Exonic deletions in IMMP2L in schizophrenia with enhanced glycation stress subtype

Inner Mitochondrial Membrane Peptidase 2-Like Deletion Aggravates Mitochondrial Apoptosis and Inhibits Autophagy After Hyperglycemia Stroke

This study investigated the effects of inner mitochondrial membrane peptidase 2-like (Immp2l) deletion on mitochondrial apoptosis and mitochondrial autophagy under hyperglycemic conditions. The middle cerebral artery occlusion (MCAO) model was established in wild-type (WT) mice and Immp2l+/- mice; animals were then exposed to hyperglycemic (induced using 1% streptozotocin) and normoglycemic conditions. Tissues were collected at various time points post-reperfusion. The production of reactive oxygen species (ROS) was assessed by fluorescent measurements, and mitochondrial membrane potential was evaluated using a JC-1 assay kit. Autophagy was analyzed by measuring LC3II/LC3I protein expression and Beclin 1 expression. Mitochondrial ultrastructure was examined through transmission electron microscopy (TEM); neuronal autophagosomes were also assessed. Immp2l mutation in a hyperglycemic environment exacerbated brain injury by increasing ROS production, compromising mitochondrial membrane potential, inducing apoptotic cascades, and impairing mitochondrial autophagy. These findings highlight the critical role of Immp2l in modulating the response to hyperglycemic cerebral ischemia-reperfusion (I/R) injury. Furthermore, the deficiency of Immp2l appears to contribute to increased oxidative stress, mitochondrial dysfunction, and cell death, thereby exacerbating brain injury. These data may provide new insights into therapeutic strategies for reducing the impact of diabetes on stroke outcomes.

Mitochondrial proteases modulate mitochondrial stress signalling and cellular homeostasis in health and disease

Maintenance of mitochondrial homeostasis requires a plethora of coordinated quality control and adaptations' mechanisms in which mitochondrial proteases play a key role. Their activation or loss of function reverberate beyond local mitochondrial biochemical and metabolic remodelling into coordinated cellular pathways and stress responses that feedback onto the mitochondrial functionality and adaptability. Mitochondrial proteolysis modulates molecular and organellar quality control, metabolic adaptations, lipid homeostasis and regulates transcriptional stress responses. Defective mitochondrial proteolysis results in disease conditions most notably, mitochondrial diseases, neurodegeneration and cancer. Here, it will be discussed how mitochondrial proteases and mitochondria stress signalling impact cellular homeostasis and determine the cellular decision to survive or die, how these processes may impact disease etiopathology, and how modulation of proteolysis may offer novel therapeutic strategies.

The missing hallmark of health: psychosocial adaptation

The eight biological hallmarks of health that we initially postulated (Cell. 2021 Jan 7;184(1):33-63) include features of spatial compartmentalization (integrity of barriers, containment of local perturbations), maintenance of homeostasis over time (recycling & turnover, integration of circuitries, rhythmic oscillations) and an array of adequate responses to stress (homeostatic resilience, hormetic regulation, repair & regeneration). These hallmarks affect all eight somatic strata of the human body (molecules, organelles, cells, supracellular units, organs, organ systems, systemic circuitries and meta-organism). Here we postulate that mental and socioeconomic factors must be added to this 8×8 matrix as an additional hallmark of health ("psychosocial adaptation") and as an additional stratum ("psychosocial interactions"), hence building a 9×9 matrix. Potentially, perturbation of each of the somatic hallmarks and strata affects psychosocial factors and vice versa. Finally, we discuss the (patho)physiological bases of these interactions and their implications for mental health improvement.

Ciliary phenotyping in renal epithelial cells in a cranioectodermal dysplasia patient with WDR35 variants

Background: Cranioectodermal dysplasia (CED) is a skeletal autosomal recessive ciliopathy. The characteristic clinical features of CED are facial dysmorphisms, short limbs, narrow thorax, brachydactyly, ectodermal abnormalities, and renal insufficiency. Thus far, variants in six genes are known to be associated with this disorder: WDR35, IFT122, IFT140, IFT144, IFT52, and IFT43. Objective: The goal of this study was to perform cilium phenotyping in human urine-derived renal epithelial cells (hURECs) from a CED patient diagnosed with second-stage chronic kidney disease (CKD) and three unrelated and unaffected pediatric controls. Methods: Genetic analysis by WDR35 screening was performed in the affected individual. Cilium frequency and morphology, including cilium length, height, and width, were evaluated by immunofluorescence (IF) experiments in hURECs using two markers visualizing the ciliary axoneme (Acet-Tub and ARL13B) and the base of the cilium (PCNT). The IF results were analyzed using a confocal microscope and IMARIS software. Results: WDR35 analysis revealed the presence of a known nonsense p. (Leu641*) variant and a novel missense variant p. (Ala1027Thr). Moreover, comparative genomic hybridization analysis showed that the patient carries a microdeletion on chromosome 7q31.1. Ciliary phenotyping performed on hURECs showed morphological differences in the patient's cilia as compared to the three controls. The cilia of the CED patient were significantly wider and longer. Conclusion: The obtained results suggest that CED-related second-stage CKD might be associated with cilia abnormalities, as identified in renal epithelial cells from a CED patient harboring variants in WDR35. This study points out the added value of hURECs in functional testing for ciliopathies.