Inhibition of Calpain Alleviates Apoptosis in Coxsackievirus B3-induced Acute Virus Myocarditis Through Suppressing Endoplasmic Reticulum Stress.

Virus myocarditis (VMC) is a common cardiovascular disease and a major cause of sudden death in young adults. However, there is still a lack of effective treatments. Our previous studies found that calpain activation was involved in VMC pathogenesis. This study aims to explore the underlying mechanisms further. Neonatal rat cardiomyocytes (NRCMs) and transgenic mice overexpressing calpastatin (Tg-CAST), the endogenous calpain inhibitor, were used to establish VMC model. Hematoxylin and eosin and Masson staining revealed inflammatory cell infiltration and fibrosis. An ELISA array detected myocardial injury. Cardiac function was measured using echocardiography. CVB3 replication was assessed by capsid protein VP1. Apoptosis was measured by TUNEL staining, flow cytometry, and western blot. The endoplasmic reticulum (ER) stress-related proteins were detected by western blot. Our data showed that CVB3 infection resulted in cardiac injury, as evidenced by increased inflammatory responses and fibrosis, which induced myocardial apoptosis. Inhibiting calpain, both by PD150606 and calpastatin overexpression, could attenuate these effects. Furthermore, ER stress was activated during CVB3 infection. However, calpain inhibition could downregulate some ER stress-associated protein levels such as GRP78, pancreatic ER kinase-like ER kinase (PERK), and inositol-requiring enzyme-1α (IRE-1α), and ER stress-related apoptotic factors, during CVB3 infection. In conclusion, calpain inhibition attenuated CVB3-induced myocarditis by suppressing ER stress, thereby inhibiting cardiomyocyte apoptosis.

Gut microbe-derived metabolite trimethylamine N-oxide accelerates fibroblast-myofibroblast differentiation and induces cardiac fibrosis.

BACKGROUND: Trimethylamine N-oxide (TMAO), a gut microbe-derived metabolite of dietary choline and other trimethylamine-containing nutrients, has been associated with poor prognosis in coronary heart disease. However, the role and underlying mechanisms of TMAO in the cardiac fibrosis after myocardial infarction (MI) remains unclear. METHODS: We used mouse MI models and primary cardiac fibroblasts cultures to study the role of TMAO in the heart and in cardiac fibroblasts. C57BL/6 mice were fed a control diet, high choline (1.2%) or/and DMB diet or a diet containing TMAO (0.12%) starting 3 weeks before MI. DMB, a structural analogue of choline, inhibited microbial TMA lyases and reduced the level of TMAO in mice. Cardiac function was measured 7 days after MI using echocardiography. One week post MI, myocardial tissues were collected to evaluate cardiac fibrosis, and blood samples were evaluated for TMAO levels. The expression of TGF-ß receptor, P-Smad2, α-SMA or collagen I in myocardial tissues and fibroblasts were analyzed by western blot or immunocytochemistry. RESULTS: We demonstrated that cardiac function and cardiac fibrosis were significantly deteriorated in mice fed either TMAO or high choline diets compared with the control diet, and DMB reversed the cardiac function damage of high choline diet (p < .05). Cardiomyocyte necrosis, apoptosis and macrophage infiltration after MI was significantly increased after treatment with TMAO or high choline diets. The size and migration of fibroblasts were increased after TMAO treatment compared with non-treated fibroblasts in vitro. Furthermore, TMAO increased TGF-ß receptor I expression, which promoted the phosphorylation of Smad2 and up-regulated the expression of α-SMA and collagen I. The ubiquitination of TGF-ßRI was decreased in neonatal mouse fibroblasts after TMAO treatment. TMAO also inhibited the expression of smurf2. Inhibition of TGF-ß1 receptor with the small molecule inhibitor SB431542 decreased TGF-ß receptor I expression, reduced the phosphorylation of Smad2, down-regulated TMAO-induced α-SMA and collagen I expression in cardiac fibroblasts. CONCLUSIONS: Cardiac function and cardiac fibrosis were significantly exacerbated in mice fed diets supplemented with either choline or TMAO, probably through accelerating the transformation of fibroblasts into myofibroblasts, indicating activation of TGF-ßRI/Smad2 pathway.

Naoxintong Retards Atherosclerosis by Inhibiting Foam Cell Formation Through Activating Pparα Pathway.

