Marlene Antônia dos Reis

Early modulation of inflammation by mesenchymal stem cell after acute kidney injury

Therapy with stem cells has showed to be promising for acute kidney injury (AKI), although how it works is still controversial. Modulation of the inflammatory response is one possible mechanism. Most of published data relies on early time and whether the protection is still maintained after that is not known. Here, we analyzed whether immune modulation continues after 24 h of reperfusion. MSC were obtained from male Wistar rats. After 3-5 passages, cells were screened for CD73, CD90, CD44, CD45, CD29 and CD 31. In addition, MSC were submitted to differentiation in adipocyte and in osteocyte. AKI was induced by bilaterally clamping of renal pedicles for 60 min. Six hours after injury, MSC (2 x 10(5) cells) were administered intravenously. MSC-treated animals presented the lowest serum creatinine compared to non-treated animals (24 h: 1.3+/-0.21 vs. 3.23+/-0.89 mg/dl, p<0.05). The improvement in renal function was followed by a lower expression of IL-1b, IL-6 and TNF-alpha and higher expression of IL-4 and IL-10. However, 48 h after reperfusion, this cytokine profile has changed. The decrease in Th1 cytokines was less evident and IL-6 was markedly up regulated. PCNA analysis showed that regeneration occurs faster in kidney tissues of MSC-treated animals than in controls at 24 h. And also ratio of Bcl-2/Bad was higher at treated animals after 24 and 48 h. Our data demonstrated that the immunomodulatory effects of MSC occur at very early time point, changing the inflammation profile toward a Th2 profile.

TLR2, TLR4 and the MYD88 Signaling Pathway Are Crucial for Neutrophil Migration in Acute Kidney Injury Induced by Sepsis

The aim of this study was to investigate the role of TLR2, TLR4 and MyD88 in sepsis-induced AKI. C57BL/6 TLR2−/−, TLR4−/− and MyD88−/− male mice were subjected to sepsis by cecal ligation and puncture (CLP). Twenty four hours later, kidney tissue and blood samples were collected for analysis. The TLR2−/−, TLR4−/− and MyD88−/− mice that were subjected to CLP had preserved renal morphology, and fewer areas of hypoxia and apoptosis compared with the wild-type C57BL/6 mice (WT). MyD88−/− mice were completely protected compared with the WT mice. We also observed reduced expression of proinflammatory cytokines in the kidneys of the knockout mice compared with those of the WT mice and subsequent inhibition of increased vascular permeability in the kidneys of the knockout mice. The WT mice had increased GR1+low cells migration compared with the knockout mice and decreased in GR1+high cells migration into the peritoneal cavity. The TLR2−/−, TLR4−/−, and MyD88−/− mice had lower neutrophil infiltration in the kidneys. Depletion of neutrophils in the WT mice led to protection of renal function and less inflammation in the kidneys of these mice. Innate immunity participates in polymicrobial sepsis-induced AKI, mainly through the MyD88 pathway, by leading to an increased migration of neutrophils to the kidney, increased production of proinflammatory cytokines, vascular permeability, hypoxia and apoptosis of tubular cells.

Adipose tissue-derived stem cell treatment prevents renal disease progression.

Adipose tissue-derived stem cells (ASCs) are an attractive source of stem cells with regenerative properties that are similar to those of bone marrow stem cells. Here, we analyze the role of ASCs in reducing the progression of kidney fibrosis. Progressive renal fibrosis was achieved by unilateral clamping of the renal pedicle in mice for 1 h; after that, the kidney was reperfused immediately. Four hours after the surgery, 2 × 105 ASCs were intraperitoneally administered, and mice were followed for 24 h posttreatment and then at some other time interval for the next 6 weeks. Also, animals were treated with 2 × 105 ASCs at 6 weeks after reperfusion and sacrificed 4 weeks later to study their effect when interstitial fibrosis is already present. At 24 h after reperfusion, ASC-treated animals showed reduced renal dysfunction and enhanced regenerative tubular processes. Renal mRNA expression of IL-6 and TNF was decreased in ASC-treated animals, whereas IL-4, IL-10, and HO-1 expression increased despite a lack of ASCs in the kidneys as determined by SRY analysis. As expected, untreated kidneys shrank at 6 weeks, whereas the kidneys of ASC-treated animals remained normal in size, showed less collagen deposition, and decreased staining for FSP-1, type I collagen, and Hypoxyprobe. The renal protection seen in ASC-treated animals was followed by reduced serum levels of TNF-α, KC, RANTES, and IL-1α. Surprisingly, treatment with ASCs at 6 weeks, when animals already showed installed fibrosis, demonstrated amelioration of functional parameters, with less tissue fibrosis observed and reduced mRNA expression of type I collagen and vimentin. ASC therapy can improve functional parameters and reduce progression of renal fibrosis at early and later times after injury, mostly due to early modulation of the inflammatory response and to less hypoxia, thereby reducing the epithelial–mesenchymal transition.

