Novel activities of CYP11A1 and their potential physiological significance

In the paper

“Ex-utero incubations of human placentae [8] and ex-vivo incubations of pig adrenal glands [23] with 7DHP resulted in its transformation to 7-dehydroprogesterone.”

What the sources say

• Not checked yetcites [8] Slominski AT Kim TK Chen J Nguyen MN Li W Yates CR Sweatman T Janjetovic Z Tuckey RC Cytochrome P450scc-dependent metabolism of 7-dehydrocholesterol in placenta and epidermal keratinocytes Int. J. Biochem. Cell Biol 2012 44 2003 2018 22877869 PMC3520099 source
• Not checked yetcites [23] Slominski AT Zmijewski MA Semak I Sweatman T Janjetovic Z Li W Zjawiony JK Tuckey RC Sequential metabolism of 7-dehydrocholesterol to steroidal 5,7-dienes in adrenal glands and its biological implication in the skin PLoS ONE 2009 4 e4309 19190754 PMC2629546 source

In the paper

“In accordance with this, our studies with pig adrenal glands showed the transformation of 7DHP to 17(OH)7DHP during ex-vivo incubations, but 21(OH)7DHP could not be detected [23].”

What the sources say

• Not checked yetcites [23] Slominski AT Zmijewski MA Semak I Sweatman T Janjetovic Z Li W Zjawiony JK Tuckey RC Sequential metabolism of 7-dehydrocholesterol to steroidal 5,7-dienes in adrenal glands and its biological implication in the skin PLoS ONE 2009 4 e4309 19190754 PMC2629546 source

In the paper

“It should be noted that we also detected production of two other hydroxy-7DHC metabolites by human CYP11A1 of which the identity remains to be established [8]. Neither of them corresponded to 20 (OH)7DHC as demonstrated by their different retention times.”

What the sources say

• Not checked yetcites [8] Slominski AT Kim TK Chen J Nguyen MN Li W Yates CR Sweatman T Janjetovic Z Tuckey RC Cytochrome P450scc-dependent metabolism of 7-dehydrocholesterol in placenta and epidermal keratinocytes Int. J. Biochem. Cell Biol 2012 44 2003 2018 22877869 PMC3520099 source

In the paper

“CYP27B1 also 1α-hydroxylates 20(OH)D2 producing 1,20 (OH)2D2, with an efficiency much lower than for the conversion of 25(OH)D2 to 1,25(OH)2D2 [112].”

What the sources say

• Not checked yetcites [112] Slominski AT Kim TK Janjetovic Z Tuckey RC Bieniek R Yue J Li W Chen J Nguyen MN Tang EK Miller D Chen TC Holick M 20-Hydroxyvitamin D2 is a noncalcemic analog of vitamin D with potent antiproliferative and prodifferentiation activities in normal and malignant cells Am. J. Physiol. Cell Physiol 2011 300 C526 C541 21160030 PMC3063966 source

In the paper

“Although the side chains of D2 and ergosterol are identical, no epoxidation of the double bond between C22 and C23 occurs for D2, indicating its different positioning in the active site.”

In the paper

“Thus, keratinocytes transformed D3 to 20(OH)D3, 22(OH) D3, 20,23(OH)2D3, 20,22(OH)2D3, and 17,20,23(OH)3D3, with CYP27B1-dependent production of 1,20(OH)2D3 and 1,20,23 (OH)3D3 also being observed [27].”

What the sources say

• Not checked yetcites [27] Slominski AT Kim TK Shehabi HZ Semak I Tang EK Nguyen MN Benson HA Korik E Janjetovic Z Chen J Yates CR Postlethwaite A Li W Tuckey RC In vivo evidence for a novel pathway of vitamin D(3) metabolism initiated by P450scc and modified by CYP27B1 FASEB J 2012 26 3901 3915 22683847 PMC3425822 source

In the paper

“Detection of a monohydroxyvitamin D3 compound with a retention time corresponding to 20(OH) D3 in human serum, albeit at a level 20 times lower than that of 25 (OH)D3, indicates that 20(OH)D3 produced in these organs can enter the systemic circulation [27].”

What the sources say

• Not checked yetcites [27] Slominski AT Kim TK Shehabi HZ Semak I Tang EK Nguyen MN Benson HA Korik E Janjetovic Z Chen J Yates CR Postlethwaite A Li W Tuckey RC In vivo evidence for a novel pathway of vitamin D(3) metabolism initiated by P450scc and modified by CYP27B1 FASEB J 2012 26 3901 3915 22683847 PMC3425822 source

In the paper

“Caco-2 cells also metabolized exogenous vitamin D3 to 20 (OH)D3 as the predominant metabolite, with lesser production of 22(OH)D3 and 25(OH)D3. These were further metabolized to 20,23 (OH)2D3, 1,20(OH)2D3, and 1,25(OH)2D3 [103].”

What the sources say

• Not checked yetcites [103] Slominski AT Kim Li TKW Yi AK Postlethwaite A Tuckey RC The role of CYP11A1 in the production of vitamin D metabolites and their role in the regulation of epidermal functions J. Steroid Biochem. Mol. Biol 2014 144PA 28 39 24176765 PMC4002668 source

In the paper

“Most importantly, the in vivo studies represented by ex-vivo and ex-utero incubations of vitamin D3 with fragments of adrenal glands and human placentae, respectively, clearly demonstrate the CYP11A1-catalyzed metabolism of vitamin D3 with 20(OH) D3 being the major metabolite. Less abundant products included 22(OH)D3, 20,23(OH)2D3, 20,22(OH)2D3, and 17,20,23(OH)3D3 [27].”

