Sable Systems
@sablesys.bsky.social
510 followers 880 following 320 posts
Thoughts, visions & revisions from John Lighton PhD, president & chief innovation officer of Sable Systems International (=the world's most advanced metabolic measurement systems)
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sablesys.bsky.social
More interesting Promethion-powered research from Dr. Elias & colleagues at University of Michigan - glutamate release from MCH neurons drives sex-specific effects on reproduction & metabolism! 🧪 bsd.biomedcentral.com/articles/10....
Lack of glutamate neurotransmission in melanin-concentrating hormone neurons alters mouse reproduction and metabolism in a sex-specific manner - Biology of Sex Differences
Melanin-concentrating hormone (MCH) is a neuropeptide important for the regulation of metabolism, sleep, circadian rhythms, and other body functions. MCH neurons contain the excitatory neurotransmitter glutamate, which is released via vesicular glutamate transporter 2 (VGLUT2). The release of glutamate from MCH neurons is known to play a role in metabolism in males, but its action in female physiology has not been determined. Furthermore, little is known about the role of glutamate release from MCH neurons in reproductive function. We developed a new transgenic mouse model that expresses Cre recombinase driven by the MCH gene (Pmch) and deleted Vglut2 from the MCH neurons. We then assessed reproductive and metabolic function in both sexes. Females exhibited late-onset leanness, delayed sexual maturation, and increased latency to pregnancy. On a high-fat diet, males showed improved insulin resistance, and both sexes displayed an improved daily pattern of food intake. These findings highlight the importance of considering sex as a relevant biological variable in MCH neuronal function. Melanin-concentrating hormone (MCH) neurons contribute to the regulation of a diverse array of physiological functions including glucose and energy homeostasis. MCH neurons express genes involved in the synthesis, packaging, and release of glutamate, the brain’s predominant excitatory neurotransmitter. Deletion of vesicular glutamate transporter 2 (VGLUT2, Slc17a6 gene) in MCH neurons of male mice results in a hypophagic, hyperactive, lean phenotype. However, the metabolic and reproductive effects of VGLUT2 deletion in females have not been fully addressed. Previous studies have utilized Pmch-Cre mice generated using a bacterial artificial chromosome (BAC). The loci of insertion for the BAC are random and may fail to recapitulate epigenetic regulation at the native gene locus. Here, we generated a novel knock-in Pmch-iCre mouse model and investigated the effects of deleting Slc17a6 from MCH neurons in both male and female mice. Assessment of sexual maturation, fertility, glucose homeostasis and energy balance (food intake, body composition, energy expenditure, locomotion, glucose and fat oxidation) on regular chow and high fat diet (HFD) were performed in both sexes. Lack of glutamate neurotransmission in MCH neurons (PmchΔVglut2 mice) delays puberty onset and completion in female, but not male mice. PmchΔVglut2 females were also protected against (HFD)-induced disruption of estrous cycles. On a regular chow diet, neither male nor female PmchΔVglut2 mice showed differences in body weight, food intake, or lean and fat masses compared to littermate controls until 20 weeks of age. At 24 weeks of age, PmchΔVglut2 females exhibited reduced total body mass, and males had lower fat mass. PmchΔVglut2 female mice also gained less weight on HFD than littermate controls. An attenuation of HFD-induced disruption of daily feeding pattern was observed in PmchΔVglut2 mice of both sexes, while only males were protected against insulin resistance on HFD. Glutamate neurotransmission from MCH neurons has a sex-specific role in sexual maturation, fertility, typical weight gain trajectory, and HFD-induced weight gain and insulin resistance. In addition, a sex-independent role in daily feeding pattern was observed.
bsd.biomedcentral.com
sablesys.bsky.social
More intriguing Promethion-powered science from O. MacDougald & colleagues at University of Michigan - FGF21, soluble TGFBR2 & ambient temperature shape metabolic dysfunction in lipodystrophic mice! 🧪 insight.jci.org/articles/vie...
JCI Insight - Effects of FGF21, soluble TGFBR2, and environmental temperature on metabolic dysfunction in lipodystrophic mice
insight.jci.org
sablesys.bsky.social
She has a way with words.
Reposted by Sable Systems
joshuajfriedman.com
One of my favorite anecdotes from THE PREHISTORY OF THE FAR SIDE: "That doesn't sound like the Jane Goodall we know."
A few days after this cartoon was published, my syndicate received a very indignant letter from someone representing the Jane Goodall Institute.
Not only did my syndicate and I both get read the Riot Act, there was a vague implication that litigation over this cartoon might be around the corner.
I was horrified. Not so much from a fear of being sued (I just couldn't see how this cartoon could be construed as anything but silly, but because of my deep respect for Jane Goodall and her well-known contributions to pri-matology. The last thing in the world I would have intentionally done was offend Dr. Goodall in any way.
Before I had a chance to write my apology, another complication arose.
The National Geographic Society contacted my syndicate and expressed a desire to reprint the cartoon in a special centennial issue of their magazine. My editor, aware of what had just occurred, declined, explaining why.
Apparently, whoever it was that sent the inquiry from National Geographic was shocked. They told my editor that "that doesn't sound like the Jane Goodall we know." They did some checking themselves, and an interesting fact was eventually discovered: Jane Goodall loved the cartoon. Furthermore, she was totally unaware that any of this "stuff" was going on. Some phone calls were made, and the cartoon was not only reprinted in the centennial issue of National Geographic, but was also used by her Institute on a T-shirt for fund-raising purposes.
I've since had an opportunity to visit Dr. Goodall at her research facility in Gombe. It's a wonderful place (sort of like right out of National Geographic).