A Role for galectin‐3 in renal tissue damage triggered by ischemia and reperfusion injury

Ischemic‐reperfusion injury (IRI) triggers an inflammatory response involving neutrophils/macrophages, lymphocytes and endothelial cells. Galectin‐3 is a multi‐functional lectin with a broad range of action such as promotion of neutrophil adhesion, induction of oxidative stress, mastocyte migration and degranulation, and production of pro‐inflammatory cytokines. The aim of this study was evaluate the role of galectin‐3 in the inflammation triggered by IRI. Galectin‐3 knockout (KO) and wild type (wt) mice were subjected to 45 min of renal pedicle occlusion. Blood and kidney samples were collected at 6, 24, 48 and 120 h. Blood urea was analyzed enzymatically, while MCP‐1, IL‐6 and IL‐1β were studied by real‐time PCR. Reactive oxygen species (ROS) was investigated by flow cytometry. Morphometric analyses were performed at 6, 24, 48 and 120 h after reperfusion. Urea peaked at 24 h, being significantly lower in knockout animals (wt = 264.4 ± 85.21 mg/dl vs. gal‐3 KO = 123.74 ± 29.64 mg/dl, P = 0.001). Galectin‐3 knockout animals presented less acute tubular necrosis and a more prominent tubular regeneration when compared with controls concurrently with lower expression of MCP‐1, IL‐6, IL‐1β, less macrophage infiltration and lower ROS production at early time points. Galectin‐3 seems to play a role in renal IRI involving the secretion of macrophage‐related chemokine, pro‐inflammatory cytokines and ROS production.

Mucosal Immunity in the Female Genital Tract, HIV/AIDS

Mucosal immunity consists of innate and adaptive immune responses which can be influenced by systemic immunity. Despite having been the subject of intensive studies, it is not fully elucidated what exactly occurs after HIV contact with the female genital tract mucosa. The sexual route is the main route of HIV transmission, with an increased risk of infection in women compared to men. Several characteristics of the female genital tract make it suitable for inoculation, establishment of infection, and systemic spread of the virus, which causes local changes that may favor the development of infections by other pathogens, often called sexually transmitted diseases (STDs). The relationship of these STDs with HIV infection has been widely studied. Here we review the characteristics of mucosal immunity of the female genital tract, its alterations due to HIV/AIDS, and the characteristics of coinfections between HIV/AIDS and the most prevalent STDs.

Neonatal Sepsis and Inflammatory Mediators

Neonatal sepsis is a major cause of morbidity and mortality and its signs and symptoms are nonspecific, which makes the diagnosis difficult. The routinely used laboratory tests are not effective methods of analysis, as they are extremely nonspecific and often cause inappropriate use of antibiotics. Sepsis is the result of an infection associated with a systemic inflammatory response with production and release of a wide range of inflammatory mediators. Cytokines are potent inflammatory mediators and their serum levels are increased during infections, so changes from other inflammatory effector molecules may occur. Although proinflammatory and anti-inflammatory cytokines have been identified as probable markers of neonatal infection, in order to characterize the inflammatory response during sepsis, it is necessary to analyze a panel of cytokines and not only the measurement of individual cytokines. Measurements of inflammatory mediators bring new options for diagnosing and following up neonatal sepsis, thus enabling early treatment and, as a result, increased neonatal survival. By taking into account the magnitude of neonatal sepsis, the aim of this review is to address the role of cytokines in the pathogenesis of neonatal sepsis and its value as a diagnostic criterion.

Ocorrência de cisticercose (Cysticercus cellulosae) encefálica e cardíaca em necropsias

OBJECTIVE To review the incidence and pathologic findings of cysticercosis diagnosed at autopsies, with emphasis on the most common organs affected. METHODS Reports of 1.596 autopsies performed between 1974 and 1997 at a school hospital in Uberaba, MG, Brazil were studied. The following data were obtained: age, sex, ethnic group, body mass index, and the site of the cysticercosis. RESULTS The study found diagnosis of cysticercosis in 53 autopsies (3.3%). The average age of patients with cysticercosis was 50 (range: 15 to 86 years); 62.3% were male, and 64.1% Caucasian. The most affected organs were: brain (79.2%), heart (22.6%), skeletal muscle (11.3%), and other organs (5.7%). No statistical differences were found comparing age, gender, ethnic group, and body mass index of the affected and the non-affected patients. In two cases of neurocysticercosis the lesions were located in the ventromedial nucleus of the hypothalamus. CONCLUSION Both the overall incidence of cysticercosis and the incidence of cardiac cysticercosis were greater in the study than in other autopsy series from the same geographic areas. In two cases there was an association between hypothalamic cysticercosis and obesity