BACKGROUNDS: We recently reported that Naoxintong (NXT), a China Food and Drug Administration (FDA)-approved cardiac medicine, could reduce the plaque size, but the underlying mechanism remains elusive now. OBJECTIVE: In this study, we investigated the effects of NXT on foam cell accumulation both in vivo and in vitro and explored related mechanisms. METHOD: THP-1 cells and bone marrow-derived macrophages were incubated with oxidized low-density lipoprotein (ox-LDL) with/without Naoxintong. ApoE-/- mice fed an atherogenic diet were administered to receive NXT for eight weeks. Macrophage-derived foam cell formation in plaques was measured by immunohistochemical staining. Expression of proteins was evaluated by Western blot. Lentivirus was used to knockdown PPARα in THP-1 cells. RESULTS: After NXT treatment, foam cell accumulation was significantly reduced in atherosclerotic plaques. Further investigation revealed that oxidized low-density lipoprotein (ox-LDL) uptake was significantly decreased and expression of scavenger receptor class A (SR-A) and class B (SR-B and CD36) was significantly downregulated post-NXT treatment. On the other hand, NXT increased cholesterol efflux and upregulated ATP-binding cassette (ABC) transporters (ABCA-1 and ABCG-1) in macrophages. Above beneficial effects of NXT were partly abolished after lentiviral knockdown of PPARα. CONCLUSION: Our findings suggest that NXT could retard atherosclerosis by inhibiting foam cell formation through reducing ox-LDL uptake and enhancing cholesterol efflux and above beneficial effects are partly mediated through PPARα pathway.

Naoxintong attenuates Ischaemia/reperfusion Injury through inhibiting NLRP3 inflammasome activation.

Naoxintong (NXT) is a Chinese Materia Medica standardized product extracted from 16 various kinds of Chinese traditional herbal medicines including Salvia miltiorrhiza, Angelica sinensis, Astragali Radix. Naoxintong is clinically effective in treating ischaemia heart disease. Nucleotide-binding oligomerization domain-Like Receptor with a Pyrin domain 3 (NLRP3) inflammasome has been critically involved in myocardial ischaemia/reperfusion (I/R) injury. Here, we have been suggested that NXT might attenuate myocardial I/R injury via suppression of NLRP3 inflammasome activation. Male C57BL6 mice were subjected to myocardial I/R injury via 45 min. coronary ligation and release for the indicated times. Naoxintong (0.7 g/kg/day) and PBS were orally administrated for 2 weeks before surgery. Cardiac function assessed by echocardiography was significantly improved in the NXT group compared to PBS group at day 2 after myocardial I/R. NLRP3 inflammasome activation is crucially involved in the initial inflammatory response after myocardial I/R injury, leading to cleaved caspase-1, mature interleukin (IL)-1ß production, accompanying by macrophage and neutrophil infiltration. The cardioprotective effect of NXT was associated with a diminished NLRP3 inflammasome activation, decreased pro-inflammatory macrophage (M1 macrophages) and neutrophil infiltration after myocardial I/R injury. In addition, serum levels of IL-1ß, indicators of NLRP3 inflammasome activation, were also significantly suppressed in the NXT treated group after I/R injury. Naoxintong exerts cardioprotive effects at least partly by suppression of NLRP3 inflammasome activation in this I/R injury model.

Mas receptor mediates cardioprotection of angiotensin-(1-7) against Angiotensin II-induced cardiomyocyte autophagy and cardiac remodelling through inhibition of oxidative stress.

Angiotensin II (Ang II) plays an important role in the onset and development of cardiac remodelling associated with changes of autophagy. Angiotensin1-7 [Ang-(1-7)] is a newly established bioactive peptide of renin-angiotensin system, which has been shown to counteract the deleterious effects of Ang II. However, the precise impact of Ang-(1-7) on Ang II-induced cardiomyocyte autophagy remained essentially elusive. The aim of the present study was to examine if Ang-(1-7) inhibits Ang II-induced autophagy and the underlying mechanism involved. Cultured neonatal rat cardiomyocytes were exposed to Ang II for 48 hrs while mice were infused with Ang II for 4 weeks to induce models of cardiac hypertrophy in vitro and in vivo. LC3b-II and p62, markers of autophagy, expression were significantly elevated in cardiomyocytes, suggesting the presence of autophagy accompanying cardiac hypertrophy in response to Ang II treatment. Besides, Ang II induced oxidative stress, manifesting as an increase in malondialdehyde production and a decrease in superoxide dismutase activity. Ang-(1-7) significantly retarded hypertrophy, autophagy and oxidative stress in the heart. Furthermore, a role of Mas receptor in Ang-(1-7)-mediated action was assessed using A779 peptide, a selective Mas receptor antagonist. The beneficial responses of Ang-(1-7) on cardiac remodelling, autophagy and oxidative stress were mitigated by A779. Taken together, these result indicated that Mas receptor mediates cardioprotection of angiotensin-(1-7) against Ang II-induced cardiomyocyte autophagy and cardiac remodelling through inhibition of oxidative stress.

