MCP-1/IL-12 ratio expressions correlated with adventitial collagen depositions in renal vessels and IL-4/IFN-γ expression correlated with interstitial collagen depositions in the kidneys of dogs with canine leishmaniasis

Structural characterization and immune activity evaluation of polysaccharide purified from Viola phillipica

This study investigated the structure of Viola phillipica polysaccharide (VPP) and its effect as an immune adjuvant for the Newcastle disease vaccine (ND Vaccine). The results showed that VPP comprised of the galacturonic acid, galactose, rhamnose, arabinose with the molar ratio of 36.20: 23.41: 19.72: 11.54 and a molecular weight (Mw) of 1080 kDa. Additionally, the composition of VPP was assessed via FT-IR, methylation, AFM and SEM analyses, indicating that the backbone of the VPP was consisted of T-Ara (f), T-Gal (p), 4-Gal (p)-UA, and T-Rha (p) linkages. Furthermore, VPP was used as an immune adjuvant in combination with ND vaccine in chickens. Remarkable enhancements were observed in the thymus, spleen, and bursa indices of the chickens, the serum levels of ND antibodies and the expression of IL-4 and IFN-γ cytokines, thereby fostering the proliferation of T and B lymphocytes within the spleen. Notably, histopathological analysis indicated that the VPP groups showed increased lymphoid follicles and splenic nodules, as well as greater splenic red pulp density and bursa of Fabricius area. In summary, these findings suggest that VPP could serve as an adjuvant to enhance the immunogenicity of NDV.

Enhanced apoptosis, inflammatory cellularity, collagen deposition, and interaction between fibroblasts and Leishmania amastigotes in undamaged ear skin of dogs with leishmaniosis

Fibroblasts are located close to the area of skin inoculation of Leishmania promastigotes. They are a potential cellular target for early parasite infection, harboring amastigotes of Leishmania spp. This study aimed to determine the apoptosis in fibroblasts, and to correlate these results with inflammation, parasite load, AgNOR (Argyrophilic Nucleolar Organizer Region) index, and clinical features in Leishmania-affected dogs. Fragments from the undamaged ear skin of 16 Leishmania-infected and seven uninfected dogs were evaluated by histomorphometry and immunohistochemical analysis, which correlated fibroblast apoptosis to clinical manifestation and parasite load. Ultra-thin sections were examined under transmission electronic microscopy (TEM). When applying immunohistochemical analysis, Leishmania amastigotes were only found in clinically affected dogs. The cellularity of the inflammatory infiltrate and the AgNOR index (fibroblasts and inflammatory infiltrate) were higher in clinically affected dogs. The collagen deposition score was statistically significantly higher in Leishmania-infected dogs. The apoptotic index of inflammatory cells and fibroblasts proved to be higher in clinically affected dogs. From an ultrastructural point of view, apoptotic cells shrank, while the nuclear chromatin and cytoplasm condensed. Amastigotes were observed within inflammatory cells (neutrophils and macrophages) and in the inner portions of fibroblasts. Fibroblast apoptosis was related to both the increase in the parasite load and the intensity of the inflammatory response. Histomorphometric assessments (inflammation, parasite load, AgNOR index, and apoptosis) and clinical manifestations were also associated. Collagen deposition was positively correlated with AgNOR expression and the apoptotic index (inflammatory cell and fibroblast). Therefore, fibroblast apoptosis contributes to the infection process, pathogenesis, and chronicity of canine leishmaniosis. Moreover, fibroblasts may well provide an escape mechanism for immune defenses against Leishmania.

Hypoxia and collagen deposition in the kidneys infected with Acanthamoeba sp

Acanthamoeba spp. are facultative, opportunistic pathogens that are found in diverse environments. In the hosts, they lead to multi-organ disease. Recent studies reported that they may induce changes in the kidneys of hosts. The aim of the study was to determine the influence of Acanthamoeba sp. on hypoxia and collagen deposition in the kidneys of immunocompetent and immunosuppressed mice infected with Acanthamoeba sp. The results strongly suggest that Acanthamoeba sp. induces hypoxia in mice with normal and reduced immune response by increasing gene and/or protein expression of HIF1α as well as HIF2α. Additionally, the activation of these factors is probably induced via NOX2/ROS. Hypoxia promotes vessel formation, and we found that angiogenesis occurs in the kidneys of mice infected with the parasite regardless of their immunological status. The proangiogenic factors released in hypoxic conditions cause modulation and inflammation in the kidney cells, which in turn leads to collagen deposition via TGF-β. This work reveals mechanisms occurring in the hosts infected with Acanthamoeba sp., highlights as well as supports the relevance of pathophysiology in the kidneys in hosts with systematic acanthamoebiasis.

