Efficient bioremediation of multiple steroid hormones by halotolerant 17ß-hydroxysteroid dehydrogenase derived from moderately halophilic Pontibacillus chungwhensis HN14.

Steroid hormones exhibit potent endocrine disrupting activity and have been shown to disrupt the equilibrium of aquatic ecosystems and pose a threat to public health through their persistent and carcinogenic effects. Pontibacillus chungwhensis HN14, a moderately halophilic bacterium with the capacity to effectively degrade various polycyclic aromatic hydrocarbons and other organic pollutants, was previously isolated. Additionally, the strain HN14 showed strong environmental adaptability under various environmental stress conditions. In this study, the steroid degradation by strain HN14 was studied for the first time. We demonstrated that strain HN14 could degrade estradiol (E2) to maintain the growth of the strain and could convert E2 to estrone. Additionally, the efficient substrate degradation efficiency of P. chungwhensis HN14 under high salinity and high substrate concentration conditions was demonstrated. Furthermore, a 17ß-hydroxysteroid dehydrogenase, 17ß-HSD(HN14), was identified in strain HN14. Comparative analysis reveals that 17ß-HSD(HN14) shares approximately 38% sequence identity with 17ß-HSDx from Rhodococcus sp. P14. In addition, 100 µg of purified 17ß-HSD(HN14) could effectively convert about 40% of 0.25 mM of E2 within 1 h period, with an enzyme activity of 17.5 U/mg, and catalyze the dehydrogenation of E2 and testosterone at the C-17 position. The characterization of purified enzyme properties reveals that 17ß-HSD(HN14) exhibits exceptional structural robustness and enzymatic efficacy even under high salinity conditions of up to 20%. Overall, this study enhances our comprehension of steroid biodegradation in strain HN14 and contributes novel ideas and theoretical underpinnings for advancing bioremediation technologies targeting steroid pollution in high-saline environments.

Expression and purification of active human 17ß-Hydroxysteroid dehydrogenase type 1 from Escherichia coli.

Breast cancer cell growth is often dependent on the presence of steroidal hormones. The 17ß-hydroxysteroid dehydrogenase type 1 isoform (17ßHSD1) catalyzes NADPH-dependent conversion of estrone to estradiol, a more potent estrogen, and represents potential drug target for breast cancer treatment.  To provide active enzyme for inhibitor screening, 17ßHSD1 is usually expressed in insect or mammalian cells, or isolated from human placenta. In the present study we describe a simple protocol for expression and purification of active human 17ßHSD1 from BL21(DE3) Escherichia coli cells. Soluble human 17ßHSD1 was expressed using a pET28a(+)-based plasmid, which encodes a hexahistidine tag fused to the N-terminus of the protein, and purified by nickel affinity chromatography. The enzyme activity of purified 17ßHSD1 was verified by three methods: thin-layer chromatography, an alkali assay and a spectroscopic assay. These non-radioactive enzyme assays require only standard laboratory equipment, and can be used for screening compounds that modulate 17ßHSD1 activity.

Does Genetic Variation in PNPLA3, TM6SF2 and HSD17B13 have a Role in the Development or Prognosis of Hepatocellular Carcinoma in Turkish Patients with Hepatitis B?

BACKGROUND AND AIMS: Progression to hepatocellular carcinoma (HCC) is restricted by viral suppression in chronic hepatitis B (CHB); however, some patients still progress despite antiviral therapy. Presence of single nucleotide polymorphisms (SNPs) such as PNPLA3 rs738409 and TM6SF2 rs58542926 are associated with the development and progression of steatotic liver disease to HCC, whereas a splice variant in HSD17B13 rs72613567:TA has been shown to be protective. We investigated the role of these SNPs in the development or prognosis of HCC in pure CHB etiology, in the absence of hepatic steatosis, remains unknown. MATERIALS: We analysed PNPLA3 rs738409, TM6SF2 rs58542926, and HSD17B13 rs72613567 SNPs in a prospectively recruited cohort (n=323) consisting of healthy controls, CHB and CHB-HCC patients without hepatic steatosis. SNPs were determined by PCR analysis and associations for the alleles and genotypes were investigated using adjusted-logistic regression analyses. The overall survival (OS) data were collected from CHB-HCC patients for survival analysis. RESULTS: The genotype and allelic distribution of PNPLA3 rs738409, TM6SF2 rs58542926, and HSD17B13 rs72613567 were similar between healthy controls, CHB, and CHB-HCC groups. No genotype, allele or haplotype analysis was found to be associated with increased risk for CHB-HCC. Survival analysis revealed no genotype or allele to be associated with OS in patients with CHB-HCC. CONCLUSIONS: We could not demonstrate any association of PNPLA3 rs738409, TM6SF2 rs58542926, and HSD17B13 rs72613567 with the development or prognosis of CHB-HCC, supporting the initial hypothesis that they should be considered specific hotspots for liver diseases characterized with hepatic steatosis.

