Heme oxygenase-1: potential therapeutic targets for periodontitis.

Periodontitis is one of the most prevalent inflammatory disease worldwide, which affects 11% of the global population and is a major cause of tooth loss. Recently, oxidative stress (OS) has been found to be the pivital pathophysiological mechanism of periodontitis, and overactivated OS will lead to inflammation, apoptosis, pyroptosis and alveolar bone resorption. Interestingly, heme oxygenase-1 (HO-1), a rate-limiting enzyme in heme degradation, can exert antioxidant activites through its products-carbon monoxide (CO), Fe, biliverdin and bilirubin in the inflammatory microenvironment, thus exhibiting anti-inflammatory, anti-apoptotic, anti-pyroptosis and bone homeostasis-regulating properties.

Genetic and pathogenic characterizations of a naturally occurring reassortant and homologous recombinant strain of the classical infectious bursal disease virus re-emerging in chickens in southern China.

Infectious bursal disease (IBD) classical virus strain (cIBDV) can cause morbidity and mortality in young chickens with severe long-term immunosuppression. However, since the emergence and widespread prevalence of very virulent strain (vvIBDV) in China from 1991, reports of cIBDV have become rare. A novel reassortant and recombinant strain GXYL211225 (genotype A1aB1a) with segment A originating from the classical strain (A1a) and segment B from the attenuated vaccine strain (B1a) was characterized in the study.

Discovery of a cooperative mode of inhibiting RIPK1 kinase.

RIPK1, a death domain-containing kinase, has been recognized as an important therapeutic target for inhibiting apoptosis, necroptosis, and inflammation under pathological conditions. RIPK1 kinase inhibitors have been advanced into clinical studies for the treatment of various human diseases. One of the current bottlenecks in developing RIPK1 inhibitors is to discover new approaches to inhibit this kinase as only limited chemotypes have been developed.

Mechanistic insights into the interactions of NAP1 with the SKICH domains of NDP52 and TAX1BP1.

NDP52 and TAX1BP1, two SKIP carboxyl homology (SKICH) domain-containing autophagy receptors, play crucial roles in selective autophagy. The autophagic functions of NDP52 and TAX1BP1 are regulated by TANK-binding kinase 1 (TBK1), which may associate with them through the adaptor NAP1. However, the molecular mechanism governing the interactions of NAP1 with NDP52 and TAX1BP1, as well as the effects induced by TBK1-mediated phosphorylation of NDP52 and TAX1BP1, remains elusive.

Mechanistic Insights into Recognitions of Ubiquitin and Myosin VI by Autophagy Receptor TAX1BP1.

TAX1BP1, a ubiquitin-binding adaptor, plays critical roles in the innate immunity and selective autophagy. During autophagy, TAX1BP1 may not only function as an autophagy receptor to recruit ubiquitylated substrates for autophagic degradation, but also serve as a Myosin VI cargo adaptor protein for mediating the maturation of autophagosome. However, the mechanistic basis underlying the specific interactions of TAX1BP1 with ubiquitin and Myosin VI remains elusive.

Structural insights into the ubiquitin recognition by OPTN (optineurin) and its regulation by TBK1-mediated phosphorylation.

OPTN (optineurin), a ubiquitin-binding scaffold protein, functions as an important macroautophagy/autophagy receptor in selective autophagy processes. Mutations in OPTN have been linked with human neurodegenerative diseases including ALS and glaucoma. However, the mechanistic basis underlying the recognition of ubiquitin by OPTN and its regulation by TBK1-mediated phosphorylation are still elusive.

Structural Insights into SHARPIN-Mediated Activation of HOIP for the Linear Ubiquitin Chain Assembly.

The linear ubiquitin chain assembly complex (LUBAC) is the sole identified E3 ligase complex that catalyzes the formation of linear ubiquitin chain, and it is composed of HOIP, HOIL-1L, and SHARPIN. The E3 activity of HOIP can be effectively activated by HOIL-1L or SHARPIN, deficiency of which leads to severe immune system disorders. However, the underlying mechanism governing the HOIP-SHARPIN interaction and the SHARPIN-mediated activation of HOIP remains elusive.

Structural insights into the interaction and disease mechanism of neurodegenerative disease-associated optineurin and TBK1 proteins.

Optineurin is an important autophagy receptor involved in several selective autophagy processes, during which its function is regulated by TBK1. Mutations of optineurin and TBK1 are both associated with neurodegenerative diseases. However, the mechanistic basis underlying the specific interaction between optineurin and TBK1 is still elusive.