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Exploring the genetic basis of congenital cataracts in two families identifies a molecule, lanosterol, which prevents intracellular protein aggregation of various cataract-causing mutant crystallins, and which can reduce cataract severity and increase lens transparency in vivo in dogs. Lanosterol counters cataract formation In a study of the genetic basis of congenital cataract formation in two families, Kang Zhang and colleagues demonstrate that lanosterol, a sterol present naturally in the lens, can prevent intracellular aggregation of various cataract-causing mutant crystallin proteins. The mutations identified in the genetic study impair the function of lanosterol synthase, an enzyme for synthesizing lanosterol. In dogs with naturally occurring cataracts, the application of eye drops containing lanosterol for six weeks reduced cataract severity and increased lens transparency, suggesting that lanosterol or molecules with similar activity might provide an alternative to surgery for the management of cataracts. The human lens is comprised largely of crystallin proteins assembled into a highly ordered, interactive macro-structure essential for lens transparency and refractive index. Any disruption of intra- or inter-protein interactions will alter this delicate structure, exposing hydrophobic surfaces, with consequent protein aggregation and cataract formation. Cataracts are the most common cause of blindness worldwide, affecting tens of millions of people 1 , and currently the only treatment is surgical removal of cataractous lenses. The precise mechanisms by which lens proteins both prevent aggregation and maintain lens transparency are largely unknown. Lanosterol is an amphipathic molecule enriched in the lens. It is synthesized by lanosterol synthase (LSS) in a key cyclization reaction of a cholesterol synthesis pathway. Here we identify two distinct homozygous LSS missense mutations (W581R and G588S) in two families with extensive congenital cataracts. Both of these mutations affect highly conserved amino acid residues and impair key catalytic functions of LSS. Engineered expression of wild-type, but not mutant, LSS prevents intracellular protein aggregation of various cataract-causing mutant crystallins. Treatment by lanosterol, but not cholesterol, significantly decreased preformed protein aggregates both in vitro and in cell-transfection experiments. We further show that lanosterol treatment could reduce cataract severity and increase transparency in dissected rabbit cataractous lenses in vitro and cataract severity in vivo in dogs. Our study identifies lanosterol as a key molecule in the prevention of lens protein aggregation and points to a novel strategy for cataract prevention and treatment.

Visceral leishmaniasis is a life-threatening parasitic disease, but current antileishmanial drugs have severe drawbacks. Antifungal azoles inhibit the activity of cytochrome P450 (CYP) 51 enzymes which are responsible for removing the C14α-methyl group of lanosterol, a key step in ergosterol biosynthesis in Leishmania . However, they exhibit varying degrees of antileishmanial activities in culture, suggesting the existence of unrecognized molecular targets. Our previous study reveals that, in Leishmania , lanosterol undergoes parallel C4- and C14-demethylation to form 4α,14α-dimethylzymosterol and T-MAS, respectively. In the current study, CYP5122A1 is identified as a sterol C4-methyl oxidase that catalyzes the sequential oxidation of lanosterol to form C4-oxidation metabolites. CYP5122A1 is essential for both L. donovani promastigotes in culture and intracellular amastigotes in infected mice. CYP5122A1 overexpression results in growth delay, increased tolerance to stress, and altered expression of lipophosphoglycan and proteophosphoglycan. CYP5122A1 also helps to determine the antileishmanial effect of antifungal azoles in vitro. Dual inhibitors of CYP51 and CYP5122A1 possess superior antileishmanial activity against L. donovani promastigotes whereas CYP51-selective inhibitors have little effect on promastigote growth. Our findings uncover the critical biochemical and biological role of CYP5122A1 in L. donovani and provide an important foundation for developing new antileishmanial drugs by targeting both CYP enzymes. CYP5122A1 is a sterol C4-methyl oxidase that catalyzes the sequential oxidation of lanosterol, is essential for both Leishmania donovani promastigotes in culture and intracellular amastigotes in infected mice, and provides a new target for antileishmanial drug discovery.

