ALDH1A1 Research Articles

Steric Control in Activator-Induced Nucleophilic Quencher Detachment-Based Probes: High-Contrast Imaging of Aldehyde Dehydrogenase 1A1 in Cancer Stem Cells.

Turn-on fluorescence probes can visualize the enzyme activity with high contrast. We have established a new turn-on mechanism, activator-induced nucleophilic quencher detachment (AiQd), and developed AiQd-based turn-on fluorescence probes for the detection of enzymes. Herein, we demonstrate that the precise steric control efficiently quenches the fluorescence of AiQd-based turn-on probes before the enzymatic transformation. Theoretical calculation appropriately predicted the ratio of the fluorescence-quenched closed-ring form of probes. βC5S-A, which has a sterically demanding methyl group at the β-position of a fluorescence-quenching nucleophilic mercapto group, showed a low background signal. βC5S-A responded to aldehyde dehydrogenase 1A1 (ALDH1A1) with high selectivity, thereby enabling high-contrast live imaging of cancer stem cells (signal-to-noise ratio >10). The ALDH1A1-responsiveness of βC5S-A was not significantly affected by amino acids and biological thiols, such as cysteine and glutathione.

ALDH1A2-related disorder: A new genetic syndrome due to alteration of the retinoic acid pathway.

Aldehyde Dehydrogenase 1, Family Member A2 (ALDH1A2) is essential for the synthesis of retinoic acid from vitamin A. Studies in model organisms demonstrate a critical role for ALDH1A2 in embryonic development, yet few pathogenic variants are linked to congenital anomalies in humans. We present three siblings with multiple congenital anomaly syndrome linked to biallelic sequence variants in ALDH1A2. The major congenital malformations affecting these children include tetralogy of Fallot, absent thymus, diaphragmatic eventration, and talipes equinovarus. Upper airway anomalies, hypocalcemia, and dysmorphic features are newly reported in this manuscript. In vitro functional validation of variants indicated that substitutions reduced the expression of the enzyme. Our clinical and functional data adds to a recent report of biallelic ALDH1A2 pathogenic variants in two families with a similar constellation of congenital malformations. These findings provide further evidence for an autosomal recessive ALDH1A2-deficient recognizable malformation syndrome involving the diaphragm, cardiac and musculoskeletal systems.

Inhibition of YAP/TAZ-driven TEAD activity prevents growth of NF2-null schwannoma and meningioma.

Schwannoma tumours typically arise on the eighth cranial nerve and are mostly caused by loss of the tumour suppressor Merlin (NF2). There are no approved chemotherapies for these tumours and the surgical removal of the tumour carries a high risk of damage to the eighth or other close cranial nerve tissue. New treatments for schwannoma and other NF2-null tumours such as meningioma are urgently required. Using a combination of human primary tumour cells and mouse models of schwannoma, we have examined the role of the Hippo signalling pathway in driving tumour cell growth. Using both genetic ablation of the Hippo effectors YAP and TAZ as well as novel TEAD palmitoylation inhibitors, we show that Hippo signalling may be successfully targeted in vitro and in vivo to both block and, remarkably, regress schwannoma tumour growth. In particular, successful use of TEAD palmitoylation inhibitors in a preclinical mouse model of schwannoma points to their potential future clinical use. We also identify the cancer stem cell marker aldehyde dehydrogenase 1A1 (ALDH1A1) as a Hippo signalling target, driven by the TAZ protein in human and mouse NF2-null schwannoma cells, as well as in NF2-null meningioma cells, and examine the potential future role of this new target in halting schwannoma and meningioma tumour growth.

The astroglial and stem cell functions of adult rat folliculostellate cells.