Use of PNPLA3, TM6SF2, and HSD17B13 for detection of fibrosis in MASLD in the general population.

BACKGROUND: Genetic testing can be used to evaluate disease risk. We evaluated if the use of three Single Nucleotide Polymorphisms (SNPs), alone or combined into a genetic risk score (GRS), can aid identify significant fibrosis in subjects with metabolic dysfunction-associated steatotic liver disease (MASLD). METHODS: We assessed three known risk variants: PNPLA3 rs738409, TM6SF2 rs58542926, and HSD17B13 rs72613567. The study included 414 adult individuals invited from the Danish population, who were defined as at-risk of MASLD due to elevated ALT and body mass index (BMI) >25 kg/m2. Participants were assessed clinically and by the Fibrosis-4 (FIB-4) index and Fibroscan. RESULTS: In total, 17 participants (4.1 %) had alcohol-related liver disease, 79 (19.1 %) had no evidence of liver disease, and four (1.0 %) were diagnosed with other liver diseases, including malignant disease. The remaining 314 participants (75.8 %) were diagnosed with MASLD. Of the 27 who underwent a liver biopsy for suspected fibrosis, 15 had significant fibrosis (≥F2) and 12 had no/mild fibrosis (F0/F1). The GRS was not associated with significant fibrosis (p = 0.09) but PNPLA3 was with an odds ratio of 6.75 (95 % CI 1.29 - 50.7; p = 0.039) risk allele CG/GG versus CC. The diagnostic accuracy of PNPLA3 combined with an increased Fib-4 (>1.3) was excellent for detecting significant fibrosis with a sensitivity of 1.00 (95 % CI 0.72-1.00), but the specificity was no better than for FIB-4 alone. CONCLUSIONS: This study found no evidence to support the use of GRS for diagnosing significant fibrosis in MASLD. However, the combination of PNPLA3 and Fib-4 increased sensitivity considerably. In addition, ALT remains a useful tool for screening diagnosing other liver diseases than MASLD.

HSD17B1 Compensates for HSD17B3 Deficiency in Fetal Mouse Testis but Not in Adults.

Hydroxysteroid (17ß) dehydrogenase (HSD17B) enzymes convert 17-ketosteroids to 17beta-hydroxysteroids, an essential step in testosterone biosynthesis. Human XY individuals with inactivating HSD17B3 mutations are born with female-appearing external genitalia due to testosterone deficiency. However, at puberty their testosterone production reactivates, indicating HSD17B3-independent testosterone synthesis. We have recently shown that Hsd17b3 knockout (3-KO) male mice display a similar endocrine imbalance, with high serum androstenedione and testosterone in adulthood, but milder undermasculinization than humans. Here, we studied whether HSD17B1 is responsible for the remaining HSD17B activity in the 3-KO male mice by generating a Ser134Ala point mutation that disrupted the enzymatic activity of HSD17B1 (1-KO) followed by breeding Hsd17b1/Hsd17b3 double-KO (DKO) mice. In contrast to 3-KO, inactivation of both HSD17B3 and HSD17B1 in mice results in a dramatic drop in testosterone synthesis during the fetal period. This resulted in a female-like anogenital distance at birth, and adult DKO males displayed more severe undermasculinization than 3-KO, including more strongly reduced weight of seminal vesicles, levator ani, epididymis, and testis. However, qualitatively normal spermatogenesis was detected in adult DKO males. Furthermore, similar to 3-KO mice, high serum testosterone was still detected in adult DKO mice, accompanied by upregulation of various steroidogenic enzymes. The data show that HSD17B1 compensates for HSD17B3 deficiency in fetal mouse testis but is not the enzyme responsible for testosterone synthesis in adult mice with inactivated HSD17B3. Therefore, other enzymes are able to convert androstenedione to testosterone in the adult mouse testis and presumably also in the human testis.