What the sources say

• Not checked yetcites [27] Slominski AT Kim TK Shehabi HZ Semak I Tang EK Nguyen MN Benson HA Korik E Janjetovic Z Chen J Yates CR Postlethwaite A Li W Tuckey RC In vivo evidence for a novel pathway of vitamin D(3) metabolism initiated by P450scc and modified by CYP27B1 FASEB J 2012 26 3901 3915 22683847 PMC3425822 source

In the paper

“Both tissues were also shown to express CYP27A1, CYP2R1, and CYP27B1, and to convert vitamin D3 to 25(OH)D3, and 25(OH) D3 to 1,25(OH)2D3 [27].”

What the sources say

• Not checked yetcites [27] Slominski AT Kim TK Shehabi HZ Semak I Tang EK Nguyen MN Benson HA Korik E Janjetovic Z Chen J Yates CR Postlethwaite A Li W Tuckey RC In vivo evidence for a novel pathway of vitamin D(3) metabolism initiated by P450scc and modified by CYP27B1 FASEB J 2012 26 3901 3915 22683847 PMC3425822 source

In the paper

“The latter is consistent with the ability of purified recombinant human CYP27B1 to 1α-hydroxylate 20(OH)D2 [112].”

What the sources say

• Not checked yetcites [112] Slominski AT Kim TK Janjetovic Z Tuckey RC Bieniek R Yue J Li W Chen J Nguyen MN Tang EK Miller D Chen TC Holick M 20-Hydroxyvitamin D2 is a noncalcemic analog of vitamin D with potent antiproliferative and prodifferentiation activities in normal and malignant cells Am. J. Physiol. Cell Physiol 2011 300 C526 C541 21160030 PMC3063966 source

In the paper

“Placentae ex-utero, as well as metabolizing vitamin D2 via CYP11A1, also converted D2 to 25(OH) D2 [9].”

What the sources say

• Not checked yetcites [9] Slominski AT Kim TK Shehabi HZ Tang EK Benson HA Semak I Lin Z Yates CR Wang J W Li Tuckey RC In vivo production of novel vitamin D2 hydroxy-derivatives by human placentas, epidermal keratinocytes Caco-2 colon cells and the adrenal gland Mol. Cell. Endocrinol 2014 383 181 192 24382416 PMC3997123

In the paper

“The physiological role of these new pathways remain to be established, but as for the corresponding D3 metabolites, products display biological activity when applied under in vitro or in vivo conditions (discussed in Section 5).”

In the paper

“The involvement of CYP11A1 in the conversion of D2 to 20(OH) D2, 20(OH)D2 to 17,20(OH)2D2, and the prodrug 1α(OH)D2 to 1,20 (OH)2D2 was demonstrated by its almost complete inhibition by 22R-hydroxycholesterol when placental and adrenal mitochondria were used to run the reaction [9].”

What the sources say

• Not checked yetcites [9] Slominski AT Kim TK Shehabi HZ Tang EK Benson HA Semak I Lin Z Yates CR Wang J W Li Tuckey RC In vivo production of novel vitamin D2 hydroxy-derivatives by human placentas, epidermal keratinocytes Caco-2 colon cells and the adrenal gland Mol. Cell. Endocrinol 2014 383 181 192 24382416 PMC3997123

In the paper

“Placentae ex-utero and mitochondria isolated from adrenal glands not only 1α-hydroxylated 25(OH)D2 to 1,25(OH)2D2, but also 20(OH)D2 to 1,20(OH)2D2 [9].”

What the sources say

• Not checked yetcites [9] Slominski AT Kim TK Shehabi HZ Tang EK Benson HA Semak I Lin Z Yates CR Wang J W Li Tuckey RC In vivo production of novel vitamin D2 hydroxy-derivatives by human placentas, epidermal keratinocytes Caco-2 colon cells and the adrenal gland Mol. Cell. Endocrinol 2014 383 181 192 24382416 PMC3997123

In the paper

“There was significantly higher production of 20(OH)D2 than 25(OH)D2 in Caco-2 cells that was opposite to what was observed in epidermal keratinocytes [9].”

What the sources say

• Not checked yetcites [9] Slominski AT Kim TK Shehabi HZ Tang EK Benson HA Semak I Lin Z Yates CR Wang J W Li Tuckey RC In vivo production of novel vitamin D2 hydroxy-derivatives by human placentas, epidermal keratinocytes Caco-2 colon cells and the adrenal gland Mol. Cell. Endocrinol 2014 383 181 192 24382416 PMC3997123

In the paper

“Importantly, using human placentas and bovine adrenals which express high levels of CYP11A1 [1,2], and human epithelial cells (epidermal keratinocytes and colonic Caco-2 cells) which express relatively low levels of this enzyme [14,15,111,113] we were able to demonstrate the in vivo (ex-vivo, ex-utero, and in cultured cells) transformation of D2 to 20(OH)D2,17,20(OH)2D2, and 1,20(OH)2D2 [9].”

What the sources say

• Not checked yetcites [9] Slominski AT Kim TK Shehabi HZ Tang EK Benson HA Semak I Lin Z Yates CR Wang J W Li Tuckey RC In vivo production of novel vitamin D2 hydroxy-derivatives by human placentas, epidermal keratinocytes Caco-2 colon cells and the adrenal gland Mol. Cell. Endocrinol 2014 383 181 192 24382416 PMC3997123

In the paper

“Notably, the amount of 20(OH)D2 produced from D2 was higher than that of the initial product of the classical activation pathway, 25(OH)D2, in placenta and Caco-2 cells, but similar or lower than for 25(OH)D3 in human epidermal keratinocytes.”

In the paper

“Epithelial cells expressing low CYP11A1 activity such as epidermal keratinocytes [14,83] and Caco-2 cells [111,113] metabolized D2 through the classical (25-hydroxylase-dependent) and CYP11A1-dependent pathways in a cell type dependent manner [9].”

What the sources say

• Not checked yetcites [9] Slominski AT Kim TK Shehabi HZ Tang EK Benson HA Semak I Lin Z Yates CR Wang J W Li Tuckey RC In vivo production of novel vitamin D2 hydroxy-derivatives by human placentas, epidermal keratinocytes Caco-2 colon cells and the adrenal gland Mol. Cell. Endocrinol 2014 383 181 192 24382416 PMC3997123

In the paper

“Importantly, the novel secosteroids in addition to acting as biased agonists on the vitamin D receptor (showing selectivity for certain receptor mediated effects) [103,112,122], can also interact with RORα and γ, presumably acting as inverse agonists [123].”