"To refer to Dr. Goodall as a tramp is inexcusable even by a self-described 'loony' as Larson. The cartoon was incredibly offensive and in such poor taste that readers might well question the editorial judgment of running such an atrocity in a newspaper that reputes to be supplying news to persons with a better than average intelligence. The cartoon and its message were absolutely stupid." —Excerpt from the above-mentioned letter that started the ruckus
sablesys.bsky.social
More interesting Promethion-powered research from C. Elias & colleagues at University of Michigan - glutamate release from MCH neurons drives sex-specific effects on reproduction & metabolism! 🧪 bsd.biomedcentral.com/articles/10....
Lack of glutamate neurotransmission in melanin-concentrating hormone neurons alters mouse reproduction and metabolism in a sex-specific manner - Biology of Sex Differences
Melanin-concentrating hormone (MCH) is a neuropeptide important for the regulation of metabolism, sleep, circadian rhythms, and other body functions. MCH neurons contain the excitatory neurotransmitter glutamate, which is released via vesicular glutamate transporter 2 (VGLUT2). The release of glutamate from MCH neurons is known to play a role in metabolism in males, but its action in female physiology has not been determined. Furthermore, little is known about the role of glutamate release from MCH neurons in reproductive function. We developed a new transgenic mouse model that expresses Cre recombinase driven by the MCH gene (Pmch) and deleted Vglut2 from the MCH neurons. We then assessed reproductive and metabolic function in both sexes. Females exhibited late-onset leanness, delayed sexual maturation, and increased latency to pregnancy. On a high-fat diet, males showed improved insulin resistance, and both sexes displayed an improved daily pattern of food intake. These findings highlight the importance of considering sex as a relevant biological variable in MCH neuronal function. Melanin-concentrating hormone (MCH) neurons contribute to the regulation of a diverse array of physiological functions including glucose and energy homeostasis. MCH neurons express genes involved in the synthesis, packaging, and release of glutamate, the brain’s predominant excitatory neurotransmitter. Deletion of vesicular glutamate transporter 2 (VGLUT2, Slc17a6 gene) in MCH neurons of male mice results in a hypophagic, hyperactive, lean phenotype. However, the metabolic and reproductive effects of VGLUT2 deletion in females have not been fully addressed. Previous studies have utilized Pmch-Cre mice generated using a bacterial artificial chromosome (BAC). The loci of insertion for the BAC are random and may fail to recapitulate epigenetic regulation at the native gene locus. Here, we generated a novel knock-in Pmch-iCre mouse model and investigated the effects of deleting Slc17a6 from MCH neurons in both male and female mice. Assessment of sexual maturation, fertility, glucose homeostasis and energy balance (food intake, body composition, energy expenditure, locomotion, glucose and fat oxidation) on regular chow and high fat diet (HFD) were performed in both sexes. Lack of glutamate neurotransmission in MCH neurons (PmchΔVglut2 mice) delays puberty onset and completion in female, but not male mice. PmchΔVglut2 females were also protected against (HFD)-induced disruption of estrous cycles. On a regular chow diet, neither male nor female PmchΔVglut2 mice showed differences in body weight, food intake, or lean and fat masses compared to littermate controls until 20 weeks of age. At 24 weeks of age, PmchΔVglut2 females exhibited reduced total body mass, and males had lower fat mass. PmchΔVglut2 female mice also gained less weight on HFD than littermate controls. An attenuation of HFD-induced disruption of daily feeding pattern was observed in PmchΔVglut2 mice of both sexes, while only males were protected against insulin resistance on HFD. Glutamate neurotransmission from MCH neurons has a sex-specific role in sexual maturation, fertility, typical weight gain trajectory, and HFD-induced weight gain and insulin resistance. In addition, a sex-independent role in daily feeding pattern was observed.
bsd.biomedcentral.com
sablesys.bsky.social
More intriguing Promethion-powered science from O. MacDougald & colleagues at University of Michigan - FGF21, soluble TGFBR2 & ambient temperature shape metabolic dysfunction in lipodystrophic mice! 🧪 insight.jci.org/articles/vie...
JCI Insight - Effects of FGF21, soluble TGFBR2, and environmental temperature on metabolic dysfunction in lipodystrophic mice
insight.jci.org
sablesys.bsky.social
I can't applaud this enough! Announcing the end of a decades-long era of legacy system vendors treating metabolic rate as isometric with respect to body mass (it's allometric & "normalizing" it by dividing by body mass is crazily misleading & awe-inspiringly ignorant)...
Reposted by Sable Systems
kcklatt.bsky.social
Really excited to announce that I've accepted an Assistant Professor position in the Department of Nutritional Sciences in the Faculty of Medicine at the University of Toronto! Looking forward to venturing north (🥶) & building out my own research group focused on human nutrition & metabolism 🥳
uoftnutrisci.bsky.social
Big news! Thrilled to welcome Dr. Kevin Klatt as our newest Assistant Professor in Nutritional Sciences! From Cornell → NIH → Baylor → UC Berkeley, he brings expertise in maternal & infant nutrition + micronutrients! Join us in welcoming him! @kcklatt.bsky.social @uoftmedicine.bsky.social
sablesys.bsky.social
More intriguing Promethion-powered research from Dr. X Liu & colleagues at University of Kentucky - PLK1 phosphorylation of PDHA1 rewires metabolism in lung cancer; DCA + onvansertib show synergy in mice! 🧪 www.nature.com/articles/s41...
PLK1-mediated PDHA1 phosphorylation drives metabolic reprogramming in lung cancer - Oncogene
Oncogene - PLK1-mediated PDHA1 phosphorylation drives metabolic reprogramming in lung cancer
www.nature.com
Reposted by Sable Systems
cecibaldoni.bsky.social
PhD Alert! 😍 Our lab is hiring a PhD student to study how shrews shrink in winter and grow in spring. Yes, you read that right!
tinyurl.com/shrinkingshr...
Join us at the @mpi-animalbehav.bsky.social, study a super cool animal, and join the @imprs-qbee.bsky.social community!