Skin lesions, cataracts, and congenital anomalies have been frequently associated with inherited deficiencies in enzymes that synthesize cholesterol. Lanosterol synthase (LSS) converts (S)-2,3-epoxysqualene to lanosterol in the cholesterol biosynthesis pathway. Biallelic mutations in LSS have been reported in families with congenital cataracts and, very recently, have been reported in cases of hypotrichosis. However, it remains to be clarified whether these phenotypes are caused by LSS enzymatic deficiencies in each tissue, and disruption of LSS enzymatic activity in vivo has not yet been validated. We identified two patients with novel biallelic LSS mutations who exhibited congenital hypotrichosis and midline anomalies but did not have cataracts. We showed that the blockade of the LSS enzyme reaction occurred in the patients by measuring the (S)-2,3-epoxysqualene/lanosterol ratio in the forehead sebum, which would be a good biomarker for the diagnosis of LSS deficiency. Epidermis-specific Lss knockout mice showed neonatal lethality due to dehydration, indicating that LSS could be involved in skin barrier integrity. Tamoxifen-induced knockout of Lss in the epidermis caused hypotrichosis in adult mice. Lens-specific Lss knockout mice had cataracts. These results confirmed that LSS deficiency causes hypotrichosis and cataracts due to loss-of-function mutations in LSS in each tissue. These mouse models will lead to the elucidation of the pathophysiological mechanisms associated with disrupted LSS and to the development of therapeutic treatments for LSS deficiency.

The frequency of autoimmune diseases such as rheumatoid arthritis is increasing annually. Current treatments for these diseases cause new problems due to their side effects. In this study, we investigated the impact of Ganoderic Acid A (GAA), a potent anti-inflammatory herbal molecule, to evaluate the potential efficacy of GAA in alleviating Rheumatoid arthritis (RA)-associated clinical and histopathological manifestations. 40 Balb/c male mice were randomly divided into five groups (n = mice number per each group) as control (C), acetic acid (AA), rheumatoid arthritis (RA), low dose GAA (LGA) and high dose GAA (HGA) groups. Collagen emulsion was applied intra-articularly (ia), and complete Freund’s adjuvant (CFA) was applied subcutaneously (sc) to the RA and GA groups to induce an experimental model of rheumatoid arthritis. Other groups were given physiologic saline (PS) or AA at the same dose and in the same way. The procedures were repeated on the 22nd day; however, incomplete Freund’s adjuvant was applied to the RA and GA groups instead of CFA. PS was given to groups C, AA and RA for 9 days starting from the 22nd day; GAA was applied to the LGA (20 mg/kg) and HGA (40 mg/kg) groups by gavage. We evaluated body weight, arthritis score, knee temperature, knee circumference, behavioural assessment of pain, gait, tail-flick test, hot plate test, locomotor activity test, lower extremity index, spectrophotometric and histopathological evaluation methods, respectively. Compared to the RA group, the clinical arthritis score was reduced in the HGA group (p < 0.05). GAA significantly reduced knee temperatures and knee circumference, with changes in hot plate scores and tail flip test response. In the GAA groups, serum concentrations of AST, IL-6, TNF-α, NFkB were reduced, and joint damage and arthritis scores were also reduced histologically (p < 0.05). The results of this study suggest that the arthritis regressed with GAA treatment. Edema and inflammation were found to be reduced in the GAA groups compared with the RA group. GAA treatment resulted in significant improvements in behavioural activity, reduced inflammation and the damage to cartilage and bone structure and had an antinociceptive effect.

Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common life-threatening monogenetic diseases characterized by progressive enlargement of fluid-filled renal cysts. Our previous study has shown that Ganoderma triterpenes (GT) retards PKD renal cyst development. In the present study we identified the effective ingredient of GT in suppression of kidney cyst development. Using an in vitro MDCK cystogenesis model, we identified ganoderic acid A (GA-A) as the most promising candidate among the 12 ganoderic acid (GA) monomers. We further showed that GA-A (6.25−100 μM) significantly inhibited cyst growth in MDCK cyst model and embryonic kidney cyst model in vitro, and the inhibitory effect was reversible. In kidney-specific Pkd1 knockout (kPKD) mice displaying severe cystic kidney disease, administration of GA-A (50 mg· kg −1  ·d −1 , sc) significantly attenuated renal cyst development. In both MDCK cells and kidney of kPKD mice, we revealed that GA-A dose-dependently downregulated the Ras/MAPK signaling pathway. The expression of proliferating cell nuclear antigen (PCNA) was also suppressed, suggesting a possible effect of GA-A on cell proliferation. These experimental data suggest that GA-A may be the main ingredient of GT as a potential therapeutic reagent for treating ADPKD.

Cataract caused by crystallin aggregation is the leading cause of vision impairment and blindness globally. The only available treatment option so far is surgery. In this study, we leverage lipid nanoparticles (LNPs)-formulated mRNA encoding human lanosterol synthase (hLSS) to elevate lanosterol levels in the lens as a potential anti-cataract therapy. hLSS mRNA delivered with aromatized LNPs can be avidly taken up and translated into hLSS proteins in mammalian cells. mRNA formulations administered via intravitreal, subconjunctival, intracameral, or subretinal injection in rats display distinct kinetics and bio-distribution profiles, among which intracameral injection achieves sustained and selective protein expression in the lens. In comparison to clinically used LNPs, aromatized LNPs show more than seven-fold higher mRNA delivery potency in rats upon intracameral injection, without inducing significant ocular lesions. Furthermore, ocular delivery of hLSS mRNA-loaded formulations leads to elevated levels of hLSS proteins and lanosterol within the lens and a remarkable improvement in cataract symptoms in two rat models of cataract. Collectively, topical delivery of hLSS mRNA-LNPs to the eyes offers a potential strategy to reduce intracellular aggregation of crystallins and ameliorate cataract development. Surgery is currently the only treatment option for cataract. Here, the authors report on ocular delivery of lipid nanoparticles-formulated mRNA encoding lanosterol synthase as a potential anti-cataract therapy, which ameliorates cataract development in two rat cataract models.

Triterpene synthases, also known as 2,3-oxidosqualene cyclases (OSCs), synthesize diverse triterpene skeletons that form the basis of an array of functionally divergent steroids and triterpenoids. Tetracyclic and pentacyclictriterpene skeletons are synthesized via protosteryl and dammarenylcations, respectively. The mechanism of conversion between two scaffolds is not well understood. Here, we report a promiscuous OSC from rice (Oryza sativa) (OsOS) that synthesizes a novel pentacyclictriterpeneorysatinol as its main product. The OsOS gene is widely distributed in indica subspecies of cultivated rice and in wild rice accessions. Previously, we havecharacterized a different OSC, OsPS, a tetracyclic parkeol synthase found in japonica subspecies. Phylogenetic and protein structural analyses identified three key amino acid residues (#732, #365, #124) amongst 46 polymorphic sites that determine functional conversion between OsPS and OsOS, specifically, the chair–semi(chair)–chair and chair–boat–chair interconversions. The different orientation of a fourth amino acid residue Y257 was shown to be important for functional conversion The discovery of orysatinol unlocks a new path to triterpene diversity in nature. Our findings also reveal mechanistic insights into the cyclization of oxidosqualene into tetra- and pentacyclic skeletons, and provide a new strategy to identify key residues determining OSC specificity.