What the sources say

• Not checked yetcites [103] Slominski AT Kim Li TKW Yi AK Postlethwaite A Tuckey RC The role of CYP11A1 in the production of vitamin D metabolites and their role in the regulation of epidermal functions J. Steroid Biochem. Mol. Biol 2014 144PA 28 39 24176765 PMC4002668 source
• Not checked yetcites [112] Slominski AT Kim TK Janjetovic Z Tuckey RC Bieniek R Yue J Li W Chen J Nguyen MN Tang EK Miller D Chen TC Holick M 20-Hydroxyvitamin D2 is a noncalcemic analog of vitamin D with potent antiproliferative and prodifferentiation activities in normal and malignant cells Am. J. Physiol. Cell Physiol 2011 300 C526 C541 21160030 PMC3063966 source
• Not checked yetcites [122] Kim T-K Wang J Janjetovic Z Chen J Tuckey RC Nguyen MN Tang EKY Miller D Li W Slominski AT Correlation between secosteroid induced vitamin D receptor activity in melanoma cells and computer-modeled receptor binding strength Mol. Cell. Endocrinol 2012 361 143 152 doi: http://dx.doi.org/10.1016/j.mce.2012.04.001 22546549 PMC3409337 source
• Not checked yetcites [123] Slominski AT Kim Takeda TKY Janjetovic Z Brozyna AA Skobowiat C Wang J Postlethwaite A Li W Tuckey RC Jetten AM RORalpha and ROR gamma are expressed in human skin and serve as receptors for endogenously produced noncalcemic 20-hydroxy- and 20,23-dihydroxyvitamin D FASEB J 2014 28 2775 2789 24668754 PMC4062828

In the paper

“Photochemical opening of the B-ring of 7DHC, as seen in D3 (Fig. 3), prevents side chain cleavage from occurring, even when the pattern of hydroxylation would seem to make it possible as no cleavage of 20,22(OH)2D3 is observed.”

In the paper

“Pharmacologically administered 20(OH) D3 shows antifibrotic activities both in vitro [57,117,118] and in vivo in bleomycin induced scleroderma [118].”

What the sources say

• Not checked yetcites [57] Slominski A Kim TK Zmijewski MA Janjetovic Z Li W Chen J Kusniatsova EI Semak I Postlethwaite A Miller DD Zjawiony JK Tuckey RC Novel vitamin D photoproducts and their precursors in the skin Dermatoendocrinol 2013 5 7 19 24494038 PMC3897599 source
• Not checked yetcites [117] Slominski AT Li W Bhattacharya SK Smith RA Johnson PL Chen J Nelson KE Tuckey RC Miller D Jiao Y Gu W Postlethwaite AE Vitamin D analogs 17,20S(OH) 2pD and 17,20R(OH) 2pD are noncalcemic and exhibit antifibrotic activity J. Invest. Dermatol 2011 131 1167 1169 21228816 PMC3078214 source
• Not checked yetcites [118] Slominski A Janjetovic Z Tuckey RC Nguyen MN Bhattacharya KG Wang J Li W Jiao Y Gu W Brown M Postlethwaite AE 20S-Hydroxyvitamin D3 noncalcemic product of CYP11A1 action on vitamin D3, exhibits potent antifibrogenic activity in vivo J. Clin. Endocrinol. Metab 2013 98 E298 E303 23295467 PMC3565109 source

In the paper

“Studies of SLOS patients clearly show that under pathological conditions 7DHC can serve as a substrate for CYP11A1, with downstream Δ7 steroidal products possibly being responsible for some of the disease symptoms [58–61,63,64].”

What the sources say

• Not checked yetcites [58] Nowaczyk MJ Waye JS The Smith-Lemli-Opitz syndrome: a novel metabolic wayofunderstanding developmental biology, embryogenesis, and dysmorphology Clin. Genet 2001 59 375 386 11453964
• Not checked yetcites [59] Tint GS Irons M Elias ER Batta AK Frieden R Chen TS Salen G Defective cholesterol biosynthesis associated with the Smith-Lemli-Opitz syndrome N. Engl. J. Med 1994 330 107 113 8259166
• Not checked yetcites [60] Shackleton CH Roitman E Kelley R Neonatal urinary steroids in Smith-Lemli-Opitz syndrome associated with 7-dehydrocholesterol reductase deficiency Steroids 1999 64 481 490 10443904
• Not checked yetcites [61] Shackleton CH Role of a disordered steroid metabolome in the elucidation of sterol and steroid biosynthesis Lipids 2012 47 1 12 21874273 PMC3564490
• Not checked yetcites [63] Marcos J Guo LW Wilson WK Porter FD Shackleton C The implications of 7-dehydrosterol-7-reductase deficiency (Smith-Lemli-Opitz syndrome) to neurosteroid production Steroids 2004 69 51 60 14715377
• Not checked yetcites [64] Shackleton C Roitman E Guo LW Wilson WK Porter FD Identification of 7(8) and 8(9) unsaturated adrenal steroid metabolites produced by patients with 7-dehydrosterol-delta7-reductase deficiency (Smith-Lemli-Opitz syndrome) J. Steroid Biochem. Mol. Biol 2002 82 225 232 12477489

In the paper

“with 7DHC being better and vitamins D3 and D2 being poorer substrates than cholesterol.”

• Also stated in: § 2.2. In vitro and in vivo models of 7DHC metabolism by CYP11A1 · hedged

  “In fact, human CYP11A1 has a slightly higher catalytic efficiency with 7DHC as a substrate (higher Kcat/Km) than with cholesterol, indicating that 7DHC can be used preferentially by the enzyme depending on its availability [8,14].”

