The complement system in the pathogenesis and progression of kidney diseases: What doesn't kill you makes you older

The Complement System is an evolutionarily conserved component of immunity that plays a key role in host defense against infections and tissue homeostasis. However, the dysfunction of the Complement System can result in tissue damage and inflammation, thereby contributing to the development and progression of various renal diseases, ranging from atypical Hemolytic Uremic Syndrome to glomerulonephritis. Therapeutic interventions targeting the complement system have demonstrated promising results in both preclinical and clinical studies. Currently, several complement inhibitors are being developed for the treatment of complement-mediated renal diseases. This review aims to summarize the most recent insights into complement activation and therapeutic inhibition in renal diseases. Furthermore, it offers potential directions for the future rational use of complement inhibitor drugs in the context of renal diseases.

PALS1 is a key regulator of the lateral distribution of tight junction proteins in renal epithelial cells

The evolutionarily conserved apical Crumbs (CRB) complex, consisting of the core components CRB3a (an isoform of CRB3), PALS1 and PATJ, plays a key role in epithelial cell-cell contact formation and cell polarization. Recently, we observed that deletion of one Pals1 allele in mice results in functional haploinsufficiency characterized by renal cysts. Here, to address the role of PALS1 at the cellular level, we generated CRISPR/Cas9-mediated PALS1-knockout MDCKII cell lines. The loss of PALS1 resulted in increased paracellular permeability, indicating an epithelial barrier defect. This defect was associated with a redistribution of several tight junction-associated proteins from bicellular to tricellular contacts. PALS1-dependent localization of tight junction proteins at bicellular junctions required its interaction with PATJ. Importantly, reestablishment of the tight junction belt upon transient F-actin depolymerization or upon Ca2+ removal was strongly delayed in PALS1-deficient cells. Additionally, the cytoskeleton regulator RhoA was redistributed from junctions into the cytosol under PALS1 knockout. Together, our data uncover a critical role of PALS1 in the coupling of tight junction proteins to the F-actin cytoskeleton, which ensures their correct distribution along bicellular junctions and the formation of tight epithelial barrier.

The Rotterdam Study. Design update and major findings between 2020 and 2024

The Rotterdam Study is a population-based cohort study, started in 1990 in the district of Ommoord in the city of Rotterdam, the Netherlands, with the aim to describe the prevalence and incidence, unravel the etiology, and identify targets for prediction, prevention or intervention of multifactorial diseases in mid-life and elderly. The study currently includes 17,931 participants (overall response rate 65%), aged 40 years and over, who are examined in-person every 3 to 5 years in a dedicated research facility, and who are followed-up continuously through automated linkage with health care providers, both regionally and nationally. Research within the Rotterdam Study is carried out along two axes. First, research lines are oriented around diseases and clinical conditions, which are reflective of medical specializations. Second, cross-cutting research lines transverse these clinical demarcations allowing for inter- and multidisciplinary research. These research lines generally reflect subdomains within epidemiology. This paper describes recent methodological updates and main findings from each of these research lines. Also, future perspective for coming years highlighted.

tRNA-Derived Small RNAs: A Novel Regulatory Small Noncoding RNA in Renal Diseases

Background

tRNA-derived small RNAs (tsRNAs) are an emerging class of small noncoding RNAs derived from tRNA cleavage.

Summary

With the development of high-throughput sequencing, various biological roles of tsRNAs have been gradually revealed, including regulation of mRNA stability, transcription, translation, direct interaction with proteins and as epigenetic factors, etc. Recent studies have shown that tsRNAs are also closely related to renal disease. In clinical acute kidney injury (AKI) patients and preclinical AKI models, the production and differential expression of tsRNAs in renal tissue and plasma were observed. Decreased expression of tsRNAs was also found in urine exosomes from chronic kidney disease patients. Dysregulation of tsRNAs also appears in models of nephrotic syndrome and patients with lupus nephritis. And specific tsRNAs were found in high glucose model in vitro and in serum of diabetic nephropathy patients. In addition, tsRNAs were also differentially expressed in patients with kidney cancer and transplantation.

Key Messages

In the present review, we have summarized up-to-date works and reviewed the relationship and possible mechanisms between tsRNAs and kidney diseases.

Association between gingival bleeding and hematuria as biomarkers of periodontitis and renal disease: a review

Gingival bleeding is a common complaint and symptom in patients with periodontitis. In clinics, gingival bleeding is regarded as an important sign of gingival inflammation, which is also of great significance in predicting the activity of periodontitis. Existing research has indicated that periodontitis has an impact on distant sites, such as the kidney. Hematuria is the principal feature of glomerular disease, which can reflect the degree and condition of glomerular inflammation. Previous studies have revealed an association between periodontal diseases with renal diseases, so a study is necessary to discuss their representative signs of them. For the moment, there are no reports that are concerned about the correlation between gingival bleeding with hematuria. The main point of this text is to review the potential association between gingival bleeding with hematuria, reveal their underlying mechanisms, and provide instructions for the therapy of periodontitis and glomerular diseases.

Global trends and focuses of GLP-1RA in renal disease: a bibliometric analysis and visualization from 2005 to 2022

Glucagon-like peptide 1 receptor agonist (GLP-1RA) is a new class of glucose-lowing agents with the kidney benefit effect. This paper aims at finding the current state and hotspots of the research on GLP-1RA in kidney disease by using bibliometric methodologies and visualization maps to analyze publications and provide the direction for future studies on that topic. Literature information was obtained by retrieving the WoSCC database. Then, software like Microsoft Excel, VOSviewer, and CiteSpace was used to analyze and process obtained data. Bibliometric analysis and visualization of nations, authors, organizations, journals, keywords, and references were also done by VOSviewer and CiteSpace. A total of 991 publications written by 4747 authors from 1637 organizations in 75 countries on GLP-1RA in renal disease in Web of Science Core Collection were retrieved. The number of publications and citations kept growing from 2015 to 2022. The USA, Univ Copenhagen, and Rossing Peter are the leading country, organization, and author on this topic, respectively. All literature was published in 346 journals, and DIABETES OBESITY & METABOLISM is the journal with the most contributions. Meanwhile, most references are from DIABETES CARE. "Cardiovascular outcome" is the most frequent keyword in the total publications, and the reference cited most times is "Liraglutide and Cardiovascular Outcomes in Type 2 Diabetes" by Marso SP. The topic of GLP-1RA in renal disease has attracted more and more attention all over the world. Existing studies are mainly about clinical use in patients with diabetes, and studies on the mechanism are lacking.

Novel insights into STAT3 in renal diseases

Signal transducer and activator of transcription 3 (STAT3) is a cell-signal transcription factor that has attracted considerable attention in recent years. The stimulation of cytokines and growth factors can result in the transcription of a wide range of genes that are crucial for several cellular biological processes involved in pro- and anti-inflammatory responses. STAT3 has attracted considerable interest as a result of a recent upsurge in study because of their role in directing the innate immune response and sustaining inflammatory pathways, which is a key feature in the pathogenesis of many diseases, including renal disorders. Several pathological conditions which may involve STAT3 include diabetic nephropathy, acute kidney injury, lupus nephritis, polycystic kidney disease, and renal cell carcinoma. STAT3 is expressed in various renal tissues under these pathological conditions. To better understand the role of STAT3 in the kidney and provide a theoretical foundation for STAT3-targeted therapy for renal disorders, this review covers the current work on the activities of STAT3 and its mechanisms in the pathophysiological processes of various types of renal diseases.

