Tamoxifen associated to the conservative CKD treatment promoted additional antifibrotic effects on experimental hypertensive nephrosclerosis.

CKD progression depends on the activation of an intricate set of hemodynamic and inflammatory mechanisms, promoting renal leukocyte infiltration, inflammation and fibrosis, leading to renal function loss. There are currently no specific drugs to detain renal fibrogenesis, which is a common end-point for different nephropathies. Clinical therapy for CKD is mostly based on the management of hypertension and proteinuria, partially achieved with renin-angiotensin-aldosterone system (RAAS) blockers, and the control of inflammation by immunosuppressive drugs. The aim of the present study was to verify if the administration of tamoxifen (TAM), an estrogen receptor modulator, clinically employed in the treatment of breast cancer and predicted to exert antifibrotic effects, would promote additional benefits when associated to a currently used therapeutic scheme for the conservative management of experimental CKD. Wistar rats underwent the NAME model of hypertensive nephrosclerosis, obtained by daily oral administration of a nitric oxide synthesis inhibitor, associated to dietary sodium overload. The therapeutic association of TAM to losartan (LOS), and mofetil mycophenolate (MMF) effectively reduced the severe hypertension, marked albuminuria and glomerular damage exhibited by NAME animals. Moreover, the association also succeeded in limiting renal inflammation in this model, and promoted further reduction of ECM interstitial accumulation and renal fibrosis, compared to the monotherapies. According to our results, the association of TAM to the currently used conservative treatment of CKD added significant antifibrotic effects both in vivo and in vitro, and may represent an alternative to slow the progression of chronic nephropathy.

Early effects of bone marrow-derived mononuclear cells on lung and kidney in experimental sepsis.

BACKGROUND: In experimental sepsis, functional and morphological effects of bone marrow-derived mononuclear cell (BMDMC) administration in lung tissue have been evaluated 1 and 7 days after therapy. However, to date no study has evaluated the early effects of BMDMCs in both lung and kidney in experimental polymicrobial sepsis. MATERIAL AND METHODS: Twenty-five female C57BL/6 mice were randomly divided into the following groups: 1) cecal ligation and puncture (CLP)-induced sepsis; and 2) Sham (surgical procedure without CLP). After 1 h, CLP animals received saline (NaCl 0.9%) (CLP-Saline) or 106 BMDMCs (CLP-Cell) via the jugular vein. At 6, 12, and 24 h after saline or BMDMC administration, lungs and kidneys were removed for histology and molecular biology analysis. RESULTS: In lungs, CLP-Saline, compared to Sham, was associated with increased lung injury score (LIS) and keratinocyte chemoattractant (KC) mRNA expression at 6, 12, and 24 h. BMDMCs were associated with reduced LIS and KC mRNA expression regardless of the time point of analysis. Interleukin (IL)- 10 mRNA content was higher in CLP-Cell than CLP-Saline at 6 and 24 h. In kidney tissue, CLP-Saline, compared to Sham, was associated with tubular cell injury and increased neutrophil gelatinase-associated lipocalin (NGAL) levels, which were reduced after BMDMC therapy at all time points. Surface high-mobility-group-box (HMGB)- 1 levels were higher in CLP-Saline than Sham at 6, 12, and 24 h, whereas nuclear HMGB-1 levels were increased only at 24 h. BMDMCs were associated with decreased surface HMGB-1 and increased nuclear HMGB-1 levels. Kidney injury molecule (KIM)- 1 and IL-18 gene expressions were reduced in CLP-Cell compared to CLP-Saline at 12 and 24 h. CONCLUSION: In the present experimental polymicrobial sepsis, early intravenous therapy with BMDMCs was able to reduce lung and kidney damage in a time-dependent manner. BMDMCs thus represent a potential therapy in well-known scenarios of sepsis induction. PURPOSE: To evaluate early bone marrow-derived mononuclear cell (BMDMC) therapy on lung and kidney in experimental polymicrobial sepsis. METHODS: Twenty-five female C57BL/6 mice were randomly divided into the following groups: cecal ligation and puncture (CLP)-induced sepsis; and sham (surgical procedure without CLP). After 1 h, CLP animals received saline (CLP-saline) or 106 BMDMCs (CLP-cell) via the jugular vein. Lungs and kidneys were evaluated for histology and molecular biology after 6, 12, and 24 h. RESULTS: In lungs, BMDMCs reduced the lung injury score and keratinocyte chemoattractant mRNA expression regardless of the time point of analysis; interleukin-10 mRNA content was higher in CLP-cell than CLP-saline at 6 and 24 h. In kidneys, BMDMCs reduced neutrophil gelatinase-associated lipocalin levels at all time points. BMDMCs decreased surface high mobility group box (HMGB)- 1 but increased nuclear HMGB-1 levels. CONCLUSION: Early BMDMC therapy reduced lung and kidney damage in a time-dependent manner.

