Objective: ATP6V0d2 is a subunit of the vacuolar-type H+-ATPase (V-ATPase) that pumps H+ ions into lysosomes. TRPML1 (MCOLN1/Mcoln1) transports cations out of lysosomes.Mcoln1^(-/-) mice recapitulate the lysosomal sto...Objective: ATP6V0d2 is a subunit of the vacuolar-type H+-ATPase (V-ATPase) that pumps H+ ions into lysosomes. TRPML1 (MCOLN1/Mcoln1) transports cations out of lysosomes.Mcoln1^(-/-) mice recapitulate the lysosomal storage disorder mucolipidosis type IV (MLIV) phenotype. We previously demonstrated thatMcoln1^(-/-) female mice quickly became infertile at 5 months old (5M) with degenerating corpora lutea (CL) and progesterone (P4) deficiency. We tested our hypothesis thatAtp6v0d2 deficiency could partially compensate forMcoln1 deficiency to restore CL functions inAtp6v0d2^(-/-)Mcoln1^(-/-) mice.Methods: Control andAtp6v0d2^(-/-)Mcoln1^(-/-) female mice underwent fertility test from 2M to 7M. A subset of them was dissected at 5M on day 3.5 post-coitum (D3.5). The D3.5 ovaries from 5M control,Mcoln1^(-/-), andAtp6v0d2^(-/-)Mcoln1^(-/-) mice were evaluated for CL morphology, lipid droplet staining, and markers of mitochondria and P4 steroidogenesis in the luteal cells.Results: The fertility test ofAtp6v0d2^(-/-)Mcoln1^(-/-) female mice (2M–7M) revealed normal mating activity but reduced fertility compared with the control;yet ~25% of them remained fertile at 5M to 7M but with dystocia. We analyzed a subset of 11Atp6v0d2^(-/-)Mcoln1^(-/-) mice (5M) in the fertility test on D3.5: three (27.3%) had normal P4 levels and all examined CL parameters, indicating full restoration of CL function compared withMcoln1^(-/-), whereas eight had P4 deficiency, with two (18.2%) infertile and six (54.5%) once fertile. In contrast toMcoln1^(-/-) CLs, which had extensive amorphous cellular debris, indicating cell degeneration,Atp6v0d2^(-/-)Mcoln1^(-/-) CLs had reduced amorphous cellular debris regardless of P4 levels. However, similar toMcoln1^(-/-) CLs, P4-deficientAtp6v0d2^(-/-)Mcoln1^(-/-) CLs showed impaired differentiation, enlarged lipid droplets, disorganized expression of endothelial basal lamina marker collagen IV, and reduced expression of mitochondrial marker heat shock protein 60 (HSP60) and steroidogenesis rate-limiting protein StAR, indicating that additionalAtp6v0d2 deficiency compensates forMcoln1 deficiency-induced cell degeneration, but is insufficient to restore luteal cell differentiation and P4 steroidogenesis in P4-deficientAtp6v0d2^(-/-)Mcoln1^(-/-) CLs.Conclusion: This study shows thatAtp6v0d2^(-/-)Mcoln1^(-/-) CLs had varied improvements compared withMcoln1^(-/-) CLs, and it providesin vivo genetic evidence of the coordination between different lysosomal channels in CL function.展开更多
Dear Editor, mTORCI, as a center regulatory hub of metabolism, senses the cellular energy status, nutrition and extracellular stimuli and regulates cell growth, differentiation and functions of immune cells (Powell et...Dear Editor, mTORCI, as a center regulatory hub of metabolism, senses the cellular energy status, nutrition and extracellular stimuli and regulates cell growth, differentiation and functions of immune cells (Powell et al., 2012). Lysosomal localization of key signal comp orients is critical for mTORCI activati on: mTORCI activation requires co-localization of activated Rheb and mTORCI to the lysosome membrane (Buerger et al., 2006). Signals in eluding growth factors, cellular stresses and energy levels act on the disruption the formation of tuberous sclerosis complex (TSC) complex, comprised of TSC1, TSC2 and TBC1D7, which leads to the translocation and activation of Rheb on the lysosome membrane (Dibble et al., 2012). In response to nutrient levels, specifically the availability of amino acids and glucose (Efeyan et al., 2013), mTORCI is recruited to the lysosomal surface by Rag GTPases that are heterodimers of RagA or RagC bound to RagB or RagD. Multiple protein complexes have been implicated in regulation of mTORCI upon nutrient sensing including Ragulator, GATOR1, GATOR2, KICSTOR and vacuolar ATPases (Wolfson et al., 2017). Vacuolar ATPases are large multiple-protein complexes that acidify the lysosome and may mediate additional functions independent of their proton pump activity (Nishi and Forgac, 2002).展开更多
基金funded by NIH R01HD065939(co-funded by ORWH and NICHD)NIH R03HD097384NIH R03 HD100652 to X.Y.
