Biochemical effects of KH 1060 and anti-TNF monoclonal antibody on human peripheral blood mononuclear cells

The Impact of Vitamin D on Response to Anti-tumor Necrosis Factor-α Therapy in Children With Inflammatory Bowel Disease

OBJECTIVES

Experimental studies have shown that vitamin D has an immunomodulatory effect on the innate and adaptive immune systems. Associations between vitamin D deficiency and development or progression of inflammatory bowel diseases (IBDs) are reported, but a cause-and-effect relationship between pretreatment 25 hydroxyvitamin D [25(OH)D] levels and response to anti-tumor necrosis factor-α (anti-TNF) therapy is not established.

METHODS

This retrospective study evaluated pediatric IBD patients who had 25(OH)D levels drawn within 3 months of initiating infliximab and/or adalimumab treatment. Demographic features, Paris classification, baseline 25(OH)D levels, disease activity, and laboratory results before and after 3 months of anti-TNF therapy were collected. The interaction between vitamin D insufficiency at induction and lack of response to anti-TNF therapy at 3 months was determined.

RESULTS

Of the 383 patients, 76 met inclusion criteria. Sixty-five patients (85.5%) had Crohn disease (CD) and 11 (14.5%) had ulcerative colitis. Seven patients had 25(OH)D levels obtained during both infliximab and adalimumab induction; hence 83 subjects were evaluated (infliximab: 70 patients, adalimumab: 13 patients). 25(OH)D <30 ng/mL was found in 55 of 83 (66.3%) subjects. There were no differences in gender, IBD type, disease activity scores between vitamin D-sufficient and vitamin D-insufficient groups. In CD, proximal gastrointestinal tract inflammation was associated with vitamin D insufficiency (P = 0.019), but other Paris classification parameters and laboratory results were similar in 2 groups. Early termination of anti-TNF therapy was significantly higher in patients who had vitamin D insufficiency (14.5% vs 0%, P = 0.034).

CONCLUSIONS

Vitamin D insufficiency before anti-TNF treatment may result in poor response to induction therapy.

Vitamin D regulates claudin-2 and claudin-4 expression in active ulcerative colitis by p-Stat-6 and Smad-7 signaling

PURPOSE

The tight junctions (TJ) responsible for the integrity of the intestinal barrier are altered in patients with inflammatory bowel disease (IBD), but the physiopathological mechanisms that lead to this alteration are not yet clear. The aim of this study was to determine whether vitamin D, which regulates the integrity of the epithelial barrier by expressing TJ proteins, reduces claudin-2 (Cl-2) levels by inhibiting Stat-6 phosphorylation and whether it increases claudin-4 (Cl-4) levels by blocking Smad-7 activity.

METHODS

Biopsies were obtained from inflamed and non-inflamed tracts of the right side colon (caecum or ascending colon) from the same patient with active UC. All the patients were affected by a recent flare-up of ulcerative rectocolitis (RCU), with no previous biologic or immunosuppressive therapy, and all the biopsies were obtained before any treatments. The biopsies were cultured in the presence or not of 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃). We also used T84 cells as an in vitro model to perform transfection experiments with Stat-6 and Smad-7.

RESULTS

Our results indicate that 1,25(OH)₂D₃ is able to regulate CL-2 and CL-4 protein levels, which are increased and reduced in the intestinal mucosa of UC patients, respectively. In the biopsies obtained from UC patients 1,25(OH)₂D₃ reduces Cl-2 levels by blocking Stat-6 phosphorylation and increases Cl-4 levels by blocking Smad-7 activity. T84 cells, transfected with siRNA of Stat-6 and Smad-7, showed reduced Cl-2 levels and increased Cl-4 levels, confirming that 1,25(OH)₂D₃ regulates Cl-2 and Cl-4 by decreasing p-Stat-6 and Smad-7 levels.

CONCLUSIONS

Our results indicate that the effects of vitamin D on Cl-2 and Cl-4 are mediated by p-Stat-6 and Smad-7 signal, respectively. The study suggests that vitamin D administration to UC patients could be a useful therapeutic intervention, given that vitamin D deficiency is found in these patients.

Fat-soluble Vitamin Deficiencies and Inflammatory Bowel Disease: Systematic Review and Meta-Analysis

BACKGROUND

Vitamin deficiency is frequently associated with inflammatory bowel disease (IBD). Supplementation of vitamins could thus serve as an adjunctive therapy. The present meta-analysis reviews the deficiencies and alterations in serum fat-soluble vitamins (A, D, E, and K) reported in IBD patients.

