CRISPR and gene editing for kidney diseases: where are we?

ABSTRACT

Genome editing technologies, particularly clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9, have transformed biomedical research by enabling precise genetic modifications. Due to its efficiency, cost-effectiveness and versatility, CRISPR has been widely applied across various stages of research, from fundamental biological investigations in preclinical models to potential therapeutic interventions. In nephrology, CRISPR represents a groundbreaking tool for elucidating the molecular mechanisms underlying kidney diseases and developing innovative therapeutic approaches. This review synthesizes the latest advancements in CRISPR-based gene editing within nephrology, highlighting its applications in genetic kidney disorders, polygenic nephropathies and functional genomic studies. Preclinical studies utilizing CRISPR-engineered kidney organoids and animal models have provided crucial insights into disease pathophysiology, offering platforms for drug discovery and precision medicine. Additionally, CRISPR-based functional screens have identified novel disease-associated pathways, particularly in diabetic nephropathy and glomerular disorders. Beyond experimental research, the therapeutic potential of CRISPR in nephrology is emerging, with recent advances in base editing and prime editing demonstrating the feasibility of correcting pathogenic mutations in conditions such as Alport syndrome and autosomal dominant polycystic kidney disease. Moreover, CRISPR plays a pivotal role in xenotransplantation, with gene-edited porcine kidneys addressing key immunological and virological barriers. Despite its promise, clinical translation faces challenges, including delivery efficiency, off-target effects and ethical considerations. This review provides an overview of the current state and future directions of CRISPR-based gene editing in nephrology, underscoring its transformative potential in advancing kidney disease research and therapeutics.

INTRODUCTION

CRISPR technology: how it started

Clustered regularly interspaced short palindromic repeats (CRISPR) were first identified in 1987 by a group of Japanese researchers as repetitive DNA sequences in Escherichia coli [1] (see Box 1 for definitions of technical terms). These DNA sequences were palindromic, meaning they could be read the same backward and forward, ≈30 base pairs (bp) long and separated by spacers that were not palindromic and ≈36 bp long [2, 3]. In 1990, Francisco Mojica, identified the same palindromic repeats in Archaea, discovered that the spacers matched viral DNA and hypothesized the role of these spacers in bacterial immunity against viral infections [4]. Some years later, in 2007, Philippe Horvath proved that CRISPR was a sort of adaptive immune response against viruses [5]. Essentially, it was discovered that CRISPR sequences play a crucial role in microbial adaptive immunity, enabling microbes to recognize and eliminate specific foreign DNA sequences from invading viruses [6, 7]. A gene adjacent to the palindromic repeats is responsible for the cutting. This gene encodes for the Cas9 protein, an endonuclease responsible for cutting viral DNA sequences and protecting the bacteria from infection [8]. Building on these foundational discoveries, Jennifer Doudna and Emmanuelle Charpentier introduced the fully resolved CRISPR-Cas9 system in 2012 [9] by identifying the missing component of this complex system: transactivating CRISPR-RNA (tracrRNA), the RNA sequence that guides the CRISPR system [10]. They later synthesized a single guide RNA sequence (sgRNA) [11] to substitute for tracrRNA. With the complete system composed of palindromic repeats, spacers, sequence encoding for Cas9 and sgRNA, the CRISPR-Cas9 system was later translated into mammalian cells for gene-editing purposes. Gene editing is a process that involves modifying a cell's DNA sequence and its genetic information.

The advent of CRISPR-Cas9 ushered in a transformative era in gene editing [1]. This groundbreaking tool precisely targets DNA sequences with the Cas9 protein, which induces double-stranded DNA breaks, thereby enabling efficient and targeted genomic modifications [12]. Unlike earlier gene-editing technologies such as meganucleases, zinc-finger nucleases and transcription activator-like effector nucleases—which required labour-intensive and costly protein engineering for each target sequence—CRISPR's RNA-guided approach dramatically simplifies the process [13]. By merely altering the sgRNA sequence, researchers can efficiently direct Cas9 to almost any genomic target, akin to programming a Global Positioning System to navigate to a desired destination [13].