Synergic Renoprotective Effects of Combined ASC Therapy with RAAS Blockade in Experimental Advanced CKD.

Global prevalence of chronic kidney disease (CKD) has increased considerably in the recent decades. Overactivity of the renin-angiotensin-aldosterone system (RAAS), associated to renal inflammation and fibrosis, contributes to its evolution. The treatments currently employed to control CKD progression are limited and mainly based on the pharmacological inhibition of RAAS, associated with diuretics and immunosuppressive drugs. However, this conservative management promotes only partial deceleration of CKD evolution and does not completely avoid the progression of the disease and the loss of renal function, which motivates the medical and scientific community to investigate new therapeutic approaches to detain renal inflammation/fibrosis and CKD progression. Recent studies have shown the application of mesenchymal stem cells (mSC) to exert beneficial effects on the renal tissue of animals submitted to experimental models of CKD. In this context, the aim of the present study was to evaluate the effects of subcapsular application of adipose tissue-derived mSC (ASC) in rats submitted to the 5/6 renal ablation model, 15 days after the establishment of CKD, when the nephropathy was already severe. We also verify whether ASC associated to Losartan would promote greater renoprotection when compared to the respective monotherapies. Animals were followed until 30 days of CKD, when body weight, systolic blood pressure, biochemical, histological, immunohistochemical, and gene expression analysis were performed. The combination of ASC and Losartan was more effective than Losartan monotherapy in reducing systolic blood pressure and glomerulosclerosis and also promoted the complete normalization of proteinuria and albuminuria, a significant reduction in renal interstitial macrophage infiltration and downregulation of renal IL-6 gene expression. The beneficial effects of ACS are possibly due to the immunomodulatory and anti-inflammatory role of factors secreted by these cells, modulating the local immune response. Although studies are still required, our results demonstrated that a subcapsular inoculation of ASC, associated with the administration of Losartan, exerted additional renoprotective effect in rats submitted to a severe model of established CKD, when compared to Losartan monotherapy, thus suggesting ASC may be a potential adjuvant to RAAS-blockade therapy currently employed in the conservative management of CKD.

Diabetic rats present higher urinary loss of proteins and lower renal expression of megalin, cubilin, ClC-5, and CFTR.

Diabetic nephropathy (DN) occurs in around 40% of those with diabetes. Proteinuria is the main characteristic of DN and develops as a result of increased permeability of the glomerulus capillary wall and/or decreased proximal tubule endocytosis. The goal of this work was to evaluate renal function and the expression of megalin, cubilin, CFTR (cystic fibrosis transmembrane conductance regulator), and ClC-5 in the proximal tubule and renal cortex of rats with type 1 diabetes. Male Wistar rats were randomly assigned to control (CTRL) and diabetic (DM) groups for 4 weeks. Renal function was assessed in 24-h urine sample by calculating clearance and fractional excretion of solutes. The RNA and protein contents of ClC-5, CFTR, megalin, and cubilin were determined in the renal proximal tubule and cortex using real-time polymerase chain reaction and western blotting techniques, respectively. The results showed higher creatinine clearance and higher urinary excretion of proteins, albumin, and transferrin in the DM group than in the CTRL group. Furthermore, the renal cortex and proximal tubule of diabetic animals showed downregulation of megalin, cubilin, ClC-5, and CFTR, critical components of the endocytic apparatus. These data suggest dysfunction in proximal tubule low-molecular-weight endocytosis and protein glomerulus filtration in the kidney of diabetic rats.

Tyrosine Mutation in AAV9 Capsid Improves Gene Transfer to the Mouse Lung.

