GS rats. The reasons leading to these variations are unclear. Whatever they are, the properties of down-regulate inflammatory/proliferative programs may make ATRA an attractive potential candidate for future therapeutic use in kidney disease.

Pathogenesis of Henoch-Schönlein purpura nephritis

The severity of renal involvement is the major factor determining the long-term outcome of children with Henoch-Schönlein purpura (HSP) nephritis (HSPN). Approximately 40% children with HSP develop nephritis, usually within 4 to 6 weeks after the initial onset of the typical purpuric rashes. Although the pathogenetic mechanisms are still not fully delineated, several studies suggest that galactose-deficient IgA1 (Gd-IgA1) is recognized by anti-glycan antibodies, leading to the formation of the circulating immune complexes and their mesangial deposition that induce renal injury in HSPN.