CRISPR technology: advantages

Due to its unparalleled precision, efficiency and cost-effectiveness, CRISPR has rapidly become an indispensable tool in biomedical research [1]. Its applications span from preclinical studies involving cell and animal models to its emerging therapeutic potential in clinical practice [14]. When CRISPR induces double-stranded DNA breaks, cells utilize two main pathways for repair: non-homologous end joining (NHEJ) and homologous recombination (HR) [15]. NHEJ, although faster and more prevalent, is error prone and can result in insertions or deletions at the repair site [15]. Conversely, HR is a more precise mechanism, leveraging a DNA template—either naturally present or externally supplied—for accurate repair [15]. HR facilitates the correction of point mutations, deletions and other genetic alterations underlying many diseases. To further enhance its versatility, various CRISPR variants, such as CasMINI and Cas14, have been developed [16–18]. These innovations extend CRISPR's capabilities to include small-target editing and compact delivery systems, broadening the range of applications across diverse fields of research and therapy.

CRISPR-based gene-editing therapies are now transitioning from concept to clinical reality. In 2019, the U.S. Food and Drug Administration (FDA) approved a CRISPR-based cell therapy for sickle cell disease and beta-thalassemia, marking a significant milestone in the field [19–21]. These therapies primarily function by inducing targeted gene disruption through the NHEJ repair mechanism ex vivo, prior to cell administration. In the future, as the technology matures, CRISPR may expand its therapeutic reach to a broader spectrum of diseases, including immune disorders and rare genetic conditions.

In the field of nephrology, CRISPR presents unprecedented opportunities for advancing kidney disease research. By enabling precise genomic modifications, CRISPR offers a powerful tool to elucidate the molecular mechanisms underlying kidney diseases and to develop innovative therapeutic strategies. This review synthesizes the latest evidence on the application of CRISPR-Cas and related gene-editing technologies in nephrology, emphasizing their transformative potential in advancing the diagnosis and treatment of kidney diseases (Fig. 1).

Figure 1:

Schematic diagram of CRISPR gene editing for preclinical and clinical application.

GENE-EDITING APPLICABILITY IN NEPHROLOGY

Therapeutic potential in kidney diseases

Chronic kidney disease (CKD) represents a significant global health challenge, ranking as the ninth leading cause of mortality according to the World Health Organization (WHO) in 2021 [22]. Affecting more than 10% of the global population, the prevalence of CKD is anticipated to increase due to increasing life expectancy and the growing prevalence of chronic comorbidities such as diabetes and hypertension. Kidney diseases span a diverse range of genetic, polygenic and acquired conditions, many of which are associated with well-characterized molecular pathways and genetic alterations [23].

Monogenic kidney diseases

Congenital nephrotic syndrome (CNS) is an example of a group of genetic kidney disorders, presenting early in life with symptoms including massive proteinuria, hypoalbuminaemia, severe oedema and hyperlipidaemia [24]. At least three key pathogenic genes are implicated in CNS: NPHS1 (encoding nephrin), NPHS2 (encoding podocin) and an unidentified gene located in the 11q21-22 region [25]. Furthermore, monogenic kidney disorders such as autosomal dominant polycystic kidney disease (ADPKD), Alport syndrome and nephronophthisis are caused by mutations in genes including PKD1, PKD2, COL4A and NPHP3. Advances in genome-wide association studies (GWAS) and genetic analyses have identified >600 nephropathy-associated genes, providing an invaluable resource for understanding the genetic contributors to kidney diseases [26]. CRISPR-mediated gene editing provides the potential for precise correction of such mutations, offering a promising approach to halt or reverse disease progression.