Combination Treatment With Antihypertensive Agents Enhances the Effect of Qiliqiangxin on Chronic Pressure Overload-induced Cardiac Hypertrophy and Remodeling in Male Mice.

We previously showed that Qiliqiangxin (QL) capsules could ameliorate cardiac hypertrophy and remodeling in a mouse model of pressure overload. Here, we compared the effects of QL alone with those of QL combined with the following 3 types of antihypertensive drugs on cardiac remodeling and dysfunction induced by pressure overload for 4 weeks in mice: an angiotensin II type 1 receptor (AT1-R) blocker (ARB), an angiotensin-converting enzyme inhibitor (ACEI), and a ß-adrenergic receptor (ß-AR) blocker (BB). Adult male mice (C57B/L6) were subjected to either transverse aortic constriction or sham operation for 4 weeks, and the drugs (or saline) were orally administered through gastric tubes. Cardiac function and remodeling were evaluated through echocardiography, catheterization, histology, and analysis of hypertrophic gene expression. Cardiomyocyte apoptosis and autophagy, AT1-R and ß1-AR expression, and cell proliferation-related molecules were also examined. Although pressure overload-induced cardiac remodeling and dysfunction, hypertrophic gene reprogramming, AT1-R and ß1-AR expression, and ERK phosphorylation were significantly attenuated by QL alone, QL + ARB, QL + ACEI, and QL + BB, the attenuation was stronger in the combination treatment groups. Moreover, apoptosis was reduced to a larger extent by each combination treatment than by QL alone, whereas autophagy was more strongly attenuated by either QL + ARB or QL + ACEI. None of the treatments significantly upregulated ErbB2 or ErbB4 phosphorylation, and none significantly downregulated C/EBPß expression. Therefore, the effects of QL on chronic pressure overload-induced cardiac remodeling may be significantly increased when QL is combined with an ARB, an ACEI, or a BB.

Qiliqiangxin inhibits angiotensin II-induced transdifferentiation of rat cardiac fibroblasts through suppressing interleukin-6.

Qiliqiangxin (QL), a traditional Chinese medicine, had long been used to treat chronic heart failure. Recent studies revealed that differentiation of cardiac fibroblasts (CFs) into myofibroblasts played an important role in cardiac remodelling and development of heart failure, however, little was known about the underlying mechanism and whether QL treatment being involved. This study aimed to investigate the effects of QL on angiotensin II (AngII)-induced CFs transdifferentiation. Study was performed on in vitro cultured CFs from Sprague-Dawley rats. CFs differentiation was induced by AngII, which was attenuated by QL through reducing transforming growth factor-ß1 (TGF-ß1 ) and α-smooth muscle actin (α-SMA). Our data showed that AngII-induced IL-6 mRNA as well as typeI and typeIII collagens were reduced by QL. IL-6 deficiency could suppress TGF-ß1 and α-SMA, and both IL-6 siRNA and QL-mediated such effect was reversed by foresed expression of recombined IL-6. Increase in actin stress fibres reflected the process of CFs differentiation, we found stress fibres were enhanced after AngII stimulation, which was attenuated by pre-treating CFs with QL or IL-6 siRNA, and re-enhanced after rIL-6 treatment. Importantly, we showed that calcineurin-dependent NFAT3 nuclear translocation was essential to AngII-mediated IL-6 transcription, QL mimicked the effect of FK506, the calcineurin inhibitor, on suppression of IL-6 expression and stress fibres formation. Collectively, our data demonstrated the negative regulation of CFs differentiation by QL through an IL-6 transcriptional mechanism that depends on inhibition of calcineurin/NFAT3 signalling.

