Regenerative Role of Lrig1+ Cells in Kidney Repair.

BACKGROUND: In response to severe kidney injury, the kidney epithelium displays remarkable regenerative capabilities driven by adaptable resident epithelial cells. To date, it has been widely considered that the adult kidney lacks multipotent stem cells; thus, the cellular lineages responsible for repairing proximal tubule damage are incompletely understood. Leucine-rich repeats and immunoglobulin-like domains protein 1-expressing cells (Lrig1+ cells) have been identified as a long-lived cell in various tissues that can induce epithelial tissue repair. Therefore, we hypothesized that Lrig1+ cells participate in kidney development and tissue regeneration. METHODS: We investigated the role of Lrig1+ cells in kidney injury using mouse models. The localization of Lrig1+ cells in the kidney was examined throughout mouse development. The function of Lrig1+ progeny cells in acute kidney injury repair was examined in vivo using a tamoxifen-inducible Lrig1-specific Cre recombinase-based lineage tracing in three different kidney injury mouse models. Additionally, we conducted single-cell RNA-sequencing to characterize the transcriptional signature of Lrig1+ cells and to trace their progeny. RESULTS: Lrig1+ cells were present during kidney development and contributed to formation of the proximal tubule and collecting duct structures in mature mouse kidneys. In three-dimensional culture, single Lrig1+ cells demonstrated long-lasting propagation and differentiated into the proximal tubule and collecting duct lineages. These Lrig1+ proximal tubule cells highly expressed progenitor-like and quiescence-related genes, giving rise to a novel cluster of cells with regenerative potential in adult kidneys. Moreover, these long-lived Lrig1+ cells expanded and repaired damaged proximal tubules in response to three types of acute kidney injury in mice. CONCLUSIONS: These findings highlight the critical role of Lrig1+ cells in kidney regeneration.

PARK2 as a susceptibility factor for nontuberculous mycobacterial pulmonary disease.

BACKGROUND: The genetic signatures associated with the susceptibility to nontuberculous mycobacterial pulmonary disease (NTM-PD) are still unknown. In this study, we performed RNA sequencing to explore gene expression profiles and represent characteristic factor in NTM-PD. METHODS: Peripheral blood samples were collected from patients with NTM-PD and healthy individuals (controls). Differentially expressed genes (DEGs) were identified by RNA sequencing and subjected to functional enrichment and immune cell deconvolution analyses. RESULTS: We enrolled 48 participants, including 26 patients with NTM-PD (median age, 58.0 years; 84.6% female), and 22 healthy controls (median age, 58.5 years; 90.9% female). We identified 21 upregulated and 44 downregulated DEGs in the NTM-PD group compared to those in the control group. NTM infection did not have a significant impact on gene expression in the NTM-PD group compared to the control group, and there were no differences in the proportion of immune cells. However, through gene ontology (GO), gene set enrichment analysis (GSEA), and protein-protein interaction (PPI) analysis, we discovered that PARK2 is a key factor associated with NTM-PD. The PARK2 gene, which is linked to the ubiquitination pathway, was downregulated in the NTM-PD group (fold change, - 1.314, P = 0.047). The expression levels of PARK2 remained unaltered after favorable treatment outcomes, suggesting that the gene is associated with host susceptibility rather than with the outcomes of infection or inflammation. The area under the receiver operating characteristic curve for the PARK2 gene diagnosing NTM-PD was 0.813 (95% confidence interval, 0.694-0.932). CONCLUSION: We identified the genetic signatures associated with NTM-PD in a cohort of Korean patients. The PARK2 gene presents as a potential susceptibility factor in NTM-PD .

Clinical Characteristics and Audiological Profiles of Patients with Pathogenic Variants of WFS1.

