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Background Coronavirus disease 2019 (COVID-19) is an emerged pandemic disease with no specific treatment. One of the potential treatments in newly found infectious disease is plasma exchange (PE) with convalescent plasma transfusion (CPT). This case series aimed to evaluate the primary PE and CPT in five Iranian COVID-19 patients. Methods Five patients with confirmed COVID-19 who had acute respiratory distress syndrome and were supported by mechanical ventilation were treated with two consecutive PE containing fresh frozen plasma (FFP) of healthy donors and 0.9 % saline solution containing 5 % human albumin. Thereafter, CPT was performed just like PE, except that the FFP in this step was substituted with convalescent ABO-matched plasma. Clinical and laboratory factors were evaluated before and after treatments. Results Three to Four patients showed lower body temperature and improved oxygen saturation as well as reduced laboratory factors such as c-reactive protein, lactate dehydrogenase, creatine phosphokinase (total and myocardial isoform), aspartate aminotransferase, blood urea nitrogen, bilirubin (total and direct), D-dimer, interleukin-6, and CD4+/CD8 + T cells ratio initially after PE and continued to improve so that they were discharged. One patient due to secondary hemophagocytic lymphohistiocytosis and extensive lung fungal infection was expired. Discussion Overall, the PE followed by CPT was beneficial in reducing acute inflammation led to a considerable improvement in patients’ clinical features. It seems that PE along with CPT could provide clearance of pro-inflammatory mediators as well as the positive effects of CPT. Controlled studies are required to confirm the effect of PE/CPT compared with other therapeutic approaches.

Aberrant expression and function of microRNAs (miRNAs) in leukemia have added a new layer of complexity to the understanding of development and progression of the disease state. However, their targeting of specific signaling pathways responsible for the maintenance and survival properties of leukemic stem cell (LSC) still remains to be further clarified. Hedgehog (Hh) signaling, a highly conserved developmental pathway, has been proven as a functional pathway for LSCs, and loss of this pathway impairs the development of BCR‐ABL‐induced chronic myeloid leukemia (CML) and depletes CML stem cells. Here, we revealed that upregulation of the Hh smoothened (Smo) signal transducer was associated with reduced expression of miR‐326 in the CD34+ cells from a group of patients with CML at diagnosis. Additionally, overexpression of miR‐326 led to downregulation of Smo, resulted in decreased cell proliferation and elevated rate of apoptosis in CML CD34+ cells. Interestingly, restoration of Smo expression levels reversed the effect of miR‐326 and rescued K562 cells from the antiproliferative effects of this miRNA. Thus, Smo appears to be an essential target of miR‐326 during the pathogenesis of CML. These findings lead us to suggest that downregulation of miR‐326 may be a possible mechanism for unrestricted activation of Smo signal transducer of the oncogenic Hh pathway in CML; therefore, the restoration of miR‐326 expression could be of benefit in eradicating CD34+ CML stem/progenitor cells that represent a potential source of relapse in patients suffering CML.

The sprouting of new blood vessels by angiogenesis is critical in vascular development and homeostasis. Aberrant angiogenesis leads to enormous pathological conditions such as ischemia and cancer. MicroRNAs (also known as miRNAs or miRs) play key roles in regulation of a range of cellular processes by posttranscriptional suppression of their target genes. Recently, new studies have indicated that miRNAs are involved in certain angiogenic settings and signaling pathways use these non-coding RNAs to promote or suppress angiogenic processes. Herein, VEGFR2 and FGFR1 were identified as miR-129-1 and miR-133 targets using bioinformatic algorithms, respectively. Afterwards, using luciferase reporter assay and gene expression analysis at both mRNA and protein levels, VEGFR2 and FGFR1 were validated as miR-129-1 and miR-133 targets. In addition, we showed that miR-129-1 and miR-133 suppress angiogenesis properties such as proliferation rate, cell viability, and migration activity of human umbilical vein endothelial cells (HUVEC) in vitro. We conclude that these miRNAs can suppress key factors of angiogenesis by directly targeting them. These results have important therapeutic implications for a variety of diseases involving deregulation of angiogenesis, including cancer.

We aimed to construct a biodegradable transparent scaffold for culturing corneal endothelial cells by incorporating chitosan nanoparticles (CSNPs) into chitosan/polycaprolactone (PCL) membranes. Various ratios of CSNP/PCL were prepared in the presence of constant concentration of chitosan and the films were constructed by solvent casting method. Scaffold properties including transparency, surface wettability, FTIR, and biocompatibility were examined. SEM imaging, H&E staining, and cell count were performed to investigate the HCECs adhesion. The phenotypic maintenance of the cells during culture was investigated by flow cytometry. Transparency and surface wettability improved by increasing the CSNP/PCL ratio. The CSNP/PCL 50/25, which has the lowest WCA, showed comparable transparency with human acellular corneal stroma. The scaffold was not cytotoxic and promoted the HCECs proliferation as evaluated by MTT assay. Cell counting, flow cytometry, SEM, and H&E results showed appropriate attachment of HCECs to the scaffold which formed a compact monolayer. The developed scaffold seems to be suitable for use in corneal endothelial regeneration in terms of transparency and biocompatibility.