Daily Endocrinology Research Analysis
Analyzed 35 papers and selected 3 impactful papers.
Summary
Analyzed 35 papers and selected 3 impactful articles.
Selected Articles
1. Mitochondrial fission factor regulates mitochondrial Ca
Cell type–specific loss of MFF in hypothalamic AgRP neurons enlarged mitochondria in somata and axons and was associated with increased mitochondrial Ca2+. These data link mitochondrial fission machinery to neuronal Ca2+ handling in circuits governing systemic energy balance.
Impact: Reveals a mechanistic bridge between mitochondrial architecture and Ca2+ homeostasis in key neuroendocrine neurons controlling energy balance. Offers a potential mitochondrial-dynamics target for metabolic disease.
Clinical Implications: While preclinical, the findings suggest that modulating mitochondrial fission/fusion or Ca2+ handling in AgRP neurons could be an upstream strategy to influence appetite and energy expenditure in obesity and metabolic disorders.
Key Findings
- Loss of MFF in AgRP neurons increased mitochondrial size in neuronal somata and axons.
- AgRP neuron MFF deficiency was associated with increased mitochondrial Ca2+.
- Findings mechanistically connect mitochondrial fission machinery to neuronal Ca2+ handling in circuits regulating systemic energy homeostasis.
Methodological Strengths
- Cell type–specific genetic manipulation in defined hypothalamic neurons
- In vivo assessment of organelle morphology and compartment-specific analysis
Limitations
- Abstracted findings do not report systemic metabolic phenotypes or behavioral outcomes.
- Sample size and replication across models are not specified in the provided text.
Future Directions: Define how MFF-dependent mitochondrial dynamics in AgRP neurons modulate feeding and energy expenditure in vivo; test pharmacologic modulators of mitochondrial fission/fusion for metabolic benefit.
Mitochondria represent central regulators of neuronal function, and their network is dynamically restructured via fission and fusion. The mitochondrial fission factor (MFF) serves as an adaptor protein that recruits and organizes the core fission machinery at the outer mitochondrial membrane. Here, we investigated the role of MFF in Agouti-related peptide (AgRP) neurons of the arcuate nucleus of the hypothalamus (ARC) in their regulation of systemic energy homeostasis. We demonstrated that mice lacking MFF in AgRP neurons exhibited increased mitochondrial size, both in AgRP neuron somata and their axonal compartments. This translated into increased mitochondrial Ca
2. Peroxisome-derived ether lipids regulate lysosomal exocytosis.
A genome-wide CRISPR screen and perturbation studies identify ether lipids as bidirectional regulators of lysosomal abundance and exocytosis, acting independently of TFEB and mannose-6-phosphate trafficking. Manipulating ether lipid synthesis or supplying hexadecylglycerol respectively enhances or suppresses lysosomal degradative capacity.
Impact: Defines a previously unrecognized peroxisome–lysosome metabolic axis with actionable lipid mediators, reshaping understanding of organelle crosstalk relevant to metabolic, lysosomal, and peroxisomal disorders.
Clinical Implications: Targeting ether lipid synthesis or signaling may provide novel strategies to enhance lysosomal clearance in lysosomal storage diseases and to modulate organelle homeostasis in peroxisomal disorders.
Key Findings
- Genome-wide CRISPR screen in LYSET-deficient mucolipidosis V cells implicates ether lipid synthesis genes and peroxins in controlling lysosomal accumulation.
- Inhibiting ether lipid synthesis enhances lysosomal exocytosis and clearance of undigested material independently of mannose-6-phosphate trafficking.
- Supplementation with hexadecylglycerol increases lysosome abundance and reduces degradative capacity; regulation occurs independently of TFEB.
Methodological Strengths
- Unbiased genome-wide CRISPR/Cas9 screen identifying causal pathways
- Convergent genetic, pharmacologic, and supplementation experiments demonstrating bidirectional control
Limitations
- Predominantly cell-based models; in vivo validation in animal models is not described in the abstract.
- Disease-specific efficacy and safety of targeting ether lipids remain to be established.
Future Directions: Test modulation of ether lipid pathways in animal models of lysosomal/peroxisomal disorders; delineate molecular targets linking ether lipids to exocytosis machinery; evaluate translational biomarkers.