Inhibiting HSD17B8 suppresses the cell proliferation caused by PTEN failure.

Loss of the tumor suppressor PTEN homolog daf-18 in Caenorhabditis elegans (C. elegans) triggers diapause cell division during L1 arrest. While prior studies have delved into established pathways, our investigation takes an innovative route. Through forward genetic screening in C. elegans, we pinpoint a new player, F12E12.11, regulated by daf-18, impacting cell proliferation independently of PTEN's typical phosphatase activity. F12E12.11 is an ortholog of human estradiol 17-beta-dehydrogenase 8 (HSD17B8), which converts estradiol to estrone through its NAD-dependent 17-beta-hydroxysteroid dehydrogenase activity. We found that PTEN engages in a physical interplay with HSD17B8, introducing a distinctive suppression mechanism. The reduction in estrone levels and accumulation of estradiol may arrest tumor cells in the G2/M phase of the cell cycle through MAPK/ERK. Our study illuminates an unconventional protein interplay, providing insights into how PTEN modulates tumor suppression by restraining cell division through intricate molecular interactions.

PNPLA3 risk allele is associated with risk of hepatocellular carcinoma but not decompensation in compensated cirrhosis.

BACKGROUND: The PNPLA3-rs738409-G, TM6SF2-rs58542926-T, and HSD17B13-rs6834314-A polymorphisms have been associated with cirrhosis, hepatic decompensation, and HCC. However, whether they remain associated with HCC and decompensation in people who already have cirrhosis remains unclear, which limits the clinical utility of genetics in risk stratification as HCC is uncommon in the absence of cirrhosis. We aimed to characterize the effects of PNPLA3, TM6SF2, and HSD17B13 genotype on hepatic decompensation, HCC, and liver-related mortality or liver transplant in patients with baseline compensated cirrhosis. METHODS: We conducted a single-center retrospective study of patients in the Michigan Genomics Initiative who underwent genotyping. The primary predictors were PNPLA3, TM6SF2, and HSD17B13 genotypes. Primary outcomes were either hepatic decompensation, HCC, or liver-related mortality/transplant. We conducted competing risk Fine-Gray analyses on our cohort. RESULTS: We identified 732 patients with baseline compensated cirrhosis. During follow-up, 50% of patients developed decompensation, 13% developed HCC, 24% underwent liver transplant, and 27% died. PNPLA3-rs738409-G genotype was associated with risk of incident HCC: adjusted subhazard hazard ratio 2.42 (1.40-4.17), p=0.0015 for PNPLA3-rs738409-GG vs. PNPLA3-rs738409-CC genotype. The 5-year cumulative incidence of HCC was higher in PNPLA3-rs738409-GG carriers than PNPLA3-rs738409-CC/-CG carriers: 15.6% (9.0%-24.0%) vs. 7.4% (5.2%-10.0%), p<0.001. PNPLA3 genotype was not associated with decompensation or the combined outcome of liver-related mortality or liver transplant. TM6SF2 and HSD17B13 genotypes were not associated with decompensation or HCC. CONCLUSIONS: The PNPLA3-rs738409-G allele is associated with an increased risk of HCC among patients with baseline compensated cirrhosis. People with cirrhosis and PNPLA3-rs738409-GG genotype may warrant more intensive HCC surveillance.

Integrating genetic and socioeconomic data to predict the progression of nonalcoholic fatty liver disease.