Naoxintong protects against atherosclerosis through lipid-lowering and inhibiting maturation of dendritic cells in LDL receptor knockout mice fed a high-fat diet.

Naoxintong (NXT), a Chinese Materia Medica standardized product, extracted from 16 various kinds of Chinese traditional herbal medicines including Salvia miltiorrhiza, Angelica sinennsis, Astragali Radix, is clinically effective in treating atherosclerosisrelated diseases. Here, we tested the hypothesis that the anti-atherosclerosis effects of NXT might be mediated by suppressing maturation of dendritic cells (DCs) in a mice model of atherosclerosis. LDLR(-/-) mice fed a high-fat diet were treated with placebo, NXT (0.7 g/kg/d, oral diet) or simvastatin (100mg/kg/d, oral diet) for 8 weeks, respectively. NXT treatment significantly reduced plasma triglyceride (112 ± 18 mg/dl vs. 192 ± 68 mg/dl, P<0.05) and total cholesterol (944 ± 158 mg/dl vs. 1387 ± 208 mg/dl, P<0.05) compared to placebo treatment. Vascular lesions were significantly smaller and macrophage content and amount of DCs in plaques were significantly less in NXT and simvastatin groups than in placebo group (all P<0.05). In addition, expressions of splenic DC membrane molecules (CD40, CD86 and CD80) and the plasma level of IL-12p70 were significantly lower in NXT and simvastatin groups than in placebo group. In conclusion, NXT protects against atherosclerosis through lipid-lowering and inhibiting DCs maturation in this mice model of atherosclerosis.

Danhong inhibits oxidized low-density lipoprotein-induced immune maturation of dentritic cells via a peroxisome proliferator activated receptor γ-mediated pathway.

Danhong injection (DHI), a Chinese Materia Medica standardized product extracted from Radix Salviae miltiorrhizae and Flos Carthami tinctorii, is effective in the treatment of atherosclerosis (AS)-related diseases. It is widely recognized that AS is a complex inflammatory disease of the arterial wall and the dendritic cells (DCs) is a major player in the pathogenesis of AS via mediating atherosclerotic antigen presenting and T lymphocytes. Here, we determined the effect and possible mechanism of DHI on oxidized low-density lipoprotein (ox-LDL)-induced maturation and immune function of DCs. Human monocyte-derived DCs were incubated with DHI or ciglitazone and were subsequently stimulated with ox-LDL to induce maturation. Similar to ciglitazone, a peroxisome proliferator activated receptor (PPAR) γ agonist, DHI, could significantly reduce ox-LDL-induced expressions of mature markers, enhance the endocytotic function, and inhibit secretions of cytokine on DCs. These effects of DHI could be partly reversed by silencing the PPARγ. In conclusion, DHI could inhibit ox-LDL-induced maturation of DCs partly through activating a PPARγ-mediated signaling pathway.

Qiliqiangxin inhibits the development of cardiac hypertrophy, remodeling, and dysfunction during 4 weeks of pressure overload in mice.

Qiliqiangxin (QL), a traditional Chinese medicine, has been used in the treatment of chronic heart failure. However, whether QL can benefit cardiac remodeling in the hypertensive state is unknown. We here examined the effects of QL on the development of cardiac hypertrophy through comparing those of losartan in C57BL/6 mice underlying transverse aorta constriction for 4 weeks. QL and losartan were administrated at 0.6 mg and 13.4 mg·kg·d, respectively. Cardiac hypertrophy, function, and remodeling were evaluated by echocardiography, catheterization, histology, and examination of specific gene expression and ERK phosphorylation. Cardiac apoptosis, autophagy, tumor necrosis factor α/insulin-like growth factor-1, and angiotensin II type 1 receptor expression and especially the proliferation of cardiomyocytes and phosphorylation of ErbB receptors were examined in vivo to elucidate the mechanisms. Transverse aorta constriction for 2 weeks resulted in a significant cardiac hypertrophy, which was significantly suppressed by either QL or losartan treatment. At 4 weeks after transverse aorta constriction, although the development of cardiac dysfunction and remodeling and the increases in apoptosis, autophagy, tumor necrosis factor α/insulin-like growth factor-1, and angiotensin II type 1 receptor expression were abrogated comparably between QL and losartan treatments, QL, but not losartan, enhanced proliferation of cardiomyocytes, which was paralleled with dowregulation of CCAAT/enhancer-binding protein ß, upregulation of CBP/p300-interacting transactivator with ED-rich carboxy-terminal domain 4, and increases in ErbB2 and ErbB4 phosphorylation. Furthermore, inhibition of either ErbB2 or CBP/p300-interacting transactivator with ED-rich carboxy-terminal domain 4 abolished the cardiac protective effects of QL. Thus, QL inhibits myocardial inflammation and cardiomyocyte death and promotes cardiomyocyte proliferation, leading to an ameliorated cardiac remodeling and function in a mouse model of pressure overload. The possible mechanisms may involve inhibition of angiotensin II type 1 receptor and activation of ErbB receptors.