What the sources say

• Not checked yetcites [8] Slominski AT Kim TK Chen J Nguyen MN Li W Yates CR Sweatman T Janjetovic Z Tuckey RC Cytochrome P450scc-dependent metabolism of 7-dehydrocholesterol in placenta and epidermal keratinocytes Int. J. Biochem. Cell Biol 2012 44 2003 2018 22877869 PMC3520099 source
• Not checked yetcites [14] Slominski A Zjawiony J Wortsman J Semak I Stewart J Pisarchik A Sweatman T Marcos J Dunbar C Tuckey RC A novel pathway for sequential transformation of 7-dehydrocholesterol and expression of the P450scc system in mammalian skin Eur. J. Biochem 2004 271 4178 4188 15511223 PMC1201497 source
• Not checked yetcites [25] Tuckey RC W Li Zjawiony JK Zmijewski MA Nguyen MN Sweatman T Miller D Slominski A Pathways and products for the metabolism of vitamin D3 by cytochrome P450scc FEBS J 2008 275 2585 2596 18410379 PMC2562691 source

In the paper

“Studies, initially with purified enzyme, reveal that 7-dehydrocholesterol (7DHC), ergosterol, lumisterol 3, and vitamins D3 and D2 also serve as substrates for CYP11A1, with 7DHC being better and vitamins D3 and D2 being poorer substrates than cholesterol.”

What the sources say

• Not checked yetcites [8] Slominski AT Kim TK Chen J Nguyen MN Li W Yates CR Sweatman T Janjetovic Z Tuckey RC Cytochrome P450scc-dependent metabolism of 7-dehydrocholesterol in placenta and epidermal keratinocytes Int. J. Biochem. Cell Biol 2012 44 2003 2018 22877869 PMC3520099 source
• Not checked yetcites [14] Slominski A Zjawiony J Wortsman J Semak I Stewart J Pisarchik A Sweatman T Marcos J Dunbar C Tuckey RC A novel pathway for sequential transformation of 7-dehydrocholesterol and expression of the P450scc system in mammalian skin Eur. J. Biochem 2004 271 4178 4188 15511223 PMC1201497 source
• Not checked yetcites [22] Guryev O Carvalho RA Usanov S Gilep A Estabrook RW A pathway for the metabolism of vitamin D3: unique hydroxylated metabolites formed during catalysis with cytochrome P450scc (CYP11A1) Proc. Natl. Acad. Sci. U. S. A 2003 100 14754 14759 14657394 PMC299797 source
• Not checked yetcites [23] Slominski AT Zmijewski MA Semak I Sweatman T Janjetovic Z Li W Zjawiony JK Tuckey RC Sequential metabolism of 7-dehydrocholesterol to steroidal 5,7-dienes in adrenal glands and its biological implication in the skin PLoS ONE 2009 4 e4309 19190754 PMC2629546 source
• Not checked yetcites [24] Slominski A Semak I Zjawiony J Wortsman J W Li Szczesniewski A Tuckey RC The cytochrome P450scc system opens an alternate pathway of vitamin D3 metabolism FEBS J 2005 272 4080 4090 16098191 PMC2234577 source
• Not checked yetcites [25] Tuckey RC W Li Zjawiony JK Zmijewski MA Nguyen MN Sweatman T Miller D Slominski A Pathways and products for the metabolism of vitamin D3 by cytochrome P450scc FEBS J 2008 275 2585 2596 18410379 PMC2562691 source
• Not checked yetcites [26] Tuckey RC Li W Shehabi HZ Janjetovic Z Nguyen MN Chen TK Kim J Howell DE Benson HA Sweatman T Baldisseri DM Slominski A Production of 22-hydroxy-metabolites of vitamin D3 by cytochrome P450scc (CYP11A1) and analysis of their biological activities on skin cells Drug Metab. Dispos 2011 39 1577 1588 21677063 PMC3164270 source
• Not checked yetcites [27] Slominski AT Kim TK Shehabi HZ Semak I Tang EK Nguyen MN Benson HA Korik E Janjetovic Z Chen J Yates CR Postlethwaite A Li W Tuckey RC In vivo evidence for a novel pathway of vitamin D(3) metabolism initiated by P450scc and modified by CYP27B1 FASEB J 2012 26 3901 3915 22683847 PMC3425822 source
• Not checked yetcites [9] Slominski AT Kim TK Shehabi HZ Tang EK Benson HA Semak I Lin Z Yates CR Wang J W Li Tuckey RC In vivo production of novel vitamin D2 hydroxy-derivatives by human placentas, epidermal keratinocytes Caco-2 colon cells and the adrenal gland Mol. Cell. Endocrinol 2014 383 181 192 24382416 PMC3997123
• Not checked yetcites [28] Nguyen MN Slominski A W Li Ng YR Tuckey RC Metabolism of vitamin D2-17,20,24-trihydroxyvitamin D2 by cytochrome p450scc (CYPHA1) Drug Metab. Dispos 2009 37 761 767 19116262 PMC2659330 source

In the paper

“20-hydroxyvitamin D3 was detected in human serum and the epidermis.”

What the sources say

• Not checked yetcites [27] Slominski AT Kim TK Shehabi HZ Semak I Tang EK Nguyen MN Benson HA Korik E Janjetovic Z Chen J Yates CR Postlethwaite A Li W Tuckey RC In vivo evidence for a novel pathway of vitamin D(3) metabolism initiated by P450scc and modified by CYP27B1 FASEB J 2012 26 3901 3915 22683847 PMC3425822 source

In the paper

“Thus, this metabolism does appear to occur in vivo, although its quantitative importance and physiological role remain to be established.”

In the paper

“The activity of CYP11A1 is affected by the structure of the substrate with sterols having steroidal or Δ7-steroidal structures undergoing side chain cleavage following hydroxylations at C22 and C20. In contrast, metabolism of vitamin D involves sequential hydroxylations that start at C20 but do not lead to cleavage.”