Identification of Renal Transplantation Rejection Biomarkers in Blood Using the Systems Biology Approach

Background

Renal transplantation plays an essential role in the quality of life of patients with end-stage renal disease. At least 12% of the renal patients receiving transplantations show graft rejection. One of the methods used to diagnose renal transplantation rejection is renal allograft biopsy. This procedure is associated with some risks such as bleeding and arteriovenous fistula formation. In this study, we applied a bioinformatics approach to identify serum markers for graft rejection in patients receiving a renal transplantation.

Methods

Transcriptomic data were first retrieved from the blood of renal transplantation rejection patients using the GEO database. The data were then used to construct the protein-protein interaction and gene regulatory networks using Cytoscape software. Next, network analysis was performed to identify hub-bottlenecks, and key blood markers involved in renal graft rejection. Lastly, the gene ontology and functional pathways related to hub-bottlenecks were detected using PANTHER and DAVID servers.

Results

In PPIN and GRN, SYNCRIP, SQSTM1, GRAMD1A, FAM104A, ND2, TPGS2, ZNF652, RORA, and MALAT1 were the identified critical genes. In GRN, miR-155, miR17, miR146b, miR-200 family, and GATA2 were the factors that regulated critical genes. The MAPK, neurotrophin, and TNF signaling pathways, IL-17, and human cytomegalovirus infection, human papillomavirus infection, and shigellosis were identified as significant pathways involved in graft rejection.

Concusion

The above-mentioned genes can be used as diagnostic and therapeutic serum markers of transplantation rejection in renal patients. The newly predicted biomarkers and pathways require further studies.

Association between serum uric acid levels and simple renal cyst risk in a nondiabetic population: A nested case-control study

BACKGROUND

Previous studies have found a relationship between hypertension or cardiovascular disease and simple renal cysts (SRCs) in health check-up population, but SRCs incidence is still controversially associated with serum uric acid (SUA) concentration in the nondiabetic participants. In this single-centre nest case-control study, serum uric acid levels were examined in relation to the incidence of SRCs in nondiabetic individuals.

METHOD

Participants who underwent at least two renal ultrasound examinations with an interval of more than 12 months were enrolled. The results of clinical examinations, laboratory tests and abdominal ultrasound tests were recorded for each participant and analysed in this retrospective observation study.

RESULT

A total of 144 control and 144 SRC patients were ultimately confirmed and included in further analysis. Hyperuricaemia (OR 2.846, 95% CI 1.519-5.332, p = 0.001) was significantly correlated with SRC formation according to multivariable analysis. In both the male and female groups, SRC patients had significantly higher serum uric acid levels compared with control subjects. In 54 SRC patients with cyst puncture, the serum uric acid concentration was positively correlated with the uric acid concentration in cyst fluid (r = 0.6144, p < 0.0001). The serum uric acid concentration was positively correlated with the maximum cyst diameter in the SRC patients (r = 0.4531, p < 0.0001).

CONCLUSION

In a nondiabetic population, hyperuricaemia was significantly independently associated with a higher SRCs incidence. In SRC participants with cyst puncture, the SUA level had a significantly positive correlation with the uric acid level in cyst fluid. In SRC patients, the SUA level had a significantly positive correlation with cyst maximum diameter.

Flavonoids-mediated TLR4 inhibition as a promising therapy for renal diseases

Toll-like receptors (TLRs) control both innate and adaptive immunity with a wide expression on renal epithelial cells and leukocytes. Activation of TLRs results in the production of cytokines, chemokines and interferons along with activation of the transcription factor NF-κB, resulting in inflammatory perturbations. TLR4 signaling pathway is the most extensively studied of TLRs. TLR4 is expressed on renal microvascular endothelial and tubular epithelial cells. So, targeting TLR4 modulation could be a therapeutic approach to attenuate kidney diseases that are underlined by inflammatory cascade. Medicinal plants with anti-inflammatory activities display valuable effects and are employed as alternative sources to alleviate renal disease linked with inflammation. Flavonoids and other phytochemicals derived from traditional medicines possess promising pharmacological activities owing to their relatively cheap and high safety profile. Our review focuses on the potent anti-inflammatory activities of twenty phytochemicals to verify if their potential promising renoprotective effects are related to suppression of TLR4 signaling in different renal diseases, including sepsis-induced acute kidney injury, renal fibrosis, chemotherapy-induced nephrotoxicity, diabetic nephropathy and renal ischemia/reperfusion injury. Additionally, molecular docking simulations were employed to explore the potential binding affinity of these phytochemicals to TLR4 as a strategy to attenuate renal diseases associated with activated TLR4 signaling.

Ethnobotanical, pharmacological, phytochemical, and clinical investigations on Moroccan medicinal plants traditionally used for the management of renal dysfunctions

ETHNOPHARMACOLOGICAL RELEVANCE

Renal disease is a significant public health concern that affects people all over the world. The main limitations of conventional therapy are the adverse reaction on human health and the expensive cost of drugs. Indeed, it is necessary to develop new therapeutic strategies that are less expensive and have fewer side effects. As a consequence of their natural compounds, medicinal plants can be used as an alternative therapy to cure various ailments including kidney diseases.

OBJECTIVE

of the study: This review paper has two principal goals: (1) to inventory and describe the plants and their ancestral use by Moroccan society to cure renal problems, (2) to link traditional use with scientific confirmations (preclinical and clinical).

METHODS

To analyze pharmacological effects, phytochemical, and clinical trials of plants, selected for renal therapy, a bibliographical search was undertaken by examining ethnobotanical investigations conducted in Morocco between 1991 and 2019 and consulting peer-reviewed papers from all over the world.

RESULTS

Approximately 290 plant species, spanning 81 families and 218 genera have been reported as being utilized by Moroccans to manage renal illness. The most frequently mentioned species in Morocco were Herniaria hirsuta subsp. cinerea (DC.), Petroselinum crispum (Mill.) Fuss and Rosmarinus officinalis L. The leaves were the most frequently used plant parts, followed by the whole plant. Decoction and infusion were the most popular methods of preparation. A record of 71 plant species was studied in vitro and/or in vivo for their therapeutic efficacy against kidney disorders, including 10 plants attempting to make it to the clinical stage. Twenty compounds obtained from 15 plants have been studied for the treatment of kidney diseases.

CONCLUSION

Medicinal herbs could be a credible alternative therapy for renal illness. However, additional controlled trials are required to confirm their efficiency in patients with kidney failure. Overall, this work could be used as a database for future exploration.

Protective effects of berberine on various kidney diseases: Emphasis on the promising effects and the underlined molecular mechanisms

Berberine (BBR) is a pentacyclic benzylisoquinoline alkaloid that can be found in diversity of medicinal plants. BBR has a wide range of pharmacological bioactivities, in addition when administrated orally, it has a broad safety margin. It has been used as an antidiarrheal, antimicrobial, and anti-diabetic drug in Ayurvedic and Chinese medicine. Several scholars have found that BBR has promising renoprotective effects against different renal illnesses, including diabetic nephropathy, renal fibrosis, renal ischemia, renal aging, and renal stones. Also, it has renoprotective effects against nephrotoxicity induced by chemotherapy, heavy metal, aminoglycosides, NSAID, and others. These effects imply that BBR has an evolving therapeutic potential against acute renal failure and chronic renal diseases. Hence, we report herein the beneficial therapeutic renoprotective properties of BBR, as well as the highlighted molecular mechanism. In conclusion, the studies discussed throughout this review will afford a comprehensive overview about renoprotective effect of BBR and its therapeutic impact on different renal diseases.