Salvianolic acid B suppresses maturation of human monocyte-derived dendritic cells by activating PPARγ.

BACKGROUND AND PURPOSE: Salvianolic acid B (Sal B), a water-soluble antioxidant derived from a Chinese medicinal herb, is known to be effective in the prevention of atherosclerosis. Here, we tested the hypothesis that the anti-atherosclerotic effect of Sal B might be mediated by suppressing maturation of human monocyte-derived dendritic cells (h-monDC). EXPERIMENTAL APPROACH: h-monDC were derived by incubating purified human monocytes with GM-CSF and IL-4. h-monDC were pre-incubated with or without Sal B and stimulated by oxidized low-density lipoprotein (ox-LDL) in the presence or absence of PPARγ siRNA. Expression of h-monDC membrane molecules (CD40, CD86, CD1a, HLA-DR) were analysed by FACS, cytokines were measured by elisa and the TLR4-associated signalling pathway was determined by Western blotting. KEY RESULTS: Ox-LDL promoted h-monDC maturation, stimulated CD40, CD86, CD1a, HLA-DR expression and IL-12, IL-10, TNF-α production; and up-regulated TLR4 signalling. These effects were inhibited by Sal B. Sal B also triggered PPARγ activation and promoted PPARγ nuclear translocation, attenuated ox-LDL-induced up-regulation of TLR4 and myeloid differentiation primary-response protein 88 and inhibited the downstream p38-MAPK signalling cascade. Knocking down PPARγ with the corresponding siRNA blocked these effects of Sal B. CONCLUSIONS AND IMPLICATIONS: Our data suggested that Sal B effectively suppressed maturation of h-monDC induced by ox-LDL through PPARγ activation.

Tongxinluo inhibits oxidized low-density lipoprotein-induced maturation of human dendritic cells via activating peroxisome proliferator-activated receptor gamma pathway.

TongXinLuo (TXL) is a traditional Chinese herbal medicine with multiple vasoprotective activities. Dendritic cells (DCs) play an active role in the immunological processes related to atherosclerosis. The purpose of this study was to determine the effect and possible mechanisms of TXL on oxidized low-density lipoprotein (OX-LDL)-induced maturation and immune function of DCs. Human monocyte-derived DCs were incubated with TXL or ciglitazone and were subsequently stimulated with OX-LDL to induce maturation. Similar to ciglitazone, a peroxisome proliferator-activated receptor (PPAR) gamma agonist, TXL could significantly reduce the maturation-associated markers induced by OX-LDL, such as CD40, CD86, CD1a, and human leukocyte antigen-DR; improved the endocytotic function; and decreased secretions of cytokine interleukin-12 and tumor necrosis factor alpha. These inhibitory effects of TXL could be partly reversed by silencing the expression of PPAR gamma in DCs. In conclusion, TXL could inhibit OX-LDL-induced maturation of DCs through activating PPAR gamma pathway.

Inhibiting effects of total saponins of panax ginseng on immune maturation of dendritic cells induced by oxidized-low density lipoprotein.

Total saponins of panax ginseng (TSPG) are the major active components in panax ginseng. Dendritic cells (DCs) play an active role in the immunological processes related to atherosclerosis. The purpose of this study was to determine the effect and possible mechanisms of TSPG on the maturation and immune function of DCs. Compared with those untreated, the DCs pre-treated with TSPG and then induced by oxidized-LDL exhibited a significantly lower expression of the maturation-associated markers of CD40, CD86, HLA-DR, and CD1a, together with an increased endocytosic function as well as decreased secretions of cytokine. However, silencing the expression of PPARgamma in DCs, the inhibitory effect of TSPG on the maturation DCs was significantly reduced. In conclusion, TSPG could inhibit the maturation of DCs induced by oxidized-LDL which suggests beneficial effects on atherosclerosis and this effect was partly dependent on the PPARgamma pathway at least.