What the sources say

• Not checked yetcites [1] Tuckey RC Progesterone synthesis by the human placenta Placenta 2005 26 273 281 15823613 source
• Not checked yetcites [14] Slominski A Zjawiony J Wortsman J Semak I Stewart J Pisarchik A Sweatman T Marcos J Dunbar C Tuckey RC A novel pathway for sequential transformation of 7-dehydrocholesterol and expression of the P450scc system in mammalian skin Eur. J. Biochem 2004 271 4178 4188 15511223 PMC1201497 source
• Not checked yetcites [22] Guryev O Carvalho RA Usanov S Gilep A Estabrook RW A pathway for the metabolism of vitamin D3: unique hydroxylated metabolites formed during catalysis with cytochrome P450scc (CYP11A1) Proc. Natl. Acad. Sci. U. S. A 2003 100 14754 14759 14657394 PMC299797 source
• Not checked yetcites [10] Tuckey RC Nguyen MN Chen J Slominski AT Baldisseri DM Tieu EW Zjawiony JK W Li Human cytochrome P450scc (CYP11A1) catalyzes epoxide formation with ergosterol Drug Metab. Dispos 2012 40 436 444 22106170 PMC3286270 source
• Not checked yetcites [24] Slominski A Semak I Zjawiony J Wortsman J W Li Szczesniewski A Tuckey RC The cytochrome P450scc system opens an alternate pathway of vitamin D3 metabolism FEBS J 2005 272 4080 4090 16098191 PMC2234577 source
• Not checked yetcites [25] Tuckey RC W Li Zjawiony JK Zmijewski MA Nguyen MN Sweatman T Miller D Slominski A Pathways and products for the metabolism of vitamin D3 by cytochrome P450scc FEBS J 2008 275 2585 2596 18410379 PMC2562691 source
• Not checked yetcites [26] Tuckey RC Li W Shehabi HZ Janjetovic Z Nguyen MN Chen TK Kim J Howell DE Benson HA Sweatman T Baldisseri DM Slominski A Production of 22-hydroxy-metabolites of vitamin D3 by cytochrome P450scc (CYP11A1) and analysis of their biological activities on skin cells Drug Metab. Dispos 2011 39 1577 1588 21677063 PMC3164270 source
• Not checked yetcites [27] Slominski AT Kim TK Shehabi HZ Semak I Tang EK Nguyen MN Benson HA Korik E Janjetovic Z Chen J Yates CR Postlethwaite A Li W Tuckey RC In vivo evidence for a novel pathway of vitamin D(3) metabolism initiated by P450scc and modified by CYP27B1 FASEB J 2012 26 3901 3915 22683847 PMC3425822 source
• Not checked yetcites [28] Nguyen MN Slominski A W Li Ng YR Tuckey RC Metabolism of vitamin D2-17,20,24-trihydroxyvitamin D2 by cytochrome p450scc (CYPHA1) Drug Metab. Dispos 2009 37 761 767 19116262 PMC2659330 source
• Not checked yetcites [29] Slominski A Semak I Wortsman J Zjawiony J Li W Zbytek B Tuckey RC An alternative pathway of vitamin D metabolism. Cytochrome P450scc (CYP11A1)-mediated conversion to 20-hydroxyvitamin D2 and 17,20-dihydroxyvitamin D2 FEBS J 2006 273 2891 2901 16817851 PMC1893115 source

In the paper

“Importantly, catalytic activity on non-traditional substrates such as vitamin D and ergosterol does not result in side chain cleavage, but involves sequential hydroxylations of the side chain including at C17 [[10,24–30], and see below].”

What the sources say

• Not checked yetcites [10] Tuckey RC Nguyen MN Chen J Slominski AT Baldisseri DM Tieu EW Zjawiony JK W Li Human cytochrome P450scc (CYP11A1) catalyzes epoxide formation with ergosterol Drug Metab. Dispos 2012 40 436 444 22106170 PMC3286270 source
• Not checked yetcites [24] Slominski A Semak I Zjawiony J Wortsman J W Li Szczesniewski A Tuckey RC The cytochrome P450scc system opens an alternate pathway of vitamin D3 metabolism FEBS J 2005 272 4080 4090 16098191 PMC2234577 source
• Not checked yetcites [25] Tuckey RC W Li Zjawiony JK Zmijewski MA Nguyen MN Sweatman T Miller D Slominski A Pathways and products for the metabolism of vitamin D3 by cytochrome P450scc FEBS J 2008 275 2585 2596 18410379 PMC2562691 source
• Not checked yetcites [26] Tuckey RC Li W Shehabi HZ Janjetovic Z Nguyen MN Chen TK Kim J Howell DE Benson HA Sweatman T Baldisseri DM Slominski A Production of 22-hydroxy-metabolites of vitamin D3 by cytochrome P450scc (CYP11A1) and analysis of their biological activities on skin cells Drug Metab. Dispos 2011 39 1577 1588 21677063 PMC3164270 source
• Not checked yetcites [27] Slominski AT Kim TK Shehabi HZ Semak I Tang EK Nguyen MN Benson HA Korik E Janjetovic Z Chen J Yates CR Postlethwaite A Li W Tuckey RC In vivo evidence for a novel pathway of vitamin D(3) metabolism initiated by P450scc and modified by CYP27B1 FASEB J 2012 26 3901 3915 22683847 PMC3425822 source
• Not checked yetcites [28] Nguyen MN Slominski A W Li Ng YR Tuckey RC Metabolism of vitamin D2-17,20,24-trihydroxyvitamin D2 by cytochrome p450scc (CYPHA1) Drug Metab. Dispos 2009 37 761 767 19116262 PMC2659330 source
• Not checked yetcites [29] Slominski A Semak I Wortsman J Zjawiony J Li W Zbytek B Tuckey RC An alternative pathway of vitamin D metabolism. Cytochrome P450scc (CYP11A1)-mediated conversion to 20-hydroxyvitamin D2 and 17,20-dihydroxyvitamin D2 FEBS J 2006 273 2891 2901 16817851 PMC1893115 source
• Not checked yetcites [30] Slominski A Semak I Zjawiony J Wortsman J Gandy MN Li J Zbytek B W Li Tuckey RC Enzymatic metabolism of ergosterol by cytochrome p450scc to biologically active 17alpha,24-dihydroxyergosterol Chem. Biol 2005 12 931 939 16125105 source

In the paper

“7DHC was docked to the crystal structure of CYP11A1 in place of the 20R,22R-dihydroxycholesterol. It showed that the C22 hydrogen was closer to the heme iron than the hydrogen at C20, consistent with initial hydroxylation at C22 being favored.”