Cardiorenal syndrome: long road between kidney and heart

Almost 200 years ago, the first evidence described by Robert Bright (1836) showed the strong interaction between the kidneys and heart and, since then, the scientific community has dedicated itself to better understanding the mechanisms involved in the kidney-heart relationship, known in recent decades as cardiorenal syndrome (CRS). This syndrome includes a wide clinical variety that affects the kidneys and heart, in an acute or chronic manner. Moreover, it is well established in the literature that the immune system, the sympathetic nervous system, the renin-angiotensin-aldosterone, and the oxidative stress actively play a strong role in the cellular and molecular processes present in CRS. More recently, uremic molecules and epigenetic factors have been also shown to be key mediators in the development of syndrome. The present review intends to present the state of the art regarding CRS and to show the paths known, until now, in the long road between the kidneys and heart.

Endostatin in Renal and Cardiovascular Diseases

Endostatin, a protein derived from the cleavage of collagen XVIII by the action of proteases, is an endogenous inhibitor known for its ability to inhibit proliferation and migration of endothelial cells, angiogenesis, and tumor growth. Angiogenesis is defined as the formation of new blood vessels from pre-existing vasculature, which is crucial in many physiological processes, such as embryogenesis, tissue regeneration, and neoplasia.

SUMMARY

Increasing evidence shows that dysregulation of angiogenesis is crucial for the pathogenesis of renal and cardiovascular diseases. Endostatin plays a pivotal role in the regulation of angiogenesis. Recent studies have provided evidence that circulating endostatin increases significantly in patients with kidney and heart failure and may also contribute to disease progression.

KEY MESSAGE

In the current review, we summarize the latest findings on preclinical and clinical studies analyzing the impact of endostatin on renal and cardiovascular diseases.

Irreversible post-translational modifications - Emerging cardiovascular risk factors

Despite the introduction of lipid-lowering drugs, antihypertensives, antiplatelet and anticoagulation therapies for primary prevention of cardiovascular and heart diseases (CVD), it remains the number one cause of death globally, raising the question for novel/further essential factors besides traditional risk factors such as cholesterol, blood pressure and coagulation. With continuous identification and characterization of non-enzymatic post-translationally modified isoforms of proteins and lipoproteins, it is becoming increasingly clear that irreversible non-enzymatic post-translational modifications (nPTMs) alter the biological functions of native proteins and lipoproteins thereby transforming innate serum components into CVD mediators. In particular renal insufficiency and metabolic imbalance are major contributors to the systemically increased concentration of reactive metabolites and thus increased frequency of nPTMs, promoting multi-morbid disease development centering around cardiovascular disease. nPTMs are significantly involved in the onset and progression of cardiovascular disease and represent a significant and novel risk factor. These insights represent potentially new avenues for risk assessment, prevention and therapy. This review chapter summarizes all forms of nPTMs found in CKD and under metabolic imbalance and discusses the biochemical connections between molecular alterations and the pathological impact on increased cardiovascular risk, novel nPTM-associated non-traditional cardiovascular risk factors, and clinical implication of nPTM in cardiovascular disease.

Short-term exposure to fine particulate air pollution and emergency department visits for kidney diseases in the Atlanta metropolitan area

Toxicological evidence has shown that fine particulate matter (PM_2.5) may affect distant organs, including kidneys, over the short term. However, epidemiological evidence is limited.

OBJECTIVES

We investigated associations between short-term exposure to PM_2.5, major PM_2.5 components [elemental carbon (EC), organic carbon (OC), sulfate, and nitrate], and gaseous co-pollutants (O₃, CO, SO₂, NO₂, and NO_x) and emergency department (ED) visits for kidney diseases during 2002-2008 in Atlanta, Georgia.

METHODS

Log-linear time-series models were fitted to estimate the acute effects of air pollution, with single-day and unconstrained distributed lags, on rates of ED visits for kidney diseases [all renal diseases and acute renal failure (ARF)], controlling for meteorology (maximum air and dew-point temperatures) and time (season, day of week, holidays, and long-term time trend).

RESULTS

For all renal diseases, we observed positive associations for most air pollutants, particularly 8-day cumulative exposure to OC [rate ratio (RR) = 1.018, (95% confidence interval [CI]: 1.003, 1.034)] and EC [1.016 (1.000, 1.031)] per interquartile range increase exposure. For ARF, we observed positive associations particularly for 8-day exposure to OC [1.034 (1.005, 1.064)], EC [1.032 (1.002, 1.063)], nitrate [1.032 (0.996, 1.069)], and PM_2.5 [1.026 (0.997, 1.057)] per interquartile range increase exposure. We also observed positive associations for most criteria gases. The RR estimates were generally higher for ARF than all renal diseases.

CONCLUSIONS

We observed positive associations between short-term exposure to fine particulate air pollution and kidney disease outcomes. This study adds to the growing epidemiological evidence that fine particles may impact distant organs (e.g., kidneys) over the short term.

Nanobodies: new avenue to treat kidney disease

Current therapeutic options for renal diseases are limited, and the search for disease-specific treatments is ongoing. Nanobodies, single-domain antibodies with many advantages over conventional antibodies, provide flexible, easy-to-format biologicals with many possible applications. Here, we discuss the potential use of nanobodies for renal diseases.

The Danish comorbidity in liver transplant recipients study (DACOLT): a non-interventional prospective observational cohort study

Background

Liver transplantation is the only curative treatment for patients with end-stage liver disease. Short-term survival has improved due to improved surgical techniques and greater efficacy of immunosuppressive drugs. However, long-term survival has not improved to the same extent as the short-term survival, and the 10-year survival after liver transplantation is 60%. In addition to liver- and transplant-related causes, comorbidities such as cardiovascular, pulmonary, renal, and metabolic diseases have emerged as leading causes of morbidity and mortality in liver transplant recipients. The objective of this study is to assess the burden of comorbidities and identify both liver- and transplant-related risk factors as well as traditional risk factors that contribute to the pathogenesis of comorbidity in liver transplant recipients.

Methods/design

The Danish Comorbidity in Liver Transplant Recipients (DACOLT) study is an observational, longitudinal study. We aim to include all adult liver transplant recipients in Denmark (n = approx. 600). Participants will be matched by sex and age to controls from the Copenhagen General Population Study (CGPS) and the Copenhagen City Heart Study (CCHS). Physical and biological measures including blood pressure, ankle–brachial index, spirometry, exhaled nitric oxide, electrocardiogram, transthoracic echocardiography, computed tomography (CT) angiography of the heart, unenhanced CT of chest and abdomen and blood samples will be collected using uniform protocols in participants in DACOLT, CGPS, and CCHS. Blood samples will be collected and stored in a research biobank. Follow-up examinations at regular intervals up to 10 years of follow-up are planned.

Discussion

There is no international consensus standard for optimal clinical care or monitoring of liver transplant recipients. This study will determine prevalence, incidence and risk factors for comorbidity in liver transplant recipients and may be used to provide evidence for guidelines on management, treatment and screening and thereby contribute to improvement of the long-term survival.

