TRPM7 restrains plasmin activity and promotes transforming growth factor-ß1 signaling in primary human lung fibroblasts.

Sustained exposure of the lung to various environmental or occupational toxins may eventually lead to pulmonary fibrosis, a devastating disease with no cure. Pulmonary fibrosis is characterized by excessive deposition of extracellular matrix (ECM) proteins such as fibronectin and collagens. The peptidase plasmin degrades the ECM, but protein levels of the plasmin activator inhibitor-1 (PAI-1) are increased in fibrotic lung tissue, thereby dampening plasmin activity. Transforming growth factor-ß1 (TGF-ß1)-induced activation of SMAD transcription factors promotes ECM deposition by enhancing collagen, fibronectin and PAI-1 levels in pulmonary fibroblasts. Hence, counteracting TGF-ß1-induced signaling is a promising approach for the therapy of pulmonary fibrosis. Transient receptor potential cation channel subfamily M Member 7 (TRPM7) supports TGF-ß1-promoted SMAD signaling in T-lymphocytes and the progression of fibrosis in kidney and heart. Thus, we investigated possible effects of TRPM7 on plasmin activity, ECM levels and TGF-ß1 signaling in primary human pulmonary fibroblasts (pHPF). We found that two structurally unrelated TRPM7 blockers enhanced plasmin activity and reduced fibronectin or PAI-1 protein levels in pHPF under basal conditions. Further, TRPM7 blockade strongly inhibited fibronectin and collagen deposition induced by sustained TGF-ß1 stimulation. In line with these data, inhibition of TRPM7 activity diminished TGF-ß1-triggered phosphorylation of SMAD-2, SMAD-3/4-dependent reporter activation and PAI-1 mRNA levels. Overall, we uncover TRPM7 as a novel supporter of TGF-ß1 signaling in pHPF and propose TRPM7 blockers as new candidates to control excessive ECM levels under pathophysiological conditions conducive to pulmonary fibrosis.

Pan-Lysyl Oxidase Inhibitor PXS-5505 Ameliorates Multiple-Organ Fibrosis by Inhibiting Collagen Crosslinks in Rodent Models of Systemic Sclerosis.

Systemic sclerosis (SSc) is characterised by progressive multiple organ fibrosis leading to morbidity and mortality. Lysyl oxidases play a vital role in the cross-linking of collagens and subsequent build-up of fibrosis in the extracellular matrix. As such, their inhibition provides a novel treatment paradigm for SSc. A novel small molecule pan-lysyl oxidase inhibitor, PXS-5505, currently in clinical development for myelofibrosis treatment was evaluated using in vivo rodent models resembling the fibrotic conditions in SSc. Both lysyl oxidase and lysyl oxidase-like 2 (LOXL2) expression were elevated in the skin and lung of SSc patients. The oral application of PXS-5505 inhibited lysyl oxidase activity in the skin and LOXL2 activity in the lung. PXS-5505 exhibited anti-fibrotic effects in the SSc skin mouse model, reducing dermal thickness and α-smooth muscle actin. Similarly, in the bleomycin-induced mouse lung model, PXS-5505 reduced pulmonary fibrosis toward normal levels, mediated by its ability to normalise collagen/elastin crosslink formation. PXS-5505 also reduced fibrotic extent in models of the ischaemia-reperfusion heart, the unilateral ureteral obstruction kidney, and the CCl4-induced fibrotic liver. PXS-5505 consistently demonstrates potent anti-fibrotic efficacy in multiple models of organ fibrosis relevant to the pathogenesis of SSc, suggesting that it may be efficacious as a novel approach for treating SSc.

Influence of Vincristine, Clinically Used in Cancer Therapy and Immune Thrombocytopenia, on the Function of Human Platelets.