DM me for questions!
Seasonal size change and aging in shrews
imprs-qbee.mpg.de
sablesys.bsky.social
That expression... speaks volumes
Reposted by Sable Systems
donmoyn.bsky.social
"Now an extraordinarily successful scientific research system — one that took decades to build, has saved millions of lives and generated billions of dollars in profits for American companies and investors — is being dismantled before our eyes."
markhisted.org
Shutting down the war on cancer.

“New presidential administrations have usually gone out of their way to make transitions at the NIH as seamless as possible so as not to disrupt ongoing research…”

Right. That’s not what is happening now. Must-read article.

🧪
Trump Is Shutting Down the War On Cancer
www.nytimes.com
Reposted by Sable Systems
therasmussenlab.bsky.social
We are looking forward to hearing from Dr. Teresa Zimmers today in San Antonio.
Reposted by Sable Systems
jexpbiol.bsky.social
In his Commentary, Neil Metcalfe examines why it can be hard to detect trade-offs between two activities or processes competing for energy, despite energy supposedly being a limiting resource

journals.biologists.com/jeb/article/...
Screenshot of the first page of the PDF of the Commentary, How can we best measure the energetic trade-offs faced by animals?, by Neil Metcalfe. The publishing information states: © 2025. Published by The Company of Biologists | Journal of Experimental Biology (2025) 228, jeb250303. doi:10.1242/jeb.250303. The first sentence of the Abstract reads: 'Energy is commonly presumed to be a limiting resource for most animals, forcing them to trade off the benefits of allocating energy to competing activities or processes'.
Reposted by Sable Systems
Reposted by Sable Systems
canjzoology.bsky.social
NEW

Adrenergic stimulation as a means to determine in vivo brown adipose tissue thermogenic capacity

✒️ Lindsund et al.
🔗 doi.org/10.1139/cjz-...
Reposted by Sable Systems