The mammalian pituitary gland is a complex organ consisting of hormone-producing cells, anterior lobe folliculostellate cells (FSCs), posterior lobe pituicytes, vascular pericytes and endothelial cells, and Sox2-expressing stem cells. We present single-cell RNA sequencing and immunohistofluorescence analyses of pituitary cells of adult female rats with a focus on the transcriptomic profiles of nonhormonal cell types. Samples obtained from whole pituitaries and separated anterior and posterior lobe cells contained all expected pituitary resident cell types and lobe-specific vascular cell subpopulations. FSCs and pituicytes expressed S100B, ALDOC, EAAT1, ALDH1A1, and VIM genes and proteins, as well as other astroglial marker genes, some common and some cell type-specific. We also found that the SOX2 gene and protein were expressed in ~15% of pituitary cells, including FSCs, pituicytes, and a fraction of hormone-producing cells, arguing against its stem cell specificity. FSCs comprised two Sox2-expressing subclusters; FS1 contained more cells but lower genetic diversity, while FS2 contained proliferative cells, shared genes with hormone-producing cells, and expressed genes consistent with stem cell niche formation, regulation of cell proliferation and stem cell pluripotency, including the Hippo and Wnt pathways. FS1 cells were randomly distributed in the anterior and intermediate lobes, while FS2 cells were localized exclusively in the marginal zone between the anterior and intermediate lobes. These data indicate the identity of the FSCs as anterior pituitary-specific astroglia, with FS1 cells representing differentiated cells equipped for classical FSC roles and FS2 cells exhibiting additional stem cell-like features.

Relationship between Aldehyde Dehydrogenase, PD-L1 and Tumor-Infiltrating Lymphocytes with Pathologic Response and Survival in Breast Cancer.

Simple SummaryAldehyde dehydrogenase 1A1 (ALDH1A1) can be used to identify breast cancer stem cells (CSC). Interaction between CSC and the tumor microenvironment might be related to the treatment response, relapse and death. The aim of this retrospective, historical cohort study was to analyze the relationship between ALDH1A1, programmed death ligand 1 (PD-L1) and tumor-infiltrating lymphocytes (TILs), assessed through immunohistochemistry, in triple negative (TN) and human epidermal growth factor receptor 2-positive (HER2+) breast cancer tumors, and its association with clinicopathological characteristics and survival. In this study, tumors with positive ALDH1A1 expression also presented positive PD-L1 expression, higher infiltration of lymphocytes and achieved higher response to treatment. It is crucial to understand the possible implication of these biomarkers on neoadjuvant treatment response in certain subtypes of breast cancer as well as its prognostic role in early and locally advanced breast tumors, as they might be possible targets for promising treatments as immunotherapy.Aldehyde dehydrogenase 1A1 (ALDH1A1) is a cancer stem cell (CSC) marker related to clinical outcomes in breast cancer (BC). The aim of this study was to analyze the relationship between ALDH1A1, programmed death ligand 1 (PD-L1) and tumor-infiltrating lymphocytes (TILs) in triple negative (TN) and human epidermal growth factor receptor 2-positive (HER2+) BC tumors, and its association with clinicopathological characteristics and outcomes. A retrospective, historical cohort study of patients diagnosed with early or locally advanced BC treated with neoadjuvant chemotherapy was conducted. ALDH1A1, PD-L1 expression and TILs were assessed using immunohistochemistry. A total of 75 patients were analyzed (42.7% TN, 57.3% HER2+ tumors). ALDH1A1+ was related to HTILs (p = 0.005) and PD-L1+ tumors (p = 0.004). ALDH1A1+ tumors presented higher CD3+ (p = 0.008), CD4+ (p = 0.005), CD8+ (p = 0.003) and CD20+ (p = 0.006) TILs. ALDH1A1+ (p = 0.018), PD-L1+ (p = 0.004) and HTILs (p < 0.001) were related to smaller tumors. ALDH1A1+ was related to pathologic complete response (pCR) (p = 0.048). At the end of the follow-up (54.4 [38.3–87.6] months), 47 patients (62.7%) remained disease-free, and 20 (26.7%) had died. HTILs were related to improved disease-free survival (p = 0.027). ALDH1A1+ was related to PD-L1+ and HITLs, that might be related to higher pCR rates with neoadjuvant therapy.

Crystal structure of aldehyde dehydrogenase 1A1 from mouse

Aldehyde dehydrogenase 1A1 (ALDH1A1) is an enzyme that catalyzes the NAD+-dependent oxidation of aldehydes to carboxylic acids, participating in various metabolic processes. Currently, only structures from human and Ovis aries have been reported. Here we show a 2.89 Å resolution structure of ALDH1A1 from mice using X-ray crystallography. We performed a detailed analysis of the structure and compared it with ALDH1A1 structures from two other species, highlighting the significance of the differences. Structural superimposition reveals that the tetrameric molecule is asymmetrical, and the NAD+-binding domain exhibits a certain rotation. In addition, the noticeable structural differences were detected, including the unique contact between Ser461 and Asp148, as well as the side chain orientations of three amino acids residues, Asn474, Met471 and Phe466. This study helps to expand the structural diversity of the ALDH family.