What the sources say

• Not checked yetcites [8] Slominski AT Kim TK Chen J Nguyen MN Li W Yates CR Sweatman T Janjetovic Z Tuckey RC Cytochrome P450scc-dependent metabolism of 7-dehydrocholesterol in placenta and epidermal keratinocytes Int. J. Biochem. Cell Biol 2012 44 2003 2018 22877869 PMC3520099 source

In the paper

“If reduction of the Δ24-bond occurs early, cholesterol is synthesized via the Kandutsch–Russel pathway (favored in most tissues) using 7-dehydrocholesterol as the immediate precursor of cholesterol.”

• Also stated in: § 2.1. Overview of cholesterol synthesis · plain

  “In the Bloch pathway reduction of the Δ24-bond occurs as the last enzymatic step that forms cholesterol from desmosterol.”

What the sources say

• Not checked yetcites [50] Frantz DI Jr Schroepfer GJ Sterol biosynthesis Annu. Rev. Biochem 1967 36 691 726 18257735
• Not checked yetcites [53] Waterham HR Wanders RJ Biochemical and genetic aspects of 7-dehydrocholesterol reductase and Smith-Lemli-Opitz syndrome Biochim. Biophys. Acta 2000 1529 340 356 11111101
• Not checked yetcites [54] Bae SH Paik YK Cholesterol biosynthesis from lanosterol: development of a novel assay method and characterization of rat liver microsomal lanosterol delta 24-reductase Biochem. J 1997 326 Pt 2 609 616 9291139 PMC1218712

In the paper

“The reaction involves initial hydroxylation at C22 producing 22R-hydroxycholesterol, then subsequent repositioning of the side chain in the active site resulting in a second hydroxylation at C20, producing 20R,22R-dihydroxycholesterol. This is followed by oxidative cleavage of the C20—C22 bond producing pregnenolone [1–3].”

What the sources say

• Not checked yetcites [1] Tuckey RC Progesterone synthesis by the human placenta Placenta 2005 26 273 281 15823613 source
• Not checked yetcites [2] Miller WL Auchus RJ The molecular biology, biochemistry, and physiology of human steroidogenesis and its disorders Endocr. Rev 2011 32 81 151 21051590 PMC3365799 source
• Not checked yetcites [3] Burstein S Middleditch BS Gut M Mass spectrometric study of the enzymatic conversion of cholesterol to (22R)-22-hydroxycholesterol, (20R,22R)-20,22-dihydroxycholesterol, and pregnenolone, and of (22R)-22-hydroxycholesterol to the lgycol and pregnenolone in bovine adrenocortical preparations. Mode of oxygen incorporation J. Biol. Chem 1975 250 9028 9037 1238395

In the paper

“In the classical pathway of cholesterol side chain cleavage, CYP11A1 activity is substrate limited and increased rates of cholesterol delivery cause a corresponding increase in the rate of pregnenolone synthesis.”

What the sources say

• Not checked yetcites [2] Miller WL Auchus RJ The molecular biology, biochemistry, and physiology of human steroidogenesis and its disorders Endocr. Rev 2011 32 81 151 21051590 PMC3365799 source
• Not checked yetcites [11] Miller WL Boser HS Early steps in steroidogenesis: intracellular cholesterol trafficking J. Lipid Res 2011 52 2111 2135 21976778 PMC3283258
• Not checked yetcites [12] Miller WL Steroidogenic acute regulatory protein (StAR), a novel mitochondrial cholesterol transporter Biochim. Biophys. Acta 2007 1771 663 676 17433772
• Not checked yetcites [13] Hu J Zhang Z Shen WJ Azhar S Cellular cholesterol delivery, intracellular processing and utilization for biosynthesis of steroid hormones Nutr. Metab. (Lond.) 2010 7 47 20515451 PMC2890697
• Not checked yetcites [14] Slominski A Zjawiony J Wortsman J Semak I Stewart J Pisarchik A Sweatman T Marcos J Dunbar C Tuckey RC A novel pathway for sequential transformation of 7-dehydrocholesterol and expression of the P450scc system in mammalian skin Eur. J. Biochem 2004 271 4178 4188 15511223 PMC1201497 source
• Not checked yetcites [15] Slominski A Zbytek B Nikolakis G Manna PR Skobowiat C Zmijewski M W Li Janjetovic Z Postlethwaite A Zouboulis CC Tuckey RC Steroidogenesis in the skin: implications for local immune functions J. Steroid Biochem. Mol. Biol 2013 137 107 123 23435015 PMC3674137 source

In the paper

“Purified human CYP11A1 acts on the fungal membrane sterol, ergosterol, also available through the diet. No cleavage of the side chain occurs due to the presence of the double bond at C22. Rather, the C22=C23 double bond undergoes epoxidation to produce 20-hydroxy-22,23-epoxy-22,23-dihydroergosterol. The other major product is 22-keto-23-hydroxy-22,23-dihydroergosterol.”

What the sources say

• Not checked yetcites [10] Tuckey RC Nguyen MN Chen J Slominski AT Baldisseri DM Tieu EW Zjawiony JK W Li Human cytochrome P450scc (CYP11A1) catalyzes epoxide formation with ergosterol Drug Metab. Dispos 2012 40 436 444 22106170 PMC3286270 source

In the paper

“CYP21A2 does not appear to use 7DHP as a substrate, similar to its inability to act on pregnenolone [65].”