Background: Mutations in Wolfram syndrome 1 (WFS1) cause Wolfram syndrome and autosomal dominant non-syndromic hearing loss DFNA6/14/38. To date, more than 300 pathogenic variants of WFS1 have been identified. Generally, the audiological phenotype of Wolfram syndrome or DFNA6/14/38 is characterized by low-frequency hearing loss; however, this phenotype is largely variable. Hence, there is a need to better understand the diversity in audiological and vestibular profiles associated with WFS1 variants, as this can have significant implications for diagnosis and management. This study aims to investigate the clinical characteristics, audiological phenotypes, and vestibular function in patients with DFNA6/14/38. Methods: Whole-exome or targeted deafness gene panel sequencing was performed to confirm the pathogenic variants in patients with genetic hearing loss. Results: We identified nine independent families with affected individuals who carried a heterozygous pathogenic variant of WFS1. The onset of hearing loss varied from the first to the fifth decade. On a pure-tone audiogram, hearing loss was symmetrical, and the severity ranged from mild to severe. Notably, either both low-frequency and high-frequency or all-frequency-specific hearing loss was observed. However, hearing loss was non-progressive in all types. In addition, vestibular impairment was identified in patients with DFNA6/14/38, indicating that impaired WFS1 may also affect the vestibular organs. Conclusions: Diverse audiological and vestibular profiles were observed in patients with pathogenic variants of WFS1. These findings highlight the importance of comprehensive audiological and vestibular assessments in patients with WFS1 mutations for accurate diagnosis and management.

High level of gamma-glutamyltransferase is a possible risk factor for psoriasis: A nationwide population-based cohort study.

Background Gamma-glutamyl transferase (GGT) has been associated with coronary heart disease, diabetes mellitus, and hypertension, but its association with psoriasis has not yet been elucidated. Aims We conducted this study to determine the association between the risk of psoriasis and the serum GGT. Methods We conducted a nationwide population-based study. A total of 9,939,350 people met the enrolment criteria. The study population was classified into four groups based on GGT levels and the risk of psoriasis was calculated for each group. Results The incidence rates of psoriasis per 1,000 person-years were 2.96105 and 3.68577 in the lowest and highest GGT groups, respectively. After adjusting for age, sex, income, diabetes mellitus, hypertension, dyslipidemia, smoking, alcohol intake, exercise, and body mass index, the highest GGT group showed a significantly increased risk of developing psoriasis (hazard ratio: 1.057, 95% confidence interval: 1.044-1.07). This risk of psoriasis was significantly higher among the old age group (hazard ratio: 1.162, 95% confidence interval: 1.128-1.197) and women (hazard ratio: 1.14, 95% confidence interval: 1.117-1.164). Limitations The limitations of this study included the retrospective design, International Classification of Diseases code-based diagnosis, small hazard ratio, and non-availability of data on covariates. Conclusion The GGT level was found to be an independent risk factor for developing psoriasis.

Vestibular hair cells are more prone to damage by excessive acceleration insult in the mouse with KCNQ4 dysfunction.

KCNQ4 is a voltage-gated K+ channel was reported to distribute over the basolateral surface of type 1 vestibular hair cell and/or inner surface of calyx and heminode of the vestibular nerve connected to the type 1 vestibular hair cells of the inner ear. However, the precise localization of KCNQ4 is still controversial and little is known about the vestibular phenotypes caused by KCNQ4 dysfunction or the specific role of KCNQ4 in the vestibular organs. To investigate the role of KCNQ4 in the vestibular organ, 6-g hypergravity stimulation for 24 h, which represents excessive mechanical stimulation of the sensory epithelium, was applied to p.W277S Kcnq4 transgenic mice. KCNQ4 was detected on the inner surface of calyx of the vestibular afferent in transmission electron microscope images with immunogold labelling. Vestibular function decrease was more severe in the Kcnq4p.W277S/p.W277S mice than in the Kcnq4+/+ and Kcnq4+/p.W277S mice after the stimulation. The vestibular function loss was resulted from the loss of type 1 vestibular hair cells, which was possibly caused by increased depolarization duration. Retigabine, a KCNQ activator, prevented hypergravity-induced vestibular dysfunction and hair cell loss. Patients with KCNQ4 mutations also showed abnormal clinical vestibular function tests. These findings suggest that KCNQ4 plays an essential role in calyx and afferent of type 1 vestibular hair cell preserving vestibular function against excessive mechanical stimulation.