MATERIALS AND METHODS

PubMed database search was performed to identify all primary studies up to January 2015 that evaluated the serum concentrations of fat-soluble vitamin levels in IBD patients compared with healthy individuals. We estimated pooled mean differences between groups and estimated their relations with some compounding variables (age, disease duration, C-reactive protein, albumin), using a meta-regression analysis.

RESULTS

Nineteen case-control studies met selection criteria. In patients with Crohn's disease (CD), vitamin A, D, E, K status was lower than in controls [D=212 μg/L.92; 95% confidence interval (CI), 95.36-330.48 μg/L, P=0.0002; D=6.97 nmol/L, 95% CI, 1.61-12.32 nmol/L, P=0.01; D=4.72 μmol/L, 95% CI, 1.60-7.84 μmol/L, P=0.003; D=1.46 ng/mL, 95% CI, 0.48-2.43 ng/mL, P=0.003, respectively]. Patients with ulcerative colitis had lower levels of vitamin A than controls (D=223.22 μg/L, 95% CI, 44.32-402.12 μg/L, P=0.01). Patients suffering from CD for a longer time had lower levels of vitamins A (95% CI=7.1-67.58 y, P=0.02) and K (95% CI, 0.09-0.71 y, P=0.02). Meta-regression analysis demonstrated statistically significant associations between the levels of inflammatory biomarkers: C-reactive protein (P=0.03, 95% CI, -9.74 to -0.6 mgl/L) and albumin (P=0.0003, 95% CI, 402.76-1361.98 g/dL), and vitamin A status in CD patients.

CONCLUSION

Our meta-analysis shows that the levels of fat-soluble vitamins are generally lower in patients with inflammatory bowel diseases and their supplementation is undoubtedly indicated.

Immunoregulation of Inflammatory and Inhibitory Cytokines by Vitamin D3 in Patients with Inflammatory Bowel Diseases

Inflammatory bowel disease (IBD) is a group of idiopathic, chronic and relapsing inflammatory conditions of the gastrointestinal tract, caused by an aberrant and exaggerated immunological response in the gut. Supplementation of vitamin D3 in patients with IBD exerts both direct and indirect regulatory roles on the naïve T cells, thereby maintaining a balance between inflammatory and inhibitory cytokines. The direct actions of vitamin D3 on naïve T cells result in the proliferation of more regulatory T cells and inhibitory cytokines such as IL-4, IL-10 and IL-5. The binding of vitamin D to dendritic cells (DCs) through vitamin D receptors inhibits the action of IL-12 on DCs, resulting in the downregulation of Th1 and Th17. On the other hand, this interaction favours Th2 and Treg upregulation and facilitates the maintenance of immune homoeostasis between inflammatory and inhibitory cytokines which is essentially significant in the management of patients with IBD. The aim of this review was to explore the current and mounting scientific evidence on the roles of vitamin D3 in immunoregulation of inflammatory and inhibitory cytokines in patients with IBDs. An extensive literature search was conducted using keywords such as Vitamin D3*, IBD*, inflammatory cytokines*, inhibitory cytokines*, naïve-T-cells* and antigen presenting cells* through PubMed, SCOPUS and MEDLINE search engines. The results of the accumulated bodies of research that have been conducted demonstrate that vitamin D3 plays a major role not only in the immunoregulation of cytokines involved in the pathogenesis of IBDs but also in many other inflammatory disorders.

Vitamin D in hematological disorders and malignancies

Commonly known for its critical role in calcium homeostasis and bone mineralization, more recently vitamin D has been implicated in hematological cancer pathogenesis and shows promise as an anti-cancer therapy. Serum levels of 25(OH)D₃ , the precursor to the active form of vitamin D, calcitriol, are frequently lower in patients with hematological disease compared to healthy individuals. This often correlates with worse disease outcome. Furthermore, diseased cells typically highly express the vitamin D receptor, which is required for many of the anti-cancer effects observed in multiple in vivo and in vitro cancer models. In abnormal hematological cells, vitamin D supplementation promotes apoptosis, induces differentiation, inhibits proliferation, sensitizes tumor cells to other anti-cancer therapies, and reduces the production of pro-inflammatory cytokines. Although the dosage of vitamin D required to achieve these effects may induce hypercalcemia in humans, analogs and combinatorial treatments have been developed to circumvent this side effect. Vitamin D and its analogs are well tolerated in clinical trials, and thus, further investigation into the use of these agents in the clinic is warranted. Here, we review the current literature in this field.