Polygenic/multifactorial kidney diseases

While diabetes and hypertension remain the most reported causes of CKD, recent sequencing technologies have revealed its polygenic and multifactorial nature [27, 28]. Polygenic nephropathy refers to genetic predispositions influenced by multiple loci and interacting pathways. Key genes such as UMOD (encoding uromodulin), APOL1 (encoding apolipoprotein L1) and HNF1B (encoding hepatocyte nuclear factor 1 beta) have been identified as significant contributors to kidney disease susceptibility [29]. Variants in APOL1, for instance, are strongly linked to an increased risk of focal segmental glomerulosclerosis (FSGS) and hypertensive nephropathy, particularly in individuals of African ancestry [30]. APOL1 risk alleles could conceivably be disrupted using CRISPR-Cas9, as a means of genome-editing therapy. Demonstrating direct links between genetic mutations and their phenotypes requires robust functional experimental studies. CRISPR-Cas systems provide a highly effective platform for such studies, enabling precise gene modifications to investigate molecular pathways underlying kidney disease pathogenesis. This approach not only advances our understanding of disease mechanisms but also identifies potential therapeutic targets, particularly for conditions characterized by inflammation, fibrosis and metabolic dysregulation.

Diagnostic and screening potential in kidney diseases

Beyond the treatment of genetic mutations, CRISPR technology plays a role in gene screening and pathway identification. CRISPR-based functional screens have been instrumental in identifying possible regulatory networks in diabetic nephropathy, providing insights into how hyperglycaemia exacerbates kidney damage. These screens can pinpoint novel mediators of kidney injury, paving the way for the development of new therapeutic interventions. Furthermore, the nephron, comprising specialized cell types such as podocytes, tubular epithelial cells and mesangial cells, highlights the complexity of kidney function and disease. Precision tools like CRISPR are essential for studying the contributions of individual cell types to disease phenotypes. When combined with CRISPR, kidney organoids derived from human induced pluripotent stem cells (PSCs) offer a powerful platform for modelling disease-specific mutations and phenotypes in physiologically relevant contexts. These organoids enable the study of complex kidney diseases, facilitating the identification of molecular mechanisms and the evaluation of potential therapeutic strategies.

Given the multifactorial and multicellular involvement in kidney diseases, alongside their well-defined genetic background, CRISPR and gene-editing technologies present tremendous potential in nephrology. By addressing the genetic and molecular complexities of kidney diseases, CRISPR not only enhances our understanding of pathophysiology but also provides a robust framework for therapeutic development. Its ability to model, investigate and potentially correct disease-causing mutations highlights its transformative role in advancing kidney research and improving clinical outcomes.

PRECLINICAL APPLICATION OF CRISPR-CAS

Functional studies and gene-edited cell lines

GWASs have identified several genes that are associated with kidney diseases. However, in order to validate this association, experimental functional studies are required to prove that the mutation actually causes the disease and how it does so at a molecular level. CRISPR-Cas technology can answer these questions. For instance, it can be used to experimentally knock out or introduce mutations into candidate genes and then compare the phenotype to wild-type controls. Mandai et al. [31] created a knock-in human embryonic kidney cell line with an intronic polymorphism in the STK39 gene that encodes for STE20/SPS-1-related proline/alanine-rich kinase (SPAK) via CRISPR-Cas. This intronic polymorphism was identified through GWASs as one of the susceptibility genes for hypertension, and this association was also confirmed by a meta-analysis, although the biological function of the polymorphism was not determined. Mandai et al. thus demonstrated that by introducing this polymorphism, cells had higher STK39 mRNA and SPAK expression and phosphorylation, leading to an increase in the sodium–potassium–chloride cotransporter (NKCC1) that is mainly expressed in the afferent arteriole's smooth muscle cells and in the outer and inner medullary collecting duct [31, 32]. CRISPR-Cas thus allowed identification of the biochemical function of a disease-associated polymorphism.

Again, Porath et al. [33] generated a GANAB-mutated cell line using CRISPR-Cas9 to prove GANAB gene product involvement in ADPKD. GANAB is a gene that encodes for glucosidase II subunit α (GIIα) and was found to be associated with ADPKD thanks to whole-exome sequencing of unresolved ADPKD cases (ADPKD cases negative for mutations in PKD1 and PKD2) identifying a missense mutation in the gene. Using CRISPR-Cas9 technology, Porath et al. [33] proved that GIIα is necessary for the correct maturation and localization of polycystin 1 and 2 (PC1 and PC2) and therefore contributed to the genetic understanding of ADPKD.