Curcumin-based-fluorescent probes targeting ALDH1A3 as a promising tool for glioblastoma precision surgery and early diagnosis

Glioblastoma (GBM) is the most aggressive primary brain tumour for which both effective treatments and efficient tools for an early-stage diagnosis are lacking. Herein, we present curcumin-based fluorescent probes that are able to bind to aldehyde dehydrogenase 1A3 (ALDH1A3), an enzyme overexpressed in glioma stem cells (GSCs) and associated with stemness and invasiveness of GBM. Two compounds are selective versus ALDH1A3, without showing any appreciable interaction with other ALDH1A isoenzymes. Indeed, their fluorescent signal is detectable only in our positive controls in vitro and absent in cells that lack ALDH1A3. Remarkably, in vivo, our Probe selectively accumulate in glioblastoma cells, allowing the identification of the growing tumour mass. The significant specificity of our compounds is the necessary premise for their further development into glioblastoma cells detecting probes to be possibly used during neurosurgical operations.

Atorvastatin inhibits the proliferation of MKN45-derived gastric cancer stem cells in a mevalonate pathway-independent manner.

Gastric cancer stem cells (GCSCs) are a major cause of radioresistance and chemoresistance in gastric cancer (GC). Therefore, targeting GCSCs is regarded as a powerful strategy for the effective treatment of GC. Atorvastatin is a widely prescribed cholesterol-lowering drug that inhibits 3-hydroxy-3-methylglutaryl-coenzyme A reductase, a rate-limiting enzyme in the mevalonate pathway. The anticancer activity of atorvastatin, a repurposed drug, is being investigated; however, its therapeutic effect and molecular mechanism of action against GCSCs remain unknown. In this study, we evaluated the anticancer effects of atorvastatin on MKN45-derived GCSCs. Atorvastatin significantly inhibited the proliferative and tumorsphere-forming abilities of MKN45 GCSCs in a mevalonate pathway-independent manner. Atorvastatin induced cell cycle arrest at the G0/G1 phase and promoted apoptosis by activating the caspase cascade. Furthermore, atorvastatin exerted an antiproliferative effect against MKN45 GCSCs by inhibiting the expression of cancer stemness markers, such as CD133, CD44, integrin α6, aldehyde dehydrogenase 1A1, Oct4, Sox2, and Nanog, through the downregulation of β-catenin, signal transducer and activator of transcription 3, and protein kinase B activities. Additionally, the combined treatment of atorvastatin and sorafenib, a multi-kinase targeted anticancer drug, synergistically suppressed not only the proliferation and tumorsphere formation of MKN45 GCSCs but also the in vivo tumor growth in a chick chorioallantoic membrane model implanted with MKN45 GCSCs. These findings suggest that atorvastatin can therapeutically eliminate GCSCs.

An enzymatic tandem reaction to produce odor-active fatty aldehydes

Aldehydes represent a versatile and favored class of flavoring substances. A biocatalytic access to odor-active aldehydes was developed by conversion of fatty acids with two enzymes of the α-dioxygenase pathway. The recombinant enzymes α-dioxygenase (α-DOX) originating from Crocosphaera subtropica and fatty aldehyde dehydrogenase (FALDH) from Vibrio harveyi were heterologously expressed in E. coli, purified, and applied in a coupled (tandem) repetitive reaction. The concept was optimized in terms of number of reaction cycles and production yields. Up to five cycles and aldehyde yields of up to 26% were achieved. Afterward, the approach was applied to sea buckthorn pulp oil as raw material for the enzyme catalyzed production of flavoring/fragrance ingredients based on complex aldehyde mixtures. The most abundant fatty acids in sea buckthorn pulp oil, namely palmitic, palmitoleic, oleic, and linoleic acid, were used as substrates for further biotransformation experiments. Various aldehydes were identified, semi-quantified, and sensorially characterized by means of headspace–solid phase microextraction–gas chromatography–mass spectrometry–olfactometry (HS–SPME–GC–MS–O). Structural validation of unsaturated aldehydes in terms of double-bond positions was performed by multidimensional high-resolution mass spectrometry experiments of their Paternò–Büchi (PB) photoproducts. Retention indices and odor impressions of inter alia (Z,Z)-5,8-tetradecadienal (Z,Z)-6,9-pentadecadienal, (Z)-8-pentadecenal, (Z)-4-tridecenal, (Z)-6-pentadecenal, and (Z)-8-heptadecenal were determined for the first time.Key points• Coupled reaction of Csα-DOX and VhFALDH yields chain-shortened fatty aldehydes.• Odors of several Z-unsaturated fatty aldehydes are described for the first time.• Potential for industrial production of aldehyde-based odorants from natural sources.Graphical abstract