Trial registration ClinicalTrials.gov: NCT04777032; date of registration: March 02, 2021.

Toll-Like Receptors Regulate the Development and Progression of Renal Diseases

Background

Stimulated by both microbial and endogenous ligands, toll-like receptors (TLRs) play an important role in the development and progression of renal diseases.

Summary

As a highly conserved large family, TLRs have 11 members in humans (TLR1∼TLR11) and 13 members in mouse (TLR1∼TLR13). It has been widely reported that TLR2 and TLR4 signaling, activated by both exogenous and endogenous ligands, promote disease progression in both renal ischemia-reperfusion injury and diabetic nephropathy. TLR4 also vitally functions in CKD and infection-associated renal diseases such as pyelonephritis induced by urinary tract infection. Stimulation of intracellular TLR7/8 and TLR9 by host-derived nucleic acids also plays a key role in systemic lupus erythematosus. Given that certain microRNAs with GU-rich sequence have recently been found to be able to serve as TLR7/8 ligands, these microRNAs may initiate pro-inflammatory signal via activating TLR signal. Moreover, as microRNAs can be transferred across different organs via cell-secreted exosomes or protein-RNA complex, the TLR signaling activated by the miRNAs released by other injured organs may also result in renal dysfunction.

Key Messages

In this review, we sum up the recent progress in the role of TLRs in various forms of glomerulonephritis and discuss the possible prevention or therapeutic strategies for clinic treatment to renal diseases.

The Use of Curcumin for the Treatment of Renal Disorders: A Systematic Review of Randomized Controlled Trials

Chronic kidney disease (CKD) is one of the significant causes of morbidity and mortality worldwide, which could develop and progress to end-stage renal disease. Increased inflammation and reduced antioxidant capacity commonly occur in CKD and hemodialysis patients. Curcumin is a natural bioactive compound with antioxidant and anti-inflammatory properties. This systematic review was undertaken with the main aim of assessing the effects of curcumin/turmeric supplementation on renal diseases based on clinical trials. A comprehensive search was performed in PubMed/MEDLINE, Scopus, ISI Web of Science, and Google Scholar from inception up to April 6, 2020 to identify clinical trials assessing the effects of curcumin or turmeric alone, or in combination with other herbs or nutrients on renal diseases. Twelve studies met the eligibility criteria. These randomized controlled trials (RCTs) comprised 631 patients with either chronic kidney diseases (CKD), hemodialysis, diabetic proteinuria and nephropathy, and lupus nephritis. Curcumin/turmeric supplementation had favorable effects on renal diseases, particularly in terms of inflammation and oxidative stress. However, with the exception for proteinuria, their impact on clinical parameters, such as blood urea nitrogen, creatinine, glomerular filtration rate (GFR), and serum albumin, was weak and not significant. No serious adverse effects were reported following curcumin/turmeric supplementation. Within the limitations of this review, it can be concluded that curcumin/turmeric supplementation might have some beneficial effects on inflammatory and oxidative stress parameters of patients but no considerable positive impact on clinical outcomes of kidney diseases, apart from proteinuria.

Exosomes: A new horizon in modern medicine

Exosomes are a type of extracellular vesicles belonging to endocytic origin. These vesicles carry different biological cargo that play numerous physiological roles and is also indicative of different diseased state. Exosomes are considered as promising tools for therapeutic drug delivery, owing to their intrinsic features like stability, biocompatibility and a capacity of stealth. A clearer understanding of the composition, biogenesis and biology of exosomes can provide us with better insights into the pathophysiological, diagnostic, and therapeutic roles of these extracellular vesicles. In this review we have summarize existing literature regarding the production, efficacy, action mechanism, and potential therapeutic roles of exosomes in the contexts of various diseases such as cancer, renal disease, neurological disorders, cardio-vascular diseases, inflammatory diseases and some of the auto-immune diseases.

Objectives, design and main findings until 2020 from the Rotterdam Study

The Rotterdam Study is an ongoing prospective cohort study that started in 1990 in the city of Rotterdam, The Netherlands. The study aims to unravel etiology, preclinical course, natural history and potential targets for intervention for chronic diseases in mid-life and late-life. The study focuses on cardiovascular, endocrine, hepatic, neurological, ophthalmic, psychiatric, dermatological, otolaryngological, locomotor, and respiratory diseases. As of 2008, 14,926 subjects aged 45 years or over comprise the Rotterdam Study cohort. Since 2016, the cohort is being expanded by persons aged 40 years and over. The findings of the Rotterdam Study have been presented in over 1700 research articles and reports. This article provides an update on the rationale and design of the study. It also presents a summary of the major findings from the preceding 3 years and outlines developments for the coming period.

Ghrelin-mediated pathway in Apolipoprotein-E deficient mice: a survival system

Renal diseases interfere with the regulation of several metabolic pathways including dyslipidemia. The latter includes increased triglycerides, very low-density lipoprotein levels and decreased high-density lipoproteins. These lipoproteins change during renal injury. Apolipoprotein-E deficient mice (ApoE^-/-) are considered a very well accepted model of hypercholesterolemia with marked renal pathological alterations. Ghrelin hormone is mainly secreted from the stomach when the stomach is empty, but it is also found in the kidney. In this organ it has autocrine and/or paracrine roles determining glomerular filtration rate, tubular phosphate and sodium reabsorption. Interestingly, it has been demonstrated that ghrelin levels increase after fasting. This mechanism induces an interaction with sirtuin 1 (SIRT1)/p53 pathway suggesting a link between ghrelin and SIRT1 in the regulation of salt and water metabolism. The mechanisms of ghrelin-induced SIRT1 expression are not yet fully understood. Recent studies indicate that SIRT1 exerts renoprotective properties against kidney diseases. This could be a very interesting point for underlining the important role of the ghrelin-SIRT1 system. Water movement across biological cell membranes is enhanced or facilitated by tetrameric membrane-bound channels, named aquaporin (AQP) family, and in particular, AQP1 and AQP2 proteins. In this study, we evaluated the possible pathway existing among the ghrelin/SIRT1/AQP1/AQP2 system in APOE^-/- mice in order to clarify or stress the role played by said system in renal diseases associated to aging with or without comorbities. The results could provide a basis for considering ghrelin as a new target for therapeutic strategies of renal injury.

Zebrafish as a model for kidney function and disease

Kidney disease is a global problem with around three million people diagnosed in the UK alone and the incidence is rising. Research is critical to develop better treatments. Animal models can help to better understand the pathophysiology behind the various kidney diseases and to screen for therapeutic compounds, but the use especially of mammalian models should be minimised in the interest of animal welfare. Zebrafish are increasingly used, as they are genetically tractable and have a basic renal anatomy comparable to mammalian kidneys with glomerular filtration and tubular filtration processing. Here, we discuss how zebrafish have advanced the study of nephrology and the mechanisms underlying kidney disease.

Safety of live attenuated varicella-zoster vaccine in patients with underlying illnesses compared with healthy adults: a prospective cohort study

Background

In Japan, freeze-dried live attenuated varicella-zoster vaccine is available for adults aged ≥50 years to prevent herpes zoster. However, limited evidence has been accumulated regarding vaccine safety for patients with underlying illnesses, who have been considered as the high-risk group for herpes zoster.