A recent study discovered a novel, complex developmental disability syndrome, most likely caused by maternal fentanyl use disorder. This Fetal Fentanyl Syndrome (FFS) is biochemically characterized by elevated 7-dehydrocholesterol (7-DHC) levels in neonates, raising the question if fentanyl inhibition of the dehydrocholesterol reductase 7 (DHCR7) enzyme is causal for the emergence of the pathophysiology and phenotypic features of FFS . To test this hypothesis, we undertook a series of experiments on Neuro2a cells, primary mouse neuronal and astrocytic cultures, and human dermal fibroblasts (HDFs) with DHCR7 +/+ and DHCR7 +/ − genotype. Our results revealed that in vitro exposure to fentanyl disrupted sterol biosynthesis across all four in vitro models. The sterol biosynthesis disruption by fentanyl was complex, and encompassed the majority of post-lanosterol intermediates, including elevated 7-DHC and decreased desmosterol (DES) levels across all investigated models. The overall findings suggested that maternal fentanyl use in the context of an opioid use disorder leads to FFS in the developing fetus through a strong disruption of the whole post-lanosterol pathway that is more complex than a simple DHCR7 inhibition. In follow-up experiments we found that heterozygous DHCR7 +/ − HDFs were significantly more susceptible to the sterol biosynthesis inhibitory effects of fentanyl than wild-type DHCR7 +/+ fibroblasts. These data suggest that DHCR7 +/ − heterozygosity of mother and/or developing child (and potentially other sterol biosynthesis genes), when combined with maternal fentanyl use disorder, might be a significant contributory factor to the emergence of FFS in the exposed offspring. In a broader context, we believe that evaluation of new and existing medications for their effects on sterol biosynthesis should be an essential consideration during drug safety determinations, especially in pregnancy.

Static liquid culture of Ganoderma lucidum, a traditional Chinese medicinal mushroom, is a proven technology for producing ganoderic acids, which are secondary metabolites that possess antitumor properties. In this work, the addition of phenobarbital, a P450 inducer, was used to enhance the production of total and individual ganoderic acids in a two-stage cultivation involving a period of initial shake flask culture followed by static liquid culture of G. lucidum. The dosage and time of phenobarbital induction were critical for the enhanced production of ganoderic acids. The addition of 100 μM (final concentration) phenobarbital on day 5 after the shake flask culture was converted to the static liquid culture was found to be optimal, resulting in a maximal amount of total ganoderic acids of 41.4 ± 0.6 mg/g cell dry weight and increases in the levels of ganoderic acid-Mk, -T, -S, and -Me in the treated cells by 47%, 28%, 36%, and 64%, respectively. Meanwhile, the accumulation of lanosterol, a key intermediate, was found to decrease and transcriptions of three key genes encoding 3-hydroxy-3-methylglutaryl coenzyme A reductase, squalene synthase, and lanosterol synthase in the triterpene biosynthetic pathway were up-regulated under phenobarbital induction. This work demonstrated a useful strategy for the enhanced production of ganoderic acids by G. lucidum.

The paradigm that cataracts are irreversible and that vision from cataracts can only be restored through surgery has recently been challenged by reports that oxysterols such as lanosterol and 25-hydroxycholesterol can restore vision by binding to αB-crystallin chaperone protein to dissolve or disaggregate lenticular opacities. To confirm this premise, in vitro rat lens studies along with human lens protein solubilization studies were conducted. Cataracts were induced in viable rat lenses cultured for 48 hours in TC-199 bicarbonate media through physical trauma, 10 mM ouabain as Na+/K+ ATPase ion transport inhibitor, or 1 mM of an experimental compound that induces water influx into the lens. Subsequent 48-hour incubation with 15 mM of lanosterol liposomes failed to either reverse these lens opacities or prevent the further progression of cataracts to the nuclear stage. Similarly, 3-day incubation of 47-year old human lenses in media containing 0.20 mM lanosterol or 60-year-old human lenses in 0.25 and 0.50 mM 25-hydroxycholesterol failed to increase the levels of soluble lens proteins or decrease the levels of insoluble lens proteins. These binding studies were followed up with in silico binding studies of lanosterol, 25-hydroxycholesterol, and ATP as a control to two wild type ( 2WJ7 and 2KLR ) and one R120G mutant ( 2Y1Z ) αB-crystallins using standard MOE TM (Molecular Operating Environment) and Schrödinger’s Maestro software. Results confirmed that compared to ATP, both oxysterols failed to reach the acceptable threshold binding scores for good predictive binding to the αB-crystallins. In summary, all three studies failed to provide evidence that lanosterol or 25-hydroxycholesterol have either anti-cataractogenic activity or bind aggregated lens protein to dissolve cataracts.