Exploring the clinical transition of engineered exosomes designed for intracellular delivery of therapeutic proteins.

Extracellular vesicles, particularly exosomes, have emerged as promising drug delivery systems owing to their unique advantages, such as biocompatibility, immune tolerability, and target specificity. Various engineering strategies have been implemented to harness these innate qualities, with a focus on enhancing the pharmacokinetic and pharmacodynamic properties of exosomes via payload loading and surface engineering for active targeting. This concise review outlines the challenges in the development of exosomes as drug carriers and offers insights into strategies for their effective clinical translation. We also highlight preclinical studies that have successfully employed anti-inflammatory exosomes and suggest future directions for exosome therapeutics. These advancements underscore the potential for integrating exosome-based therapies into clinical practice, heralding promise for future medical interventions.

Reprogramming anchorage dependency to develop cell lines for recombinant protein expression.

As the biopharmaceutical industry continues to mature in its cost-effectiveness and productivity, many companies have begun employing larger-scale biomanufacturing and bioprocessing protocols. While many of these protocols require cells with anchorage-independent growth, it remains challenging to induce the necessary suspension adaptations in many different cell types. In addition, although transfection efficiency is an important consideration for all cells, especially for therapeutic protein production, cells in suspension are generally more difficult to transfect than adherent cells. Thus, much of the biomanufacturing industry is focused on the development of new human cell lines with properties that can support more efficient biopharmaceutical production. With this in mind, we identified a set of "Adherent-to-Suspension Transition" (AST) factors, IKZF1, BTG2 and KLF1, the expression of which induces adherent cells to acquire anchorage-independent growth. Working from the HEK293A cell line, we established 293-AST cells and 293-AST-TetR cells for inducible and reversible reprogramming of anchorage dependency. Surprisingly, we found that the AST-TetR system induces the necessary suspension adaptations with an accompanying increase in transfection efficiency and protein expression rate. Our AST-TetR system therefore represents a novel technological platform for the development of cell lines used for generating therapeutic proteins.

Immune Cells Are Differentially Affected by SARS-CoV-2 Viral Loads in K18-hACE2 Mice.

Viral load and the duration of viral shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are important determinants of the transmission of coronavirus disease 2019. In this study, we examined the effects of viral doses on the lung and spleen of K18-hACE2 transgenic mice by temporal histological and transcriptional analyses. Approximately, 1×105 plaque-forming units (PFU) of SARS-CoV-2 induced strong host responses in the lungs from 2 days post inoculation (dpi) which did not recover until the mice died, whereas responses to the virus were obvious at 5 days, recovering to the basal state by 14 dpi at 1×102 PFU. Further, flow cytometry showed that number of CD8+ T cells continuously increased in 1×102 PFU-virus-infected lungs from 2 dpi, but not in 1×105 PFU-virus-infected lungs. In spleens, responses to the virus were prominent from 2 dpi, and number of B cells was significantly decreased at 1×105 PFU; however, 1×102 PFU of virus induced very weak responses from 2 dpi which recovered by 10 dpi. Although the defense responses returned to normal and the mice survived, lung histology showed evidence of fibrosis, suggesting sequelae of SARS-CoV-2 infection. Our findings indicate that specific effectors of the immune response in the lung and spleen were either increased or depleted in response to doses of SARS-CoV-2. This study demonstrated that the response of local and systemic immune effectors to a viral infection varies with viral dose, which either exacerbates the severity of the infection or accelerates its elimination.

Anchorage Dependence and Cancer Metastasis.