Methods

A prospective cohort study of 1200 healthy adults and 300 patients with underlying illnesses such as malignancy, diabetes mellitus, autoimmune diseases, and renal diseases was conducted. All subjects were vaccinated and then their adverse events (AEs) were followed for 28 days after vaccination. Key safety measures included any AEs, severe AEs (SAEs), and vaccine-related AEs such as injection-site AEs and systemic AEs. The frequencies and 95% confidence intervals of AEs were calculated.

Results

During the follow-up period, 2 SAEs (bone fracture and acute cholecystitis) among healthy adults and 1 SAE (disseminated mycobacteriosis) among patients with underlying illnesses were reported, although none of them was diagnosed as vaccine-related. Vaccine-related AEs were reported in 42% of healthy adults and patients with underlying illnesses, and the proportions were similar between the groups. The most frequent AEs were injection-site AEs in both groups (i.e., 41 and 39%), and systemic AEs were observed in 4% of both groups. Only among healthy adults, those with a history of herpes zoster were more likely to report injection-site AEs than those without a history of herpes zoster (53% vs 39%).

Conclusions

The present study confirmed the safety of freeze-dried, live attenuated varicella-zoster vaccine even in patients with underlying illnesses. A history of herpes zoster might be related to development of injection-site AEs in healthy adults.

Trial registration

The study was prospectively registered on Japic-Clinical Trials Information as JapicCTI-163415 on October 31, 2016.

Small leucine rich proteoglycans in host immunity and renal diseases

The small leucine rich proteoglycans (SLRPs), structurally consisting of protein cores and various glycosaminoglycan side chains, are grouped into five classes based on common structural and functional properties. Besides being an important structural component of extracellular matrix (ECM), SLRPs have been implicated in the complex network of signal transduction and host immune responses. The focus of this review is on SLRPs in host immunity. Because host immunity plays an important part in the pathogenesis of renal diseases, the role of SLRPs in this set of diseases will also be discussed.

A novel glomerular basement membrane segmentation using neutrsophic set and shearlet transform on microscopic images

Purpose

Glomerular basement membrane segmentation is an ultimate step in several image processing applications for kidney diseases and abnormalities in microscopic images. However, extracting the glomerular basement membrane (GBM) regions accurately is considered challenging because of the large variants in the microscopic images. The contribution of this work is to propose a computer-aided detection system to provide accurate GBM segmentation.

Methods

A novel GBM segmentation algorithm is developed based on neutrsophic set and shearlet transform. Firstly, the shearlet features are extracted from the microscopic image samples using shearlet transform. Afterward, the neutrosophic image is defined using shearlet features, and the indeterminacy on the neutrosophic image is reduced using an α-mean operation. Lastly, the k-means clustering algorithm is applied to segment the neutrsophic image and the GBM is identified using its intensity feature.

Results

Three metrics, namely the average distance (AvgDist), the Hausdorff distance (Hdist), and percentage overlap area (POA); were employed to assess the proposed method performance. The results established that the proposed method achieved smaller distance errors and larger POAs. For the tested image, the average of AvgDist, HDist and POA are 1.99204, 4.59535 and 0.67857, respectively. The results established that the cases were segmented accurately using the proposed NS based shearlet transform.

Conclusions

The new method utilizing the shearlet features and neutrosophic set improved the accuracy of GBM segmentation. Further study is underway to improve an automated CAD system using the refined segmentation results.

AGXT2: An unnegligible aminotransferase in cardiovascular and urinary systems

Cardiovascular diseases (CVDs) and renal impairment interact in a complex and interdependent manner, which makes clarification of possible pathogenesis between CVDs and renal diseases very challenging and important. There is increasing evidence showing that both asymmetric dimethylarginine (ADMA) and symmetric dimethylarginine (SDMA) play a crucial role in the development of CVDs as well as in the prediction of cardiovascular events. Also, the plasma levels of ADMA and SDMA were reported to be significantly associated with renal function. Alanine-glyoxylate aminotransferase 2 (AGXT2) is reported to be involved in ADMA and SDMA metabolism, thus deficiency in the expression or activity of AGXT2 may play a part in the progression of cardiovascular or renal diseases through affecting ADMA/SDMA levels. Here, we focused our attention on AGXT2 and discussed its potential impact on CVDs and renal diseases. Meanwhile, the review also summarized the functions and recent advances of AGXT2, as well as the clinical association studies of AGXT2 in cardiovascular and urinary systems, which might arouse the interest of researchers in these fields.

[Interstitial nephritis in pigs]

OBJECTIVE

Interstitial nephritis as a form of renal diseases can be found frequently among pigs. Nevertheless, prevalence and aetiology need to be investigated in more detail as reports about detailed analysis are lacking.

MATERIAL AND METHODS

In the present study, a total of 169 kidneys of conventionally and organically raised pigs were randomly chosen at slaughter and classified according to the degree of inflammation and the participating inflammatory cells. Moreover, PCV2 as an infectious agent was analysed by immunohistochemistry and in-situ hybridisation.

RESULTS

All of the investigated kidneys displayed mild interstitial lesions. Inflammatory cells included lymphocytes, macrophages, plasma cells, eosinophilic and neutrophilic granulocytes. Significant (p ≤ 0.0001) differences concerning the grade of inflammation and inflammatory cell occurrence could be observed between kidneys of conventionally and organically raised pigs. In comparison to conventionally raised pigs organically raised pigs showed significant (p ≤ 0.0001) more frequently a mild form of nephritis as well as a significant (p ≤ 0.0001) more frequent occurrence of lymphocytes and macrophages. In contrast to that, conventionally raised pigs had a significant (p ≤ 0.0001) higher occurrence rate of a mild to moderate form of nephritis as well as a significant (p ≤ 0.0001) higher level in occurrence of lymphocytes, macrophages, plasma cells, and neutrophilic granulocytes when compared to organically raised pigs. PCV2 DNA was detected in the kidney of only one animal.

CONCLUSION

Interstitial nephritis was found in conventionally and organically raised pigs and PCV2 was ruled out as a major pathogen for interstitial nephritis in slaughter pigs.

CLINICAL RELEVANCE

Because of the high prevalence and unknown cause further investigations are necessary to delineate the clinic relevance of this alteration and its pathogenesis.

Treatment of primary membranous nephropathy: where are we now?

In the last 10 years, basic science and clinical research have made important contributions to the understanding and management of primary membranous nephropathy (MN). The identification of antibodies directed against the M-type phospholipase A₂ receptor (PLA2R) and thrombospondin type-1 domain-containing 7A protein have added a new perspective on diagnosis, monitoring the immunological activity, predicting prognosis and guiding therapy in patients with primary MN. Mounting evidence suggests that quantification and follow-up of antiPLA2R Abs levels can help in assessing prognosis and evaluate the response to treatment. The kidney disease improving global outcomes guidelines published in 2012 have not been updated. New data on the use of rituximab suggest it should be considered as a potential initial therapy in the treatment of patients with primary MN.

The Rotterdam Study: 2018 update on objectives, design and main results

The Rotterdam Study is a prospective cohort study ongoing since 1990 in the city of Rotterdam in The Netherlands. The study targets cardiovascular, endocrine, hepatic, neurological, ophthalmic, psychiatric, dermatological, otolaryngological, locomotor, and respiratory diseases. As of 2008, 14,926 subjects aged 45 years or over comprise the Rotterdam Study cohort. Since 2016, the cohort is being expanded by persons aged 40 years and over. The findings of the Rotterdam Study have been presented in over 1500 research articles and reports (see www.erasmus-epidemiology.nl/rotterdamstudy ). This article gives the rationale of the study and its design. It also presents a summary of the major findings and an update of the objectives and methods.