Inhibitor of Growth 4 (ING4) Plays a Tumor-repressing Role in Oral Squamous Cell Carcinoma via Nuclear Factor Kappa-B (NF-kB)/DNA Methyltransferase 1 (DNMT1) Axis-mediated Regulation of Aldehyde Dehydrogenase 1A2 (ALDH1A2).

Inhibitor of growth 4 (ING4) level was reported to be decreased in head and neck squamous cell carcinoma (HNSC) tissue, however, it is unknown whether and how ING4 participates in regulating the development of oral squamous cell carcinoma (OSCC). This study aimed to investigate the role and mechanism of ING4 in OSCC. ING4 was forced to up- or down-regulated in two OSCC cell lines, and its effects on the malignant behavior of OSCC cells were investigated in vitro. The ubiquitination level of NF-kB p65 in ING4 upregulated cells was measured by co-immunoprecipitation. Moreover, the effects of ING4 on the methylation level of ALDH1A2 were evaluated by methylation-specific polymerase chain reaction (MSP) assay. The role of ING4 in OSCC growth in vivo was observed in nude mice. Our results showed that the expression of ING4 in OSCC cell lines was lower than that in normal oral keratinocyte cells. In vitro, ING4 overexpression inhibited the proliferation, migration, and invasion of OSCC cell lines and ING4 silencing exhibited opposite results. We also demonstrated that ING4 overexpression promoted the ubiquitination and degradation of P65 and reduced DNA methyltransferase 1 (DNMT1) expression and Aldehyde dehydrogenase 1A2 (ALDH1A2) methylation. Moreover, overexpression of p65 rescued the suppression of malignant behavior, induced by ING4 overexpression. In addition, ING4 negatively regulated the growth of OSCC xenograft tumors in vivo. Our data evidenced that ING4 played a tumor-repressing role in OSCC in vivo and in vitro via NF-κB/DNMT1/ALDH1A2 axis.

In Situ-forming Collagen Hydrogels Crosslinked by Multifunctional Polyethylene Glycol as a Matrix Therapy for Corneal Defects: 2-Month Follow-up In Vivo.

We recently showed that in situ-forming collagen gels crosslinked through multifunctional polyethylene glycol (PEG) supported corneal epithelialization 7 days after treatment of lamellar keratectomy wounds. In this study, we aimed to evaluate the longer-term regenerative effects of this gel in animals. Corneal wound healing was assessed 60 days after lamellar keratectomy and gel treatment using slitlamp examination, optical coherence tomography (OCT), pachymetry, corneal topography, an ocular response analyzer, and tonometry. The corneas were evaluated for the presence of beta-tubulin, cytokeratin 3, zonula occludens-1, and alpha smooth muscle actin (SMA) markers. Gene expression of aldehyde dehydrogenase 3A1 (ALDH3A1), cluster of differentiation 31, CD163, alpha-SMA, hepatocyte growth factor, and fibroblast growth factor 2 (FGF-2) and protein expression of CD44 and collagen VI were evaluated. Intraocular pressure, corneal thickness, and hysteresis for the corneas treated with collagen-PEG gels did not significantly change compared with the saline group. However, placido disk topography revealed greater regularity of the central cornea in the gel-treated group compared to the saline group. The gel-treated group exhibited a lower degree of epithelial hyperplasia than the saline group. Immunohistochemical and gene expression analysis showed that the gel-treated corneas exhibited lower alpha-SMA expression compared with the saline group. CD163 and CD44 were found to be elevated in the saline-treated group compared with normal corneas. The in situ-forming collagen-PEG gel promoted epithelialization that improved central corneal topography, epithelial layer morphology, and reduced expression of fibrotic and inflammatory biomarkers after 60 days compared to the saline group.