The process of cancer metastasis is dependent on the cancer cells' capacity to detach from the primary tumor, endure in a suspended state, and establish colonies in other locations. Anchorage dependence, which refers to the cells' reliance on attachment to the extracellular matrix (ECM), is a critical determinant of cellular shape, dynamics, behavior, and, ultimately, cell fate in nonmalignant and cancer cells. Anchorage-independent growth is a characteristic feature of cells resistant to anoikis, a programmed cell death process triggered by detachment from the ECM. This ability to grow and survive without attachment to a substrate is a crucial stage in the progression of metastasis. The recently discovered phenomenon named "adherent-to-suspension transition (AST)" alters the requirement for anchoring and enhances survival in a suspended state. AST is controlled by four transcription factors (IKAROS family zinc finger 1, nuclear factor erythroid 2, BTG anti-proliferation factor 2, and interferon regulatory factor 8) and can detach cells without undergoing the typical epithelial-mesenchymal transition. Notably, AST factors are highly expressed in circulating tumor cells compared to their attached counterparts, indicating their crucial role in the spread of cancer. Crucially, the suppression of AST substantially reduces metastasis while sparing primary tumors. These findings open up possibilities for developing targeted therapies that inhibit metastasis and emphasize the importance of AST, leading to a fundamental change in our comprehension of how cancer spreads.

Characterization of Vestibular Phenotypes in Patients with Genetic Hearing Loss.

Background: The vestibular phenotypes of patients with genetic hearing loss are poorly understood. Methods: we performed genetic testing including exome sequencing and vestibular function tests to investigate vestibular phenotypes and functions in patients with genetic hearing loss. Results: Among 627 patients, 143 (22.8%) had vestibular symptoms. Genetic variations were confirmed in 45 (31.5%) of the 143 patients. Nineteen deafness genes were linked with vestibular symptoms; the most frequent genes in autosomal dominant and recessive individuals were COCH and SLC26A4, respectively. Vestibular symptoms were mostly of the vertigo type, recurrent, and persisted for hours in the genetically confirmed and unconfirmed groups. Decreased vestibular function in the caloric test, video head impulse test, cervical vestibular-evoked myogenic potential, and ocular vestibular-evoked myogenic potential was observed in 42.0%, 16.3%, 57.8%, and 85.0% of the patients, respectively. The caloric test revealed a significantly higher incidence of abnormal results in autosomal recessive individuals than in autosomal dominant individuals (p = 0.011). The genes, including SLC26A4, COCH, KCNQ4, MYH9, NLRP3, EYA4, MYO7A, MYO15A, and MYH9, were heterogeneously associated with abnormalities in the vestibular function test. Conclusions: In conclusion, diverse vestibular symptoms are commonly concomitant with genetic hearing loss and are easily overlooked.

Prevalence and Clinical Characteristics of Mitochondrial DNA Mutations in Korean Patients With Sensorineural Hearing Loss.

BACKGROUND: Mutations in mitochondrial DNA (mtDNA) are associated with several genetic disorders, including sensorineural hearing loss. However, the prevalence of mtDNA mutations in a large cohort of Korean patients with hearing loss has not yet been investigated. Thus, this study aimed to investigate the frequency of mtDNA mutations in a cohort of with pre- or post-lingual hearing loss of varying severity. METHODS: A total of 711 Korean families involving 1,099 individuals were evaluated. Six mitochondrial variants associated with deafness (MTRNR1 m.1555A>G, MTTL1 m.3243A>G, MTCO1 m.7444G>A and m.7445A>G, and MTTS1 m.7471dupC and m.7511T>C) were screened using restriction fragment length polymorphism. The prevalence of the six variants was also analyzed in a large control dataset using whole-genome sequencing data from 4,534 Korean individuals with unknown hearing phenotype. RESULTS: Overall, 12 of the 711 (1.7%) patients with hearing loss had mtDNA variants, with 10 patients from independent families positive for the MTRNR1 m.1555A>G mutation and 2 patients positive for the MTCO1 m.7444G>A mutation. The clinical characteristics of patients with the mtDNA variants were characterized by post-lingual progressive hearing loss due to the m.1555A>G variant (9 of 472; 1.9%). In addition, 18/4,534 (0.4%) of the Korean population have mitochondrial variants associated with hearing loss, predominantly the m.1555A>G variant. CONCLUSION: A significant proportion of Korean patients with hearing loss is affected by the mtDNA variants, with the m.1555A>G variant being the most prevalent. These results clarify the genetic basis of hearing loss in the Korean population and emphasize the need for genetic testing for mtDNA variants.