Diabetes, hypertension, obesity, and long-term risk of renal disease mortality: Racial and socioeconomic differences

AIMS/INTRODUCTION

Diabetes, hypertension, and obesity increase the risk of chronic kidney disease and associated mortality. Race and socioeconomic status (SES) differences in the effects of these risk factors are, however, still unknown. The current study aimed to investigate whether or not race and SES alter the effects of diabetes, hypertension, and obesity on mortality due to renal disease.

MATERIALS AND METHODS

Data came from the Americans' Changing Lives Study, 1986-2011, a nationally representative prospective cohort of adults with 25 years of follow up. The study included 3,361 adults aged 25 years and older who were followed for up to 25 years. The outcome was death from renal disease. Diabetes, hypertension, and obesity were the main predictors. Race and SES (education, income, and employment) were moderators. Health behaviors and health status at baseline were covariates. We used Cox proportional hazards models for data analysis.

RESULTS

In separate models, diabetes, hypertension, and obesity at baseline were associated with a higher risk of death from renal disease. From our SES indicators, education and income interacted with diabetes, hypertension, and obesity on death from renal disease. In a consistent pattern, diabetes, hypertension, and obesity showed stronger effects on the risk of death from renal disease among high-SES groups compared with low-SES individuals. Race and employment did not alter the effects of diabetes, hypertension and obesity on the risk of death from renal disease.

CONCLUSIONS

Social groups differ in how diabetes, hypertension, and obesity influence health outcomes over long-term periods. Elimination of disparities in renal disease mortality in the USA requires understanding of the complex and non-linear effects of socioeconomic and medical risk factors on health outcomes. Multidisciplinary programs and policies are required to reduce social inequality in renal disease burden caused by diabetes, hypertension, and obesity.

Rituximab for immunologic renal disease: What the nephrologist needs to know

Rituximab (RTX), a chimeric, monoclonal anti-CD20 antibody, is increasingly used in immune-mediated renal diseases. While licensed in the induction treatment of ANCA-associated vasculitis, it represents one of the most commonly prescribed off-label drugs. Much of the information regarding its safety has been drawn from experience in hematology and rheumatology. Ample evidence illustrates the safety of RTX, however, rare but serious adverse events have emerged that include progressive multifocal leucoencephalopathy and hepatitis B reactivation. Moderate to severe hypogammaglobulinemia and late-onset neutropenia following RTX therapy confer an increased infectious risk and factors predicting these side effects (i.e. a genetic basis) need to be identified. Nephrologists initiating RTX need to bear in mind that long-term risks and optimal dosing for many renal indications remain unclear. Special considerations must be given when RTX is used in women of childbearing age. We summarize practical aspects concerning the use of RTX. This review will provide nephrologists with information to guide their use of RTX alerting them to safety risks and the need for patient counselling.

Gene expression profiling to identify the toxicities and potentially relevant human disease outcomes associated with environmental heavy metal exposure

Heavy metals are the most commonly encountered toxic substances that increase susceptibility to various diseases after prolonged exposure. We have previously shown that healthy volunteers living near a mining area had significant contamination with heavy metals associated with significant changes in the expression of some detoxifying genes, xenobiotic metabolizing enzymes, and DNA repair genes. However, alterations of most of the molecular target genes associated with diseases are still unknown. Thus, the aims of this study were to (a) evaluate the gene expression profile and (b) identify the toxicities and potentially relevant human disease outcomes associated with long-term human exposure to environmental heavy metals in mining area using microarray analysis. For this purpose, 40 healthy male volunteers who were residents of a heavy metal-polluted area (Mahd Al-Dhahab city, Saudi Arabia) and 20 healthy male volunteers who were residents of a non-heavy metal-polluted area were included in the study. Total RNA was isolated from whole blood using PAXgene Blood RNA tubes and then reversed transcribed and hybridized to the gene array using the Affymetrix U219 GeneChip. Microarray analysis showed about 2129 genes were identified and differentially altered, among which a shared set of 425 genes was differentially expressed in the heavy metal-exposed groups. Ingenuity pathway analysis revealed that the most altered gene-regulated diseases in heavy metal-exposed groups included hematological and developmental disorders and mostly renal and urological diseases. Quantitative real-time polymerase chain reaction closely matched the microarray data for some genes tested. Importantly, changes in gene-related diseases were attributed to alterations in the genes encoded for protein synthesis. Renal and urological diseases were the diseases that were most frequently associated with the heavy metal-exposed group. Therefore, there is a need for further studies to validate these genes, which could be used as early biomarkers to prevent renal injury.

Should We Still Believe in Randomized Controlled Trials in Nephrology?

The randomized controlled trial (RCT) is the cornerstone upon which clinical decision-making is based. Pivotal RCTs in the nephrology area efficiently demonstrated the renoprotective effects of treatment with renin-angiotensin system inhibitors in patients with diabetic and non-diabetic proteinuric nephropathies. However, there is concern about the increasing cost, complexity and duration of clinical studies. Moreover, recent large RCTs addressing key issues for patients with renal disease failed to achieve definitive conclusions mainly due to critical flaws in the investigational strategies, including the adoption of excessive/fixed doses of the study medications, inappropriate use of the placebo-controlled design, enrollment of low-risk individuals, poor reporting of adverse events or unreliable evaluation of renal function. The information now available on the biases that characterize the current RCTs should serve as a tool to rethink the design, patient selection and implementation of future RCTs in nephrology.

Measurement of glomerulus diameter and Bowman's space width of renal albino rats

Glomerulus diameter and Bowman's space width in renal microscopic images indicate various diseases. Therefore, the detection of the renal corpuscle and related objects is a key step in histopathological evaluation of renal microscopic images. However, the task of automatic glomeruli detection is challenging due to their wide intensity variation, besides the inconsistency in terms of shape and size of the glomeruli in the renal corpuscle. Here, a novel solution is proposed which includes the Particles Analyzer technique based on median filter for morphological image processing to detect the renal corpuscle objects. Afterwards, the glomerulus diameter and Bowman's space width are measured. The solution was tested with a dataset of 21 rats' renal corpuscle images acquired using light microscope. The experimental results proved that the proposed solution can detect the renal corpuscle and its objects efficiently. As well as, the proposed solution has the ability to manage any input images assuring its robustness to the deformations of the glomeruli even with the glomerular hypertrophy cases. Also, the results reported significant difference between the control and affected (due to ingested additional daily dose (14.6mg) of fructose) groups in terms of glomerulus diameter (97.40±19.02μm and 177.03±54.48μm, respectively).

Perivascular adipose tissue: An unique fat compartment relevant for the cardiometabolic syndrome

Type 2 diabetes and its major risk factor, obesity, are an increasing worldwide health problem. The exact mechanisms that link obesity with insulin resistance, type 2 diabetes, hypertension, cardiovascular complications and renal diseases, are still not clarified sufficiently. Adipose tissue in general is an active endocrine and paracrine organ that may influence the development of these disorders. Excessive body fat in general obesity may also cause quantitative and functional alterations of specific adipose tissue compartments. Beside visceral and subcutaneous fat depots which exert systemic effects by the release of adipokines, cytokines and hormones, there are also locally acting fat depots such as peri- and epicardial fat, perivascular fat, and renal sinus fat. Perivascular adipose tissue is in close contact with the adventitia of large, medium and small diameter arteries, possesses unique features differing from other fat depots and may act also independently of general obesity. An increasing number of studies are dealing with the "good" or "bad" characteristics and functions of normally sized and dramatically increased perivascular fat mass in lean or heavily obese individuals. This review describes the origin of perivascular adipose tissue, its different locations, the dual role of a physiological and unphysiological fat mass and its impact on diabetes, cardiovascular and renal diseases. Clinical studies, new imaging methods, as well as basic research in cell culture experiments in the last decade helped to elucidate the various aspects of the unique fat compartment.

