LCM-seq reveals unique transcriptional adaptation mechanisms of resistant neurons and identifies protective pathways in spinal muscular atrophy

Nichterwitz, Susanne; Nijssen, Jik; Storvall, Helena; Schweingruber, Christoph; Comley, Laura H.; Allodi, Ilary; Lee, Mirjam van der; Deng, Qiaolin; Sandberg, Rickard; Hedlund, Eva

doi:10.1101/gr.265017.120

Cited by 37 publications

(37 citation statements)

References 84 publications

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“…Embryos were obtained from Friend leukaemia virus B (FVB) mice (University of Seville Animal Core Facility). Dissection of the spinal cord from embryonic (E12.5) were followed by the separation of neurons from the spinal cord tissue through mechanical and enzymatic cleavage as described 40 , 41 with modifications. Briefly, spinal cords were dissected and meninges removed.…”

Section: Methodsmentioning

confidence: 99%

The metabesity factor HMG20A potentiates astrocyte survival and reactive astrogliosis preserving neuronal integrity

Lorenzo¹,

Vázquez²,

López-Noriega³

et al. 2021

Theranostics

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Rationale: We recently demonstrated that the 'Metabesity' factor HMG20A regulates islet beta-cell functional maturity and adaptation to physiological stress such as pregnancy and pre-diabetes. HMG20A also dictates central nervous system (CNS) development via inhibition of the LSD1-CoREST complex but its expression pattern and function in adult brain remains unknown. Herein we sought to determine whether HMG20A is expressed in the adult CNS, specifically in hypothalamic astrocytes that are key in glucose homeostasis and whether similar to islets, HMG20A potentiates astrocyte function in response to environmental cues. Methods: HMG20A expression profile was assessed by quantitative PCR (QT-PCR), Western blotting and/or immunofluorescence in: 1) the hypothalamus of mice exposed or not to either a high-fat diet or a high-fat high-sucrose regimen, 2) human blood leukocytes and adipose tissue obtained from healthy or diabetic individuals and 3) primary mouse hypothalamic astrocytes exposed to either high glucose or palmitate. RNA-seq and cell metabolic parameters were performed on astrocytes treated or not with a siHMG20A. Astrocyte-mediated neuronal survival was evaluated using conditioned media from siHMG20A-treated astrocytes. The impact of ORY1001, an inhibitor of the LSD1-CoREST complex, on HMG20A expression, reactive astrogliosis and glucose metabolism was evaluated in vitro and in vivo in high-fat high-sucrose fed mice. Results: We show that Hmg20a is predominantly expressed in hypothalamic astrocytes, the main nutrient-sensing cell type of the brain. HMG20A expression was upregulated in diet-induced obesity and glucose intolerant mice, correlating with increased transcript levels of Gfap and Il1b indicative of inflammation and reactive astrogliosis. Hmg20a transcript levels were also increased in adipose tissue of obese non-diabetic individuals as compared to obese diabetic patients. HMG20A silencing in astrocytes resulted in repression of inflammatory, cholesterol biogenesis and epithelial-to-mesenchymal transition pathways which are hallmarks of reactive astrogliosis. Accordingly, HMG20A depleted astrocytes exhibited reduced mitochondrial bioenergetics and increased susceptibility to apoptosis. Neuron viability was also hindered in HMG20A-depleted astrocyte-derived conditioned media. ORY1001 treatment rescued expression of reactive astrogliosis-linked genes in HMG20A ablated astrocytes while enhancing cell surface area, GFAP intensity and STAT3 expression in healthy astrocytes, mimicking the effect of HMG20A. Furthermore, ORY1001 treatment protected against obesity-associated glucose intolerance in mice correlating with a regression of hypothalamic HMG20A expression, indicative of reactive astrogliosis attenuation with improved health status. Conclusion: HMG20A coordinates the astrocy...

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Section: Methodsmentioning

confidence: 99%

The metabesity factor HMG20A potentiates astrocyte survival and reactive astrogliosis preserving neuronal integrity

Lorenzo¹,

Vázquez²,

López-Noriega³

et al. 2021

Theranostics

View full text Add to dashboard Cite

show abstract

“…Embryos were obtained from Friend leukemia virus B (FVB) mice (University of Seville Animal Core Facility). Dissection of the spinal cord from embryonic (E12.5) were followed by the separation of neurons from the spinal cord tissue through mechanical and enzymatic cleavage as described [37, 38] with modifications. Briefly, spinal cords were dissected and meninges removed.…”

Section: Methodsmentioning

confidence: 99%

The Metabesity Factor HMG20A Potentiates Astrocyte Survival and Reactivity Preserving Neuronal Integrity