Clinical significance of blood cell ratios in healthy and sick Leishmania infantum-seropositive dogs

BACKGROUND

The accuracy of blood cell ratios (BCRs) as cost-effective and easily accessible diagnostic and prognostic markers of inflammatory conditions has been investigated in veterinary medicine in recent years.

METHODS

Neutrophil-to-lymphocyte (NLR), monocyte-to-lymphocyte (MLR), and platelet-to-lymphocyte (PLR) ratios were studied in 195 dogs clinically evaluated and tested for anti-Leishmania infantum (Li) antibodies (Li-seronegative (Li-), n = 10; Li-seropositive clinically healthy (Li+healthy), n = 100; Li-seropositive with clinical and/or clinicopathological abnormalities (Li+sick), n = 85). The Li+sick dogs were classified in LeishVet stages IIa/IIb (Li+IIa/IIb) (n = 66) and III/IV (Li+III/IV) (n = 19). BCR relationships with LeishVet clinical stage, antibody levels, and serum protein electrophoretic fraction concentrations were investigated.

RESULTS

Higher NLR values were found in Li+, Li+healthy, and Li+IIa/IIb sick dogs compared to Li- dogs (P < 0.001). Higher NLR and MLR were found in Li+sick (NLR, P < 0.001; MLR, P = 0.034) and Li+III/IV dogs (NLR, P < 0.001; MLR, P = 0.005) compared to Li- dogs, and in Li+III/IV dogs (NLR, P = 0.002; MLR, P < 0.001) compared to Li+healthy. All three BCRs were higher in Li+sick (NLR, MLR, P < 0.001; PLR, P = 0.023) and Li+IIa/IIb dogs (NLR P < 0.001; MLR P = 0.001; PLR, P = 0.012) compared to Li+healthy dogs. The BCRs failed to distinguish dogs with moderate (Li+IIa/IIb) and severe or very severe disease (Li+III/IV). BCRs demonstrated weak positive correlations with serum globulin fractions and antibody levels, and weak negative correlations with serum albumin level were found. Li+sick dogs presenting hypoalbuminemia showed higher MLR ratios (P = 0.001) than those with normal albumin values.

CONCLUSIONS

This study shows that BCR measures provide useful information for differentiating antibody-positive healthy and sick dogs at diagnosis. Dogs with hypoalbuminemia showed higher MLR values despite monocytosis being very rare.

Serum and urinary monocyte chemoattractant protein-1 as markers of inflammation and renal damage in dogs with naturally occurring leishmaniosis

BACKGROUND

Renal disease in canine leishmaniosis is of great importance owing to increased risk of mortality. In human visceral leishmaniosis, monocyte chemoattractant protein-1 (MCP-1) has been used as a marker of renal damage and inflammation. The purpose of this study was first to determine the serum MCP-1 and urinary MCP-1-to-creatinine ratio (uMCP-1/Cr) in healthy dogs and dogs with leishmaniosis at diagnosis, and second to determine whether these markers can differentiate disease severity at diagnosis.

METHODS

In total, 19 healthy seronegative dogs and 38 dogs with leishmaniosis were included in the study. Dogs with leishmaniosis were classified as LeishVet clinical staging and as International Renal Interest Society (IRIS) staging. Serum and urinary MCP-1 concentrations were measured with an enzyme-linked immunosorbent assay. A receiver operating characteristic (ROC) curve determined disease severity at diagnosis between two LeishVet groups (Stage II versus stage III and IV).

RESULTS

Dogs in Leishvet stages IIb, III, and IV had a median serum MCP-1 and uMCP-1/Cr concentration higher than healthy dogs (P < 0.0001). No statistical differences were found in serum MCP-1 and uMCP-1/Cr between dogs in LeishVet stage IIa and healthy dogs. The dogs in LeishVet stage IV had significantly higher serum MCP-1 and uMCP-1/Cr compared with the dogs in LeishVet stage IIa (P < 0.0001). Serum MCP-1 and uMCP-1 were significantly higher in dogs in IRIS stage I and II + III + IV compared with healthy dogs. Dogs stage II + III + IV of IRIS had a significantly higher serum MCP-1 compared with dogs in IRIS stage I (P < 0.0001). The area under the ROC curve for serum MCP-1 was 0.78 [95% confidence interval (CI) 0.64-0.93] and for uMCP-1/Cr it was 0.86 (95% CI, 0.74-0.99). The optimal cutoff value for serum MCP-1 and uMCP-1/Cr was 336.85 pg/ml (sensitivity of 79% and specificity of 68%) and 6.89 × 10-7 (sensitivity of 84% and specificity of 79%), respectively.