OBJECTIVES: Nonalcoholic fatty liver disease (NAFLD) is the leading cause of chronic liver disease globally, with an estimated prevalence exceeding 25%. Variants in the PNPLA3 and HSD17B13 genes have been a focus of investigations surrounding the etiology and progression of NAFLD and are believed to contribute to a greater burden of disease experienced by Hispanic Americans. However, little is known about socioeconomic factors influencing NAFLD progression or its increased prevalence among Hispanics. MATERIALS AND METHODS: We cross-sectionally analyzed 264 patients to assess the role of genetic and socioeconomic variables in the development of advanced liver fibrosis in individuals at risk for NAFLD. RESULTS: Adjusting for age, sex, body mass index, and PNPLA3 genotype, lacking a college degree was associated with 3.3 times higher odds of advanced fibrosis (95% confidence interval [CI]: 1.21-8.76, p = 0.019), an effect comparable to that of possessing the major PNPLA3 risk variant. Notably, the effect of PNPLA3 genotype on advanced fibrosis was attenuated to nonsignificance following adjustment for education and other socioeconomic markers. The effect of the protective HSD17B13 variant, moreover, diminished after adjustment for education (odds ratio [OR]: 0.39 [95% CI: 0.13-1.16, p = 0.092]), while lower education continued to predict advanced fibrosis following multivariable adjustment with an OR of 8.0 (95% CI: 1.91-33.86, p = 0.005). DISCUSSION: Adjusting for education attenuated the effects of genotype and Hispanic ethnicity on liver fibrosis, suggesting that social factors-rather than genes or ethnicity-may be driving disease severity within some populations. Findings reveal the importance of including socioenvironmental controls when considering the role of genetics or ethnicity in complex disease.

Expression and localization of HSD17B13 along mouse urinary tract.

17ß-Hydroxysteroid dehydrogenase-13 (HSD17B13), a newly identified lipid droplet-associated protein, plays an important role in the development of nonalcoholic fatty liver disease (NAFLD) and nonalcoholic steatohepatitis (NASH). Emerging evidence demonstrates that NASH is an independent risk factor for chronic kidney disease, which is frequently accompanied by renal lipid accumulation. In addition, the HSD17B13 rs72613567 variant is associated with lower levels of albuminuria in patients with biopsy-proven NAFLD. At present, the role of HSD17B13 in lipid accumulation in the kidney is unclear. This study utilized bioinformatic and immunostaining approaches to examine the expression and localization of HSD17B13 along the mouse urinary tract. We found that HSD17B13 is constitutively expressed in the kidney, ureter, and urinary bladder. Our findings reveal for the first time, to our knowledge, the precise localization of HSD17B13 in the mouse urinary system, providing a basis for further studying the pathogenesis of HSD17B13 in various renal and urological diseases.NEW & NOTEWORTHY HSD17B13, a lipid droplet-associated protein, is crucial in nonalcoholic fatty liver disease (NAFLD) development. NAFLD also independently raises chronic kidney disease (CKD) risk, often with renal lipid buildup. However, HSD17B13's role in CKD-related lipid accumulation is unclear. This study makes the first effort to examine HSD17B13 expression and localization along the urinary system, providing a basis for exploring its physiological and pathophysiological roles in the kidney and urinary tract.

D-Bifunctional Protein Deficiency Diagnosis-A Challenge in Low Resource Settings: Case Report and Review of the Literature.

D-bifunctional protein deficiency (D-BPD) is a rare, autosomal recessive peroxisomal disorder that affects the breakdown of long-chain fatty acids. Patients with D-BPD typically present during the neonatal period with hypotonia, seizures, and facial dysmorphism, followed by severe developmental delay and early mortality. While some patients have survived past two years of age, the detectable enzyme activity in these rare cases was likely a contributing factor. We report a D-BPD case and comment on challenges faced in diagnosis based on a narrative literature review. An overview of Romania's first patient diagnosed with D-BPD is provided, including clinical presentation, imaging, biochemical, molecular data, and clinical course. Establishing a diagnosis can be challenging, as the clinical picture is often incomplete or similar to many other conditions. Our patient was diagnosed with type I D-BPD based on whole-exome sequencing (WES) results revealing a pathogenic frameshift variant of the HSD17B4 gene, c788del, p(Pro263GInfs*2), previously identified in another D-BPD patient. WES also identified a variant of the SUOX gene with unclear significance. We advocate for using molecular diagnosis in critically ill newborns and infants to improve care, reduce healthcare costs, and allow for familial counseling.

Differential Effects of Genetic Polymorphism on Comorbid Disease in Metabolic Dysfunction-Associated Steatotic Liver Disease.