BACKGROUND/AIMS: Adeno-associated virus (AAV) vectors are being increasingly used as the vector of choice for in vivo gene delivery and gene therapy for many pulmonary diseases. Recently, it was shown that phosphorylation of surface-exposed tyrosine residues from AAV capsid targets the viral particles for ubiquitination and proteasome-mediated degradation, and mutations of these tyrosine residues lead to highly efficient vector transduction in vitro and in vivo in different organs. In this study, we evaluated the pulmonary transgene expression efficacy of AAV9 vectors containing point mutations in surface-exposed capsid tyrosine residues. METHODS: Eighteen C57BL/6 mice were randomly assigned into three groups: (1) a control group (CTRL) animals underwent intratracheal (i.t.) instillation of saline, (2) the wild-type AAV9 group (WT-AAV9, 1010 vg), and (3) the tyrosine-mutant Y731F AAV9 group (M-AAV9, 1010 vg), which received (i.t.) self-complementary AAV9 vectors containing the DNA sequence of enhanced green fluorescence protein (eGFP). Four weeks after instillation, lung mechanics, morphometry, tissue cellularity, gene expression, inflammatory cytokines, and growth factor expression were analyzed. RESULTS: No significant differences were observed in lung mechanics and morphometry among the experimental groups. However, the number of polymorphonuclear cells was higher in the WT-AAV9 group than in the CTRL and M-AAV9 groups, suggesting that the administration of tyrosine-mutant AAV9 vectors was better tolerated. Tyrosine-mutant AAV9 vectors significantly improved transgene delivery to the lung (30%) compared with their wild-type counterparts, without eliciting an inflammatory response. CONCLUSION: Our results provide the impetus for further studies to exploit the use of AAV9 vectors as a tool for pulmonary gene therapy.

Single tyrosine mutation in AAV8 vector capsid enhances gene lung delivery and does not alter lung morphofunction in mice.

BACKGROUND/AIMS: Vectors derived from adeno-associated viruses (AAVs) are important gene delivery tools for treating pulmonary diseases. Phosphorylation of surface-exposed tyrosine residues from AAV2 capsid targets the viral particles for ubiquitination and proteasome-mediated degradation, and mutations of these tyrosine residues lead to highly efficient vector transduction in vitro and in vivo in different organs. We evaluated the pulmonary transduction efficiency of AAV8 vectors containing point mutations in surface-exposed capsid tyrosine residues. METHODS: Male C57BL/6 mice (20-25 g, n=24) were randomly assigned into three groups: control group animals received intratracheal (i.t.) instillation of saline (50 µl), wild-type AAV8 group, and capsid mutant Y733F AAV8 group, which received (i.t.) AAV8 vectors containing the DNA sequence of enhanced green fluorescence protein (eGFP). Four weeks after instillation, lung mechanics and morphometry, vector transduction (immunohistochemistry and mRNA expression of eGFP), and inflammatory cytokines and growth factor expression were analyzed. RESULTS: Tyrosine-mutant AAV8 vectors displayed significantly increased transduction efficiency in the lung compared with their wild-type counterparts. No significant differences were observed in lung mechanics and morphometry between experimental groups. There was no evidence of inflammatory response in any group. CONCLUSION: AAV8 vectors may be useful for new therapeutic strategies for the treatment of pulmonary diseases.

Repeated administration of bone marrow-derived cells prevents disease progression in experimental silicosis.

BACKGROUND/AIMS: Bone marrow-derived cells (BMDCs) reduced mechanical and histologic changes in the lung in a murine model of silicosis, but these beneficial effects did not persist in the course of lung injury. We hypothesized that repeated administration of BMDCs may decrease lung inflammation and remodeling thus preventing disease progression. METHODS: One hundred and two C57BL/6 mice were randomly divided into SIL (silica, 20 mg intratracheally [IT]) and control (C) groups (saline, IT). C and SIL groups were further randomized to receive BMDCs (2×10(6) cells) or saline IT 15 and 30 days after the start of the protocol. RESULTS: By day 60, BMDCs had decreased the fractional area of granuloma and the number of polymorphonuclear cells, macrophages (total and M1 phenotype), apoptotic cells, the level of transforming growth factor (TGF)-ß' and types I and III collagen fiber content in the granuloma. In the alveolar septa, BMDCs reduced the amount of collagen and elastic fibers, TGF-ß, and the number of M1 and apoptotic cells. Furthermore, interleukin (IL)-1ß, IL-1R1, caspase-3 mRNA levels decreased and the level of IL-1RN mRNA increased. Lung mechanics improved after BMDC therapy. The presence of male donor cells in lung tissue was not observed using detection of Y chromosome DNA. CONCLUSION: repeated administration of BMDCs reduced inflammation, fibrogenesis, and elastogenesis, thus improving lung mechanics through the release of paracrine factors.