Lactobacillus plantarum ameliorates NASH-related inflammation by upregulating L-arginine production.

Lactobacillus is a probiotic with therapeutic potential for several diseases, including liver disease. However, the therapeutic effect of L. plantarum against nonalcoholic steatohepatitis (NASH) and its underlying mechanisms remain unelucidated. Therefore, we delineated the L. plantarum-mediated NASH regulation in a mouse model to understand its therapeutic effect. We used a choline-deficient high-fat diet (CD-HFD)-induced murine model that recapitulated the critical features of human metabolic syndrome and investigated the effect of L. plantarum on NASH pathogenesis using transcriptomic, metagenomic, and immunohistochemistry analyses. Validation experiments were performed using liver organoids and a murine model fed a methionine-choline-deficient (MCD) diet. L. plantarum treatment in mice significantly decreased liver inflammation and improved metabolic phenotypes, such as insulin tolerance and the hepatic lipid content, compared with those in the vehicle group. RNA-sequencing analysis revealed that L. plantarum treatment significantly downregulated inflammation-related pathways. Shotgun metagenomic analysis revealed that L-arginine biosynthesis-related microbial genes were significantly upregulated in the L. plantarum group. We also confirmed the elevated arginine levels in the serum of the L. plantarum group. We further used liver organoids and mice fed an MCD diet to demonstrate that L-arginine alone was sufficient to alleviate liver inflammation. Our data revealed a novel and counterintuitive therapeutic effect of L. plantarum on alleviating NASH-related liver inflammation by increasing circulating L-arginine.

Prostaglandin F2α analogue, bimatoprost ameliorates colistin-induced nephrotoxicity.

Colistin (polymyxin E) is an antibiotic that is effective against multidrug-resistant gram-negative bacteria. However, the high incidence of nephrotoxicity caused by colistin limits its clinical use. To identify compounds that might ameliorate colistin-induced nephrotoxicity, we obtained 1707 compounds from the Korea Chemical Bank and used a high-content screening (HCS) imaging-based assay. In this way, we found that bimatoprost (one of prostaglandin F2α analogue) ameliorated colistin-induced nephrotoxicity. To further assess the effects of bimatoprost on colistin-induced nephrotoxicity, we used in vitro and in vivo models. In cultured human proximal tubular cells (HK-2), colistin induced dose-dependent cytotoxicity. The number of terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL)-positive cells, indicative of apoptosis, was higher in colistin-treated cells, but this effect of colistin was ameliorated by cotreatment with bimatoprost. The generation of reactive oxygen species, assessed using 2,7-dichlorodihydrofluorescein diacetate, was less marked in cells treated with both colistin and bimatoprost than in those treated with colistin alone. Female C57BL/6 mice (n = 10 per group) that were intraperitoneally injected with colistin (10 mg/kg/12 hr) for 14 days showed high blood urea nitrogen and serum creatinine concentrations that were reduced by the coadministration of bimatoprost (0.5 mg/kg/12 hr). In addition, kidney injury molecule-1 (KIM1) and Neutrophil gelatinase-associated lipocalin (NGAL) expression also reduced by bimatoprost administration. Further investigation in tubuloid and kidney organoids also showed that bimatoprost attenuated the nephrotoxicity by colistin, showing dose-dependent reducing effect of KIM1 expression. In this study, we have identified bimatoprost, prostaglandin F2α analogue as a drug that ameliorates colistin-induced nephrotoxicity.