BACKGROUND & AIMS: PNPLA3 rs738409, TM6SF2 rs58542926, and HSD17B13 rs72613567 have been associated with an increased risk of liver-related events (LREs) in patients with metabolic dysfunction-associated steatotic liver disease (MASLD). In this study, we investigated the combined effects of these variants on LREs. METHODS: The longitudinal multicenter cohort study enrolled 1178 patients with biopsy-proven MASLD. We calculated the genetic risk of hepatic fibrosis and LRE according to the impact of these variants. RESULTS: Patients with genetic fibrosis scores of 2, 3, and 4 or 5 were at greater risk than patients with scores of 0 or 1, with odds ratios of 2.45 (95% CI, 1.27-4.74), 2.14 (95% CI, 1.17-3.94), and 2.54 (95% CI, 1.35-4.77), respectively. Multivariate analysis revealed that PNPLA3 and TM6SF2, but not HSD17B13, were associated significantly with LRE development. The hazard ratio of the genetic high-risk group for LRE was 1.91 (95% CI, 1.20-3.04). The higher risk of LRE development in the genetic high-risk group also was seen in patients with F ≥ 3 or Fibrosis-4 index > 2.67. The hazard ratios of the genetic high-risk group for LRE were greater in patients without obesity, without diabetes, and of younger age compared with patients with obesity, with diabetes, or of older age, respectively. CONCLUSIONS: This combination of MASLD-related genetic variants is useful for predicting LREs in Japanese patients with MASLD. The genetic risk according to these variants is useful for LRE risk assessment, especially in patients without metabolic risk factors or in younger patients in Japan.

Relevance of PNPLA3, TM6SF2, HSD17B13, and GCKR Variants to MASLD Severity in an Egyptian Population.

Metabolic dysfunction-associated steatotic liver disease (MASLD), formerly known as non-alcoholic fatty liver disease (NAFLD), is a frequent clinical condition globally. Single nucleotide polymorphisms (SNPs) associated with NAFLD have been proposed in the literature and based on bioinformatic screening. The association between NAFLD and genetic variants in Egyptians is still unclear. Hence, we sought to investigate the association of some genetic variants with NAFLD in Egyptians. Egyptians have been categorized into either the MASLD group (n = 205) or the healthy control group (n = 187). The severity of hepatic steatosis and liver fibrosis was assessed by a Fibroscan device. TaqMan-based genotyping assays were employed to explore the association of selected SNPs with MASLD. PNPLA3 rs738409 C>G variant is associated with the presence of MASLD with liver fibrosis, the severity of both hepatic steatosis and liver fibrosis, increased systolic and diastolic blood pressure and increased alanine aminotransferase (all p < 0.05), while the TM6SF2 rs58542926 C>T, HSD17B13 rs9992651 G>A, and GCKR rs1260326 T>C variants were not (all p > 0.05). The TM6SF2 rs58542926 T allele is associated with increased fasting blood glucose and a decreased waist circumference. The GCKR rs1260326 C allele is associated with decreased aspartate transaminase and diastolic blood pressure (all p < 0.05). Only after adjusting for the risk factors (age, sex, BMI, WC, HDL, TG, diabetes mellitus, and hypertension) F2 liver fibrosis score is negatively correlated with the HSD17B13 rs9992651 GA genotype. This study offers evidence for the association of the PNPLA3 rs738409 C>G variant with MASLD among Egyptians and for the association of the PNPLA3 rs738409 G allele, the TM6SF2 rs58542926 T allele, and the GCKR rs1260326 C allele with some parameters of cardiometabolic criteria.

PARVB and HSD17B13 variants are associated with nonalcoholic fatty liver disease in children.