Bone marrow-derived mononuclear cells promote improvement in glomerular function in rats with early diabetic nephropathy.

BACKGROUND/AIMS: Diabetic nephropathy is one of the main causes of end-stage renal disease. The present study investigated the effect of mononuclear cell (MC) therapy in rats subjected to diabetic nephropathy. METHODS: Male Wistar rats were divided into control (CTRL), diabetic (DM), CTRL+MC and DM+MC groups. Diabetes was induced by a single injection of streptozotocin (45 mg/kg, i.p.) and, 4 weeks later, 2×10(7) MCs were injected via the jugular vein. RESULTS: The rats in the DM and DM+MC groups showed increased glycemia, glomerular filtration rate and glomerular tuff area versus control groups. The glomerular filtration rate and glomerular tuff area were normalized in the DM+MC group. No alterations were observed in the fractional excretion of electrolytes and proteinuria between the DM and DM+MC groups. TGF-ß1 protein levels in the DM group were significantly increased versus control animals and normalized in the DM+MC group. An increase in ED1(+)/arginase I(+) macrophages and IL-10 renal expression was observed in the DM+MC group versus DM group. CONCLUSIONS: Bone marrow-derived MC therapy was able to prevent glomerular alterations and TGF-ß1 protein overexpression and modulated glomerular arginase I(+) macrophage infiltration in rats subjected to early diabetic nephropathy.

Early and late effects of bone marrow-derived mononuclear cell therapy on lung and distal organs in experimental sepsis.

We tested the hypothesis that bone marrow-derived mononuclear cells (BMDMCs) at an early phase of cecal ligation and puncture (CLP)-induced sepsis may have lasting effects on: (1) lung mechanics and histology, (2) the structural remodelling of lung parenchyma, (3) lung, kidney, and liver cell apoptosis, and (4) pro- and anti-inflammatory cytokines and growth factors. At day 1, BMDMC significantly reduced mortality, as well as caspase-3, interleukin (IL)-6 and IL-1ß, vascular endothelial growth factor, platelet-derived growth factor, hepatocyte growth factor, and transforming growth factor-ß, but increased IL-10 mRNA expression in lung tissue in septic mice contributing to endothelium and epithelium alveolar repair and improvement of lung mechanics. BMDMC also prevented the increase of apoptotic cells in lung, liver, and kidney. At day 7, these early functional and morphological effects were preserved or further improved. In conclusion, in the present model of sepsis, the beneficial effects of early administration of BMDMCs on lung and distal organs were preserved, possibly by paracrine mechanisms.

Prone position prevents regional alveolar hyperinflation and mechanical stress and strain in mild experimental acute lung injury.

Prone position may delay the development of ventilator-induced lung injury (VILI), but the mechanisms require better elucidation. In experimental mild acute lung injury (ALI), arterial oxygen partial pressure (Pa O2), lung mechanics and histology, inflammatory markers [interleukin (IL)-6 and IL-1 beta], and type III procollagen (PCIII) mRNA expressions were analysed in supine and prone position. Wistar rats were randomly divided into two groups. In controls, saline was intraperitoneally injected while ALI was induced by paraquat. After 24-h, the animals were mechanically ventilated for 1-h in supine or prone positions. In ALI, prone position led to a better blood flow/tissue ratio both in ventral and dorsal regions and was associated with a more homogeneous distribution of alveolar aeration/tissue ratio reducing lung static elastance and viscoelastic pressure, and increasing end-expiratory lung volume and Pa O2. PCIII expression was higher in the ventral than dorsal region in supine position, with no regional changes in inflammatory markers. In conclusion, prone position may protect the lungs against VILI, thus reducing pulmonary stress and strain.