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The pathogenesis of idiopathic pulmonary fibrosis (IPF) is quite similar to that of cancer pathogenesis, and several pathways appear to be involved in both disorders. The mammalian target of the rapamycin (mTOR) pathway harbors several established oncogenes and tumor suppressors. The same signaling molecules and growth factors, such as vascular endothelial growth factor (VEGF), contributing to cancer development and progression play a part in fibroblast proliferation, myofibroblast differentiation, and the production of extracellular matrix in IPF development as well. The expression of candidate genes acting upstream and downstream of mTORC1, as well as Vegf and low-density lipoprotein receptor related protein 1(Lrp1), was assessed using specific primers and quantitative polymerase chain reaction (qPCR) within the lung tissues of bleomycin (BLM)-induced IPF mouse models. Lung fibrosis was evaluated by histological examinations and hydroxyproline colorimetric assay. BLM-exposed mice developed lung injuries characterized by inflammatory manifestations and fibrotic features, along with higher levels of collagen and hydroxyproline. Gene expression analyses indicated a significant elevation of regulatory associated protein of mTOR (Raptor), Ras homolog enriched in brain (Rheb), S6 kinase 1, and Eukaryotic translation initiation factor 4E-binding protein 1 (4Ebp1), as well as a significant reduction of Vegfa, Tuberous sclerosis complex (Tsc2), and Lrp1; no changes were observed in the Tsc1 mRNA level. Our findings support the elevation of S6K1 and 4EBP1 in response to the TSC/RHEB/mTORC1 axis, which profoundly encourages the development and establishment of IPF and cancer. In addition, this study suggests a possible preventive role for VEGF-A and LRP1 in the development of IPF.

Idiopathic pulmonary fibrosis (IPF) is among the illnesses with a high mortality rate, yet no specific cause has been identified; as a result, successful treatment has not been achieved. Among the novel approaches for treating such hard-to-cure diseases are induced pluripotent stem cells (IPSCs). Some studies have shown these cells' potential in treating IPF. Therefore, we aimed to investigate the impact of IPSCs on insulin-like growth factor (Igf) signaling as a major contributor to IPF pathogenesis.  C57BL/6 mice were intratracheally instilled with Bleomycin (BLM) or phosphate-buffered saline; the next day, half of the bleomycin group received IPSCs through tail vein injection. Hydroxyproline assay and histologic examinations have been performed to assess lung fibrosis. The gene expression was evaluated using specific primers for Igf-1, Igf-2, and insulin receptor substrate 1 (Irs-1) genes and SYBR green qPCR master mix. The data have been analyzed using the 2-ΔΔCT method. The mice that received Bleomycin showed histological characteristics of the fibrotic lung injury, which was significantly ameliorated after treatment with IPSCs comparable to the control group. Furthermore, gene expression analyses revealed that in the BLM group, Igf1, Igf2, and Irs1 genes were significantly upregulated, which were returned to near-normal levels after treatment with IPSCs. IPSCs could modulate the bleomycin-induced upregulation of Igf1, Igf2, and Irs1 genes. This finding reveals a new aspect of the therapeutic impact of the IPSCs on IPF, which could be translated into other fibrotic disorders.

Systemic sclerosis is a fibrotic autoimmune disease in which aberrant remodeling of the extracellular matrix in organs disturbs their functionalities. The aim of this study was to investigate the expression of gelatinases on systemic sclerosis. Consequently, a mouse model of systemic sclerosis was employed and the gelatinolytic activity of gelatinases was evaluated on the fibrotic tissues of this model. Two groups of ten mice were considered in this work: a group of systemic sclerosis model and control group. For the generation of systemic sclerosis model, mice received bleomycin, while the control group was subjected to phosphate buffered saline (PBS) reception. Mice were tested for fibrosis by using trichrome staining, hydroxyproline measurement and α-SMA detection in tissue sections. Additionally, the gelatinolytic activity of matrix metalloproteinase 2 and matrix metalloproteinase 9 were measured using gelatin zymography in lungs and skin tissue homogenates. The obtained results indicated that subcutaneous injection of bleomycin-induced fibrosis in skin and lung tissues of mice. Pro and active forms of matrix methaloproteinase 9 were increased in fibrotic lung tissues (p<0.05 and p<0.01, respectively), while, the gelatinolytic activity of MMP2 was unaffected in these tissues. Additionally, in skin tissues of bleomycin-treated animals, both pro and active forms of MMP9 and MMP2 were increased (p<0.05). Pro and active forms of gelatinases increase differently in skin and lung tissues of bleomycin-induced scleroderma.