文摘Objective: ATP6V0d2 is a subunit of the vacuolar-type H+-ATPase (V-ATPase) that pumps H+ ions into lysosomes. TRPML1 (MCOLN1/Mcoln1) transports cations out of lysosomes.Mcoln1^(-/-) mice recapitulate the lysosomal storage disorder mucolipidosis type IV (MLIV) phenotype. We previously demonstrated thatMcoln1^(-/-) female mice quickly became infertile at 5 months old (5M) with degenerating corpora lutea (CL) and progesterone (P4) deficiency. We tested our hypothesis thatAtp6v0d2 deficiency could partially compensate forMcoln1 deficiency to restore CL functions inAtp6v0d2^(-/-)Mcoln1^(-/-) mice.Methods: Control andAtp6v0d2^(-/-)Mcoln1^(-/-) female mice underwent fertility test from 2M to 7M. A subset of them was dissected at 5M on day 3.5 post-coitum (D3.5). The D3.5 ovaries from 5M control,Mcoln1^(-/-), andAtp6v0d2^(-/-)Mcoln1^(-/-) mice were evaluated for CL morphology, lipid droplet staining, and markers of mitochondria and P4 steroidogenesis in the luteal cells.Results: The fertility test ofAtp6v0d2^(-/-)Mcoln1^(-/-) female mice (2M–7M) revealed normal mating activity but reduced fertility compared with the control;yet ~25% of them remained fertile at 5M to 7M but with dystocia. We analyzed a subset of 11Atp6v0d2^(-/-)Mcoln1^(-/-) mice (5M) in the fertility test on D3.5: three (27.3%) had normal P4 levels and all examined CL parameters, indicating full restoration of CL function compared withMcoln1^(-/-), whereas eight had P4 deficiency, with two (18.2%) infertile and six (54.5%) once fertile. In contrast toMcoln1^(-/-) CLs, which had extensive amorphous cellular debris, indicating cell degeneration,Atp6v0d2^(-/-)Mcoln1^(-/-) CLs had reduced amorphous cellular debris regardless of P4 levels. However, similar toMcoln1^(-/-) CLs, P4-deficientAtp6v0d2^(-/-)Mcoln1^(-/-) CLs showed impaired differentiation, enlarged lipid droplets, disorganized expression of endothelial basal lamina marker collagen IV, and reduced expression of mitochondrial marker heat shock protein 60 (HSP60) and steroidogenesis rate-limiting protein StAR, indicating that additionalAtp6v0d2 deficiency compensates forMcoln1 deficiency-induced cell degeneration, but is insufficient to restore luteal cell differentiation and P4 steroidogenesis in P4-deficientAtp6v0d2^(-/-)Mcoln1^(-/-) CLs.Conclusion: This study shows thatAtp6v0d2^(-/-)Mcoln1^(-/-) CLs had varied improvements compared withMcoln1^(-/-) CLs, and it providesin vivo genetic evidence of the coordination between different lysosomal channels in CL function.
文摘Dear Editor, mTORCI, as a center regulatory hub of metabolism, senses the cellular energy status, nutrition and extracellular stimuli and regulates cell growth, differentiation and functions of immune cells (Powell et al., 2012). Lysosomal localization of key signal comp orients is critical for mTORCI activati on: mTORCI activation requires co-localization of activated Rheb and mTORCI to the lysosome membrane (Buerger et al., 2006). Signals in eluding growth factors, cellular stresses and energy levels act on the disruption the formation of tuberous sclerosis complex (TSC) complex, comprised of TSC1, TSC2 and TBC1D7, which leads to the translocation and activation of Rheb on the lysosome membrane (Dibble et al., 2012). In response to nutrient levels, specifically the availability of amino acids and glucose (Efeyan et al., 2013), mTORCI is recruited to the lysosomal surface by Rag GTPases that are heterodimers of RagA or RagC bound to RagB or RagD. Multiple protein complexes have been implicated in regulation of mTORCI upon nutrient sensing including Ragulator, GATOR1, GATOR2, KICSTOR and vacuolar ATPases (Wolfson et al., 2017). Vacuolar ATPases are large multiple-protein complexes that acidify the lysosome and may mediate additional functions independent of their proton pump activity (Nishi and Forgac, 2002).