Vincristine is a clinically used antimicrotubule drug for treating patients with lymphoma. Due to its property of increasing platelet counts, vincristine is also used to treat patients with immune thrombocytopenia. Moreover, antiplatelet agents were reported to be beneficial in thrombotic thrombocytopenic purpura (TTP). Therefore, we investigated the detailed mechanisms underlying the antiplatelet effect of vincristine. Our results revealed that vincristine inhibited platelet aggregation induced by collagen, but not by thrombin, arachidonic acid, and the thromboxane A2 analog U46619, suggesting that vincristine exerts higher inhibitory effects on collagen-mediated platelet aggregation. Vincristine also reduced collagen-mediated platelet granule release and calcium mobilization. In addition, vincristine inhibited glycoprotein VI (GPVI) signaling, including Syk, phospholipase Cγ2, protein kinase C, Akt, and mitogen-activated protein kinases. In addition, the in vitro PFA-100 assay revealed that vincristine did not prolong the closure time, and the in vivo study tail bleeding assay showed that vincristine did not prolong the tail bleeding time; both findings suggested that vincristine may not affect normal hemostasis. In conclusion, we demonstrated that vincristine exerts antiplatelet effects at least in part through the suppression of GPVI signaling. Moreover, this property of antiplatelet activity of vincristine may provide additional benefits in the treatment of TTP.

ER-anchored CRTH2 antagonizes collagen biosynthesis and organ fibrosis via binding LARP6.

Excessive deposition of extracellular matrix, mainly collagen protein, is the hallmark of organ fibrosis. The molecular mechanisms regulating fibrotic protein biosynthesis are unclear. Here, we find that chemoattractant receptor homologous molecule expressed on TH2 cells (CRTH2), a plasma membrane receptor for prostaglandin D2, is trafficked to the endoplasmic reticulum (ER) membrane in fibroblasts in a caveolin-1-dependent manner. ER-anchored CRTH2 binds the collagen mRNA recognition motif of La ribonucleoprotein domain family member 6 (LARP6) and promotes the degradation of collagen mRNA in these cells. In line, CRTH2 deficiency increases collagen biosynthesis in fibroblasts and exacerbates injury-induced organ fibrosis in mice, which can be rescued by LARP6 depletion. Administration of CRTH2 N-terminal peptide reduces collagen production by binding to LARP6. Similar to CRTH2, bumetanide binds the LARP6 mRNA recognition motif, suppresses collagen biosynthesis, and alleviates bleomycin-triggered pulmonary fibrosis in vivo. These findings reveal a novel anti-fibrotic function of CRTH2 in the ER membrane via the interaction with LARP6, which may represent a therapeutic target for fibrotic diseases.

Magnolol, a natural aldehyde dehydrogenase-2 agonist, inhibits the proliferation and collagen synthesis of cardiac fibroblasts.

Inhibiting myocardial fibrosis can help prevent cardiovascular diseases, including heart failure. Magnolol (Mag), a natural component of Magnoliae officinalis, has been reported to inhibit fibrosis. However, the mechanism of Mag activity and its effects on myocardial fibrosis remain unclear. Here, we investigated the involvement of ALDH2, an endogenous protective agent against myocardial fibrosis, in the Mag-mediated inhibition of cardiac fibroblast proliferation and collagen synthesis. We found that Mag significantly inhibited cardiac fibroblast proliferation and collagen synthesis, based on the results of MTT, EdU and western blot assays. Moreover, molecular docking, molecular dynamics simulation and surface plasmon resonance (SPR) assays showed that Mag could bind directly and stably to ALDH2. Further analysis of the mechanism of these effects indicated that treatment with Mag dose-dependently enhanced ALDH2 activity without altering protein expression. Mag could enhance the activity of recombinant human ALDH2 proteins with a half-maximal effective concentration of 5.79 × 10-5 M. In addition, ALDH2 activation via Alda-1 inhibited cardiac fibroblast proliferation and collagen synthesis, while ALDH2 inhibition via daidzin partially blocked the suppressive effects of Mag. In summary, Mag may act as a natural ALDH2 agonist and inhibit cardiac fibroblast proliferation and collagen synthesis.