Gene-edited organoids

Organoids are heterocellular structures that mimic bodily tissues and organs to study biology and disease. Human kidney organoids can be derived from induced PSCs. The hallmark of these organoids is the appearance of podocytes, proximal tubules and distal tubules in contiguous segments. In current practice, induced PSCs are typically edited in the undifferentiated state to generate stable cell lines, which are subsequently differentiated into organoids to study the effects of mutations [34, 35].

CRISPR-Cas technology has been instrumental in exploring gene functions and modelling kidney diseases using in vitro kidney organoids [34, 36] (Table 1). Kidney organoids derived from human iPS cells have been used to create genetic disease models. For polycystic kidney disease, introducing loss-of-function mutations in PKD1 and PKD2 via CRISPR-Cas9 produced cysts from kidney tubules upon differentiation, indicating that the pathognomonic disease phenotype could be recapitulated in a simplified system in vitro [34]. Additional studies identified a critical role for microenvironmental factors in cystogenesis as well as glucose absorption in PKD organoid cystogenesis [36, 37]. Cystogenesis could also be introduced via a cytosine base editor to create nonsense mutations [38]. Tubuloids derived from adult kidney also exhibit a cystic phenotype after CRISPR editing to disrupt PKD1 or PKD2 [39].

Table 1:

List of genes that were modified using CRISPR gene editing in preclinical kidney organoid models of disease.

Kidney disease	Target gene	Target cell type	Technical method	Function/phenotype	References
Polycystic kidney	PKD1 or PKD2	Tubule	CRISPR-Cas9 or cytosine base editor knock-out	↑ cystogenesis, ↓ polycystin-1 levels, ↓ ciliary polycystin-2, ↓ ECM compaction	[34, 36, 84, 38]
	PKHD1	Tubule	CRISPR-Cas9 knock-out	↑ cystogenesis	[85]
Nephrotic syndrome	PODXL	Podocyte	CRISPR-Cas9 knock-out	↓ junctional migration, ↓ cell–cell spacing, ↓ microvillus formation	[34, 40]
	NPHS1	Podocyte	CRISPR-Cas9 knock-in	↓ slit diaphragm protein expression/localization	[86]
FSGS	APOL1	Podocyte, endothelial	CRISPR-Cas9 knock-in	Dedifferentiation of podocytes, loss of endothelial cells	[42]
Ciliopathy	KIF3A or KIF3B	Tubule	CRISPR-Cas9 knock-out	↓ nephrogenesis, ↑ cystogenesis	[87]
Fabry syndrome	GLA	Podocyte	CRISPR-Cas9 knock-out	↓ lysosomal aspartylglucosaminidase enzyme activity	[88–90]
Alport syndrome	COL4A3 or COL4A5	Podocyte	CRISPR-Cas9 knock-in, variant correction	Reserve podocyte number	[50]
	COL4A5	Podocyte	CRISPR-Cas9 knock-out	Parietal cell hyperplasia, mesangial sclerosis and interstitial fibrosis	[91]

Additionally, CRISPR-Cas has been used to investigate phenotypes related to podocyte dysfunction and glomerular disease. Knockout of PODXL, encoding podocalyxin, a key protein in podocyte junction organization, resulted in apical diffusion of slit diaphragm proteins within podocyte clusters in organoids [34, 40]. Findings in kidney organoids were validated in mouse models, where podocalyxin-deficient mice succumbed to kidney failure postnatally, aligning with clinical cases of congenital nephrotic syndrome caused by PODXL mutations. One interesting gene target for CRISPR is APOL1, for which human-specific risk variants exist that predispose individuals for glomerular disease [41]. It has been shown that APOL1 can be induced in kidney organoids by treatment with interferon-gamma and is associated with changes in gene expression consistent with dedifferentiation of kidney podocytes, as well as the loss of endothelial cells via pyroptosis [42, 43]. Future work may utilize such systems to develop CRISPR treatments that disrupt APOL1 risk alleles, thus protecting the kidneys from deleterious effects.

