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Vanichapol, T.

Publications and source records attributed to Vanichapol, T..

5 recordsLinked to original sources

Somites are a source of nephron progenitors in zebrafish

For over a century it has been believed that the vertebrate kidney arises exclusively from the intermediate mesoderm. Here, we overturn this paradigm by demonstrating that some nephrons, the functional units of the kidney, originate from the somites--blocks of paraxial mesoderm best known for their contribution to muscle and connective tissues. Using a combination of the GESTALT technique to assign developmental ancestry, somite transplantation experiments and Cre-lox fate-mapping, we show that somites can contribute to the nephrons in the adult zebrafish kidney. Our findings uncover an unexpected developmental connection between the somites and kidneys, potentially offering new pathways for developing regenerative treatments for kidney diseases.

developmental biology↗

High efficiency organoid-derived cyst cultures as a drug discovery platform for polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) causes the slow, progressive formation of fluid-filled cysts within the kidney that ultimately leads to renal failure. Despite being the most common genetic kidney disease, the range of therapies for ADPKD is limited. Ureteric bud (UB) organoids derived from human pluripotent stem cells (hPSCs) have been used to model ADPKD. Here, we describe a protocol to generate UB organoids in large-scale suspension culture that is amenable to drug discovery. When differentiated from PKD2-deficient hPSCs, the UB organoids robustly form cysts within 7 days and reach nearly 100% cyst efficiency within [~]20 days. Cystic UB organoids express ADPKD markers and are responsive to cyst-reducing compounds, such as the BET inhibitor JQ1 and the NF-{kappa}B inhibitor QNZ, but not tolvaptan. As proof-of-principle of the platform as a drug discovery tool, we screened a small molecule library comprised of nutrient conjugates and identified M1, a palmitate-glucosamine-glycine conjugate, that reduced cyst formation. These results demonstrate that our scalable method of cystic UB organoid production provides a simple and highly efficient platform for ADPKD drug discovery. TRANSLATIONAL STATEMENTAutosomal dominant polycystic kidney disease (ADPKD) affects over 12 million people worldwide, yet the currently available therapy tolvaptan only moderately delays disease progression and is burdened with adverse effects. Improved treatments that are well tolerated and effective are urgently needed. We established a human ureteric bud organoid platform that enables ADPKD-like cysts to be cultured at large scale and low cost. These cystic organoids resemble human ADPKD cysts and are suitable for drug discovery. Identification of the nutrient conjugate M1 as a new lead molecule for reducing cyst formation highlights the clinical relevance of this model.

molecular biology↗

Partial repair causes permanent defects in papillary structure and function after reversal of urinary obstruction

Urinary obstruction causes injury to the renal papilla and leads to defects in the ability to concentrate urine which predisposes to progressive kidney injury. However, the regenerative capacity of the papilla after reversal of obstruction is poorly understood. To address this, we developed a mouse model of reversible urinary obstruction which is characterized by extensive papillary injury, followed by a robust regeneration response and complete histological recovery over a 3- month period. However, these mice have a pronounced defect in urinary concentrating capacity. We now show that this is due to permanent changes in the composition, organization, and transcriptional signatures of epithelial, endothelial, and interstitial cell lineages in the papilla. There are persistent inflammatory responses that are also seen in patients with renal stone disease but are associated with cell-specific adaptive responses to the increasingly hypoxic environment of the papilla after reversal of obstruction. Taken together, our analysis of a new model of reversible urinary obstruction reveals that partial repair leads to permanent changes in the structure and function of all of the major cellular compartments in the papilla that include both shared and distinct responses to different types of renal papillary injury in humans and mice. SummaryPartial repair after reversal of urinary obstruction leads to permanent changes in structure and function of all major cellular compartments in the renal papilla O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=145 SRC="FIGDIR/small/612436v1_ufig1.gif" ALT="Figure 1"> View larger version (57K): org.highwire.dtl.DTLVardef@1438af5org.highwire.dtl.DTLVardef@157ff60org.highwire.dtl.DTLVardef@3f09c0org.highwire.dtl.DTLVardef@9950b1_HPS_FORMAT_FIGEXP M_FIG C_FIG

pathology↗

Inhibition of Retinoic Acid Signaling in Proximal Tubular Epithelial cells Protects against Acute Kidney Injury by Enhancing Kim-1-dependent Efferocytosis

Retinoic acid receptor (RAR) signaling is essential for mammalian kidney development, but in the adult kidney is restricted to occasional collecting duct epithelial cells. We now show there is widespread reactivation of RAR signaling in proximal tubular epithelial cells (PTECs) in human sepsis-associated acute kidney injury (AKI), and in mouse models of AKI. Genetic inhibition of RAR signaling in PTECs protects against experimental AKI but is associated with increased expression of the PTEC injury marker, Kim-1. However, Kim-1 is also expressed by de-differentiated, proliferating PTECs, and protects against injury by increasing apoptotic cell clearance, or efferocytosis. We show that the protective effect of inhibiting PTEC RAR signaling is mediated by increased Kim-1 dependent efferocytosis, and that this is associated with de-differentiation, proliferation, and metabolic reprogramming of PTECs. These data demonstrate a novel functional role that reactivation of RAR signaling plays in regulating PTEC differentiation and function in human and experimental AKI. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=97 SRC="FIGDIR/small/545113v1_ufig1.gif" ALT="Figure 1"> View larger version (18K): org.highwire.dtl.DTLVardef@140ba6borg.highwire.dtl.DTLVardef@8f02f0org.highwire.dtl.DTLVardef@10a123eorg.highwire.dtl.DTLVardef@33b564_HPS_FORMAT_FIGEXP M_FIG C_FIG

pathology↗

AN INTEGRATIVE APPROACH DISCOVERS A NOVEL ANTI-LEUKEMIC PEPTIDE FROM HUMAN MILK

Chemotherapy in childhood leukemia is associated with late morbidity in leukemic survivors, while certain patient subsets are relatively resistant to standard chemotherapy. It is therefore important to identify new agents with sensitivity and selectivity towards leukemic cells, while having less systemic toxicity. Peptide-based therapeutics has gained much attention during the last few years. Here, we used an integrative workflow combining mass spectrometric peptide library construction, in silico anticancer peptide screening, and in vitro leukemic cell studies to discover a novel anti-leukemic peptide having 3+charges and alpha-helical structure, namely HMP-S7, from human breast milk. HMP-S7 showed cytotoxic activity against four distinct leukemic cell lines in a dose-dependent manner but had no effect on solid malignancies or representative normal cells. HMP-S7 induced leukemic cell death by penetrating the plasma membrane to enter the cytoplasm and cause leakage of lactate dehydrogenase, thus acting in a membranolytic manner. Importantly, HMP-S7 exhibited anti-leukemic effect against patient-derived leukemic cells ex vivo. In conclusion, HMP-S7 is a selective anti-leukemic peptide with promise which requires further validation in preclinical and clinical studies. TeaserIn silico screening of naturally occurring human milk peptides discovers a new anticancer peptide that kills leukemic cells in vitro and ex vivo.

pharmacology and toxicology↗