Taohong siwu decoction attenuates myocardial fibrosis by inhibiting fibrosis proliferation and collagen deposition via TGFBR1 signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Myocardial fibrosis after myocardial infarction (MI) leads to cardiac remodeling and loss of function. Taohong siwu decoction (THSWD), a well-known traditional Chinese medicinal prescription, has been clinically used to treat various cardiovascular and cerebrovascular diseases, but its potential functions in myocardial fibrosis after MI remain uncharacterized. AIM OF THE STUDY: The purpose of current study was to explore the potential mechanism action and anti-myocardial fibrosis effects of treatment with THSWD in vivo and in vitro. MATERIALS AND METHODS: Mouse underwent ligation of coronary artery to induce MI and divided equally into the sham group, model group and THSWD treatment groups. After 4 weeks, the effects of THSWD treatment on cardiac function were estimated by echocardiography. HE staining was used to detect the pathologic changes and Masson trichrome staining was used to estimate tissue fibrosis. To further explore the regulatory molecular mechanisms of THSWD, transcriptome analysis was performed. Furthermore, in vitro, we investigated the effect of THSWD on cell proliferation and collagen deposition in primary cardiac fibrosis cells and its possible mechanism of action. Overexpression of TGFBR1 was achieved by infection with an adenovirus vector encoding TGFBR1. RESULTS: Treatment with THSWD significantly decreased myocardial fibrosis and recovered cardiac function in the post-MI mouse. The transcriptomics data imply that the TGF-ß pathway might be a target in the anti-fibrosis effect of THSWD. THSWD inhibits TGF-ß1-induced proliferation of primary cardiac fibroblasts. THSWD decreased collagen expression and TGFBR1 and Smad2/3 phosphorylation. Moreover, the inhibitory effect of THSWD on CFs proliferation and collagen deposition, as well as TGFBR1 signaling pathway-associated proteins expression was partially abrogated by overexpression of TGFBR1. CONCLUSION: Collectively, the results implicate that THSWD attenuates myocardial fibrosis by inhibiting fibrosis proliferation and collagen deposition via inhibiting TGFBR1, and might be a potential therapeutic agent for treatment of myocardial fibrosis post-MI.

Prolonged Scar-in-a-Jar: an in vitro screening tool for anti-fibrotic therapies using biomarkers of extracellular matrix synthesis.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a rapidly progressing disease with challenging management. To find novel effective therapies, better preclinical models are needed for the screening of anti-fibrotic compounds. Activated fibroblasts drive fibrogenesis and are the main cells responsible for the accumulation of extracellular matrix (ECM). Here, a prolonged Scar-in-a-Jar assay was combined with clinically validated biochemical markers of ECM synthesis to evaluate ECM synthesis over time. To validate the model as a drug screening tool for novel anti-fibrotic compounds, two approved compounds for IPF, nintedanib and pirfenidone, and a compound in development, omipalisib, were tested. METHODS: Primary human lung fibroblasts from healthy donors were cultured for 12 days in the presence of ficoll and were stimulated with TGF-ß1 with or without treatment with an ALK5/TGF-ß1 receptor kinase inhibitor (ALK5i), nintedanib, pirfenidone or the mTOR/PI3K inhibitor omipalisib (GSK2126458). Biomarkers of ECM synthesis were evaluated over time in cell supernatants using ELISAs to assess type I, III, IV, V and VI collagen formation (PRO-C1, PRO-C3, PRO-C4, PRO-C5, PRO-C6), fibronectin (FBN-C) deposition and α-smooth muscle actin (α-SMA) expression. RESULTS: TGF-ß1 induced synthesis of PRO-C1, PRO-C6 and FBN-C as compared with unstimulated fibroblasts at all timepoints, while PRO-C3 and α-SMA levels were not elevated until day 8. Elevated biomarkers were reduced by suppressing TGF-ß1 signalling with ALK5i. Nintedanib and omipalisib were able to reduce all biomarkers induced by TGF-ß1 in a concentration dependent manner, while pirfenidone had no effect on α-SMA. CONCLUSIONS: TGF-ß1 stimulated synthesis of type I, III and VI collagen, fibronectin and α-SMA but not type IV or V collagen. Synthesis was increased over time, although temporal profiles differed, and was modulated pharmacologically by ALK5i, nintedanib, pirfenidone and omipalisib. This prolonged 12-day Scar-in-a-Jar assay utilising biochemical markers of ECM synthesis provides a useful screening tool for novel anti-fibrotic compounds.

Structure-Activity Relationship Study on Col-003, a Protein-Protein Interaction Inhibitor between Collagen and Hsp47.