Serum vitamin D and colonic vitamin D receptor in inflammatory bowel disease

AIM: To determine serum vitamin D levels and colonic vitamin D receptor (VDR) expression in inflammatory bowel disease (IBD) and non-IBD patients and correlate these with histopathology.

METHODS: Puerto Rican IBD (n = 10) and non-IBD (n = 10) patients ≥ 21 years old scheduled for colonoscopy were recruited. Each patient completed a questionnaire and provided a serum sample and a colonic biopsy of normal-appearing mucosa. For IBD patients, an additional biopsy was collected from visually diseased mucosa. Serum vitamin D levels were measured by ultra-performance liquid chromatography and mass spectrometry. Hematoxylin and eosin stained tissue sections from colonic biopsies were classified histologically as normal or colitis (active/inactive), and scored for the degree of inflammation present (0-3, inactive/absent to severe). Tissue sections from colonic biopsies were also stained by immunohistochemistry for VDR, for which representative diagnostic areas were photographed and scored for staining intensity using a 4-point scale.

RESULTS: The IBD cohort was significantly younger (40.40 ± 5.27, P < 0.05) than the non-IBD cohort (56.70 ± 1.64) with a higher prevalence of vitamin D deficiency (40% vs 20%, respectively) and insufficiency (70% vs 50%, respectively). Histologic inflammation was significantly higher in visually diseased mucosa from IBD patients (1.95 ± 0.25) than in normal-appearing mucosa from control patients (0.25 ± 0.08, P < 0.01) and from IBD patients (0.65 ± 0.36, P < 0.05) and correlated inversely with VDR expression in visually diseased colonic tissue from IBD patients (r = -0.44, P < 0.05) and from IBD patients with Crohn’s disease (r = -0.69, P < 0.05), but not in normal-appearing colonic tissue from control patients or IBD patients. Control and IBD patient serum vitamin D levels correlated positively with VDR expression in normal colon from control and IBD patients (r = 0.38, P < 0.05) and with patient age (r = 0.54, P < 0.01).

CONCLUSION: Levels of serum vitamin D correlate positively with colonic VDR expression in visually normal mucosa whereas inflammation correlates negatively with colonic VDR expression in visually diseased mucosa in Puerto Rican patients.

Role of Vitamin D in Infliximab-induced Remission in Adult Patients with Crohn's Disease

BACKGROUND

Vitamin D is a key immunomodulator and its deficiency is prevalent among Crohn's patients. The interaction between vitamin D and the response to infliximab induction therapy has not been previously described.

METHODS

Patients with moderate-severe Crohn's disease, defined as having a modified Harvey Bradshaw index ≥8, who were being induced with infliximab were recruited. Patients were divided into low and normal vitamin D groups. Patients were followed prospectively for 14 weeks for achievement of clinical remission (Harvey Bradshaw index <5). At week 14, vitamin D deficient patients were supplemented with intramuscular cholecalciferol; all patients were re-assessed at week 22. Serum cytokine levels were measured at weeks 0, 14, and 22.

RESULTS

Twenty-eight patients initiating infliximab were included, with 54% of patients in the low vitamin D group. The proportion of patients in clinical remission was greater in the low vitamin D group compared with the normal vitamin D group at both week 14 (80% versus 23%, P = 0.007) and week 22 (79% versus 17%, P = 0.005). The low vitamin D group had higher baseline IL-6 levels (median, 4.4 [interquartile range, 2.0-5.7] versus 1.1 [0.8-1.7] pg/mL, P = 0.004) and lower interleukin-12 levels (0.3 [0.1-0.4] versus 0.5 [0.5-0.6] pg/mL, P = 0.006) compared with the normal vitamin D group. At week 14, IL-8 levels were significantly lower in the low vitamin D group compared with the normal vitamin D group (11.2 [9.1-13.8] versus 20.5 [17.9-37.2] pg/mL, P = 0.005).

CONCLUSIONS

Crohn's patients initiating infliximab with a low vitamin D level are more likely to achieve infliximab-induced clinical remission at week 14.

