Lupus nephritis (LN), a severe manifestation of systemic lupus erythematosus, poses a substantial risk of progression to end-stage renal disease, with increased mortality. Conventional therapy for LN relies on broad-spectrum immunosuppressants such as glucocorticoids, mycophenolate mofetil, and calcineurin inhibitors. Although therapeutic regimens have evolved over the years, they have inherent limitations, including non-specific targeting, substantial adverse effects, high relapse rates, and prolonged maintenance and remission courses. These drawbacks underscore the need for targeted therapeutic strategies for LN. Recent advancements in our understanding of LN pathogenesis have led to the identification of novel therapeutic targets and the emergence of biological agents and small-molecule inhibitors with improved specificity and reduced toxicity. This review provides an overview of the current evidence on targeted therapies for LN, elucidates the biological mechanisms of responses and failure, highlights the challenges ahead, and outlines strategies for subsequent clinical trials and integrated immunomodulatory approaches.

The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) system, belonging to the type II CRISPR/Cas system, is an effective gene-editing tool widely used in different organisms, but the size of Streptococcus pyogenes Cas9 (SpCas9) is quite large (4.3 kb), which is not convenient for vector delivery. In this study, we used a codon-optimized Staphylococcus aureus Cas9 (SaCas9) system to edit the tyrosinase (tyr), oculocutaneous albinism II (oca2), and paired box 6.1 (pax6.1) genes in the fish model medaka(Oryzias latipes), in which the size of SaCas9 (3.3 kb) is much smaller and the necessary protospacer-adjacent motif (PAM) sequence is 5'-NNGRRT-3'. We also used a transfer RNA (tRNA)‍-single-guide RNA (sgRNA) system to express the functional sgRNA by transcription eitherin vivo or in vitro, and the combination of SaCas9 and tRNA-sgRNA was used to edit the tyr gene in the medaka genome. The SaCas9/sgRNA and SaCas9/tRNA-sgRNA systems were shown to edit the medaka genome effectively, while the PAM sequence is an essential part for the efficiency of editing. Besides, tRNA can improve the flexibility of the system by enabling the sgRNA to be controlled by a common promoter such as cytomegalovirus. Moreover, the all-in-one cassette cytomegalovirus (CMV)‍-SaCas9-tRNA-sgRNA-tRNA is functional in medaka gene editing. Taken together, the codon-optimized SaCas9 system provides an alternative and smaller tool to edit the medaka genome and potentially other fish genomes.
Animals ; Oryzias/genetics* ; Gene Editing/methods* ; CRISPR-Cas Systems ; Codon ; RNA, Guide, CRISPR-Cas Systems/genetics* ; Monophenol Monooxygenase/genetics* ; CRISPR-Associated Protein 9/genetics* ; RNA, Transfer/genetics* ; Staphylococcus aureus/genetics* ; PAX6 Transcription Factor/genetics*

Generation of mutants with clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) is commonly carried out in fish species by co-injecting a mixture of Cas9 messenger RNA (mRNA) or protein and transcribed guide RNA (gRNA). However, the appropriate expression system to produce functional gRNAs in fish embryos and cells is rarely present. In this study, we employed a poly-transfer RNA (tRNA)-gRNA (PTG) system driven by cytomegalovirus (CMV) promoter to target the medaka (Oryzias latipes) endogenous gene tyrosinase(tyr) or paired box 6.1 (pax6.1) and illustrated its function in a medaka cell line and embryos. The PTG system was combined with the CRISPR/Cas9 system under high levels of promoter to successfully induce gene editing in medaka. This is a valuable step forward in potential application of the CRISPR/Cas9 system in medaka and other teleosts.
Animals ; CRISPR-Cas Systems ; Cell Line ; Gene Editing ; Oryzias/genetics* ; RNA, Guide/genetics* ; RNA, Transfer/genetics*