This study demonstrates the structure-activity relationship of Col-003, a potent collagen-heat-shock protein 47 (Hsp47) interaction inhibitor. Col-003 analogues were successfully synthesized by Pd(0)-catalyzed cross-coupling reactions of 5-bromosalicylaldehyde derivatives with alkyl-metal species, and the inhibitory activities of the synthetic analogues were evaluated using surface plasmon resonance analysis (BIAcore). We succeeded in discovering two potent inhibitors that showed 85 and 81% inhibition at a concentration of 1.9 µM against the collagen-Hsp47 interaction. This indicates that elongation of an alkyl linker between two aromatic rings could considerably improve inhibitory activity due to the adjustment of a pendant phenyl moiety to an appropriate position, in addition to the hydrophobic interaction with an alkyl linker moiety.

Down-regulation of GLT25D1 inhibited collagen secretion and involved in liver fibrogenesis.

Collagen ß (1-O) galactosyltransferase 1 (GLT25D1) has been reported to transfer galactose to hydroxylysine residues via ß (1-O) linkages in collagen. However, the role of Glt25d1 in liver fibrogenesis is still unknow. Recently, we generated a Glt25d1 knockout mouse to elucidate the role of Glt25d1 in vivo. However, we found that complete deletion of the Glt25d1 gene resulted in embryonic lethality at E11.5. Histopathological analysis revealed that dysplasia in Glt25d1-/- labyrinth with defects of the vascular network. Immunohistochemical showed that the decrease in proliferation of Glt25d1-/- liver and the developing central nervous system (CNS). The role of Glt25d1 in liver fibrogenesis was explored by Glt25d1+/- mice. Glt25d1+/- mice and wild-type (WT) mice were injected intraperitoneally with the same dose of CCl4. The higher level of serum alanine aminotransferase was observed in Glt25d1+/- mice. Reverse transcription-quantitative polymerase chainreaction demonstrated that the mRNA expression levels of the inflammatory cytokines such as, Tnf-α, Cxcl-1 and Mcp-1, showed a significantly increase in CCl4-treated Glt25d1+/- mice. Collagen-I, collagen-III and α-SMA transcripts accumulation was markedly increased in the Glt25d1+/- mice. However, Masson's trichrome staining revealed a trend to decrease in the ECM proteins deposition of Glt25d1+/- liver. Immunohistochemistry and Western blots revealed that the protein expression of Collagen-III was reduced and a trend to a decrease in collagen-I was observed in the Glt25d1+/- liver compared with those of WT mice. Our results demonstrate that Glt25d1 knockout results in embryonic lethality and down-regulation of Glt25d1 may inhibit collagen secretion during liver fibrogenesis.

Targeting inflammatory sites through collagen affinity enhances the therapeutic efficacy of anti-inflammatory antibodies.

Enhancing the therapeutic efficacy of drugs for inflammatory diseases is of high demand. One possible approach is targeting drugs to the extracellular matrix of the inflamed area. Here, we target collagens in the matrix, which are inaccessible in most tissues yet are exposed to the bloodstream in the inflamed area because of vascular hyperpermeability. We conferred collagen affinity to anti-tumor necrosis factor-α (α-TNF) antibody by conjugating a collagen-binding peptide (CBP) derived from the sequence of decorin. CBP-α-TNF accumulated in the inflamed paw of the arthritis model, and arthritis development was significantly suppressed by treatment with CBP-α-TNF compared with the unmodified antibody. Similarly, CBP-anti-transforming growth factor-ß (α-TGF-ß) accumulated in the inflamed lung of pulmonary fibrosis model and significantly suppressed pulmonary fibrosis compared with the unmodified antibody. Together, collagen affinity enables the anticytokine antibodies to target arthritis and pulmonary fibrosis accompanied by inflammation, demonstrating a clinically translational approach to treat inflammatory diseases.