Lorenzo

Fuente-Martín

Mellado-Gil

et al. 2021

Preprint

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Rationale: We recently demonstrated that the Metabesity factor HMG20A regulates islet beta-cell functional maturity and adaptation to physiological stress such as pregnancy and pre-diabetes. HMG20A also dictates central nervous system (CNS) development via inhibition of the LSD1/CoREST complex but its expression pattern and function in the adult brain remains unknown. Herein we sought to determine whether HMG20A is expressed in the adult CNS, specifically in hypothalamic astrocytes that are key in glucose homeostasis and whether similar to islets, HMG20A potentiates astrocyte function in response to environmental cues. Methods: HMG20A expression profile was assessed by quantitative PCR (RT-PCR) and/or immunofluorescence in 1) the hypothalamus of mice exposed or not to a high-fat diet, 2) human blood leukocytes and adipose tissue obtained from healthy or diabetic individuals 3) primary mouse hypothalamic astrocytes exposed to either high glucose or palmitate. To investigate the function and regulatory mechanism of HMG20A, RNA-seq and cell metabolic parameters were performed on astrocytes treated or not with a siHMG20A. The regulatory function of HMG20A on astrogliosis was also assessed pharmacologically using ORY1001. Astrocyte-mediated neuronal survival was evaluated using conditioned media from siHMG20A-treated astrocytes. Results: We show that Hmg20a is predominantly expressed in hypothalamic astrocytes, the main nutrient-sensing cell type of the brain. Hmg20A expression was upregulated in diet-induced obesity and glucose-intolerant mice, correlating with increased transcript levels of Gfap and Il1b indicative of inflammation and astrogliosis. Expression levels were also increased in adipose tissue of obese non-diabetic individuals as compared to obese diabetic patients. HMG20A silencing in astrocytes resulted in repression of inflammatory, cholesterol biogenesis and epithelial-to-mesenchymal transition pathways with a concomitant increase in apoptosis and reduced mitochondrial bioenergetics. Motoneuron viability was also hindered in HMG20A-depleted astrocyte-derived conditioned media. Astrogliosis was induced using ORY1001, a pharmacological inhibitor of the LSD1/CoREST complex, mimicking the effect of HMG20A. Conclusion: HMG20A coordinates the astrocyte polarization state. Under physiological pressure such as obesity and insulin resistance that induces low-grade inflammation, HMG20A expression is increased to induce astrogliosis in an attempt to preserve the neuronal network and glucose homeostasis. Nonetheless, a chronic metabesity state or functional mutations will result in lower levels of HMG20A, failure to promote astrogliosis and increase the susceptibility of neurons to stress-mediated apoptosis. Such effects could be therapeutically reversed by ORY1001-induced astrogliosis.

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“…A recent study by Nichterwitz et al (2020) [ 115 ] determined that p53 pathway activation occurs in both resistant (ocular) and vulnerable (spinal) somatic motoneurons microdissected by laser capture from SMNΔ7 mice, indicating cellular stress in both populations. However, resistant (ocular) motoneurons exhibited decreased expression of pro-apoptotic genes, increased expression of survival factors, and upregulation of pathways involved in neurotransmission, neurite outgrowth, and axon regeneration.…”

Section: Lower α-Motoneuron Pathologiesmentioning

confidence: 99%

“…However, resistant (ocular) motoneurons exhibited decreased expression of pro-apoptotic genes, increased expression of survival factors, and upregulation of pathways involved in neurotransmission, neurite outgrowth, and axon regeneration. In contrast, vulnerable (spinal) motoneurons upregulated genes related to axon degeneration and axonal transport deficits [ 115 ]. Doktor et al (2017) performed RNA sequencing on symptomatic Taiwanese SMA mice (a severe SMA mouse model) at P5, an age preceding spinal motoneuron loss [ 116 , 117 ].…”

Section: Lower α-Motoneuron Pathologiesmentioning

confidence: 99%

In Search of a Cure: The Development of Therapeutics to Alter the Progression of Spinal Muscular Atrophy

2021

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Until the recent development of disease-modifying therapeutics, spinal muscular atrophy (SMA) was considered a devastating neuromuscular disease with a poor prognosis for most affected individuals. Symptoms generally present during early childhood and manifest as muscle weakness and progressive paralysis, severely compromising the affected individual’s quality of life, independence, and lifespan. SMA is most commonly caused by the inheritance of homozygously deleted SMN1 alleles with retention of one or more copies of a paralog gene, SMN2, which inversely correlates with disease severity. The recent advent and use of genetically targeted therapies have transformed SMA into a prototype for monogenic disease treatment in the era of genetic medicine. Many SMA-affected individuals receiving these therapies achieve traditionally unobtainable motor milestones and survival rates as medicines drastically alter the natural progression of this disease. This review discusses historical SMA progression and underlying disease mechanisms, highlights advances made in therapeutic research, clinical trials, and FDA-approved medicines, and discusses possible second-generation and complementary medicines as well as optimal temporal intervention windows in order to optimize motor function and improve quality of life for all SMA-affected individuals.

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LCM-seq reveals unique transcriptional adaptation mechanisms of resistant neurons and identifies protective pathways in spinal muscular atrophy

Cited by 37 publications

References 84 publications

The metabesity factor HMG20A potentiates astrocyte survival and reactive astrogliosis preserving neuronal integrity

The metabesity factor HMG20A potentiates astrocyte survival and reactive astrogliosis preserving neuronal integrity

The Metabesity Factor HMG20A Potentiates Astrocyte Survival and Reactivity Preserving Neuronal Integrity

In Search of a Cure: The Development of Therapeutics to Alter the Progression of Spinal Muscular Atrophy

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