Cover Story Current Issue

In the hypothalamic arcuate nucleus (ARH), two distinct neuronal cell types differentially modulate energy homeostasis: the proopiomelanocortin (POMC) and neuropeptide Y/agouti-related peptide (NPY/AgRP) neurons. NPY and AgRP are co-expressed in the same ARH neurons, and AgRP is the endogenous antagonist for the melanocortin (MC4) receptor, thus blocking the anorectic effects of the POMC peptide, α-melanocyte-stimulating hormone.

Todd L. Stincic, Martha A. Bosch, Avery C. Hunker, Barbara Juarez, ... Martin J. Kelly

Full text

 

Current Issue

CRISPR knockdown of Kcnq3 attenuates the M-current and increases excitability of NPY/AgRP neurons to alter energy balance

Todd L. Stincic, Martha A. Bosch, Avery C. Hunker, Barbara Juarez, ... Martin J. Kelly

 

Objective

Arcuate nucleus neuropeptide Y/agouti-related peptide (NPY/AgRP) neurons drive ingestive behavior. The M-current, a subthreshold non-inactivating potassium current, plays a critical role in regulating NPY/AgRP neuronal excitability. Fasting decreases while 17β-estradiol increases the M-current by regulating the mRNA expression of Kcnq23, and 5 (Kv7.2, 3, and 5) channel subunits. Incorporating KCNQ3 into heteromeric channels has been considered essential to generate a robust M-current. Therefore, we investigated the behavioral and physiological effects of selective Kcnq3 deletion from NPY/AgRP neurons.

Methods

We used a single adeno-associated viral vector containing a recombinase-dependent Staphylococcus aureus Cas9 with a single-guide RNA to selectively delete Kcnq3 in NPY/AgRP neurons. Single-cell quantitative measurements of mRNA expression and whole-cell patch clamp experiments were conducted to validate the selective knockdown. Body weight, food intake, and locomotor activity were measured in male mice to assess disruptions in energy balance.

Results

The virus reduced the expression of Kcnq3 mRNA without affecting Kcnq2 or Kcnq5. The M-current was attenuated, causing NPY/AgRP neurons to be more depolarized, exhibit a higher input resistance, and require less depolarizing current to fire action potentials, indicative of increased excitability. Although the resulting decrease in the M-current did not overtly alter ingestive behavior, it significantly reduced the locomotor activity as measured by open-field testing. Control mice on a high-fat diet exhibited an enhanced M-current and increased Kcnq2 and Kcnq3 expression, but the M-current remained significantly attenuated in KCNQ3 knockdown animals.

Conclusions

The M-current plays a critical role in modulating the intrinsic excitability of NPY/AgRP neurons that is essential for maintaining energy homeostasis.

CRISPR knockdown of Kcnq3 attenuates the M-current and increases excitability of NPY/AgRP neurons to alter energy balance

Todd L. Stincic, Martha A. Bosch, Avery C. Hunker, Barbara Juarez, ... Martin J. Kelly

 

Objective

Arcuate nucleus neuropeptide Y/agouti-related peptide (NPY/AgRP) neurons drive ingestive behavior. The M-current, a subthreshold non-inactivating potassium current, plays a critical role in regulating NPY/AgRP neuronal excitability. Fasting decreases while 17β-estradiol increases the M-current by regulating the mRNA expression of Kcnq23, and 5 (Kv7.2, 3, and 5) channel subunits. Incorporating KCNQ3 into heteromeric channels has been considered essential to generate a robust M-current. Therefore, we investigated the behavioral and physiological effects of selective Kcnq3 deletion from NPY/AgRP neurons.

Methods

We used a single adeno-associated viral vector containing a recombinase-dependent Staphylococcus aureus Cas9 with a single-guide RNA to selectively delete Kcnq3 in NPY/AgRP neurons. Single-cell quantitative measurements of mRNA expression and whole-cell patch clamp experiments were conducted to validate the selective knockdown. Body weight, food intake, and locomotor activity were measured in male mice to assess disruptions in energy balance.

Results

The virus reduced the expression of Kcnq3 mRNA without affecting Kcnq2 or Kcnq5. The M-current was attenuated, causing NPY/AgRP neurons to be more depolarized, exhibit a higher input resistance, and require less depolarizing current to fire action potentials, indicative of increased excitability. Although the resulting decrease in the M-current did not overtly alter ingestive behavior, it significantly reduced the locomotor activity as measured by open-field testing. Control mice on a high-fat diet exhibited an enhanced M-current and increased Kcnq2 and Kcnq3 expression, but the M-current remained significantly attenuated in KCNQ3 knockdown animals.

Conclusions

The M-current plays a critical role in modulating the intrinsic excitability of NPY/AgRP neurons that is essential for maintaining energy homeostasis.

2020 impact factor: 7.4

The 60 Second Metabolist

In this section authors briefly report on their work recently published in Molecular Metabolism.

Watch the most recent interviews by clicking the video still. 

Here is a video of Vimeo. When the iframes is activated, a connection to Vimeo is established and, if necessary, cookies from Vimeo are also used. For further information on cookies policy click here.

Here is a video of Vimeo. When the iframes is activated, a connection to Vimeo is established and, if necessary, cookies from Vimeo are also used. For further information on cookies policy click here.