Impact of dietary vitamin D on immunoregulation and disease pathology in lupus-prone NZB/W F1 mice

Vitamin D (VD) deficiency is a highly prevalent worldwide phenomenon and is extensively discussed as a risk factor for the development of systemic lupus erythematosus (SLE) and other immune-mediated diseases. In addition, it is now appreciated that VD possesses multiple immunomodulatory effects. This study aims to explore the impact of dietary VD intake on lupus manifestation and pathology in lupus-prone NZB/W F1 mice and identify the underlying immunological mechanisms modulated by VD. Here, we show that low VD intake accelerates lupus progression, reflected in reduced overall survival and an earlier onset of proteinuria, as well higher concentrations of anti-double-stranded DNA autoantibodies. This unfavorable effect gained statistical significance with additional low maternal VD intake during the prenatal period. Among examined immunological effects, we found that low VD intake consistently hampered the adoption of a regulatory phenotype in lymphocytes, significantly reducing both IL-10-expressing and regulatory CD4+ T cells. This goes along with a mildly decreased frequency of IL-10-expressing B cells. We did not observe consistent effects on the phenotype and function of innate immune cells, including cytokine production, costimulatory molecule expression, and phagocytic capacity. Hence, our study reveals that low VD intake promotes lupus pathology, likely via the deviation of adaptive immunity, and suggests that the correction of VD deficiency might not only exert beneficial functions by preventing osteoporosis but also serve as an important module in prophylaxis and as an add-on in the treatment of lupus and possibly other immune-mediated diseases. Further research is required to determine the most appropriate dosage, as too-high VD serum levels may also induce adverse effects, possibly also on lupus pathology.

Vitamin D and Glomerulonephritis

Vitamin D presents a plethora of different functions that go beyond its role in skeletal homeostasis. It is an efficient endocrine regulator of the Renin–Angiotensin–Aldosterone System (RAAS) and erythropoiesis, exerts immunomodulatory effects, reduces the cardiovascular events and all-cause mortality. In Chronic Kidney Disease (CKD) patients, Vitamin D function is impaired; the renal hydrolyzation of its inactive form by the action of 1α-hydroxylase declines at the same pace of reduced nephron mass. Moreover, Vitamin D major carrier, the D-binding protein (DBP), is less represented due to Nephrotic Syndrome (NS), proteinuria, and the alteration of the cubilin–megalin–amnionless receptor complex in the renal proximal tubule. In Glomerulonephritis (GN), Vitamin D supplementation demonstrated to significantly reduce proteinuria and to slow kidney disease progression. It also has potent antiproliferative and immunomodulating functions, contributing to the inhibitions of kidney inflammation. Vitamin D preserves the structural integrity of the slit diaphragm guaranteeing protective effects on podocytes. Activated Vitamin D has been demonstrated to potentiate the antiproteinuric effect of RAAS inhibitors in IgA nephropathy and Lupus Nephritis, enforcing its role in the treatment of glomerulonephritis: calcitriol treatment, through Vitamin D receptor (VDR) action, can regulate the heparanase promoter activity and modulate the urokinase receptor (uPAR), guaranteeing podocyte preservation. It also controls the podocyte distribution by modulating mRNA synthesis and protein expression of nephrin and podocin. Maxalcalcitol is another promising alternative: it has about 1/600 affinity to vitamin D binding protein (DBP), compared to Calcitriol, overcoming the risk of hypercalcemia, hyperphosphatemia and calcifications, and it circulates principally in unbound form with easier availability for target tissues. Doxercalciferol, as well as paricalcitol, showed a lower incidence of hypercalcemia and hypercalciuria than Calcitriol. Paricalcitol demonstrated a significant role in suppressing RAAS genes expression: it significantly decreases angiotensinogen, renin, renin receptors, and vascular endothelial growth factor (VEGF) mRNA levels, thus reducing proteinuria and renal damage. The purpose of this article is to establish the Vitamin D role on immunomodulation, inflammatory and autoimmune processes in GN.

Heparanase expression in blood is sensitive to monitor response to anticancer treatment in pancreatic cancer, a pilot study

BACKGROUND

/Objectives: High heparanase level was shown in maliganant tumor; however, whether or not heparanase may serve as a sensitive marker to monitor response to anticancer treatment is still unknown.

METHODS

In the pilot study, heparanase mRNA expression in peripheral blood mononuclear cell fraction (PBMC) and activity in plasma and urine were detected by quantitative real time RT-PCR and heparan-degrading enzyme assay in 31 pancreatic cancer patients.

RESULTS

Heparanase mRNA and activity in samples from cancer patients were significantly higher than that in healthy donors. Both heparanase mRNA and activity in plasma and urine decreased significantly in 17 patients who underwent R₀ resection, but increased remarkably in 6 patients when recurrence or metastasis occurred (P < 0.05). However, those who underwent R₁ or R₂ resection in 6 patients kept stable. For 8 patients who received chemotherapy, heparanase mRNA and activity in plasma and urine decreased in each of the samples (P < 0.05). Patients with high heparanase mRNA (≥a cutoff value of 1.84) in PBMC and activity in plasma (≥1.30U/ml) were associated with a poor postoperative survival (P = 0.02 and P = 0.04).

CONCLUSIONS

Heparanase mRNA in PBMC and activity in plasma are closely correlated with therapeutic responsiveness and survival time, indicating that heparanase level in blood might be a sensitive but non-specific marker to monitor patients' response to anticancer treatment and to predict survival.

Evaluation of the C-domain of heparanase during AGE-induced macrophage inflammatory response

Diabetic vasculopathy is intensified by macrophage inflammation caused by advanced glycation end products (AGEs). Heparanase (HPA) is a unique endoglycosidase, which cleaves heparan sulfate proteoglycans (HSPGs) including syndecan-1 (Syn-1) to further stimulate macrophage cell migration and inflammation. The present study was planned to evaluated the role of C-domain (if any) of HPA in AGE inflammatory response in macrophages. Cell viability was assessed using MTT assay, migration assay, ELISA for tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) levels, mRNA expression by RT-PCR and heparan degrading enzyme assay for HPA activity. In the present study, we found that pretreatment with anti-HPA antibody, which recognizes the C-domain of HPA inhibited macrophage migration, secretion of IL-1β and TNF-α as well as decreased HPA enzymatic activity and increased Syn-1 protein expression in AGE-induced macrophages. Compared with anti-HPA antibody pretreatment, co-pretreatment with anti-HPA plus Syn-1 antibodies promoted macrophage migration, and secretion of IL-1β and TNF-α significantly in AGE-induced macrophages. In addition, pretreatment with anti-HPA or anti-HPA plus Syn-1 antibodies did not markedly change the mRNA levels of IL-1β and TNF-α concentration AGE-treated macrophages. The results showed that C-domain of HPA mediates AGE-induced macrophage migration and inflammatory cytokine release via Syn-1 protein expression. Furthermore, C-domain of HPA may have a key role in diabetic vascular complication-associated inflammatory response.