Gene-edited animals

Animal models of human diseases are fundamental to advance research and to investigate the underlying pathophysiology of several diseases. Unfortunately, there aren't many animals that mimic human anatomy, physiology and pathology accurately. Currently the two best animal models are mice and rats, with rats being physiologically more similar to humans but more difficult to manipulate genetically than mice.

Besides cell cultures, CRISPR-Cas can be used to create gene-edited animals, not only for a single gene but for multiple genes simultaneously [44]. For example, Xu et al. [45] created a mouse model using CRISPR-Cas to tag the odd-skipped related 1 (Osr1) protein, a protein involved in the early stages of nephrogenesis. Heterozygous mutations are associated with decreased kidney size and function [46], whereas homozygous mutations lead to lethal congenital kidney malformations [47]. Tagging Osr1 through CRISPR-Cas clarified the biological function of Osr1 in the early stage of kidney development [45].

The pathogenic role of APOL1, a gene associated with FSGS in African Americans, was clarified in CRISPR-Cas9-edited zebrafish embryos [48]. Similarly, the link between Sec61 translocon alpha 1 subunit (SEC6A1A) and autosomal dominant tubulointerstitial kidney disease was confirmed in CRISPR-Cas9-edited zebrafish [49].

CLINICAL APPLICATION OF CRISPR-CAS

Potential gene-editing therapy for genetic kidney diseases

Another exciting potential application of CRISPR-Cas and gene-editing technology is the treatment of genetic diseases. These modifications can be done in somatic cells or in germinal cells, the latter ensuring that the modification can be inherited. As a therapeutic approach, it has been reported in preclinical studies for specific genetic kidney diseases such as Alport syndrome. The study conducted by Daga et al. [50] demonstrated a 40% reversion of variants with a small percentage of off-target indels in urine-derived human podocyte lineage–carrying mutations in the X-linked COL4A5 and autosomal COL4A3 gene.

In the previously mentioned study by Vishy et al. [38], the cytosine base editor–related cystogenesis in ADPKD organoids was fully reversed when homozygous mutants were converted to heterozygotes using an adenine base editor, suggesting that partial restoration of gene function may be sufficient to prevent disease progression. Recently, another tool for genetic editing, called adenine base editor (ABE), was successfully used for ADPKD [51] and primary hyperoxaluria type 1 [52]. Wang et al. [51] reported the successful use of ABE to correct PKD1 mutations in human induced PSCs from peripheral blood mononuclear cells (PBMCs) of a heterozygous ADPKD patient. Kidney organoids developed from the corrected cells did not develop cysts upon treatment with forskolin. Lastly, Chen et al. [52] delivered specific ABEs through AAVs in vivo in a mouse model of primary hyperoxaluria type 1, restoring the production of hepatic alanine glyoxylate aminotransferase.

Besides the treatment of genetic diseases, Jerke et al. [53] demonstrated the applicability of CRISPR-Cas9 for autoimmune diseases such as anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis. Interestingly, they showed that introducing a mutation in the gene encoding for proteinase 3 (one of the two main targets of autoimmunity in ANCA-associated vasculitis) in human CD34⁺ haematopoietic stem and progenitor cells, selectively reduced the abundance and activity of the protein. This is a potential breakthrough for ANCA-associated vasculitis and a promising avenue for immunosuppressant-free tolerance induction in autoimmune diseases.

The latest breakthrough involves using CRISPR technology to potentially treat diseases caused by enzymatic deficiencies. A recent article by Musunuru et al. [54] showed promising results for a customized base-editing therapy in a neonate affected by a rare metabolic disorder (carbamoyl-phosphate synthetase 1 deficiency). This opens a new avenue for CRISPR in metabolic nephropathies caused by enzymatic deficiencies such as adenine phosphoribosyltransferase enzyme deficiency, primary hyperoxalurias, Fabry disease or glycogen storage diseases.