Ceramide profiling of stratum corneum in Sjögren–Larsson syndrome

BackgroundSjögren–Larsson syndrome (SLS) is a neurocutaneous disorder whose causative gene is the fatty aldehyde dehydrogenase ALDH3A2 and of which ichthyosis is the major skin symptom. The stratum corneum contains a variety of ceramides, among which ω-O-acylceramides (acylceramides) and protein-bound ceramides are essential for skin permeability barrier formation. ObjectivesTo determine the ceramide classes/species responsible for SLS pathogenesis and the enzymes that are impaired in SLS. MethodsGenomic DNA was collected from peripheral blood samples from an SLS patient and her parents, and whole-genome sequencing and Sanger sequencing were performed. Lipids were extracted from stratum corneum samples from the SLS patient and healthy volunteers and subjected to ceramide profiling via liquid chromatography coupled with tandem mass spectrometry. ResultsA duplication (c.55_130dup) and a missense mutation (p.Lys447Glu) were found in the patient’s ALDH3A2 gene. The patient had reduced levels of all acylceramide classes, with total acylceramide levels at 25 % of healthy controls. Reductions were also observed for several nonacylated ceramides: ceramides with phytosphingosine or 6-hydroxysphingosine in the long-chain base moiety were reduced to 24 % and 41 % of control levels, respectively, and ceramides with an α-hydroxy fatty acid as the fatty acid moiety were reduced to 29 %. The fatty acid moiety was shortened in many nonacylated ceramide classes. ConclusionThese results suggest that reduced acylceramide levels are a primary cause of the ichthyosis symptoms of SLS, but reductions in other ceramide classes may also be involved.

Role of Aldehyde Dehydrogenase 3A1 in Cancer Progression

Role of Aldehyde Dehydrogenase 3A1 in Cancer Progression

ALDH6A1 weakens the progression of colon cancer via modulating the RAS/RAF/MEK/ERK pathway in cancer cell lines

BackgroundAldehyde dehydrogenase 6 family member A1 (ALDH6A1) is associated with multiple diseases, but its pathogenesis in colon cancer (CC) is ambiguous and needs further study so that this research explores the function of ALDH6A1 in CC. MethodsThe level of ALDH6A1 in colon adenocarcinoma (COAD), CC tissues, and cells was measured by starBase v2.0, quantitative real-time polymerase chain reaction (qRT-PCR), and western blot. Post transfection with overexpressed (oe)-ALDH6A1, cell biological behaviors, as well as apoptosis-, matrix metalloproteinase (MMP)-, and rat sarcoma virus (RAS)/rapidly accelerated fibrosarcoma (RAF)/mitogen-activated protein kinase (MEK)/extracellular signal-regulated kinase (ERK) pathway-related markers were measured by cell function experiments, qRT-PCR, and western blot. Next, the effects of small interfering RNA targeting ALDH6A1 (si-ALDH6A1) and RAS/RAF inhibitor (MCP110) on cell biological behaviors, as well as apoptosis-, MMP-, and RAS/RAF/MEK/ERK pathway-related markers were detected again. ResultsALDH6A1 was low-expressed in COAD, CC tissues, and cells. Oe-ALDH6A1 weakened cell vitality, migration and invasionbut facilitated apoptosis; while it reduced expression levels of Bcl-2, MMP-2, MMP-9 and the RAS/RAF/MEK/ERK pathway-related markers but promoted Bax level. However, the regulation of si-ALDH6A1 on cell biological behaviors and related genes was opposite to that of oe-ALDH6A1. Moreover, MCP110 rescued the regulation of si-ALDH6A1 on cell biological behaviors, expressions of apoptosis- MMP- as well as RAS/RAF/MEK/ERK pathway-related markers. To sum up, ALDH6A1 attenuated CC progression by down-regulating the expressions of RAS/RAF/MEK/ERK pathway-related markers.

A Novel ALDH1A1 Inhibitor Blocks Platinum-Induced Senescence and Stemness in Ovarian Cancer.