Vitamin D improves inflammatory bowel disease outcomes: Basic science and clinical review

Vitamin D deficiency is commonly diagnosed among patients with inflammatory bowel disease (IBD). Patients with IBD are at risk of low bone density and increased fractures due to low vitamin D levels, long standing disease, and frequent steroid exposures; as a result, it is well established that vitamin D supplementation in this population is important. There is increasing support for the role of vitamin D in strengthening the innate immune system by acting as an immunomodulator and reducing inflammation in experimental and human IBD. The active form of vitamin D, 1,25(OH)D3, acts on T cells to promote T helper (Th)2/regulatory T responses over Th1/Th17 responses; suppresses dendritic cell inflammatory activity; induces antibacterial activity; and regulates cytokine production in favor of an anti-inflammatory response. Murine and human IBD studies support a therapeutic role of vitamin D in IBD. Risk factors for vitamin D deficiency in this population include decreased sunlight exposure, disease duration, smoking, and genetics. Vitamin D normalization is associated with reduced risk of relapse, reduced risk of IBD-related surgeries, and improvement in quality of life. Vitamin D is an inexpensive supplement which has been shown to improve IBD outcomes. However, further research is required to determine optimal serum vitamin D levels which will achieve beneficial immune effects, and stronger evidence is needed to support the role of vitamin D in inducing disease response and remission, as well as maintaining this improvement in patients’ disease states.

Vitamin D and gastrointestinal diseases: inflammatory bowel disease and colorectal cancer

Over the past 5 years, there has been a rapid resurgence of interest in vitamin D outside of its traditional role in metabolic bone disease. Some nontraditional roles ascribed to vitamin D include anti-inflammatory and immune-modulating effects. These effects have led to possible implications in the pathophysiology of immune-mediated diseases including multiple sclerosis and inflammatory bowel disease (IBD). In addition, vitamin D insufficiency has been linked to higher rates of cancers including colon, prostate and breast cancers. Given these diverse associations of vitamin D and disease states, this review describes recent advances with regard to vitamin D and gastrointestinal diseases, in particular IBD and colorectal cancer.

Combination treatment with progesterone and vitamin D hormone may be more effective than monotherapy for nervous system injury and disease

More than two decades of pre-clinical research and two recent clinical trials have shown that progesterone (PROG) and its metabolites exert beneficial effects after traumatic brain injury (TBI) through a number of metabolic and physiological pathways that can reduce damage in many different tissues and organ systems. Emerging data on 1,25-dihydroxyvitamin D(3) (VDH), itself a steroid hormone, have begun to provide evidence that, like PROG, it too is neuroprotective, although some of its actions may involve different pathways. Both agents have high safety profiles, act on many different injury and pathological mechanisms, and are clinically relevant, easy to administer, and inexpensive. Furthermore, vitamin D deficiency is prevalent in a large segment of the population, especially the elderly and institutionalized, and can significantly affect recovery after CNS injury. The combination of PROG and VDH in pre-clinical and clinical studies is a novel and compelling approach to TBI treatment.

Is there convincing biological or behavioral evidence linking vitamin D deficiency to brain dysfunction?

Vitamin D insufficiency is common in the United States; the elderly and African-Americans are at particularly high risk of deficiency. This review, written for a broad scientific readership, presents a critical overview of scientific evidence relevant to a possible causal relationship between vitamin D deficiency and adverse cognitive or behavioral effects. Topics discussed are 1) biological functions of vitamin D relevant to cognition and behavior; 2) studies in humans and rodents that directly examine effects of vitamin D inadequacy on cognition or behavior; and 3) immunomodulatory activity of vitamin D relative to the proinflammatory cytokine theory of cognitive/behavioral dysfunction. We conclude there is ample biological evidence to suggest an important role for vitamin D in brain development and function. However, direct effects of vitamin D inadequacy on cognition/behavior in human or rodent systems appear to be subtle, and in our opinion, the current experimental evidence base does not yet fully satisfy causal criteria. Possible explanations for the apparent inconsistency between results of biological and cognitive/behavioral experiments, as well as suggested areas for further research are discussed. Despite residual uncertainty, recommendations for vitamin D supplementation of at-risk groups, including nursing infants, the elderly, and African-Americans appear warranted to ensure adequacy.

