Guilherme Baldo

Bone marrow derived cells decrease inflammation but not oxidative stress in an experimental model of acute myocardial infarction

AIMS Bone marrow cell (BMC) therapy is thought to exert beneficial effects on the infarcted heart. We assessed cardiac function and its correlation with redox status and inflammation in cardiac tissue early post-AMI in rats treated with BMC. MAIN METHODS Male Wistar rats (8-week-old) were randomized into four groups: Sham-operated (S); AMI; S+treatment (ST) and AMI+treatment (AMIT). Therapy with BMC was carried out immediately post-experimental left anterior coronary artery ligation induced-AMI, and assessments made 48h later. Cardiac function and morphometrics were evaluated by echocardiographyc parameters in vivo. Cardiac tissue tumor necrosis factor (TNF)-α and interleukin (IL)-6 were measured by Western Blot. Oxidative stress parameters including reduced (GSH) and oxidized (GSSG) glutathione ratio, hydrogen peroxide level, lipid and protein oxidation, superoxide dismutase, catalase and glutathione peroxidase activities were measured spectrophotometrically. KEY FINDINGS Ejection fraction was lower in infarcted groups and did not improve in BMC-treated animals: AMI (51±5%) vs. S (74±7%) and AMIT (56±10%) vs. ST groups (73±3%). Both TNF-α and IL-6 myocardial expression increased post-AMI and were reduced following BMC therapy. Nonetheless, there was a decrease in GSH/GSSG ratio in infarcted groups which was greater in BMC-treated groups: AMI (8.21±3.8) vs. S (14.61±3.4) and AMIT (2.1±0.7) vs. ST (4.7±1.5). SIGNIFICANCE The data suggest that BMC promoted a redox status favorable to the oxidation of the pro-inflammatory cytokines in the myocardium, exerting an anti-inflammatory-like effect.

Pathogenesis of aortic dilatation in mucopolysaccharidosis VII mice may involve complement activation

Mucopolysaccharidosis VII (MPS VII) is due to mutations within the gene encoding the lysosomal enzyme β-glucuronidase, and results in the accumulation of glycosaminoglycans. MPS VII causes aortic dilatation and elastin fragmentation, which is associated with upregulation of the elastases cathepsin S (CtsS) and matrix metalloproteinase 12 (MMP12). To test the role of these enzymes, MPS VII mice were crossed with mice deficient in CtsS or MMP12, and the effect upon aortic dilatation was determined. CtsS deficiency did not protect against aortic dilatation in MPS VII mice, but also failed to prevent an upregulation of cathepsin enzyme activity. Further analysis with substrates and inhibitors specific for particular cathepsins suggests that this enzyme activity was due to CtsB, which could contribute to elastin fragmentation. Similarly, MMP12 deficiency and deficiency of both MMP12 and CtsS could not prevent aortic dilatation in MPS VII mice. Microarray and reverse-transcriptase real-time PCR were performed to look for upregulation of other elastases. This demonstrated that mRNA for complement component D was elevated in MPS VII mice, while immunostaining demonstrated high levels of complement component C3 on surfaces within the aortic media. Finally, we demonstrate that neonatal intravenous injection of a retroviral vector encoding β-glucuronidase reduced aortic dilatation. We conclude that neither CtsS nor MMP12 are necessary for elastin fragmentation in MPS VII mouse aorta, and propose that CtsB and/or complement component D may be involved. Complement may be activated by the GAGs that accumulate, and may play a role in signal transduction pathways that upregulate elastases.

Adult derived mononuclear bone marrow cells improve survival in a model of acetaminophen-induced acute liver failure in rats

INTRODUCTION Acute liver failure (ALF) is characterized by a rapid loss of hepatic function, with high mortality. Acetaminophen (APAP) intoxication and viral hepatitis are common causes of ALF. Several studies have shown the capacity of adult bone marrow cells to differentiate in hepatocytes, suggesting their use for treating ALF. AIM In the present study, we tested the use of adult derived mononuclear bone marrow fraction to improve the survival of Wistar rats with APAP-induced ALF. METHODS Forty-eight female Wistar rats pre-induced with phenobarbital were given APAP in a single dose of 1g/kg via intraperitoneal injection. Bone marrow mononuclear cells were purified from male rats using FICOLL gradient and injected through the portal vein in a volume of 0.2mL containing 1x10(6) cells stained with DAPI. Treatment was administered 24h after APAP injection. The sham group (n=24), received 0.2mL of saline through the portal vein 24h after APAP administration. Survival, liver histology and ALT levels were observed. RESULTS Survival 72h post-APAP administration was 33% in the sham group and 70.8% in the group receiving bone marrow cells. Liver histology in treated animals showed less intense necrosis and the presence of DAPI-positive cells. CONCLUSIONS We have shown that bone marrow derived cells are capable of significantly increasing the survival rate of APAP-induced ALF in 37.5% (95% CI, 27.8-40.3%).