Renal transplantation outcomes : a comparative analysis between elderly and younger recipients

Abstract:  Renal transplantation is presently the best treatment for end‐stage renal disease, although considered contraindicated for elderly patients. However, more investigation is needed due to higher life expectancy rates of the general population and the increasing number of over 60‐yr‐old patients with chronic renal failure dependant upon dialysis. This study aims to determine graft and patient survival rates of renal transplant patients 60 yr and older compared to a younger group (50–59 yr old). Relevant pre‐ and post‐transplant clinical data related to graft and patient survival in both groups were also investigated. Three‐hundred and twenty consecutive renal transplant patients were enrolled in this study and grouped based on age at the time of the transplantation: one‐hundred and ten patients at or over 60 yr old (elderly group) and 210 patients ranging from 50 to 59 yr old (younger group). There were no statistical differences in either group regarding clinical characteristics and immunological risk factors. The incidence of acute rejection was higher in the younger group (37.6%) than in the elderly (22.7%) (p = 0.01). Censored to death graft survivals at five yr were respectively 86.7% for patients ≥ 60 yr and 82.1% for patients 50–59 yr old (p = 0.49). Patient survival rates at five yr were respectively 76.2% for patients ≥ 60 yr and 81.6% for patients 50–59 yr old (p = 0.33). Our data show that renal transplantation for elderly patients has similar results to those found in younger individuals, which does not make age, in and of itself, a contraindication for transplantation.

Acute Renal Failure in Experimental Envenomation with Africanized Bee Venom

Human victims of multiple bee or wasp stings have been reported and develop severe clinical signs and symptoms. Acute renal failure (ARF), usually due to acute tubular necrosis (ATN) was a frequent complication. The pathogenetic mechanisms of ATN occurring in these accidents are still unclear. In the present study, female Wistar rats weighing 150-200 g were injected intravenously with Africanized bee venom at a dose of 0.4 microL/100 g body weight, and the kidney was observed under light and transmission electron microscopy and in immunohistochemical studies. The animals were divided into two groups: an Early group studied 3 to 8 hours after inoculation, and a Late group studied 24 to 30 hours after inoculation. The animals showed ATN mainly in the cortex and outer medulla with cast formation. After 24 hours, frequent mitotic figures were found in the tubular epithelium. Immunohistochemical studies revealed the presence of myoglobin and muscle actin in the tubular casts. Under electron microscopy, proximal tubule segments showed increasing intracytoplasmic vacuoles and attenuation of the brush border and of the basolateral infolding. This segment and the thick ascending limb of Henles loop showed hydropic degeneration. Dead cells with apoptosis or necrosis due to cellular disintegration resulted in tubular basement membrane denudation. In the Late group, figures of intracytoplasmic myelin could be observed, some of them containing mitochondrial fragments. These changes are likely to be due to interactive effects of venom components, mainly mellitin and enzymes such as phospholipases, both acting on biological membranes. The ATN found was probably due to multiple causes, mainly a direct action of the venom on tubular cells, myoglobinuria, and perhaps ischemic mechanisms.

A role for regulatory T cells in renal acute kidney injury.

Ischemia reperfusion injury (IRI) is a potential contributor for the development of chronic allograft nephropathy. T cells are important mediators of injury, even in the absence of alloantigens. We performed a depletion of TCD4(+)CTLA4(+)Foxp3(+) cells with anti-CD25(PC61), a treatment with anti-GITR (DTA-1) and rat-IgG, followed by 45 min of ischemia and 24/72 h of reperfusion, and then analyzed blood urea, kidney histopathology and gene expression in kidneys by QReal Time PCR. After 24 h of reperfusion, depletion of TCD4(+)CTLA4(+)Foxp3(+) cells reached 30.3%(spleen) and 67.8%(lymph nodes). 72 h after reperfusion depletion reached 43.1%(spleen) and 90.22%(lymph nodes) and depleted animals presented with significantly poorer renal function, while DTA-1(anti-GITR)-treated ones showed a significant protection, all compared to serum urea from control group (IgG: 150.10+/-50.04; PC61: 187.23+/-31.38; DTA-1: 64.53+/-25.65, mg/dL, p<0.05). These data were corroborated by histopathology. We observed an increase of HO-1 expression in animals treated with DTA-1 at 72 h of reperfusion with significant differences. Thus, our results suggest that PC61(anti-CD25) mAb treatment is deleterious, while DTA-1(anti-GITR) mAb treatment presents a protective role in the renal IRI, indicating that some regulatory populations of T cells might have a role in IRI.