CONCLUSIONS

Serum MCP-1 and uMCP-1/Cr are increased in dogs with leishmaniosis compared with healthy dogs, suggesting the presence of inflammation and renal injury. Serum MCP-1 and uMCP-1/Cr were more elevated in the advanced stages of the disease compared with the moderate stages and, therefore, can be markers of the severity of the disease process.

A compared histopathological study on kidneys and eye bulbs in distinct clinical presentations of canine leishmaniasis by Leishmania infantum

Canine leishmaniasis (CanL) caused by Leishmania infantum commonly progresses with renal and ophthalmic lesions associated with active systemic disease. As chronic inflammation related to immune complex deposits is a pathophysiological factor in the development of both glomerulonephritis and uveitis, we aimed to evaluate renal and ocular histopathological lesions and analyze whether they were related to each other and the clinical degree of the disease. For that, we evaluated 15 dogs from CanL-endemic areas. L. infantum PCR-positive dogs were studied according to disease severity into two different groups: Group-1 (G1) had data from seven dogs with mild to moderate CanL and no history of treatment, and G2 was formed with eight dogs with severe to terminal disease that had not responded to CanL treatment. Histopathological analysis of kidneys showed higher frequencies and intensities of glomerular basement membrane thickening (p = 0.026), deposits in glomeruli (p = 0.016), epithelial necrosis (p = 0.020), tubular dilatation (p = 0.003) and interstitial fibrosis (p = 0.04) in G2 dogs than in G1 dogs. Surprisingly, the histopathology of eye bulbs showed a higher frequency and intensity of retinitis (p = 0.019) in G1 dogs than in G2 dogs. The comparative analysis showed that there was no correspondence between histopathological findings in kidneys versus eyes in milder or more severe CanL. Our findings suggested that (1) clinically undetectable eye alterations can be more precocious than those in kidneys in the development of CanL, and (2) the lower frequency of eye lesions and higher frequency of renal lesions in dogs with terminal disease even after treatment indicate that therapy may have been effective in reducing CanL-associated ophthalmic disease but not proportionally in reducing kidney disease.

Hegemony of inflammation in atherosclerosis and coronary artery disease

Inflammation drives coronary artery disease and atherosclerosis implications. Lipoprotein entry, retention, and oxidative modification cause endothelial damage, triggering innate and adaptive immune responses. Recruited immune cells orchestrate the early atherosclerotic lesions by releasing proinflammatory cytokines, expediting the foam cell formation, intraplaque haemorrhage, secretion of matrix-degrading enzymes, and lesion progression, eventually promoting coronary artery syndrome via various inflammatory cascades. In addition, soluble mediators disrupt the dynamic anti- and prothrombotic balance maintained by endothelial cells and pave the way for coronary artery disease such as angina pectoris. Recent studies have established a relationship between elevated levels of inflammatory markers, including C-reactive protein (CRP), interleukins (IL-6, IL-1β), and tumour necrosis factor-alpha (TNF-α) with the severity of CAD and the possibility of future cardiovascular events. High-sensitivity C-reactive protein (hs-CRP) is a marker for assessing systemic inflammation and predicting the risk of developing CAD based on its peak plasma levels. Hence, understanding cross-talk interactions of inflammation, atherogenesis, and CAD is highly warranted to recalculate the risk factors that activate and propagate arterial lesions and devise therapeutic strategies accordingly. Cholesterol-inflammation lowering agents (statins), monoclonal antibodies targeting IL-1 and IL-6 (canakinumab and tocilizumab), disease-modifying antirheumatic drugs (methotrexate), sodium-glucose transport protein-2 (SGLT2) inhibitors, colchicine and xanthene oxidase inhibitor (allopurinol) have shown promising results in reducing inflammation, regressing atherogenic plaque and modifying the course of CAD. Here, we review the complex interplay between inflammatory, endothelial, smooth muscle and foam cells. Moreover, the putative role of inflammation in atherosclerotic CAD, underlying mechanisms and potential therapeutic implications are also discussed herein.