Xenotransplantation

Kidney transplantation is the best therapeutic option for most patients with end-stage kidney disease (ESKD). Since the first successful human kidney transplantation [55] performed by Murray in 1954 in Boston, Massachusetts, USA, tremendous improvements have been made from the surgical, immunological and nephrological perspectives to ensure better short- and long-term outcomes, survival and quality of life of kidney transplant recipients [56]. Despite the increasing global incidence of kidney transplantation [57, 58] and the ever-growing transplantation of expanded criteria donor organs [59, 60], demand still exceeds supply. This has forced the medical, surgical and scientific community to look for an alternative, such as xenotransplantation (transplantation of living cells, tissues or organs from one species to another). The domestic pig (Sus scrofa f. domestica) presents a potential source of non-human tissue because it is easy to breed, its litter size is relatively large and its organs are anatomically similar to those of humans [61, 62]. Unsurprisingly, this has raised several immunological, xenozoonosis-related, physiological and ethical concerns. CRISPR technology could serve as an exciting and promising tool to bridge some of these gaps. To obviate the immunological barriers, CRISPR and gene editing can be used to reduce the immunogenicity of porcine kidneys and therefore modulate the recipient's immune response. As previously mentioned, one of the biggest limitations of xenotransplantation is the hyperimmunogenicity of xenografts. This is partly due to the presence of antigens on porcine cells that cause a violent immunological response known as hyperacute rejection (HAR) in the recipient [63, 64]. HAR is a type of humoral rejection mediated by pre-existing recipient antibodies that recognize epitopes expressed on xenograft endothelial cells [65]. This leads to complement activation and destruction of xenograft vascular integrity, with its immediate failure [66]. It normally happens minutes to hours after xenotransplantation. The antigens involved in xenograft HAR include galactose-α1,3-galactose (α-Gal), an epitope synthesized by the α-1,3-galactosyltransferase (GGTA1) enzyme encoded by the porcine GGTA1 gene [67]; cytidine monophospho-N-acetylneuraminic acid hydroxylase (CMAH), encoded by the porcine CMAH gene [68]; and β-1,4-N-acetylgalactosaminyltransferase 2 (β4GalNT2) encoded by the porcine β4GalNT2 gene [69]. CRISPR gene editing has been used to engineer knock-out (KO) pigs for the three surface antigens (GGTA1, CMAH and β4GalNT2) that are involved in HAR, and this has shown decreased immunoreactivity of human antibodies (IgM and IgG) towards KO PBMCs [70]. Gene-editing technology has also been used to reduce the risk of acute humoral rejection (AHR) and acute cellular rejection (ACR). For AHR, gene-editing technology has been used to modify the class I swine major histocompatibility complex (SLA) [71], reduce the toxicity of natural killer cells [72], inhibit complement activity and inhibit macrophage phagocytosis [63]. For ACR, CRISPR-Cas technology has been used to reduce T-lymphocyte activity [73] (although this approach was unsuccessful) and to reduce the expression of both class I and class II [74] SLA molecules. However, there is a need for further preclinical studies.

Another avenue worth exploring to reduce the hyperimmunogenicity of xenografts is the use of CRISPR to harvest human kidneys in pigs. More specifically, this could be possible thanks to a technology called interspecies blastocyst complementation that consists of the injection of PSCs of a species (human, for example) into the blastocyst of another species. This has been previously done in rats and mice for pancreas, heart and eyes, but could be expanded to kidneys [75].

Besides immunogenicity, another problem for pig xenotransplantation is the risk of xenozoonosis, which is the transmission of infectious agents between two species via a xenograft. Porcine endogenous retroviruses are viruses that are integrated into the pig genome and that should be eliminated before xenotransplantation. This could be done via CRISPR [76].

Significant advances have been made over recent years in the clinical use of gene-edited pig kidneys in human recipients, when initial xenotransplants were undertaken in brain dead donors [77–80]. Within the last year, the first genetically edited pig kidney was transplanted into a live human recipient [81, 82] at the Massachusetts General Hospital, Boston, MA, USA. The recipient was a 62-year-old man with ESKD undergoing haemodialysis after previous graft loss with a medical history of type 2 diabetes and hypertension. The recipient had primary graft function, experienced early T cell–mediated rejection, which was treated with augmented immunosuppression, but died with a functioning graft at day 52 post-transplant from a cardiac event.