Distal, intermediate, and proximal mediators of racial disparities in renal disease mortality in the United States

Background: Kidney failure and associated mortality is one of the major components of racial disparities in the United States.

Objectives: The current study aimed to investigate the role of distal (socioeconomic status, SES), intermediate (chronic medical diseases), and proximal (health behaviors) factors that may explain Black-White disparities in mortality due to renal diseases.

Patients and Methods: This is a nationally representative prospective cohort with 25 years of follow up. Data came from the Americans’ Changing Lives (ACL) study, 1986 to 2011. The study included 3361 Black (n = 1156) or White (n = 2205) adults who were followed for up to 25 years. Race was the main predictor and death due to renal disease was the outcome. SES, chronic medical disease (diabetes, hypertension, obesity), and health behaviors (smoking, drinking, and exercise) at baseline were potential mediators. We used Cox proportional hazards models for data analysis.

Results: In age and gender adjusted models, Blacks had higher risk of death due to renal disease over the follow up period. Separate models suggested that SES, health behaviors and chronic medical disease fully explained the effect of race on renal disease mortality.

Conclusions: Black-White disparities in rate of death due to renal diseases in the United States are not genuine but secondary to racial differences in income, health behaviors, hypertension, and diabetes. As distal, intermediate, and proximal factors contribute to racial disparities in renal disease mortality, elimination of such disparities requires a wide range of policies and programs that target income, medical conditions, and health behaviors.

NF-κB in inflammation and renal diseases

Nuclear factor κB (NF-κB) is a family of inducible transcription factors that plays a vital role in different aspects of immune responses. NF-κB is normally sequestered in the cytoplasm as inactive complexes via physical association with inhibitory proteins termed IκBs. In response to immune and stress stimuli, NF-κB members become activated via two major signaling pathways, the canonical and noncanonical pathways, and move to the nucleus to exert transcriptional functions. NF-κB is vital for normal immune responses against infections, but deregulated NF-κB activation is a major cause of inflammatory diseases. Accumulated studies suggest the involvement of NF-κB in the pathogenesis of renal inflammation caused by infection, injury, or autoimmune factors. In this review, we discuss the current understanding regarding the activation and function of NF-κB in different types of kidney diseases.

The Rotterdam Study: 2016 objectives and design update

The Rotterdam Study is a prospective cohort study ongoing since 1990 in the city of Rotterdam in The Netherlands. The study targets cardiovascular, endocrine, hepatic, neurological, ophthalmic, psychiatric, dermatological, otolaryngological, locomotor, and respiratory diseases. As of 2008, 14,926 subjects aged 45 years or over comprise the Rotterdam Study cohort. The findings of the Rotterdam Study have been presented in over 1200 research articles and reports (see www.erasmus-epidemiology.nl/rotterdamstudy ). This article gives the rationale of the study and its design. It also presents a summary of the major findings and an update of the objectives and methods.

Hyperuricemia: A Biomarker of Renal Hemodynamic Impairment

BACKGROUND

Many epidemiological, clinical, and experimental reports have demonstrated an association between serum uric acid concentration and a variety of cardiovascular and renal diseases, particularly in hypertension. At present, there seems to be no resolution to the question whether this relationship is causal or coincidental.

SUMMARY

This discussion examines a number of biological, pathophysiological, fundamental, and clinical relationships between serum uric acid concentration and several of these disorders. To this end, discussion and review provide some specific insight conclusions and recommendations related to their clinical relevance.

KEY MESSAGES

We suggest that, in most instances (especially in patients with essential hypertension), the increase in serum uric acid concentration is coincidental, serving as a useful biomarker that relates the magnitude of circulating plasma uric acid concentration with the extent of impaired cardiovascular and renal function. Moreover, the value of certain pharmaceutical agents affecting the serum uric acid level should be considered carefully by taking into consideration the associated pathophysiological derangements.

Lipidomics: new insight into kidney disease

Due to the incidence of type-2 diabetes and hypertension, chronic kidney disease (CKD) has emerged as a major public health problem worldwide. CKD results in premature death from accelerated cardiovascular disease and various other complications. Early detection, careful monitoring of renal function, and response to therapeutic intervention are critical for prevention of CKD progression and its complications. Unfortunately, traditional biomarkers of renal function are insufficiently sensitive or specific to detect early stages of disease when therapeutic intervention is most effective. Therefore, more sensitive biomarkers of kidney disease are needed for early diagnosis, monitoring, and effective treatment. CKD results in profound changes in lipid and lipoprotein metabolism that, in turn, contribute to progression of CKD and its cardiovascular complications. Lipids and lipid-derived metabolites play diverse and critically important roles in the structure and function of cells, tissues, and biofluids. Lipidomics is a branch of metabolomics, which encompasses the global study of lipids and their biologic function in health and disease including identification of biomarkers for diagnosis, prognosis, prevention, and therapeutic response for various diseases. This review summarizes recent developments in lipidomics and its application to various kidney diseases including chronic glomerulonephritis, IgA nephropathy, chronic renal failure, renal cell carcinoma, diabetic nephropathy, and acute renal failure in clinical and experimental research. Analytical technologies, data analysis, as well as currently known metabolic biomarkers of kidney diseases are addressed. Future perspectives and potential limitations of lipidomics are discussed.

Cecropia pachystachya extract attenuated the renal lesion in 5/6 nephrectomized rats by reducing inflammation and renal arginase activity

ETHNOPHARMACOLOGICAL RELEVANCE

The plant Cecropia pachystachya Trécul has been used in Brazilian folk medicine to treat hypertension, bladder and kidney inflammation and renal diseases. The aim of this study was to evaluate the potential of the aqueous fraction from the ethanolic extract of Cecropia pachystachya (FCP) in the management of hypertension, inflammation and progressive renal disease in rats submitted to 5/6 nephrectomy.

MATERIALS AND METHODS

Thirty male Wistar rats submitted to 5/6 nephrectomy (5/6 NE) were untreated (NE) or treated (NE+FCP) with the FCP (0.5g/kg/day). The treatment started 15 days after surgery, and the rats were followed for a period of 60 days. Systolic blood pressure (SBP) and albuminuria were evaluated from 15-60 days after the surgical procedure. Function and estructural renal changes, TGF-β (transforming growth factor β), MCP-1 (monocyte chemoattractant protein-1) and nitric oxide (NO) urinary excretion were analyzed. Expression and activity of the renal enzymes arginase (ARG), angiotensin converting enzyme (ACE), and MAP kinase p-JNK expression also were analyzed.