What the sources say

• Not checked yetcites [65] Sushko TA Gilep AA Yantsevich AV Usanov SA Role of microsomal steroid hydroxylases in Delta7-steroid biosynthesis Biochemistry (Mosc.) 2013 78 282 289 23586722

In the paper

“Human and bovine CYP11A1 have been shown to cleave the side chain of cholesterol sulfate, with lower catalytic efficiency than cholesterol for the purified enzymes [71], but at higher rates than cholesterol by CYP11A1 in ovarian mitochondria, due to its more rapid movement to the inner mitochondrial membrane [72].”

What the sources say

• Not checked yetcites [71] Tuckey RC Lawrence J Cameron KJ Side-chain cleavage of cholesterol esters by human cytochrome P-450(scc) J. Steroid Biochem. Mol. Biol 1996 58 605 610 8918988
• Not checked yetcites [72] Tuckey RC Side-chain cleavage of cholesterol sulfate by ovarian mitochondria J. Steroid Biochem. Mol. Biol 1990 37 121 127 2242345

In the paper

“17α,24-Dihydroxyergosterol is biologically active on cultured human skin cells, inhibiting DNA synthesis, but the other products remain to be tested, as does any in vivo function.”

What the sources say

• Not checked yetcites [30] Slominski A Semak I Zjawiony J Wortsman J Gandy MN Li J Zbytek B W Li Tuckey RC Enzymatic metabolism of ergosterol by cytochrome p450scc to biologically active 17alpha,24-dihydroxyergosterol Chem. Biol 2005 12 931 939 16125105 source

In the paper

“Bovine CYP11A1 also acts on ergosterol but the product profile varies compared to that seen for human CYP11A1, with major products including 24-hydroxyergosterol and 17α,24-dihydroxyergosterol [30].”

What the sources say

• Not checked yetcites [30] Slominski A Semak I Zjawiony J Wortsman J Gandy MN Li J Zbytek B W Li Tuckey RC Enzymatic metabolism of ergosterol by cytochrome p450scc to biologically active 17alpha,24-dihydroxyergosterol Chem. Biol 2005 12 931 939 16125105 source

In the paper

“The above findings are consistent with a well described phenomenon of increased accumulation of 7DHC, and production of 7DHP and its downstream steroid metabolites in Smith-Lemli-Opitz syndrome (SLOS), characterized by a deficiency of 7DHC Δ-reductase [58–61].”

What the sources say

• Not checked yetcites [58] Nowaczyk MJ Waye JS The Smith-Lemli-Opitz syndrome: a novel metabolic wayofunderstanding developmental biology, embryogenesis, and dysmorphology Clin. Genet 2001 59 375 386 11453964
• Not checked yetcites [59] Tint GS Irons M Elias ER Batta AK Frieden R Chen TS Salen G Defective cholesterol biosynthesis associated with the Smith-Lemli-Opitz syndrome N. Engl. J. Med 1994 330 107 113 8259166
• Not checked yetcites [60] Shackleton CH Roitman E Kelley R Neonatal urinary steroids in Smith-Lemli-Opitz syndrome associated with 7-dehydrocholesterol reductase deficiency Steroids 1999 64 481 490 10443904
• Not checked yetcites [61] Shackleton CH Role of a disordered steroid metabolome in the elucidation of sterol and steroid biosynthesis Lipids 2012 47 1 12 21874273 PMC3564490

In the paper

“CYP11A1 initially hydroxylates lumisterol 3 at C22 or C24. 22-Hydroxylumisterol is then hydroxylated at C20 producing 20,22-dihydroxylumisterol 3 and some of this undergoes hydroxylation at other sites while some undergoes cleavage to pregnalumisterol [31].”

What the sources say

• Not checked yetcites [31] Tuckey RC Slominski AT Y Cheng C Chen J K Kim T Xiao M W Li Lumisterol is metabolized by CYP11A1: discovery of a new pathway Int. J. Biochem. Cell Biol 2014 55 24 34 25130438 PMC4252613 source

In the paper

“Pregnalumisterol and some synthetic hydroxylumisterol 3 derivatives exhibit biological activity [76,77] further suggesting that metabolism of lumisterol by CYP11A1 in the skin may produce metabolites with physiological activity.”

What the sources say

• Not checked yetcites [76] Dixon KM Norman AW Sequeira VB Mohan R Rybchyn MS Reeve VE Halliday GM Mason RS 1alpha 25(OH)(2)-vitamin D and a nongenomic vitamin D analogue inhibit ultraviolet radiation-induced skin carcinogenesis Cancer Prev. Res. (Phila.) 2011 4 1485 1494 21733837
• Not checked yetcites [77] Slominski AT Janjetovic Z Fuller BE Zmijewski MA Tuckey RC Nguyen MN Sweatman T Li W Zjawiony J Miller D Chen TC Lozanski G Holick MF Products of vitamin D3 or 7-dehydrocholesterol metabolism by cytochrome P450scc show anti-leukemia effects, having low or absent calcemic activity PLoS ONE 2010 5 e9907 20360850 PMC2845617 source

In the paper

“These studies defined the conversions: D3→20(OH)D3→20,23(OH)2D3→17,20,23(OH)3D3 as the major pathway of vitamin D3 metabolism by CYP11A1 with D3 → 20(OH)D3 + 22(OH)D3 → 20,22(OH)2D3 as a minor pathway [103].”

What the sources say

• Not checked yetcites [103] Slominski AT Kim Li TKW Yi AK Postlethwaite A Tuckey RC The role of CYP11A1 in the production of vitamin D metabolites and their role in the regulation of epidermal functions J. Steroid Biochem. Mol. Biol 2014 144PA 28 39 24176765 PMC4002668 source

In the paper

“However, the conversion of vitamin D3 to 20(OH)D3 by CYP11A1 is less efficient (lower Kcat/Km) than hydroxylation of cholesterol by this enzyme [25], supported by molecular modeling [7], with bovine CYP11A1 metabolizing vitamin D3 more efficiently than the human enzyme [7,25,27].”