Future opportunities and challenges

While CRISPR technology offers promising avenues for the treatment of kidney diseases, its clinical translation faces several significant challenges spanning delivery systems, technical limitations, safety, ethics and regulatory frameworks. The structural and functional complexity of the kidney presents unique obstacles for effective delivery systems. Urine-directed delivery leverages the accessibility of the urinary system, with mechanisms such as glomerular filtration aiding in the targeted localization of CRISPR components to kidney cells. This method shows potential for targeting tubular epithelial cells by delivering components directly through the urinary tract. Tubular-specific delivery methods employ molecular carriers or nanoparticles engineered to selectively bind to receptors expressed on tubular cells. Strategies such as ligand-conjugated nanoparticles and kidney-specific promoters are actively being explored to improve delivery efficiency and specificity. While promising, these methods remain in the experimental phase and require further refinement to ensure safety and feasibility in clinical applications.

Similar to other complex biological systems, the diverse cellular architecture of the kidney complicates precise gene editing. Efficiently targeting specific cell populations, addressing repair pathway biases (which favour non-homologous end joining over homologous recombination) and minimizing off-target effects are critical areas requiring optimization. Additionally, maintaining the stability of CRISPR components during systemic delivery and ensuring consistent therapeutic outcomes are key challenges that must be addressed to facilitate the transition from preclinical success to clinical application (Fig. 2).

Figure 2:

CRISPR gene editing range of possible opportunities and challenges in kidney diseases.

CRISPR technology also raises significant concerns in the domains of safety, ethics and regulation. Unintended off-target effects could lead to harmful genetic modifications, while CRISPR-induced cellular stress may impair cell viability or hinder editing success. Some cells may recover from editing but others may undergo apoptosis or senescence, limiting therapeutic efficacy. Ethical concerns include the potential for CRISPR to be used for non-therapeutic human enhancement, such as improving physical or cognitive traits, which could exacerbate social inequities. Germline editing introduces additional risks, such as permanent genetic changes that could affect future generations, raising complex ethical questions. In 2018, an international group of scientists called for a moratorium on germline editing research, underscoring the need for a globally accepted ethical framework. The Somatic Cell Genome Editing Consortium of the National Institutes of Health was also founded in 2018, to improve the technology and assess the biological effects of genome editing [83]. In 2020, Doudna and Charpentier were awarded the Nobel Prize in Chemistry for the invention of CRISPR gene editing. With so much attention being paid to gene editing around the globe, this technology is sure to produce many significant advances in the years to come, including novel gene therapies for kidney disorders.

CONCLUSIONS

In summary, CRISPR-Cas technology is a revolutionary tool for research with a high potential for clinical translation. In nephrology, CRISPR-Cas has mainly been used for preclinical models, whether they be cell lines, gene-edited organoids or animals. These preclinical models shed some light onto the pathophysiology of certain diseases, such as monogenic and polygenic kidney disorders, and helped us understand the intracellular pathways involved. However, during the last decade the clinical application of this technology has expanded. From gene-editing therapies for genetic kidney diseases to induction of tolerance in autoimmune diseases and xenotransplantation, CRISPR technology is already revolutionizing the field of nephrology.

FUNDING

This study is supported by the Ministry of Education of Singapore for AcRF Tier 2 funding (T2EP30221-0013), by the National Institutes of Health (U01AI176460, U2CTR004867) and the Lara Nowak-Macklin Research Fund (to B.S.F.).

AUTHORS’ CONTRIBUTIONS

VDA and FP conceptualized the manuscript. VDA and CH prepared the initial draft. BF supervised the manuscript. All authors contributed to reviewing and editinging.

DATA AVAILABILITY STATEMENT

No new data were generated or analysed in support of this research.

CONFLICT OF INTEREST STATEMENT

VDA received consultancy fees from Allena Pharmaceuticals. FP received honoraria from AstraZeneca, GKS and Otsuka. BSF received support for the present manuscript from NIH. BSF received grants of contracts from Cystinosis Research Foundation, royalties or licences from STEMCELL Technologies and received consulting fees from Plurexa LLC. BSF holds ownership interests in Plurexa and patent from Partners Healthcare. KS, RE, NV and CH have no conflict of interest.