Role of fibroblast growth factor 23 and klotho cross talk in idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive fibrosing interstitial pneumonia that mainly affects the elderly. Several reports have demonstrated that aging is involved in the underlying pathogenic mechanisms of IPF. α-Klotho (KL) has been well characterized as an "age-suppressing" hormone and can provide protection against cellular senescence and oxidative stress. In this study, KL levels were assessed in human plasma and primary lung fibroblasts from patients with idiopathic pulmonary fibrosis (IPF-FB) and in lung tissue from mice exposed to bleomycin, which showed significant downregulation when compared with controls. Conversely, transgenic mice overexpressing KL were protected against bleomycin-induced lung fibrosis. Treatment of human lung fibroblasts with recombinant KL alone was not sufficient to inhibit transforming growth factor-ß (TGF-ß)-induced collagen deposition and inflammatory marker expression. Interestingly, fibroblast growth factor 23 (FGF23), a proinflammatory circulating protein for which KL is a coreceptor, was upregulated in IPF and bleomycin lungs. To our surprise, FGF23 and KL coadministration led to a significant reduction in fibrosis and inflammation in IPF-FB; FGF23 administration alone or in combination with KL stimulated KL upregulation. We conclude that in IPF downregulation of KL may contribute to fibrosis and inflammation and FGF23 may act as a compensatory antifibrotic and anti-inflammatory mediator via inhibition of TGF-ß signaling. Upon restoration of KL levels, the combination of FGF23 and KL leads to resolution of inflammation and fibrosis. Altogether, these data provide novel insight into the FGF23/KL axis and its antifibrotic/anti-inflammatory properties, which opens new avenues for potential therapies in aging-related diseases like IPF.

Inhibition of CTRP6 prevented survival and migration in hepatocellular carcinoma through inactivating the AKT signaling pathway.

C1qTNF-related proteins (CTRPs) are a member of the adiponectin paralogs family, which are implicated in regulation of various biological processes. Recently, CTRP6 was found upregulated in human hepatocellular carcinomas (HCC). However, the specific roles and molecular mechanisms of CTRP6 in HCC remain unclear. Here, we investigated the effects of CTRP6 on the vitality, apoptosis, migration, and invasion of HCC cells. Firstly, we measured the levels of CTRP6 in HCC tissues and cell lines. Our results showed that CTRP6 was markedly upregulated in HCC tissues and Hep3B cells. Then, the CTRP6 siRNA was transfected into Hep3B cells. Cell counting kit-8 (CCK-8) assay and flow cytometry analysis revealed that silencing CTRP6-induced cell viability inhibition, and apoptosis. The wound-healing and transwell assay showed that CTRP6 deficiency suppressed the migration and invasion of Hep3B cells. Meanwhile, the AKT phosphorylation level was reduced by CTRP6 silencing. Next, Hep3B cells were pretreated with insulin-like growth factor-1 (IGF-1) (an activator of AKT), and then transfected with CTRP6 siRNA, and the cell vitality, apoptosis, migration, and invasion were measured again. We found that all these alterations caused by CTRP6 inhibition could be reversed by IGF-1 treatment. Taken together, CTRP6 suppression blocked cell survival, migration, and invasion and promoted cell apoptosis through inactivating the AKT signaling pathway. Our findings present a novel potential molecular target for HCC therapy.

Inhibition of collagen production delays malignant mesothelioma tumor growth in a murine model.

Malignant mesothelioma is an aggressive fibrous tumor, predominantly of the pleura, with a very poor prognosis. Cell-matrix interactions are recognized important determinants of tumor growth and invasiveness but the role of the extracellular matrix in mesothelioma is unknown. Mesothelioma cells synthesize collagen as well as transforming growth factor-beta (TGF-ß), a key regulator of collagen production. This study examined the effect of inhibiting collagen production on mesothelioma cell proliferation in vitro and tumor growth in vivo. Collagen production by mesothelioma cells was inhibited by incubating cells in vitro with the proline analogue thiaproline (thiazolidine-4-carboxylic acid) or by oral administration of thiaproline in a murine tumor model. Cell cytotoxicity was measured using neutral red uptake and lactate dehydrogenase assays. Proliferation was measured by tritiated thymidine incorporation, and inflammatory cell influx, proliferation, apoptosis and angiogenesis in tumors examined by immunohistochemical labelling. Tumor size was determined by tumor weight and collagen production was measured by HPLC. Thiaproline at non-toxic doses significantly reduced basal and TGF-ß-induced collagen production by over 50% and cell proliferation by over 65%. In vivo thiaproline administration inhibited tumor growth at 10 days, decreasing the median tumor weight by 80%. The mean concentration of collagen was 50% lower in the thiaproline-treated tumors compared with the controls. There were no significant differences in vasculature or inflammatory cell infiltration but apoptosis was increased in thiaproline treated tumors at day 10. In conclusion, these observations strongly support a role for collagen in mesothelioma growth and establish the potential for inhibitors of collagen synthesis in mesothelioma treatment.

