Highly efficient expression of human extracellular superoxide dismutase (rhEcSOD) with ultraviolet‐B‐induced damage‐resistance activity in transgenic silkworm cocoons

Abstract

Extracellular superoxide dismutase (EcSOD) protects tissues from oxidative stress, and thus is considered as a therapeutic agent for many diseases such as atherosclerosis, hypertension, and cancer. However, cost‐effective production of bioactive recombinant human EcSOD (rhEcSOD) remains a challenge. Herein, we developed an efficient strategy for producing active rhEcSOD by transgenic silkworms. rhEcSOD was successfully synthesized as homodimers and homotetramers in the middle silk gland and spun into the cocoons with a concentration of 9.48 ± 0.21 mg/g. Purification of rhEcSOD from the cocoons could be conveniently achieved with a purity of 99.50% and a yield of 3.5 ± 0.5 mg/g. Additionally, N‐glycosylation at the only site of N89 in rhEcSOD with 10 types were identified. The purified rhEcSOD gained the potent enzymatic activity of 4 162 ± 293 U/mg after Cu/Zn ions incorporation. More importantly, rhEcSOD was capable of penetrating and accumulating in the nuclei of cells to maintain cell morphology and attenuate ultraviolet B‐induced cell apoptosis by eliminating reactive oxygen species and inhibiting the C‐Jun N‐terminal kinase signaling pathway. These results demonstrated that the transgenic silkworm could successfully produce rhEcSOD with enzymatic and biological activities for biomedical applications.

Silkworm Cocoon: Dual Functions as a Traditional Chinese Medicine and the Raw Material of Promising Biocompatible Carriers

“…The therapeutic actions of SS and SF are extensive, including antidiabetic effects [6,7], cardioprotective properties [8][9][10], and lipid-lowering capabilities [11]. Concurrently, the ability to modulate inflammatory responses [12][13][14] and resist oxidative stress [15][16][17][18] broadens their application in disease prevention and treatment. Furthermore, the inherent antimicrobial [4,19,20] and antiviral [21] properties of these proteins enhance their effectiveness in developing cutting-edge medical interventions.…”