What the sources say

• Not checked yetcites [7] Strushkevich N MacKenzie F Cherkesova T Grabovec I Usanov S Park HW Structural basis for pregnenolone biosynthesis by the mitochondrial monooxygenase system Proc. Natl. Acad. Sci. U. S. A 2011 108 10139 10143 21636783 PMC3121847 source
• Not checked yetcites [25] Tuckey RC W Li Zjawiony JK Zmijewski MA Nguyen MN Sweatman T Miller D Slominski A Pathways and products for the metabolism of vitamin D3 by cytochrome P450scc FEBS J 2008 275 2585 2596 18410379 PMC2562691 source
• Not checked yetcites [27] Slominski AT Kim TK Shehabi HZ Semak I Tang EK Nguyen MN Benson HA Korik E Janjetovic Z Chen J Yates CR Postlethwaite A Li W Tuckey RC In vivo evidence for a novel pathway of vitamin D(3) metabolism initiated by P450scc and modified by CYP27B1 FASEB J 2012 26 3901 3915 22683847 PMC3425822 source

In the paper

“The products can be further hydroxylated by CYP27B1, CYP27A1, and CYP24A1 (reviewed in [103], and see below), which is an alternative to the classical pathway (see above), although its physiological importance remains to be established.”

What the sources say

• Not checked yetcites [103] Slominski AT Kim Li TKW Yi AK Postlethwaite A Tuckey RC The role of CYP11A1 in the production of vitamin D metabolites and their role in the regulation of epidermal functions J. Steroid Biochem. Mol. Biol 2014 144PA 28 39 24176765 PMC4002668 source

In the paper

“Importantly, CYP11A1 does not metabolize 25-hydroxyvitamin D3 indicating that hydroxylation at C25 protects the secosteroid against hydroxylation of the side chain by CYP11A1 [24] and therefore, that this enzyme does not compete with CYP27B1 for activation of 25(OH)D3 [103].”

What the sources say

• Not checked yetcites [24] Slominski A Semak I Zjawiony J Wortsman J W Li Szczesniewski A Tuckey RC The cytochrome P450scc system opens an alternate pathway of vitamin D3 metabolism FEBS J 2005 272 4080 4090 16098191 PMC2234577 source
• Not checked yetcites [103] Slominski AT Kim Li TKW Yi AK Postlethwaite A Tuckey RC The role of CYP11A1 in the production of vitamin D metabolites and their role in the regulation of epidermal functions J. Steroid Biochem. Mol. Biol 2014 144PA 28 39 24176765 PMC4002668 source

In the paper

“An excellent docking score for 8-dehydrocholesterol in conjunction with the presence of Δ8-steroids in body fluids of SLOS patients [60,61,63,64], predicts that it is also a substrate for CYP11A1 that undergoes cleavage of its side chain similar to 7-DHC and cholesterol.”

What the sources say

• Not checked yetcites [60] Shackleton CH Roitman E Kelley R Neonatal urinary steroids in Smith-Lemli-Opitz syndrome associated with 7-dehydrocholesterol reductase deficiency Steroids 1999 64 481 490 10443904
• Not checked yetcites [61] Shackleton CH Role of a disordered steroid metabolome in the elucidation of sterol and steroid biosynthesis Lipids 2012 47 1 12 21874273 PMC3564490
• Not checked yetcites [63] Marcos J Guo LW Wilson WK Porter FD Shackleton C The implications of 7-dehydrosterol-7-reductase deficiency (Smith-Lemli-Opitz syndrome) to neurosteroid production Steroids 2004 69 51 60 14715377
• Not checked yetcites [64] Shackleton C Roitman E Guo LW Wilson WK Porter FD Identification of 7(8) and 8(9) unsaturated adrenal steroid metabolites produced by patients with 7-dehydrosterol-delta7-reductase deficiency (Smith-Lemli-Opitz syndrome) J. Steroid Biochem. Mol. Biol 2002 82 225 232 12477489

In the paper

“In summary, ex-vivo, ex-utero, and cell culture studies indicate that D2 can be metabolized in vivo in tissues expressing CYP11A1, with further modification of products by CYP27B1, with metabolite profiles that are tissues- and cell-type specific [9].”

What the sources say

• Not checked yetcites [9] Slominski AT Kim TK Shehabi HZ Tang EK Benson HA Semak I Lin Z Yates CR Wang J W Li Tuckey RC In vivo production of novel vitamin D2 hydroxy-derivatives by human placentas, epidermal keratinocytes Caco-2 colon cells and the adrenal gland Mol. Cell. Endocrinol 2014 383 181 192 24382416 PMC3997123

In the paper

“Interestingly, 7-dehydrodesmosterol and lathosterol intermediates of the cholesterol biosynthetic pathway, as well as tachysterol which is a product of UVB transformation of pre-D, have excellent docking scores suggesting that they could also serve as substrates for CYP11A1 in tissues expressing this enzyme and producing sufficient concentrations of these compounds.”

In the paper

“Thus, the active site of CYP11A1 can accommodate a range of steroids but it should be emphasized that they are all closely related to cholesterol in structure, with the biggest structural variation being for the secosteroids which contain a broken B-ring.”

In the paper

“The structure of the substrate affects both the regio-selectivity of hydroxylation and the catalytic efficiency.”

In the paper

“Despite the presence of a Δ7 double bond in ergosterol it does not undergo cleavage due to the C22=C23 double bond in the side chain making it unfavorable to undergo hydroxylation at C22.”

In the paper

“It can generate several intermediates and products that are biologically active in a context dependent manner when administered exogenously, but for which physiological roles remain to be defined.”