Targeting FLT3-TAZ signaling to suppress drug resistance in blast phase chronic myeloid leukemia.

BACKGROUND: Although the development of BCR::ABL1 tyrosine kinase inhibitors (TKIs) rendered chronic myeloid leukemia (CML) a manageable condition, acquisition of drug resistance during blast phase (BP) progression remains a critical challenge. Here, we reposition FLT3, one of the most frequently mutated drivers of acute myeloid leukemia (AML), as a prognostic marker and therapeutic target of BP-CML. METHODS: We generated FLT3 expressing BCR::ABL1 TKI-resistant CML cells and enrolled phase-specific CML patient cohort to obtain unpaired and paired serial specimens and verify the role of FLT3 signaling in BP-CML patients. We performed multi-omics approaches in animal and patient studies to demonstrate the clinical feasibility of FLT3 as a viable target of BP-CML by establishing the (1) molecular mechanisms of FLT3-driven drug resistance, (2) diagnostic methods of FLT3 protein expression and localization, (3) association between FLT3 signaling and CML prognosis, and (4) therapeutic strategies to tackle FLT3+ CML patients. RESULTS: We reposition the significance of FLT3 in the acquisition of drug resistance in BP-CML, thereby, newly classify a FLT3+ BP-CML subgroup. Mechanistically, FLT3 expression in CML cells activated the FLT3-JAK-STAT3-TAZ-TEAD-CD36 signaling pathway, which conferred resistance to a wide range of BCR::ABL1 TKIs that was independent of recurrent BCR::ABL1 mutations. Notably, FLT3+ BP-CML patients had significantly less favorable prognosis than FLT3- patients. Remarkably, we demonstrate that repurposing FLT3 inhibitors combined with BCR::ABL1 targeted therapies or the single treatment with ponatinib alone can overcome drug resistance and promote BP-CML cell death in patient-derived FLT3+ BCR::ABL1 cells and mouse xenograft models. CONCLUSION: Here, we reposition FLT3 as a critical determinant of CML progression via FLT3-JAK-STAT3-TAZ-TEAD-CD36 signaling pathway that promotes TKI resistance and predicts worse prognosis in BP-CML patients. Our findings open novel therapeutic opportunities that exploit the undescribed link between distinct types of malignancies.

Increased Risk of Renal Malignancy in Patients with Moderate to Severe Atopic Dermatitis.

BACKGROUND: Evidence for an association between atopic dermatitis (AD) and cancer is still insufficient. In particular, the association between the risk of renal malignancy and the severity of AD has not been thoroughly investigated. OBJECTIVE: To investigate the risk of renal malignancy and determine the association between AD severity and cancer risk using data from the Korean National Health Insurance Service (KNHIS) database. METHODS: We performed a population-based cohort study using the National Health Claims database from the NHIS in Korea. RESULTS: We found a statistically significant association between AD and overall malignancy (for mild AD, hazard ratio (HR): 1.061, 95% confidence interval (CI): 1.006-1.118; for moderate to severe AD, HR: 1.061, 95% CI: 1.014-1.11) compared with the no AD group. The moderate to severe AD group showed a significantly increased risk for renal malignancy (adjusted HR: 1.533, 95% CI: 1.209-1.944) compared with the no AD group. LIMITATIONS: Patient inclusion is solely based on diagnostic codes. We had no data about drug use, genetic factors, or other medical history that could affect the cancer risk. CONCLUSION: In our large population-based cohort study, moderate to severe AD was associated with increased risk of renal malignancy. Regular check-ups for renal malignancy are recommended in this population.

Novel Variant in CEP250 Causes Protein Mislocalization and Leads to Nonsyndromic Autosomal Recessive Type of Progressive Hearing Loss.