BACKGROUND AND AIM: The aim of this study was to investigate the comprehensive genetic effects of exploratory variants of LYPLAL1, GCKR, HSD17B13, TRIB1, APOC3, MBOAT7, and PARVB on pediatric nonalcoholic fatty liver disease in addition to the previously reported variants of TM6SF2, PNPLA3, and SAMM50 in Korean children. METHODS: A prospective case-control study was conducted involving 309 patients diagnosed using ultrasound and 339 controls. Anthropometric measurements, liver function tests, and metabolic marker analysis were conducted, and fibrosis scores were calculated. Transient elastography was performed in 69 some patients with nonalcoholic fatty liver disease. TaqMan allelic discrimination assays were used for genotyping. The genetic risk scores were calculated using significant variants, namely, HSD17B13, PARVB, PNPLA3, SAMM50, and TM6SF2, to evaluate the additive effect. RESULTS: Risk allele carriers of the PARVB variant showed significantly higher levels of aminotransferases, gamma-glutamyl transferase, alkaline phosphatase, pediatric nonalcoholic fatty liver disease fibrosis score, and aspartate aminotransferase/platelet ratio index. Individuals with a homozygous variant of HSD17B13 showed significantly lower levels of aminotransferase, gamma-glutamyl transferase, liver stiffness measurement, and aspartate aminotransferase/platelet ratio index than those with other genotypes. These parameters did not significantly differ among other variants of LYPLAL1, GCKR, TRIB1, APOC3, and MBOAT7. The genetic risk scores was identified as an independent risk factor for nonalcoholic fatty liver disease and had a positive association with severity. CONCLUSION: HSD17B13 has protective effects on the severity of pediatric nonalcoholic fatty liver disease. Variants of HSD17B13, PARVB, PNPLA3, SAMM50, and TM6SF2 had an additive effect on nonalcoholic fatty liver disease.

A comprehensive meta-analysis of transcriptome data to identify signature genes associated with pancreatic ductal adenocarcinoma.

PURPOSE: Pancreatic ductal adenocarcinoma (PDAC) has a five-year survival rate of less than 5%. Absence of symptoms at primary tumor stages, as well as high aggressiveness of the tumor can lead to high mortality in cancer patients. Most patients are recognized at the advanced or metastatic stage without surgical symptom, because of the lack of reliable early diagnostic biomarkers. The objective of this work was to identify potential cancer biomarkers by integrating transcriptome data. METHODS: Several transcriptomic datasets comprising of 11 microarrays were retrieved from the GEO database. After pre-processing, a meta-analysis was applied to identify differentially expressed genes (DEGs) between tumor and nontumor samples for datasets. Next, co-expression analysis, functional enrichment and survival analyses were used to determine the functional properties of DEGs and identify potential prognostic biomarkers. In addition, some regulatory factors involved in PDAC including transcription factors (TFs), protein kinases (PKs), and miRNAs were identified. RESULTS: After applying meta-analysis, 1074 DEGs including 539 down- and 535 up-regulated genes were identified. Pathway enrichment analyzes using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) revealed that DEGs were significantly enriched in the HIF-1 signaling pathway and focal adhesion. The results also showed that some of the DEGs were assigned to TFs that belonged to 23 conserved families. Sixty-four PKs were identified among the DEGs that showed the CAMK family was the most abundant group. Moreover, investigation of corresponding upstream regions of DEGs identified 11 conserved sequence motifs. Furthermore, weighted gene co-expression network analysis (WGCNA) identified 8 modules, more of them were significantly enriched in Ras signaling, p53 signaling, MAPK signaling pathways. In addition, several hubs in modules were identified, including EMP1, EVL, ELP5, DEF8, MTERF4, GLUP1, CAPN1, IGF1R, HSD17B14, TOM1L2 and RAB11FIP3. According to survival analysis, it was identified that the expression levels of two genes, EMP1 and RAB11FIP3 are related to prognosis. CONCLUSION: We identified several genes critical for PDAC based on meta-analysis and system biology approach. These genes may serve as potential targets for the treatment and prognosis of PDAC.

The glucocorticoid-activating enzyme 11ß-hydroxysteroid dehydrogenase type 1 catalyzes the activation of testosterone.

Testosterone biosynthesis from its precursor androstenedione is thought to be exclusively catalysed by the 17ß-hydroxysteroid dehydrogenases-HSD17B3 in testes, and AKR1C3 in the ovary, adrenal and peripheral tissues. Here we show for the first time that the glucocorticoid activating enzyme 11ß-hydroxysteroid dehydrogenase type 1 (HSD11B1) can also catalyse the 17ß-reduction of androstenedione to testosterone, using a combination of in vitro enzyme kinetic assays, mathematical modelling, and molecular docking analysis. Furthermore, we show that co-expression of HSD11B1 and AKR1C3 increases testosterone production several-fold compared to the rate observed with AKR1C3 only, and that HSD11B1 is likely to contribute significantly to testosterone production in peripheral tissues.