Asiatic acid enhances intratumor delivery and the antitumor effect of pegylated liposomal doxorubicin by reducing tumor-stroma collagen.

Tumor-targeted drug delivery systems (Tt-DDSs) are proposed as a promising strategy for cancer care. However, the dense collagen network in tumors stroma significantly reduces the penetration and efficacy of Tt-DDS. In order to investigate the effect of asiatic acid (AA) on antitumor effect of pegylated liposomal doxorubicin (PLD) by attenuating stroma-collagen, colon cancer xenograft mice (SW620 cell line) were treated by PLD, AA, or combined regimes, respectively; the collagen levels were estimated by Sirius red/fast green dual staining and immunohistochemistry (IHC) staining; the intratumor exposure of doxorubicin was visualized by ex vivo fluorescence imaging and quantified by HPLC/MS analysis. In addition, the impact of AA on collagen synthesis of fibroblast cell (HFL-1) and cytotoxic effect of PLD and doxorubicin to cancer cell (SW620) were studied in vitro. In the presence of AA (4 mg/kg), the intratumor collagen level was restricted in vivo (reduced by 22%, from 4.14% ± 0.30% to 3.24% ± 0.25%, P = 0.051) and in vitro. Subsequently, doxorubicin level was increased by ~30%. The antitumor activity of PLD was significantly improved (57.3% inhibition of tumor growth and 44% reduction in tumor weight) by AA combination. Additionally, no significant improvement in cytotoxic effect of PLD or doxorubicin induced by AA was observed. In conclusion, AA is a promising sensitizer for tumor treatment by enhancing intratumor drug exposure via stromal remodeling.

Dysregulation of let-7 by PEG modified graphene oxide in nematodes with deficit in epidermal barrier.

In nematode Caenorhabditis elegans, epidermal RNA interference (RNAi) knockdown of bli-1 encoding a cuticular collagen caused the toxicity induction of GO-PEG (PEG surface modified graphene oxide). In this study, we further found that epidermal RNAi knockdown of bli-1 increased expression of a microRNA let-7, and let-7 mutation suppressed the susceptibility of bli-1(RNAi) nematodes to GO-PEG toxicity. let-7 regulated the toxicity induction of GO-PEG by suppressing expression and function of its direct targets (HBL-1 and LIN-41). Like the nematodes with epidermal RNAi knockdown of bli-1, epidermal RNAi knockdown of hbl-1 or lin-41 also induced functional abnormality in epidermal barrier. Therefore, a signaling cascade of BLI-1-let-7-HBL-1/LIN-41 was raised to be involved in GO-PEG toxicity induction. Our data imply the dysregulation of let-7-mediated molecular machinery for developmental timing control by GO-PEG in nematodes with deficit in epidermal barrier caused by bli-1(RNAi).

The lysyl oxidase like 2/3 enzymatic inhibitor, PXS-5153A, reduces crosslinks and ameliorates fibrosis.

Fibrosis is characterized by the excessive deposition of extracellular matrix and crosslinked proteins, in particular collagen and elastin, leading to tissue stiffening and disrupted organ function. Lysyl oxidases are key players during this process, as they initiate collagen crosslinking through the oxidation of the ε-amino group of lysine or hydroxylysine on collagen side-chains, which subsequently dimerize to form immature, or trimerize to form mature, collagen crosslinks. The role of LOXL2 in fibrosis and cancer is well documented, however the specific enzymatic function of LOXL2 and LOXL3 during disease is less clear. Herein, we describe the development of PXS-5153A, a novel mechanism based, fast-acting, dual LOXL2/LOXL3 inhibitor, which was used to interrogate the role of these enzymes in models of collagen crosslinking and fibrosis. PXS-5153A dose-dependently reduced LOXL2-mediated collagen oxidation and collagen crosslinking in vitro. In two liver fibrosis models, carbon tetrachloride or streptozotocin/high fat diet-induced, PXS-5153A reduced disease severity and improved liver function by diminishing collagen content and collagen crosslinks. In myocardial infarction, PXS-5153A improved cardiac output. Taken together these results demonstrate that, due to their crucial role in collagen crosslinking, inhibition of the enzymatic activities of LOXL2/LOXL3 represents an innovative therapeutic approach for the treatment of fibrosis.

Androgen receptor regulates cardiac fibrosis in mice with experimental autoimmune myocarditis by increasing microRNA-125b expression.