Simple SummaryOvarian cancer is the deadliest amongst the gynecologic malignancies. Most ovarian cancer patients initially respond to chemotherapy but will eventually relapse and become chemoresistant. A specialized subpopulation of cells within the tumor known as cancer stem cells are known to contribute to recurrence and chemoresistance. Ovarian cancer stem cells have a high expression of ALDH1A1, and patients with a high level of ALDH1A1 in their tumor have worse survival. Thus, specifically targeting ALDH1A1 could be an effective strategy to inhibit cancer stemness and disease relapse. We describe the discovery of a novel ALDH1A1 inhibitor called 974 and show that targeting ALDH1A1 with 974 decreases the population of ovarian cancer stem cells. Furthermore, inhibiting ALDH1A1 suppresses chemotherapy-induced senescence and stemness. Collectively, our data demonstrate that targeting ALDH1A1 in cancer stem cells could be an effective strategy to overcome chemotherapy resistance in ovarian cancer.Ovarian cancer is a deadly disease attributed to late-stage detection as well as recurrence and the development of chemoresistance. Ovarian cancer stem cells (OCSCs) are hypothesized to be largely responsible for the emergence of chemoresistant tumors. Although chemotherapy may initially succeed at decreasing the size and number of tumors, it leaves behind residual malignant OCSCs. In this study, we demonstrate that aldehyde dehydrogenase 1A1 (ALDH1A1) is essential for the survival of OCSCs. We identified a first-in-class ALDH1A1 inhibitor, compound 974, and used 974 as a tool to decipher the mechanism of stemness regulation by ALDH1A1. The treatment of OCSCs with 974 significantly inhibited ALDH activity, the expression of stemness genes, and spheroid and colony formation. An in vivo limiting dilution assay demonstrated that 974 significantly inhibited CSC frequency. A transcriptomic sequencing of cells treated with 974 revealed a significant downregulation of genes related to stemness and chemoresistance as well as senescence and the senescence-associated secretory phenotype (SASP). We confirmed that 974 inhibited the senescence and stemness induced by platinum-based chemotherapy in functional assays. Overall, these data establish that ALDH1A1 is essential for OCSC survival and that ALDH1A1 inhibition suppresses chemotherapy-induced senescence and stemness. Targeting ALDH1A1 using small-molecule inhibitors in combination with chemotherapy therefore presents a promising strategy to prevent ovarian cancer recurrence and has the potential for clinical translation.

Efflux capacity and aldehyde dehydrogenase both contribute to CD8+ T-cell resistance to posttransplant cyclophosphamide

AbstractMechanisms of T-cell survival after cytotoxic chemotherapy, including posttransplantation cyclophosphamide (PTCy), are not well understood. Here, we explored the impact of PTCy on human CD8+ T-cell survival and reconstitution, including what cellular pathways drive PTCy resistance. In major histocompatibility complex (MHC)-mismatched mixed lymphocyte culture (MLC), treatment with mafosfamide, an in vitro active cyclophosphamide analog, preserved a relatively normal distribution of naïve and memory CD8+ T cells, whereas the percentages of mucosal-associated invariant T (MAIT) cells and phenotypically stem cell memory (Tscm) T-cell subsets were increased. Activated (CD25+) and proliferating CD8+ T cells were derived from both naïve and memory subsets and were reduced but still present after mafosfamide. By contrast, cyclosporine-A (CsA) or rapamycin treatment preferentially maintained nonproliferating CD25− naïve cells. Drug efflux capacity and aldehyde dehydrogenase-1A1 expression were increased in CD8+ T cells in allogeneic reactions in vitro and in patients, were modulated by common γ-chain cytokines and the proliferative state of the cell, and contributed to CD8+ T-cell survival after mafosfamide. The CD8+ T-cell composition early after hematopoietic cell transplantation (HCT) in PTCy-treated patients was dominated by CD25+ and phenotypically memory, including Tscm and MAIT, cells, consistent with MLC. Yet, MHC-mismatched murine HCT studies revealed that peripherally expanded, phenotypically memory T cells 1 to 3 months after transplant originated largely from naïve-derived rather than memory-derived T cells surviving PTCy, suggesting that initial resistance and subsequent immune reconstitution are distinct. These studies provide insight into the complex immune mechanisms active in CD8+ T-cell survival, differentiation, and reconstitution after cyclophosphamide, with relevance for post-HCT immune recovery, chemotherapy use in autologous settings, and adoptive cellular therapies.