Characterization of eight types of 17ß-hydroxysteroid dehydrogenases from the Japanese sardine Sardinops melanostictus: The probable role of type 12a in ovarian estradiol synthesis.

17ß-hydroxysteroid dehydrogenases (Hsd17bs) play a critical role in sex steroid biosynthesis. Although multiple types of Hsd17b have been found in fish, there is limited research on their expression and function. Recently, we succeeded in identifying eight types of Hsd17b (types 3, 4, 7, 8, 10, 12a, 12b, and 14) by RNA sequencing in the Japanese sardine Sardinops melanostictus, a commercially important clupeoid fish; however, a homologous sequence of Hsd17b1, which catalyzes the key reaction of estradiol-17ß (E2) synthesis, was absent. Here, we aimed to identify the Hsd17b type that plays a major role in E2 synthesis during ovarian development in Japanese sardine. The cDNAs encoding those eight types of Hsd17b were cloned and sequenced. The expressions of hsd17b3, hsd17b12a, and hsd17b12b were higher in ovary than in testis. In particular, hsd17b12a was predominantly expressed in the ovary. Expression of hsd17b3, hsd17b4, hsd17b12a, and hsd17b12b in the ovary increased during ovarian development. The enzymatic activities of Hsd17b3, Hsd17b12a, and Hsd17b12b were evaluated by expressing their recombinants in human embryonic kidney 293T cells. Hsd17b12a and Hsd17b12b catalyzed the conversion of androstenedione (AD) to testosterone (T) and estrone (E1) to E2. The results of in vitro bioassays using sardine ovaries indicated that E2 is synthesized from pregnenolone via AD and T, but not E1. These results suggest that Hsd17b12a plays a major role in E2 synthesis in sardine ovary by catalyzing the conversion of AD to T.

Involvement of Type 10 17ß-Hydroxysteroid Dehydrogenase in the Pathogenesis of Infantile Neurodegeneration and Alzheimer's Disease.

Type 10 17ß-hydroxysteroid dehydrogenase (17ß-HSD10) is the HSD17B10 gene product playing an appreciable role in cognitive functions. It is the main hub of exercise-upregulated mitochondrial proteins and is involved in a variety of metabolic pathways including neurosteroid metabolism to regulate allopregnanolone homeostasis. Deacetylation of 17ß-HSD10 by sirtuins helps regulate its catalytic activities. 17ß-HSD10 may also play a critical role in the control of mitochondrial structure, morphology and dynamics by acting as a member of the Parkin/PINK1 pathway, and by binding to cyclophilin D to open mitochondrial permeability pore. 17ß-HSD10 also serves as a component of RNase P necessary for mitochondrial tRNA maturation. This dehydrogenase can bind with the Aß peptide thereby enhancing neurotoxicity to brain cells. Even in the absence of Aß, its quantitative and qualitative variations can result in neurodegeneration. Since elevated levels of 17ß-HSD10 were found in brain cells of Alzheimer's disease (AD) patients and mouse AD models, it is considered to be a key factor in AD pathogenesis. Since data underlying Aß-binding-alcohol dehydrogenase (ABAD) were not secured from reported experiments, ABAD appears to be a fabricated alternative term for the HSD17B10 gene product. Results of this study would encourage researchers to solve the question why elevated levels of 17ß-HSD10 are present in brains of AD patients and mouse AD models. Searching specific inhibitors of 17ß-HSD10 may find candidates to reduce senile neurodegeneration and open new approaches for the treatment of AD.

Serum steroid metabolite profiling by LC-MS/MS in two phenotypic male patients with HSD17B3 deficiency: Implications for hormonal diagnosis.