Systemic sclerosis is a female predominant, a fibrotic autoimmune disease in which disturbance in tissue homeostasis and cell turnover including cell apoptosis are central events in pathogenesis. Sex hormones are known as the important players in sexual dimorphism of autoimmune diseases and in tissue homeostasis. Progesterone influences autoimmune disease via its immunomodulatory effect or by its direct action on parenchymal cell function. On the other hand, this hormone impacts tissue homeostasis by acting on cell apoptosis in a different situation. The objective of this study was to examine the effect of progesterone on cellular apoptosis of skin and lung tissues in a mouse model of scleroderma. Four group of mice were involved in this study with 10 mice in each. The fibrotic model was induced by daily subcutaneous injection of bleomycin for 28 days. One week after initiation of fibrosis induction, mice received subcutaneous progesterone alone or with bleomycin for 21 days. Control group received only Phosphate buffered saline PBS. After 28 days, under lethal anesthesia skin and lung tissues were harvested for histological assessment and hydroxyproline measurement. Apoptosis in tissue sections was detected by TUNEL assay technique. Bleomycin administration induced fibrosis in skin and lung tissues. Severe apoptosis was seen in skin and lung tissues of the bleomycin-treated group (p<0.001 in the skin and p<0.05 in the lung). Progesterone injection either in the skin (p>0.05) or in the lung (p>0.05) did not alter apoptosis in bleomycin-treated animals. Our data confirm the role of apoptosis in the pathogenesis of fibrosis in this model; however, progesterone does not affect cellular apoptosis in skin and lung tissues of bleomycin-injured animals.

Gender medicine is a new era of science which focuses on the impact of sex hormones and gender on normal physiology, pathobiology and clinical features of diseases. In this study we investigated the impact of pregnancy doses of progesterone hormone on the expression of a couple of matrix metalloproteinase (MMPs), which are known to be involved in tissue remodeling of lungs in health and disease, namely MMP7 and 13. Pregnancy maintenance dose of progesterone was administered to female BALB/c mice for 21 and 28 days, the control group received PBS for the same days. After removal of the lungs and RNA extraction, quantitative real-time PCR was done using specific primers for MMP7 and MMP13. We found that progesterone can slightly (not significantly) decrease the expression of MMP13 but had no effect on MMP7. Our results shows that progesterone has minimal effect on the expression of matrix metalloproteinase7 and matrix metalloproteinase 13, but it may still have an effect on corresponding tissue inhibitor of matrix metalloproteinases (TIMPs) or other components of the Extracellular matrix  which remains to be elucidated. Also, the effect of progesterone on these MMPs can be further studied in a fibrosis model.

T cell exhaustion is an immunosuppressive mechanism which occurs in chronic viral infections, solid tumors and hematologic malignancies. Exhausted T cell has increased the expression of inhibitory receptors, and functional impairment. In this study, we investigated the expression from some of those inhibitory receptors being Programmed death 1 (PD-1), T cell immunoglobulin and mucin domain containing molecules 3 (TIM-3) and CD244 on T cells from Iranian acute myeloid leukemia (AML) patients. Peripheral blood samples were collected from Iranian newly diagnosed AML patients and flow cytometric analysis was accomplished for cell surface expression of PD-1, TIM-3, and CD244 on T lymphocytes. Functionality and proliferation assay were done in the presence of anti-PD-1 and anti-CD244 blocking antibodies. Immunophenotyping of T cells showed a significant increase of PD-1 and CD244 expression on CD4+ and CD8+ T cells of AML patients. Whereas blockade of PD1 and CD244 increased the proliferation of CD4+ and CD8+ T lymphocytes of AML patients but IFN-γ production was not significantly increased. In conclusion, our data indicate that CD4+ and CD8+ T cells from AML patients appeared to be exhausted and blockade of some immune checkpoints can improve the proliferation of those cells.

Siglec-F (SF) is a surface glycoprotein expressed by mouse eosinophils and induces caspase- and mitochondria-dependent apoptosis after engagement with its cognate ligand or specific antibodies. This targeting eosinophils by monoclonal antibodies may help diverse diseases associated with increased frequency of eosinophils including allergy and asthma. In this paper, production of murine and rat monoclonal antibodies (mAbs) against Siglec-F has been addressed. Balb/c mice were immunized with siglec-F1 (SF1) and siglec-F2 (SF2) synthetic peptides conjugated to a carrier protein. Rats were immunized with Chinese hamster ovary CHO cells overexpressing Siglec-F (CHO-SF) or with Siglec-F-human immunoglobulin FC fusion protein (CHO-SF-Ig). Hybridomas were produced by standard protocol and screened for their reactivity by enzyme-linked immunosorbent assay (ELISA), western blotting (WB), and flow cytometry. In parallel, polyclonal antibodies were generated in New Zealand White rabbits immunized with SF1 and SF2 peptides. Three mouse and three rat mAbs were generated against synthetic peptides and SF-Ig, respectively. All mouse monoclonal and rabbit polyclonal antibodies reacted well with immunizing molecules in ELISA and detected specific band of Siglec-F in WB. However, they failed to detect native molecule in flow cytometry analysis. Quite the contrary, rat mAbs did not reacted with the denatured protein in WB, instead exhibited significant reactivity with CHO-SF cells in flow cytometry. Based on the heavily glycosylated nature of Siglec-F, it seems that generation of anti-SF antibodies able to detect native protein needs a properly folded molecule for immunization. Monoclonal antibodies reported here are invaluable tools for studying linear and conformation epitopes of SF and tracing mouse eosinophils.