Sjogren- Larsson Syndrome with Type-1 Distal Renal Tubular Acidosis in Siblings

Sjogren-Larsson syndrome (SLS) is a rare autosomal recessive lipid metabolic disorder caused because of the defect in fatty alcohol oxidation resulting from fatty aldehyde dehydrogenase (FALDH3A2) deficiency. Sjogren-Larsson syndrome is constituted by the trio of generalised spastic paralysis, intellectual impairment, &amp; ichthyosis. The inability of hydrogen ions secretion from the distal tubule characterises dRTA (distal (Type 1) renal tubular acidosis). The dRTA aetiology is diverse, but it can be acquired or inherited. We report siblings who presented with congenital ichthyotic hyperkeratosis, spastic diplegia and severe learning disabilities, which were suggestive of SLS. Distal renal tubular acidosis diagnosis was done on the basis of severe serum hypokalaemia, urine electrolytes showing high potassium levels, metabolic acidosis with a positive anion gap, high pH of urine, Urinary &amp; Blood PCO2 difference (UB PCO2) on the lower side, (FeHCO3%) showing mild bicarbonaturia (&lt;5%), medullary nephrocalcinosis, Hypercalciuria as well as the omission of other differential diagnosis. Management in SLS was supportive. The child demonstrated symptomatic improvement after starting standard therapy for SLS &amp; distal renal tubular acidosis. To conclude, distal renal tubular acidosis ailment in children can be controlled with a good long-term prognosis, but precise diagnosis as well as management are critical. Early detection can assist the physician in implementing appropriate supportive care as well as possible curative gene therapy. Keywords: Ichthyosis, spastic diplegia, Intellectual disability, Distal Renal Tubular Acidosis, Hypokalaemia

Persistent γ-H2AX Formation and Expression of Stem Cell Markers in N-Butyl-N-(4-Hydroxybutyl)Nitrosamine-Induced Bladder Carcinogenesis in Rats.

We investigated γ-H2AX formation, a biomarker of DNA damage, and expression of stem cell markers (SCMs), including cytokeratin 14, aldehyde dehydrogenase 1A1 (ALDH1A1), and CD44, in the development of rat bladder tumors induced by short-term administration of N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN). Histopathological examination showed that diffuse simple hyperplasia of the bladder urothelium induced by BBN recovered to the normal-appearing urothelium after withdrawal, whereas focal proliferative lesions were newly developed and subsequently progressed to benign papilloma and carcinoma. Immunohistochemical analysis revealed that BBN-induced γ-H2AX formation and ALDH1A1 and CD44 expression persisted at higher levels in the normal-appearing urothelium than those in the control group for long periods after withdrawal. Since persistent chronic inflammation was observed even after withdrawal, targeted gene expression analysis of inflammation-related factors revealed 101 genes, including Stat3 and Myc, that showed persistent high expression. Pathway analysis suggested that Stat3 and/or Myc activation may be associated with SCM expression. We focused on hepatocyte growth factor (Hgf), one of the genes predicted in relation to Stat3/Myc, and confirmed that HGF-positive cells increased by BBN persisted in the normal-appearing urothelium after withdrawal and colocalized with γ-H2AX and SCMs. These results suggested that the long-term persistence of γ-H2AX formation and SCM expression, which occurred during the early stages of bladder tumorigenesis, is not a transient response to exposure and might contribute to bladder tumorigenesis. Although further studies are needed, BBN-induced rat bladder tumors may originate from focal hyperplasia arising from SCM-positive cells via activation of the STAT3/MYC pathway after DNA damage involving γ-H2AX formation.

Vitamin A supplementation downregulates ADH1C and ALDH1A1 mRNA expression in weaned beef calves.

Our previous studies demonstrated that oral vitamin A supplementation during late-stage pregnancy and the neonatal stage enhances birth weight, growth performance, and mRNA expression related to muscle and preadipocyte development in beef cattle. The alcohol dehydrogenase 1C (ADH1C) c.-64T > C genotype also correlated with vitamin A concentration in beef production. This study aimed to investigate the effects of vitamin A supplementation on the muscle development and vitamin A metabolism in weaned beef calves with different ADH1C genotypes. Twenty male calves (90 d of age; initial BW: 89.03 kg [SD 8.60]) were stratified according to ADH1C genotype and vitamin A treatment (duration: 3 months) and randomly assigned to 4 groups with a 2 × 2 factorial arrangement. Vitamin A treatments included the following: control (10,000 IU/kg of as-fed, a. TT type; b. TC type); treatment (40,000 IU/kg of as-fed, c. TT type; and d. TC type). Parameters including BW, FI, blood, longissimus dorsi muscle, and liver status during the experimental period were analyzed using the generalized linear model (GLM) procedure and Tukey's test by SAS 9.4 program. Serum vitamin A was significantly increased (P < 0.05) in the vitamin A treatment group at 4 and 6 months of age. TT type calves showed higher serum vitamin A concentration (P < 0.05) than the TC type calves. Serum triglyceride and non-esterified fatty acid (NEFA) levels increased (P < 0.05) in the treatment group compared with the control at 6 months of age. However, BW, ADG and FI showed no differences between the groups. In addition, mRNA expression in longissimus dorsi muscle revealed upregulation of paired box 7 (PAX7) (P < 0.05) after the vitamin A treatment period based on biopsy results. Both ADH1C and aldehyde dehydrogenase (ALDH) 1A1 mRNA expression was downregulated (P < 0.01) by vitamin A supplementation. The TC type of ADH1C showed higher mRNA expression than the TT type. However, no effect was observed on adipogenic mRNA expression (preadipocyte factor-1 [PREF-1], peroxisome proliferator-activated receptor gamma [PPARγ], fatty acid binding protein 4 [FABP4]) in all groups. Our findings suggest that weaned calves treated with vitamin A may promote the storage of satellite cells by elevating PAX7 gene expression in the muscle. The TC type calves may show increased capacity for vitamin A metabolism, which can be used in genetically customizing feed management to maximize beef production in the calves.

