Transient Expression of Lumbrokinase (PI239) in Tobacco (Nicotiana tabacum) Using a Geminivirus-Based Single Replicon System Dissolves Fibrin and Blood Clots

The potential role of ischaemia-reperfusion injury in chronic, relapsing diseases such as rheumatoid arthritis, Long COVID, and ME/CFS: evidence, mechanisms, and therapeutic implications

Ischaemia-reperfusion (I-R) injury, initiated via bursts of reactive oxygen species produced during the reoxygenation phase following hypoxia, is well known in a variety of acute circumstances. We argue here that I-R injury also underpins elements of the pathology of a variety of chronic, inflammatory diseases, including rheumatoid arthritis, ME/CFS and, our chief focus and most proximally, Long COVID. Ischaemia may be initiated via fibrin amyloid microclot blockage of capillaries, for instance as exercise is started; reperfusion is a necessary corollary when it finishes. We rehearse the mechanistic evidence for these occurrences here, in terms of their manifestation as oxidative stress, hyperinflammation, mast cell activation, the production of marker metabolites and related activities. Such microclot-based phenomena can explain both the breathlessness/fatigue and the post-exertional malaise that may be observed in these conditions, as well as many other observables. The recognition of these processes implies, mechanistically, that therapeutic benefit is potentially to be had from antioxidants, from anti-inflammatories, from iron chelators, and via suitable, safe fibrinolytics, and/or anti-clotting agents. We review the considerable existing evidence that is consistent with this, and with the biochemical mechanisms involved.

Efficacy and safety of lumbrokinase plus aspirin versus aspirin alone for acute ischemic stroke (LUCENT): study protocol for a multicenter randomized controlled trial

Background

Lumbrokinase has been widely used for patients with acute ischemic stroke (AIS) in China; however, because rigorously designed studies are lacking, safety and efficacy of lumbrokinase in the treatment of acute ischemic stroke remains largely unknown. In this multicenter, randomized, and controlled trial, we aim to compare lumbrokinase plus aspirin versus aspirin alone in patients with acute ischemic stroke.

Methods

A total of 220 eligible participants will be randomized to either the intervention or control group with a 1:1 ratio. These participants must be diagnosed with acute ischemic stroke for the first time, whose symptoms appear within 72 h. Their NIHSS score must be greater than 5 and less than 15, and their age must be between 35 and 85 years old. They must have not received intravenous thrombolysis, arterial thrombolysis, or intravascular intervention. Participants in the intervention group will be treated with lumbrokinase plus aspirin for the first 90 days. Participants in the control group will use placebo plus aspirin for the first 90 days. Then, all participants will be treated with aspirin only and followed up for another 90 days (180-day follow-up). The primary outcome is the modified Rankin Scale (mRS) score. The secondary outcomes are National Institutes of Health Stroke Scale (NIHSS) score, Activity of Daily Living (ADL) Scale score, coagulation function, and serum hypersensitive C-reactive protein. The exploratory outcomes are fasting lipid panel, recurrence rate, the occurrence of cardiovascular and cerebrovascular events, and the mortality rate. Safety evaluations include liver function and kidney function, serum fibrinogen, adverse events, serious adverse events, and bleeding events. Adherence of participants will also be assessed.

Discussion

This trial will investigate the efficacy and safety of lumbrokinase plus aspirin as compared to aspirin alone in the treatment of acute ischemic stroke.

Trial registration

Chinese Clinical Trial Registry, ChiCTR2000032952. Registered on May 16, 2020.

Application of Plant Viruses in Biotechnology, Medicine, and Human Health

Plant-based nanotechnology programs using virus-like particles (VLPs) and virus nanoparticles (VNPs) are emerging platforms that are increasingly used for a variety of applications in biotechnology and medicine. Tobacco mosaic virus (TMV) and potato virus X (PVX), by virtue of having high aspect ratios, make ideal platforms for drug delivery. TMV and PVX both possess rod-shaped structures and single-stranded RNA genomes encapsidated by their respective capsid proteins and have shown great promise as drug delivery systems. Cowpea mosaic virus (CPMV) has an icosahedral structure, and thus brings unique benefits as a nanoparticle. The uses of these three plant viruses as either nanostructures or expression vectors for high value pharmaceutical proteins such as vaccines and antibodies are discussed extensively in the following review. In addition, the potential uses of geminiviruses in medical biotechnology are explored. The uses of these expression vectors in plant biotechnology applications are also discussed. Finally, in this review, we project future prospects for plant viruses in the fields of medicine, human health, prophylaxis, and therapy of human diseases.

Transient expression of human serum albumin (HSA) in tobacco leaves

Today, recombinant human proteins make up a considerable part of FDA-approved biotechnological drugs. The selection of proper expression platform for manufacturing recombinant protein is a vital factor in achieving the optimal yield and quality of a biopharmaceutical in a timely fashion. This experiment was aimed to compare the transient expression level of human serum albumin gene in different tobacco genotype. For this, the Agrobacterium tumefaciens strains LB4404 and GV3101 harboring pBI121-HSA binary vector were infiltered in leaves of three tobacco genotypes, including Nicotiana benthamiana and N. tabacum cv Xanthi and Samsun. The qRT-PCR, SDS-PAGE, western blotting and ELISA analysis were performed to evaluate the expression of HSA gene in transgenic plantlets. Our results illustrated that the expression level of rHSA in tobacco leaves was highly dependent on Agrobacterium strains, plant genotypes and harvesting time. The highest production of recombinant HSA protein was obtained in Samsun leaves infected with A. tumefaciens strain GV3101 after 3 days of infiltration.

Transient expression of etanercept therapeutic protein in tobacco (Nicotiana tabacum L.)

Etanercept is a recombinant fusion protein of TNFR2 with the Fc portion of human IgG1. Etanercept, an anti-TNF drug, treats autoimmune diseases and improves patients' health. The main goal of the present study was to investigate the possibility of expressing recombinant protein of etanercept in a plant system. For this aim, first a modified version of pCAMBIA1305.1 plasmid with a new multiple cloning site and signal sequence of KDEL for protein secretion was constructed (pCAMBIA1305.1-linker). Then etanercept gene was cloned into the linker fragment of pCAMBIA1305.1-linker vector. Cloning was confirmed by PCR, enzymatic digestion and sequencing techniques. To evaluate the transient expression of the gene, agroinfiltrated tobacco leaves were inoculated with Agrobacterium tumefaciens containing etanercept gene cassette. The recombinant etanercept protein was examined by dot blot and ELISA assays. Our results using anti-human IgG HRP-conjugated antibody confirmed a high level expression of etanercept gene in the tobacco leaves.