Emerging drugs for the treatment of mucopolysaccharidoses.

ABSTRACT Introduction: Despite being reported for the first time almost one century ago, only in the last few decades effective have treatments become available for the mucopolysaccharidoses (MPSs), a group of 11 inherited metabolic diseases that affect lysosomal function. These diseases are progressive, usually severe, and, in a significant number of cases, involve cognitive impairment. Areas covered: This review will not cover established treatments such as bone marrow/hematopoietic stem cell transplantation and classic intravenous enzyme replacement therapy (ERT), whose long-term outcomes have already been published (MPS I, MPS II, and MPS VI), but it instead focuses on emerging therapies for MPSs. That includes intravenous ERT for MPS IVA and VII, intrathecal ERT, ERT with fusion proteins, substrate reduction therapy, gene therapy, and other novel approaches. Expert opinion: The available treatments have resulted in improvements for several disease manifestations, but they still do not represent a cure for these diseases; thus, it is important to develop alternative methods to approach the unmet needs (i.e. bone disease, heart valve disease, corneal opacity, and central nervous system (CNS) involvement). The work in progress with novel approaches makes us confident that in 2017, when MPS will commemorate 100 years of its first report, we will be much closer to an effective cure for these challenging conditions.

Recombinant Encapsulated Cells Overexpressing Alpha-L-Iduronidase Correct Enzyme Deficiency in Human Mucopolysaccharidosis Type I Cells

Mucopolysaccharidosis I (MPS I) is an autosomal recessive lysosomal storage disease due to deficient α-L-iduronidase (IDUA) activity. It results in the accumulation of the glycosaminoglycans (GAGs) heparan and dermatan sulfate and leads to several clinical manifestations. Available treatments are limited in their efficacy to treat some aspects of the disease. Thus, new approaches have been studied for the treatment of MPS I. Here, we tested the ability of recombinant baby hamster kidney cells transfected with human IDUA cDNA in correcting skin fibroblasts from MPS I patients in vitro. Our results showed an increase in IDUA activity in MPS I fibroblasts after 15, 30 and 45 days of coculture with the capsules. Cytological analysis showed a marked reduction in GAG storage within MPS I cells. Enzyme uptake by the fibroblasts was blocked in a dose-dependent manner with mannose-6-phosphate (M6P), indicating that cells use the M6P receptor to internalize the recombinant enzyme. Capsules were effective in correcting MPS I cells even after a 12-month period of cryopreservation. Taken together, our results indicate that cell encapsulation is a potential approach for treatment of MPS I. This approach becomes particularly interesting as a complementary approach, since the capsules could be implanted in sites which current treatments available are not able to reach. Future studies will focus on the efficacy of this approach in vivo.

Effects of Cryopreservation and Hypothermic Storage on Cell Viability and Enzyme Activity in Recombinant Encapsulated Cells Overexpressing Alpha‐L‐Iduronidase

Here, we show the effects of cryopreservation and hypothermic storage upon cell viability and enzyme release in alginate beads containing baby hamster kidney cells overexpressing alpha-L-iduronidase (IDUA), the enzyme deficient in mucopolysaccharidosis type I. In addition, we compared two different concentrations of alginate gel (1% and 1.5%) in respect to enzyme release from the beads and their shape and integrity. Our results indicate that in both alginate concentrations, the enzyme is released in lower amounts compared with nonencapsulated cells. Alginate 1% beads presented increased levels of IDUA release, although this group presented more deformities when compared with alginate 1.5% beads. Importantly, both encapsulated groups presented higher cell viability after long cryopreservation period and hypothermic storage. In addition, alginate 1.5% beads presented higher enzyme release after freezing protocols. Taken together, our findings suggest a benefic effect of alginate upon cell viability and functionality. These results may have important application for treatment of both genetic and nongenetic diseases using microencapsulation-based artificial organs.