Genetic hearing loss is the most common hereditary sensorial disorder. Though more than 120 genes associated with deafness have been identified, unveiled causative genes and variants of diverse types of hearing loss remain. Herein, we identified a novel nonsense homozygous variant in CEP250 (c.3511C>T; p.Gln1171Ter) among the family members with progressive moderate sensorineural hearing loss in nonsyndromic autosomal recessive type but without retinal degeneration. CEP250 encodes C-Nap1 protein belonging to the CEP protein family, comprising 30 proteins that play roles in centrosome aggregation and cell cycle progression. The nonsense variant in CEP250 led to the early truncating protein of C-Nap1, which hindered centrosome localization; heterologous expression of CEP250 (c.3511C>T) in NIH3T3 cells within cilia expression condition revealed that the truncating C-Nap1 (p.Gln1171Ter) was not localized at the centrosome but was dispersed in the cytosol. In the murine adult cochlea, Cep250 was expressed in the inner and outer hair cells. Knockout mice of Cep250 showed significant hair cell degeneration and progressive hearing loss in auditory brainstem response. In conclusion, a nonsense variant in CEP250 results in a deficit of centrosome localization and hair cell degeneration in the cochlea, which is associated with the progression of hearing loss in humans and mice.

LRRC6 regulates biogenesis of motile cilia by aiding FOXJ1 translocation into the nucleus.

BACKGROUND: LRRC6 is an assembly factor for dynein arms in the cytoplasm of motile ciliated cells, and when mutated, dynein arm components remained in the cytoplasm. Here, we demonstrate the role of LRRC6 in the active nuclear translocation of FOXJ1, a master regulator for cilia-associated gene transcription. METHODS: We generated Lrrc6 knockout (KO) mice, and we investigated the role of LRRC6 on ciliopathy development by using proteomic, transcriptomic, and immunofluorescence analysis. Experiments on mouse basal cell organoids confirmed the biological relevance of our findings. RESULTS: The absence of LRRC6 in multi-ciliated cells hinders the assembly of ODA and IDA components of cilia; in this study, we showed that the overall expression of proteins related to cilia decreased as well. Expression of cilia-related transcripts, specifically ODA and IDA components, dynein axonemal assembly factors, radial spokes, and central apparatus was lower in Lrrc6 KO mice than in wild-type mice. We demonstrated that FOXJ1 was present in the cytoplasm and translocated into the nucleus when LRRC6 was expressed and that this process was blocked by INI-43, an importin α inhibitor. CONCLUSIONS: Taken together, these results hinted at the LRRC6 transcriptional regulation of cilia-related genes via the nuclear translocation of FOXJ1. Video Abstract.

Disease modeling of ADAMTS9-related nephropathy using kidney organoids reveals its roles in tubular cells and podocytes.

Introduction: Mutations in ADAMTS9 cause nephronophthisis-related ciliopathies (NPHP-RC), which are characterized by multiple developmental defects and kidney diseases. Patients with NPHP-RC usually have normal glomeruli and negligible or no proteinuria. Herein, we identified novel compound-heterozygous ADAMTS9 variants in two siblings with NPHP-RC who had glomerular manifestations, including proteinuria. Methods: To investigate whether ADAMTS9 dysfunction causes NPHP and glomerulopathy, we differentiated ADAMTS9 knockout human induced pluripotent stem cells (hiPSCs) into kidney organoids. Single-cell RNA sequencing was utilized to elucidate the gene expression profiles from the ADAMTS9 knockout kidney organoids. Results: ADAMTS9 knockout had no effect on nephron differentiation; however, it reduced the number of primary cilia, thereby recapitulating renal ciliopathy. Single-cell transcriptomics revealed that podocyte clusters express the highest levels of ADAMTS9, followed by the proximal tubules. Loss of ADAMTS9 increased the activity of multiple signaling pathways, including the Wnt/PCP signaling pathway, in podocyte clusters. Conclusions: Mutations in ADMATS9 cause a glomerulotubular nephropathy in kidney and our study provides insights into the functional roles of ADMATS9 in glomeruli and tubules.