Cardiac fibrosis is an important cardiac remodeling event in the development of inflammation dilated cardiomyopathy （iDCM）. We have previously observed that degradation enhancer of androgen receptor (ASC-J9®) could improve cardiac inflammation and fibrosis. Using Primary CFs, we demonstrated that ASC-J9® attenuates the expression of miR-125b, which subsequently inhibits the generation of collagen. In contrast, overexpressed AR in CFs induced collagen production, increases mir-125b.We also found that inhibition of miR-125b attenuates fibrosis which induced by the overexpression of AR. Our results indentify the functional role for AR as a regulator of cardiac fibrosis due to myocarditis and further show that AR exerts its effect by increasing microRNA-125b expression. Treatment with degradation enhancer of AR limits cardiac fibrosis in iDCM, thereby providing potentially a therapeutic approach for patients with iDCM.

Captopril mitigates splenomegaly and myelofibrosis in the Gata1low murine model of myelofibrosis.

Allogeneic stem cell transplantation is currently the only curative therapy for primary myelofibrosis (MF), while the JAK2 inhibitor, ruxolitinib. Has been approved only for palliation. Other therapies are desperately needed to reverse life-threatening MF. However, the cell(s) and cytokine(s) that promote MF remain unclear. Several reports have demonstrated that captopril, an inhibitor of angiotensin-converting enzyme that blocks the production of angiotensin II (Ang II), mitigates fibrosis in heart, lung, skin and kidney. Here, we show that captopril can mitigate the development of MF in the Gata1low mouse model of primary MF. Gata1low mice were treated with 79 mg/kg/d captopril in the drinking water from 10 to 12 months of age. At 13 months of age, bone marrows were examined for fibrosis, megakaryocytosis and collagen expression; spleens were examined for megakaryocytosis, splenomegaly and collagen expression. Treatment of Gata1low mice with captopril in the drinking water was associated with normalization of the bone marrow cellularity; reduced reticulin fibres, splenomegaly and megakaryocytosis; and decreased collagen expression. Our findings suggest that treating with the ACE inhibitors captopril has a significant benefit in overcoming pathological changes associated with MF.

N-3 polyunsaturated fatty acids restore Th17 and Treg balance in collagen antibody-induced arthritis.

N-3 polyunsaturated fatty acids (PUFA) have anti-inflammatory effects and were considered useful for the treatment of rheumatoid arthritis (RA). Recently, several studies suggested that n-3 PUFAs attenuated arthritis in animal model and human, however the mechanism is still unclear. Interleukin 17 (IL-17) is a pro-inflammatory cytokine mainly produced by T helper 17 (Th17) cells which cause tissue inflammation and bone erosion leading to joint destruction. In contrast, regulatory T (Treg) cells down-regulate various immune responses by suppression of naïve T cells. The imbalance between Th17 cells and Tregs cell is important for the pathogenesis of RA. Here, we investigated whether n-3 PUFAs attenuate arthritis in collagen antibody-induced arthritis (CAIA) model. We used fat-1 transgenic mice expressing the Caenorhabditis elegans fat-1 gene encoding an n-3 fatty acid desaturase that converts n-6 to n-3 fatty acids, leading to abundant n-3 fatty acids without the need of a dietary n-3 supply. Clinical arthritis score was significantly attenuated in fat-1 mice compared to wild type (WT) mice on day 7 (1.6±1.8, p = 0.012) and day 9 (1.5±1.6, p = 0.003). Ankle thickness also decreased significantly in fat-1 mice compared to WT mice (1.82±0.11, p = 0.008). The pathologic finding showed that inflammatory cell infiltration and bone destruction were reduced in fat-1 mice compared to WT. The expression levels of IL-17 and related cytokines including IL-6 and IL-23 decreased in the spleen and ankle joint tissue of fat-1 mice compared to WT mice. Furthermore, Treg cells were expanded in the spleen of fat-1 mice and Treg cell differentiation was significantly higher in fat-1 mice than in wild type (p = 0.038). These data suggest that n-3 PUFAs could attenuate arthritis through increasing the expression of FoxP3 and the differentiation of Treg, while reducing IL-17 production. Therefore, dietary supplementation of n-3 PUFAs could have a therapeutic potential for the treatment of RA.