While regeneration occurs in a number of taxonomic groups across the Metazoa, there are very few reports of regeneration in mammals, which generally respond to wounding with fibrotic scarring rather than regeneration. A recent report described skin shedding, skin regeneration and extensive ear punch closure in two rodent species, Acomys kempi and Acomys percivali. We examined these striking results by testing the capacity for regeneration of a third species, Acomys cahirinus, and found a remarkable capacity to repair full thickness circular punches in the ear pinna. Four‐millimeter‐diameter wounds closed completely in 2 months in 100% of ear punches tested. Histology showed extensive formation of elastic cartilage, adipose tissue, dermis, epidermis and abundant hair follicles in the repaired region. Furthermore, we demonstrated abundant angiogenesis and unequivocal presence of both muscle and nerve fibers in the reconstituted region; in contrast, similar wounds in C57BL/6 mice simply healed the borders of the cut by fibrotic scarring. Our results confirm the regenerative capabilities of Acomys, and suggest this model merits further attention.

Lysosomal storage diseases (LSDs) describe a heterogeneous group of rare inherited metabolic disorders that result from the absence or loss of function of lysosomal hydrolases or transporters, resulting in the progressive accumulation of undigested material in lysosomes. The accumulation of substances affects the function of lysosomes and other organelles, resulting in secondary alterations such as impairment of autophagy, mitochondrial dysfunction, inflammation and apoptosis. LSDs frequently involve the central nervous system (CNS), where neuronal dysfunction or loss results in progressive neurodegeneration and premature death. Many LSDs exhibit signs of mitochondrial dysfunction, which include mitochondrial morphological changes, decreased mitochondrial membrane potential (ΔΨm), diminished ATP production and increased generation of reactive oxygen species (ROS). Furthermore, reduced autophagic flux may lead to the persistence of dysfunctional mitochondria. Gaucher disease (GD), the LSD with the highest prevalence, is caused by mutations in the GBA1 gene that results in defective and insufficient activity of the enzyme β-glucocerebrosidase (GCase). Decreased catalytic activity and/or instability of GCase leads to accumulation of glucosylceramide (GlcCer) and glucosylsphingosine (GlcSph) in the lysosomes of macrophage cells and visceral organs. Mitochondrial dysfunction has been reported to occur in numerous cellular and mouse models of GD. The aim of this manuscript is to review the current knowledge and implications of mitochondrial dysfunction in LSDs.

The African spiny mouse (Acomys spp.) is an emerging animal model with remarkable biological characteristics that make it a subject of interest for a broad range of research fields. Typically a desert species adapted to a low-calorie diet, spiny mice develop diabetes-related symptoms when switched to high-energy diets. Spiny mice undergo relatively long gestation periods and have small litters of highly developed pups, making them an adequate model for late organogenesis and perinatal biology. Recently, they have been shown to have remarkable healing and regeneration capabilities, which make them unique among mammals. In this work, we describe our experience in housing a colony of African spiny mice and cover all basic aspects of feeding, maintenance and breeding for research purposes.

Gaucher disease (GD) is caused by mutations in the GBA1 gene which encodes lysosomal β-glucocerebrosidase (GCase). In GD, partial or complete loss of GCase activity causes the accumulation of the glycolipids glucosylceramide (GlcCer) and glucosylsphingosine in the lysosomes of macrophages. In this manuscript, we investigated the effects of glycolipids accumulation on lysosomal and mitochondrial function, inflammasome activation and efferocytosis capacity in a THP-1 macrophage model of Gaucher disease. In addition, the beneficial effects of coenzyme Q10 (CoQ) supplementation on cellular alterations were evaluated. Chemically-induced Gaucher macrophages were developed by differentiateing THP-1 monocytes to macrophages by treatment with phorbol 12-myristate 13-acetate (PMA) and then inhibiting intracellular GCase with conduritol B-epoxide (CBE), a specific irreversible inhibitor of GCase activity, and supplementing the medium with exogenous GlcCer. This cell model accumulated up to 16-fold more GlcCer compared with control THP-1 cells. Chemically-induced Gaucher macrophages showed impaired autophagy flux associated with mitochondrial dysfunction and increased oxidative stress, inflammasome activation and impaired efferocytosis. All abnormalities were partially restored by supplementation with CoQ. These data suggest that targeting mitochondria function and oxidative stress by CoQ can ameliorate the pathological phenotype of Gaucher cells. Chemically-induced Gaucher macrophages provide cellular models that can be used to investigate disease pathogenesis and explore new therapeutics for GD.

Gaucher’s disease (GD) is the most frequently inherited lysosomal storage disease, presenting both visceral and neurologic symptoms. Mutations in acid β-glucocerebrosidase disrupt the sphingolipid catabolic pathway promoting glucosylceramide (GlcCer) accumulation in lysosomes. Current treatment options are enzyme replacement therapy (ERT) and substrate reduction therapy (SRT). However, neither of these approaches is effective in treating the neurological aspect of the disease. The use of small pharmacological compounds that act as molecular chaperones is a promising approach that is still experimental. In recent years, an association between GD and Parkinson like synucleinopathies has been discovered. Since 1992, a number of mouse models of GD have been the developed and partially reproduce phenotype of the disease. More recently, the discovery of direct reprograming has allowed the derivation of induced pluripotent stem cells (iPSc) from fibroblasts obtained from GD patients. iPSc can be expanded indefinitely in vitro and differentiated to macrophages and neurons, the main relevant cell types involved in GD. In this work, we review iPSc models of GD and summarize what we have learned from this system.

Cancer remains a leading cause of morbidity and mortality worldwide, driving extensive research into the mechanisms that contribute to its development and progression. The search for animal models capable of shedding light on mechanisms of cancer resistance has led researchers to explore various rodent species. Among these, the African Spiny Mouse ( Acomys sp.) has attracted considerable attention due to its regenerative abilities. In our study, we compared the response of Mus musculus and Acomys dimidiatus mice to treatment with the carcinogen 7,12-dimethylbenz[a]anthracene (DMBA) combined with the inducer of proliferation 12-O-tetradecanoylphorbol-13-acetate (TPA). While both Acomys and Mus mice experienced carcinogenic damage to their skin cells, mounted proliferative responses and underwent immune cell infiltration, only Mus mice developed tumors, whereas Acomys remained tumor-free. To uncover the molecular mechanisms underlying this resistance, we performed RNA sequencing on tissue samples from both species at baseline and at multiple time points during the carcinogenesis protocol. The data reveal distinctly different transcriptional responses between both species. In particular, Acomys showed massive upregulation of immune related genes, including a set of tumor suppressor genes, while Mus seemed to focus its response on modifying epidermis structure and regulation of the cell cycle. These differences correlated with an increased apoptotic response in Acomys but not Mus . In summary, our study provides compelling evidence that Acomys mice exhibit remarkable resistance to tumor development under DMBA/TPA carcinogen treatment mediated through the upregulation of a range of processes related to immune surveillance.