Abstract 897: Targeting ALDH1A1 and stemness regulatory networks in ovarian cancer

Abstract High grade serous ovarian cancer (HGSOC) is the leading cause of death from gynecologic malignancies. Ovarian cancer stem cells (OCSCs) are hypothesized to contribute to the emergence of chemoresistant tumors. Aldehyde dehydrogenase 1A1 (ALDH1A1) is an intracellular enzyme that oxidizes toxic aldehydes to carboxylic acids and plays a role in controlling cell differentiation pathways. We have previously used ALDH1A1 activity as a functional marker to identify OCSCs and demonstrated that OCSCs persist after chemotherapy and drive recurrent, drug resistant disease. However, the mechanism by which ALDH1A1 maintains stemness phenotype remains poorly understood. To examine the effect of ALDH1A1 on cellular survival signals in OCSCs, we generated a novel ALDH1A1-specific small molecule inhibitor named compound 974. Treatment of HGSOC cell lines with compound 974 reduced ALDH enzyme activity (p&amp;lt;0.01) and inhibited stem-like properties including spheroid formation (p&amp;lt;0.01) and clonogenic survival (p&amp;lt;0.05). Compound 974 treatment inhibited (p&amp;lt;0.01) stemness genes Prom1, Bmi1, Oct4 and Nanog. ALDH1A1 inhibition also reduced (p&amp;lt;0.05) cisplatin IC50 and synergized (p&amp;lt;0.05) with cisplatin treatment. To further examine the effect of compound 974 to inhibit ALDH1A1 and consequently tumor initiation, mice were injected with 106, 105 and 104 OVCAR3 cells treated in vitro with compound 974 (5µM for 48h). In a parallel study, mice were injected with 106, 105 and 104 of ALDH1A1 knockdown or scrambled control cells. In both cases, tumor initiation was significantly delayed compared to the control, and extreme limiting dilution analysis further revealed that compound 974 reduced (p&amp;lt;0.05) CSC frequency compared to control. To better understand the mechanism by which ALDH1A1 maintains OC stemness, OVCAR3 cells treated with vehicle or compound 974 were analyzed by RNA-sequencing and bioinformatics. Transcriptomic analysis revealed that compound 974 significantly (FDR &amp;lt; 0.05, fold change &amp;gt; 2) downregulated expression of markers strongly associated with CSC phenotypes (NF-κB, CD44, Klf4, Sox9, Fzd7) and chemoresistance (ABCB1). Ingenuity Pathway Analysis for downstream regulators of differentially expressed genes revealed that the senescence pathway was significantly altered. Analysis by qRT-PCR revealed that compound 974 inhibited (p&amp;lt;0.01) chemotherapy-induced expression of senescence marker p21 and senescence associated secretory phenotype (SASP) genes including IL6, IL8, CXCL1 and CXCL3. Compound 974 also inhibited(p&amp;lt;0.05) the chemotherapy-induced beta-galactosidase activity. Collectively, our findings further support the functional role for ALDH1A1 in OCSC and reveal a novel role for the enzyme in chemotherapy-induced senescence and disease relapse. Citation Format: Vaishnavi Muralikrishnan, Fang Fang, Tyler C. Given, Ram Podicheti, Douglas B. Rusch, Thomas D. Hurley, Kenneth P. Nephew. Targeting ALDH1A1 and stemness regulatory networks in ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 897.