RESULTS

The nephrectomized rats developed progressive albuminuria and increased SBP that was less intense in the treated group. There was a reduction in the glomerular filtration rate (GFR) in the nephrectomized rats, which was attenuated by treatment with FCP extract. The treatment with FCP also attenuated the histological changes, reduced the expression and activity of renal arginase, the number of macrophages (ED-1 positive cells) and the p-JNK expression in the renal cortex of the rats submitted to 5/6 NE. The urinary excretion of TGF-β was less intense in the treated group and was associated with the reduction of the expression and activity of the renal arginase.

CONCLUSIONS

These results suggest that the reduction of renal arginase activity, p-JNK and TGF-β expression can explain the mechanism by which the treatment with C. pachystachya reduced the inflammation and improved renal function. This study presents the potential use of Cecropia pachystachya in the treatment of chronic renal diseases.

Cystatin C: a new renal marker and its potential use in small animal medicine

The occurrence of chronic kidney disease is underestimated in both human and veterinary medicine. Glomerular filtration rate (GFR) is considered the gold standard for evaluating kidney function. However, GFR assessment is time-consuming and labor-intensive and therefore not routinely used in practice. The commonly used indirect GFR markers, serum creatinine (sCr) and urea, are not sufficiently sensitive or specific to detect early renal dysfunction. Serum cystatin C (sCysC), a proteinase inhibitor, has most of the properties required for an endogenous GFR marker. In human medicine, numerous studies have evaluated its potential use as a GFR marker in several populations. In veterinary medicine, this marker is gaining interest. The measurement is easy, which makes it an interesting parameter for clinical use. This review summarizes current knowledge about cystatin C (CysC) in humans, dogs, and cats, including its history, assays, relationship with GFR, and biological and clinical variations in both human and veterinary medicine.

Oxidized albumin. The long way of a protein of uncertain function

BACKGROUND

Proteins are extremely reactive to oxidants and should represent a potential target of instable reactive oxygen. This may represent a problem for plasma proteins since they may be directly modified in vivo in a compartment where antioxidant enzymatic systems are scarcely represented. On the other hand, it is possible that some plasma components have evolved over time to guarantee protection, in which case they can be considered as anti-oxidants.

SCOPE OF REVIEW

To present and discuss main studies which addressed the role of albumin in plasma antioxidant activity mainly utilizing in vitro models of oxidation. To present some advances on structural features of oxidized albumin deriving from studies carried out on in vitro models as well as albumin purified in vivo from patients affected by clinical conditions characterized by oxidative stress.

MAJOR CONCLUSIONS

There are different interaction with HOCl and chloramines. In the former case, HOCl produces an extensive alteration of (238)Trp and (162)Tyr, (425)Tyr, (47)Tyr, while thiol groups are only partially involved. Chloramines are extremely reactive with the unique free SH group of albumin ((34)Cys) with the formation of sulfenic and sulfinic acid as intermediates and sulfonic acid as end-product. Oxidized albumin has a modified electrical charge for the addition of an acidic residue and presents α-helix and random coil reorganization with subtle changes in domain orientation.

GENERAL SIGNIFICANCE

Albumin, is the major antioxidants in plasma with a concentration (0.8mM) higher than other antioxidants by an exponential factor. Functional and protective roles in the presence of oxidative stress must be defined. This article is part of a Special Issue entitled Serum Albumin.

A case of tubulointerstitial nephritis and uveitis syndrome in an elderly patient

Tubulointerstitial nephritis and uveitis (TINU) syndrome is a rare disease entity usually occurring in children. In the present study a case of TINU syndrome in an elderly patient is described and relevant literature is reviewed. A 61-year-old man presented with bilateral flank pain, urinary frequency, and foamy urine. A kidney ultrasonography revealed an increase in kidney parenchyma echogenicity. Following a kidney biopsy, the patient was diagnosed with acute tubulointerstitial nephritis. An ophthalmology examination initially performed for floater symptoms, revealed anterior uveitis in both eyes. Acute tubulointerstitial nephritis and anterior uveitis in both eyes responded to treatment with oral prednisolone, furosemide, carvedilol, and a topical steroid. TINU syndrome can occur in the elderly and should be part of the differential diagnosis when seeing a patient who has uveitis in association with renal disease; any therapy should be managed by both an internist and an ophthalmologist.

Cytoprotection behind heme oxygenase-1 in renal diseases

Renal insults are considered a public health problem and are linked to increased rates of morbidity and mortality worldwide. The heme oxygenase (HO) system consists of evolutionary specialized machinery that degrades free heme and produces carbon monoxide, biliverdin and free iron. In this sense, the inducible isoform HO-1 seems to develop an important role and is widely studied. The reaction involved with the HO-1 molecule provides protection to injured tissue, directly by reducing the toxic heme molecule and indirectly by the release of its byproducts. The up regulation of HO-1 enzyme has largely been described as providing antioxidant, antiapoptotic, anti-inflammatory and immunomodulatory properties. Several works have explored the importance of HO-1 in renal diseases and they have provided consistent evidence that its overexpression has beneficial effects in such injuries. So, in this review we will focus on the role of HO-1 in kidney insults, exploring the protective effects of its up regulation and the enhanced deleterious effects of its inhibition or gene deletion.

Pattern and outcome of renal diseases in hospitalized children in Khartoum State, Sudan

In developing countries, renal diseases in children constitute important causes of morbidity and mortality. In Sudan, data about patterns and outcome of these disorders is generally scanty. We conducted this study to provide basic renal data that may be utilized by researchers and health planners in a resource poor setting. A retrospective record review of all pediatric patients, followed in four teaching hospitals in Khartoum State over a five-year period (January 2000-June 2004), was achieved. In 150 hospitalized children a total of 200 renal diagnoses were recorded. Urinary tract infection (UTI), occurring with other underlying renal morbidities or isolated, was the commonest renal diagnosis (20%). The second common renal disorders were nephrotic syndrome (NS) and urolithiasis/stones accounting for 16% and 15.5% of cases, respectively. Acute glomerulonephritis (AGN) and congenital anomalies were relatively less common (12% and 10.5%, respectively). Other less frequently detected diseases were acute renal failure (ARF) in 6%, chronic renal failure (CRF) in 4%, hereditary nephropathies in 3.5% and renal tumors in 2.5%. There was a significant correlation between the pattern of renal diseases and age of patients (P =0.001) but not their gender or social class (P = 0.211 and 0.34, respectively). On follow up, 99 out of 150 patients (66%) recovered their normal renal function, 6/150 (4%) remained with persistent proteinuria, 30/150 (20%) progressed to CRF, 10/150 (6.7%) died, and 5/150 (3.3%) were referred to radiotherapy department for further management. Our data reflects geographical variations of patterns of renal diseases in Sudanese children as in other countries. Many of these diseases are preventable or potentially curable. Therefore, improvement of pediatric renal services and training of health workers would help in early detection and treatment of these conditions leading to reduction in their morbidity and mortality.

Levels of plasma soluble complement receptor 1 (sCR1) in normal Indian adult population

A decrease in the membrane anchored erythrocyte complement receptor 1 (CR1) is reported as an acquired phenomenon in a number of inflammatory and autoimmune diseases with concomitant rise in soluble CR1 (sCR1) levels in plasma. There is a need to establish the normal range of sCR1 in Indian adults to assess the function and disease association of this protein. The plasma sCR1 levels of 50 healthy individuals have been estimated by an indigenously developed sandwich ELISA. sCR1 levels from 26 patients suffering from nephropathies had also been assayed which was much higher than the normal controls. This observation suggests sCR1 as a potential market for the assessment of disease activity in nephropathies.