Calcitriol inhibits hepatocyte apoptosis in rat allograft by regulating apoptosis-associated genes

Calcitriol, the active form of vitamin D, exerts important immunoregulatory effects. After rat liver allografting, calcitriol suppresses acute rejection. The aim of this study was to investigate whether calcitriol regulates hepatocyte apoptosis, in parallel with its inhibition of acute rejection in rat liver allografts. Liver allografts were transplanted in a high responder strain combination (SD to Wistar rats) and calcitriol was administered to the recipients, while control recipients received no immunosuppressant. Graft specimens were harvested on postoperative days 1, 3, 5 and 7 for histological analysis and protein assay. Hepatocyte apoptosis was assessed by the TUNEL method. Levels of intragraft Bcl-2, Bcl-xL, Bax, TNF-alpha and IFN-gamma proteins were measured by Western blot analysis. Expression of Fas, Fas ligand and caspase-3 was determined by immunohistochemical analysis. Calcitriol markedly inhibited hepatocyte apoptosis. In the calcitriol-treated allografts, Bcl-2 and Bcl-xL levels increased while Bax and caspase-3 levels significantly decreased. The expression of Fas ligand was clearly reduced while Fas remained unchanged. TNF-alpha and IFN-gamma proteins were also significantly decreased in the presence of calcitriol. These results show that calcitriol acts as a promoter of the anti-apoptosis genes Bcl-2 and Bcl-xL and an inhibitor of the pro-apoptosis genes Bax and caspase-3. These effects may be related to its suppression of the Fas/Fas ligand pathway and its inhibition of cytotoxic T lymphocyte products.

The Vitamin D analogue TX 527 blocks NF-kappaB activation in peripheral blood mononuclear cells of patients with Crohn's disease

Crohn's disease (CD) is an inflammatory disease characterized by the activation of the immune system in the gut. Since tumor necrosis factor (TNF-alpha) plays an important role in the initiation and perpetuation of intestinal inflammation in CD, we investigated whether TX 527 [19-nor-14,20-bisepi-23-yne-1,25(OH)(2)D(3)], a Vitamin D analogue, could affect peripheral blood mononuclear cells (PBMC) proliferation and exert an immunosuppressive effect on TNF-alpha production in CD patients, and whether this immunosuppressive action could be mediated by NF-kappaB down-regulation. TX 527 significantly decreased cell proliferation and TNF-alpha levels. On activation, NF-kappaB, rapidly released from its cytoplasmatic inhibitor (IKB-alpha), transmigrates into the nucleus and binds to DNA response elements in gene promoter regions. The activation of NF-kappaB, stimulated by TNF-alpha, and its nuclear translocation together with the degradation of IKB-alpha were blocked by TX 527. At the same time, NF-kappaB protein levels present in cytoplasmic extracts decreased in the presence of TNF-alpha and increased when PBMC were incubated with TX 527. The results of our studies indicate that TX 527 inhibits TNF-alpha mediated effects on PBMC and the activation of NF-kappaB and that its action is mediated by Vitamin D receptor (VDR), which is activated when the cells are stimulated with TX 527.

Interaction among vitamin D(3) analogue KH 1060, TNF-alpha, and vitamin D receptor protein in peripheral blood mononuclear cells of inflammatory bowel disease patients

BACKGROUND

The active form of vitamin D, 1,25(OH)(2)D(3), exerts important effects on proliferation and differentiation of many cell types, and immunoregulatory activities in particular on T cell-mediated immunity.

AIM

The aim of this study was to investigate whether KH 1060, a vitamin D analogue, could decrease tumor necrosis factor-alpha (TNF-alpha) levels in patients with inflammatory bowel disease (IBD).

METHODS

PBMC proliferation was determined by [(3)H]thymidine incorporation. TNF-alpha levels were measured by ELISA kit; VDR, Bcl-2 and Bax protein levels with Western blot analysis.

RESULTS

KH 1060 inhibited PBMC proliferation and decreased TNF-alpha levels in IBD patients and this effect was synergistic with anti-TNF-alpha. VDR protein levels were significantly increased by PBMC treatment with KH 1060 or anti-TNF-alpha or their combination in ulcerative colitis (UC) patients, and decreased in Crohn's disease (CD) patients, treating the cells with KH 1060. In UC patients an increase in Bcl-2 and Bax levels was observed incubating, PBMC with KH 1060 or anti-TNF-alpha or their combination. In CD patients a slight decrease in Bcl-2 levels was registered when anti-TNF alone or in association with KH 1060 was used. Bax protein levels were slightly increased in the presence of KH 1060 alone or in combination with anti-TNF.

CONCLUSION

This study shows that KH 1060 acts as an immunomodulator on PBMC, acting as TNF-alpha inhibitor. This finding provides strong evidence that vitamin D status could be an important regulator of immunity IBD.