Diphtheria toxin-induced autophagic cardiomyocyte death plays a pathogenic role in mouse model of heart failure.

It is still not clear whether loss of cardiomyocytes through programmed cell death causes heart failure. To clarify the role of cell death in heart failure, we generated transgenic mice (TG) that express human diphtheria toxin receptor in the hearts. A mosaic expression pattern of the transgene was observed, and the transgene-expressing cardiomyocytes (17.3% of the total cardiomyocytes) were diffusely scattered throughout the ventricles. Intramuscular injection of diphtheria toxin induced complete elimination of the transgene-expressing cardiomyocytes within 7 days, and approximately 80% of TG showed pathophysiological features characteristic of heart failure and were dead within 14 days. Degenerated cardiomyocytes of the TG heart showed characteristic features indicative of autophagic cell death such as up-regulated lysosomal markers and abundant autophagosomes containing cytosolic organelles like cardiomyocytes of human dilated cardiomyopathy. The heart failure-inducible TG are a useful model for dilated cardiomyopathy, and provided evidence indicating that myocardial cell loss through autophagic cell death plays of a causal role in the pathogenesis heart failure.

Cytokine therapy prevents left ventricular remodeling and dysfunction after myocardial infarction through neovascularization.

Pretreatment with a combination of granulocyte colony-stimulating factor (G-CSF) and stem cell factor (SCF) has been reported to attenuate left ventricular (LV) remodeling after acute myocardial infarction (MI). We here examined whether the cytokine treatment started after MI has also beneficial effects. Anterior MI was created in the recipient mice whose bone marrow had been replaced with that of transgenic mice expressing enhanced green fluorescent protein (GFP). We categorized mice into five groups according to the following treatment: 1) saline; 2) administration of G-CSF and SCF from 5 days before MI through 3 days after; 3) administration of G-CSF and SCF for 5 days after MI; 4) administration of G-CSF alone for 5 days after MI; 5) administration of SCF alone for 5 days after MI. All the three treatment groups with G-CSF showed less LV remodeling and improved cardiac function and survival rate after MI. The number of capillaries, which express GFP, was increased and the number of apoptotic cells was decreased in the border area of all the treatment groups with G-CSF. Even if the cytokine treatment is started after MI, it could prevent LV remodeling and dysfunction after MI--at least in part--through an increase in neovascularization and a decrease in apoptosis in the border area.

Continuous blockade of L-type Ca2+ channels suppresses activation of calcineurin and development of cardiac hypertrophy in spontaneously hypertensive rats.

We examined whether Ca2+ channel blockers inhibit the activation of the Ca2+-dependent phosphatase calcineurin and the development of cardiac hypertrophy in spontaneously hypertensive rats (SHR). We randomly divided 12-week-old SHR into three groups, one each receiving vehicle, bolus injection or continuous infusion of nifedipine (10 mg/kg/day) from 12 to 24 weeks of age. Systolic blood pressure (BP) and heart rate were measured every week after the treatment using the tail-cuff plethysmography method. After 4, 8 and 12 weeks of treatment, 6 rats of each group were subjected to examinations that included an assay for calcineurin activity in the heart, magnetic resonance imaging (MRI), histology and Northern blot analysis. Continuous infusion of nifedipine consistently reduced BP, whereas bolus injection resulted in a fluctuation of BP. Continuous infusion of nifedipine not only reduced left ventricular mass but also decreased the transverse diameter of cardiomyocytes, interstitial fibrosis and the expression of the atrial natriuretic peptide and brain natriuretic peptide genes in the heart, while bolus injection of nifedipine did not significantly attenuate any of these hypertrophic responses in SHR. The activity of calcineurin in the heart was strongly suppressed by continuous but not bolus infusion of nifedipine in SHR. The results indicate that continuous blockade of Ca2+ channels with nifedipine effectively suppresses the development of cardiac hypertrophy in SHR, possibly through inhibition of the calcineurin activity.