Lysosomes and peroxisomes are essential for cellular homeostasis, yet how their activities are coordinated remains poorly understood. Here, we identify peroxisome-derived ether lipids as key regulators of lysosomal function. A genome-wide CRISPR/Cas9 screen in LYSET-deficient mucolipidosis V cells revealed that disruption of ether lipid synthesis genes or peroxins markedly reduces lysosome accumulation and restores degradative capacity. Genetic or pharmacological inhibition of ether lipid synthesis enhanced lysosomal exocytosis and promoted the clearance of undigested material independently of mannose-6-phosphate trafficking. Conversely, supplementation with the ether lipid precursor hexadecylglycerol increased lysosome abundance, while reducing their degradative capacity. These findings uncover a peroxisome-lysosome metabolic axis, in which ether lipids act as bidirectional regulators of lysosomal number and function independently of the lysosomal master regulator TFEB. Our findings reveal how peroxisome-localized lipid metabolism modulates lysosomal homeostasis, and suggest potential new strategies to combat lysosomal and peroxisomal disorders.
3. β-Hydroxybutyrate prevents bone loss partially via the histone β-hydroxybutyrylation pathway.
In OVX and db/db mouse models, BHB increased BMD, improved bone microarchitecture, and suppressed osteoclastogenesis while elevating histone β-hydroxybutyrylation marks (PanKbhb, H3K9bhb, H3K27bhb). In vitro, BHB or BHB-CoA blocked RANKL-induced osteoclast differentiation and resorption via an ACSS2/P300-dependent Kbhb mechanism.
Impact: Uncovers an epigenetic mechanism (histone β-hydroxybutyrylation via ACSS2/P300) by which a circulating metabolite, BHB, restrains osteoclastogenesis and bone loss, linking ketogenic metabolism to skeletal homeostasis.
Clinical Implications: Suggests therapeutic exploration of BHB analogues or epigenetic cofactors (ACSS2/P300 modulators) for osteoporosis in postmenopausal and diabetic contexts; informs diet/ketogenic strategies with mechanistic grounding.
Key Findings
- In OVX and db/db mice, BHB increased BMD, improved bone microstructure, and inhibited osteoclast formation.
- BHB elevated histone β-hydroxybutyrylation marks (PanKbhb, H3K9bhb, H3K27bhb) in bone tissue.
- BHB or BHB-CoA inhibited RANKL-induced osteoclastogenesis and resorption in vitro; effects required ACSS2 and P300.
Methodological Strengths
- Use of two distinct in vivo osteoporosis models (OVX and db/db) plus in vitro validation
- Mechanistic dissection of epigenetic pathway with enzyme dependency (ACSS2, P300)
Limitations
- Preclinical models; translational dosing, safety, and long-term effects in humans are unknown.
- Effects on osteoblast function and whole-bone strength beyond microarchitecture were not detailed.
Future Directions: Evaluate BHB-based or ACSS2/P300-targeted interventions in larger animal models; assess synergy with antiresorptives/anabolics; develop biomarkers of histone Kbhb for patient stratification.
Osteoporosis (OP) is a systemic metabolic bone disorder. The excessive activation of osteoclasts (OCs) leads to a decrease in bone mass and damage to the bone microstructure, which plays a crucial role in OP. β-Hydroxybutyrate (BHB), the main component of ketone bodies, not only serves as an ancillary fuel substituting for glucose but also induces anti-oxidative, anti-inflammatory, and cardioprotective features via binding to several target proteins, including histone β-hydroxybutyrylation (Kbhb). Recent research has found that BHB has a positive therapeutic effect on OP, but the underlying molecular mechanism remains unclear. In this study, we established osteoporosis (OP) animal models induced by estrogen deficiency and type 2 diabetes using ovariectomized (OVX) and db/db mice, respectively, and administered BHB to OP mice via free drinking in vivo. Our results indicated that BHB increased bone mineral density (BMD), improved bone microstructure, and inhibited the OC formation. Additionally, BHB upregulated the levels of PanKbhb, H3K9bhb, and H3K27bhb modifications in the bone tissue of OP mice. In vitro, we found that BHB or β-hydroxybutyryl-CoA (BHB-CoA) could inhibit RANKL-induced OC differentiation and bone resorption, and upregulate histone Kbhb levels in a concentration-dependent manner. Furthermore, the effects of BHB or BHB-CoA-induced histone Kbhb were reversed by inhibiting the activity of Acyl-CoA synthetase short-chain family member 2 (ACSS2) or histone acyltransferase P300. In summary, our data reveal that BHB may alleviate bone loss caused by estrogen deficiency and type 2 diabetes through ACSS2/P300-induced histone Kbhb.