Base editing of the HBG promoter induces potent fetal hemoglobin expression with no detectable off-target mutations in human HSCs.

Reactivating silenced γ-globin expression through the disruption of repressive regulatory domains offers a therapeutic strategy for treating ß-hemoglobinopathies. Here, we used transformer base editor (tBE), a recently developed cytosine base editor with no detectable off-target mutations, to disrupt transcription-factor-binding motifs in hematopoietic stem cells. By performing functional screening of six motifs with tBE, we found that directly disrupting the BCL11A-binding motif in HBG1/2 promoters triggered the highest γ-globin expression. Via a side-by-side comparison with other clinical and preclinical strategies using Cas9 nuclease or conventional BEs (ABE8e and hA3A-BE3), we found that tBE-mediated disruption of the BCL11A-binding motif at the HBG1/2 promoters triggered the highest fetal hemoglobin in healthy and ß-thalassemia patient hematopoietic stem/progenitor cells while exhibiting no detectable DNA or RNA off-target mutations. Durable therapeutic editing by tBE persisted in repopulating hematopoietic stem cells, demonstrating that tBE-mediated editing in HBG1/2 promoters is a safe and effective strategy for treating ß-hemoglobinopathies.

A potential drug combination of omeprazole and patchouli alcohol significantly normalizes oxidative stress and inflammatory responses against gastric ulcer in ethanol-induced rat model.

Omeprazole (OME) is a representative of proton pump inhibitors and widely used in anti-ulcer treatment. However, OME may cause some inevitable side effects and the long-term consequences of OME could increase the risk of diarrhea. Patchouli Alcohol (PA), the main extract of Pogostemonis Herba, have demonstrated benefits in treating gastric ulcer (GU) with low toxicity. The present study aimed to investigate the synergistically protective effects of OME and PA against ethanol-induced GU in rats to study the involvement of antioxidant and anti-inflammatory activities. Moreover, the anti-apoptosis, anti-oxidant and anti-inflammatory effects in H2O2-induced gastric epithelial cells (GES-1) and LPS-induced RAW264.7 cells were determined, as well as the modulation of signaling proteins. The results demonstrated that PA alone or combined with OME provided remarkable benefits by reducing ulcer areas, modulating oxidant stress and inflammatory factors and the therapeutic efficacy was showed to be dose-dependent, which were partly superior to that of high-dose OME only. Additionally, co-treated regimen could superiorly down-regulate cell apoptosis and regulate the levels of oxidant activities and inflammatory cytokines on H2O2-induced GES-1 cells and LPS-induced RAW264.7 cells, which involved with cleaved caspase 3, Bcl-2 and BAX protein expressions and MAPK pathway. We provided a new understanding that the combination of OME and PA possessed gastroprotective effects on modulating cell apoptosis, antioxidant stress and anti-inflammatory responses against GU. Therefore, PA was inferred to take a potential and critic role in gastric mucosa protection.

Yttrium-Catalyzed Intramolecular Hydroalkoxylation/Claisen Rearrangement Sequence: Efficient Synthesis of Medium-Sized Lactams.

An efficient yttrium-catalyzed intramolecular hydroalkoxylation/Claisen rearrangement sequence has been achieved, thus enabling facile access to a diverse array of valuable medium-sized lactams. Furthermore, a mechanistic rationale for this novel cascade reaction is well supported by a variety of control experiments.

Fabrication of three-dimensional porous scaffolds with controlled filament orientation and large pore size via an improved E-jetting technique.

Biodegradable polymeric scaffolds have been widely used in tissue engineering as a platform for cell proliferation and subsequent tissue regeneration. Conventional microextrusion methods for three-dimensional (3D) scaffold fabrication were limited by their low resolution. Electrospinning, a form of electrohydrodynamic (EHD) printing, is an attractive method due to its capability of fabricating high-resolution scaffolds at the nanometer/micrometer scale level. However, the scaffold was composed of randomly orientated filaments which could not guide the cells in a specific direction. Furthermore, the pores of the electrospun scaffold were small, thus preventing cell infiltration. In this study, an alternative EHD jet printing (E-jetting) technique has been developed and employed to fabricate 3D polycaprolactone (PCL) scaffolds with desired filament orientation and pore size. The effect of PCL solution concentration was evaluated. Results showed that solidified filaments were achieved at concentration >70% (w/v). Uniform filaments of diameter 20 µm were produced via the E-jetting technique, and X-ray diffraction and attenuated total reflectance Fourier transform infrared spectroscopic analyses revealed that there was no physicochemical changes toward PCL. Scaffold with a pore size of 450 µm and porosity level of 92%, was achieved. A preliminary in vitro study illustrated that live chondrocytes were attaching on the outer and inner surfaces of collagen-coated E-jetted PCL scaffolds. E-jetted scaffolds increased chondrocytes extracellular matrix secretion, and newly formed matrices from chondrocytes contributed significantly to the mechanical strength of the scaffolds. All these results suggested that E-jetting is an alternative scaffold fabrication technique, which has the capability to construct 3D scaffolds with aligned filaments and large pore sizes for tissue engineering applications.