Although 17ß-hydroxysteroid dehydrogenase type 3 (HSD17B3) deficiency is diagnosed when a testosterone/androstenedione (T/A-dione) ratio after human chorionic gonadotropin (hCG) stimulation is below 0.8, this cut-off value is primarily based on hormonal data measured by conventional immunoassay (IA) in patients with feminized or ambiguous genitalia. We examined two 46,XY Japanese patients with undermasculinized genitalia including hypospadias (patient 1 and patient 2). Endocrine studies by IA showed well increased serum T value after hCG stimulation (2.91 ng/mL) and a high T/A-dione ratio (4.04) in patient 1 at 2 weeks of age and sufficiently elevated basal serum T value (2.60 ng/mL) in patient 2 at 1.5 months of age. Despite such partial androgen insensitivity syndrome-like findings, whole exome sequencing identified biallelic ″pathogenic″ or ″likely pathogenic″ variants in HSD17B3 (c .188 C>T:p.(Ala63Val) and c .194 C>T:p.(Ser65Leu) in patient 1, and c.139 A>G:p.(Met47Val) and c.672 + 1 G>A in patient 2) (NM_000197.2), and functional analysis revealed reduced HSD17B3 activities of the missense variants (∼ 43% for p.Met47Val, ∼ 14% for p.Ala63Val, and ∼ 0% for p.Ser65Leu). Thus, we investigated hCG-stimulated serum steroid metabolite profiles by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in patient 1 at 7 months of age and in patient 2 at 11 months of age as well as in five control males with idiopathic micropenis aged 1 - 8 years, and found markedly high T/A-dione ratios (12.3 in patient 1 and 5.4 in patient 2) which were, however, obviously lower than those in the control boys (25.3 - 56.1) and sufficiently increased T values comparable to those of control males. The elevated T/A-dione ratios are considered be due to the residual HSD17B3 function and the measurement by LC-MS/MS. Thus, it is recommended to establish the cut-off value for the T/A-dione ratio according to the phenotypic sex reflecting the residual function and the measurement method.

Exome sequencing identified rare recurrent copy number variants and hereditary breast cancer susceptibility.

Copy number variants (CNVs) are a major source of genetic variation and can disrupt genes or affect gene dosage. They are known to be causal or underlie predisposition to various diseases. However, the role of CNVs in inherited breast cancer susceptibility has not been thoroughly investigated. To address this, we performed whole-exome sequencing based analysis of rare CNVs in 98 high-risk Northern Finnish breast cancer cases. After filtering, selected candidate alleles were validated and characterized with a combination of orthogonal methods, including PCR-based approaches, optical genome mapping and long-read sequencing. This revealed three recurrent alterations: a 31 kb deletion co-occurring with a retrotransposon insertion (delins) in RAD52, a 13.4 kb deletion in HSD17B14 and a 64 kb partial duplication of RAD51C. Notably, all these genes encode proteins involved in pathways previously identified as essential for breast cancer development. Variants were genotyped in geographically matched cases and controls (altogether 278 hereditary and 1983 unselected breast cancer cases, and 1229 controls). The RAD52 delins and HSD17B14 deletion both showed significant enrichment among cases with indications of hereditary disease susceptibility. RAD52 delins was identified in 7/278 cases (2.5%, P = 0.034, OR = 2.86, 95% CI = 1.10-7.45) and HSD17B14 deletion in 8/278 cases (2.9%, P = 0.014, OR = 3.28, 95% CI = 1.31-8.23), the frequency of both variants in the controls being 11/1229 (0.9%). This suggests a role for RAD52 and HSD17B14 in hereditary breast cancer susceptibility. The RAD51C duplication was very rare, identified only in 2/278 of hereditary cases and 2/1229 controls (P = 0.157, OR = 4.45, 95% CI = 0.62-31.70). The identification of recurrent CNVs in these genes, and especially the relatively high frequency of RAD52 and HSD17B14 alterations in the Finnish population, highlights the importance of studying CNVs alongside single nucleotide variants when searching for genetic factors underlying hereditary disease predisposition.

17ß-hydroxysteroid dehydrogenases in the progression of nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD) has become a worldwide epidemic and a major public health problem, with a prevalence of approximately 25%. The pathogenesis of NAFLD is complex and may be affected by the environment and susceptible genetic factors, resulting in a highly variable disease course and no approved drugs in the clinic. Notably, 17ß-hydroxysteroid dehydrogenase type 13 (HSD17B13), which belongs to the 17ß-hydroxysteroid dehydrogenase superfamily (HSD17Bs), is closely related to the clinical outcome of liver disease. HSD17Bs consists of fifteen members, most related to steroid and lipid metabolism, and may have the same biological function as HSD17B13. In this review, we highlight recent advances in basic research on the functional activities, major substrates, and key roles of HSD17Bs in the progression of NAFLD to develop innovative anti-NAFLD drugs targeting HSD17Bs.