Evidence of a progressive motor dysfunction in Mucopolysaccharidosis type I mice.

Mucopolysaccharidosis (MPS) type I (Hurler syndrome) is a lysosomal storage disorder characterized by deficiency of alpha-L-iduronidase (IDUA), intracellular storage of glycosaminoglycans (GAGs) and progressive neurological pathology. The MPS I mouse model provides an opportunity to study the pathophysiology of this disorder and to determine the efficacy of novel therapies. Previous work has demonstrated a series of abnormalities in MPS I mice behavior, but so far some important brain functions have not been addressed. Therefore, in the present study we aimed to determine if MPS I mice have motor abnormalities, and at what age they become detectable. MPS I and normal male mice from 2 to 8 months of age were tested in open-field for locomotor activity, hindlimb gait analysis and hang wire performance. We were able to detect a progressive reduction in the crossings and rearings in the open field test and in the hang wire test in MPS I mice from 4 months, as well as a reduction in the gait length at 8 months. Histological examination of 8-month old mice cortex and cerebellum revealed storage of GAGs in Purkinje cells and neuroinflammation, evidenced by GFAP immunostaining. However TUNEL staining was negative, suggesting that death does not occur. Our findings suggest that MPS I mice have a progressive motor dysfunction, which is not caused by loss of neuron cells but might be related to a neuroinflammatory process.

Genome Editing: Potential Treatment for Lysosomal Storage Diseases

The recent progress in genome editing technology using the engineered zinc finger nucleases (ZFN), transcriptional activator-like effector nucleases (TALEN), and more recently, clustered regularly interspaced short palindromic repeat-CRISPR-associated protein 9 (CRISPR-Cas9) system have enabled the possibility of precisely modifying target sites in the genome. This technology brings hope of a cure for many genetic diseases. With this review, our goal is to discuss how targeted genome editing can be combined with hematopoietic stem cell transplantation and other approaches to be used for the treatment of a particular group of genetic diseases, the lysosomal storage disorders. We also highlight which diseases within this group would potentially benefit from this treatment and what are the main problems to be addressed to transform this promising technology into reality.

Pathogenesis of lumbar spine disease in mucopolysaccharidosis VII

Mucopolysaccharidosis type VII (MPS VII) is characterized by deficient β-glucuronidase (GUSB) activity, which leads to accumulation of chondroitin, heparan and dermatan sulfate glycosaminoglycans (GAGs), and multisystemic disease. MPS VII patients can develop kypho-scoliotic deformity and spinal cord compression due to disease of intervertebral disks, vertebral bodies, and associated tissues. We have previously demonstrated in MPS VII dogs that intervertebral disks degenerate, vertebral bodies have irregular surfaces, and vertebral body epiphyses have reduced calcification, but the pathophysiological mechanisms underlying these changes are unclear. We hypothesized that some of these manifestations could be due to upregulation of destructive proteases, possibly via the binding of GAGs to Toll-like receptor 4 (TLR4), as has been proposed for other tissues in MPS models. In this study, the annulus fibrosus of the intervertebral disk of 6-month-old MPS VII dogs had cathepsin B and K activities that were 117- and 2-fold normal, respectively, which were associated with elevations in mRNA levels for these cathepsins as well as TLR4. The epiphyses of MPS VII dogs had a marked elevation in mRNA for the cartilage-associated gene collagen II, consistent with a developmental delay in the conversion of the cartilage to bone in this region. The spine obtained at autopsy from a young man with MPS VII exhibited similar increased cartilage in the vertebral bodies adjacent to the end plates, disorganization of the intervertebral disks, and irregular vertebral end plate morphology. These data suggest that the pathogenesis of destructive changes in the spine in MPS VII may involve upregulation of cathepsins. Inhibition of destructive proteases, such as cathepsins, might reduce spine disease in patients with MPS VII or related disorders.

Placenta analysis of prenatally diagnosed patients reveals early GAG storage in mucopolysaccharidoses II and VI

We analyzed placental tissue in one fetus with MPS II (iduronate sulphatase deficiency) and another with MPS VI (arylsulfatase B deficiency). Both were diagnosed prenatally, but families decided to continue pregnancies and placentas were collected at birth. We were able to demonstrate early storage of GAGs in both diseases by GAG measurement and microscopy analysis. Our results suggest that some alterations related to MPS storage, although not pronounced, may be observed in placental tissue of patients affected by MPS II and MPS VI.