Mitochondria are dynamic organelles ubiquitously present in nucleated eukaryotic cells, subserving multiple metabolic functions, including cellular ATP generation by oxidative phosphorylation (OXPHOS). The OXPHOS machinery comprises five transmembrane respiratory chain enzyme complexes (RC). Defective OXPHOS gives rise to mitochondrial diseases (mtD). The incredible phenotypic and genetic diversity of mtD can be attributed at least in part to the RC dual genetic control (nuclear DNA [nDNA] and mitochondrial DNA [mtDNA]) and the complex interaction between the two genomes. Despite the increasing use of next-generation-sequencing (NGS) and various -omics platforms in unraveling novel mtD genes and pathomechanisms, current clinical practice for investigating mtD essentially involves a multipronged approach including clinical assessment, metabolic screening, imaging, pathological, biochemical and functional testing to guide molecular genetic analysis. This review addresses the broad muscle pathology landscape including genotype-phenotype correlations in adult and paediatric mtD, the role of immunodiagnostics in understanding some of the pathomechanisms underpinning the canonical features of mtD, and recent diagnostic advances in the field.

Although the parasite Toxoplasma gondii is one of the most pervasive neurotropic pathogens in the world, the host-parasite interactions during CNS infection and consequences of neurological infection are just beginning to be unraveled. The chronic stages of infection have been considered dormant, although several studies have found correlations of infection with an array of host behavioral changes. These may facilitate parasite transmission and impact neurological diseases. During infection, in addition to the presence of the parasites within neurons, host-mediated neuroimmune and hormonal responses to infection are also present. T. gondii induces numerous changes to host neurons during infection and globally alters host neurological signaling pathways, as discussed in this review. Understanding the neurophysiological changes in the host brain is imperative to understanding the parasitic mechanisms and to delineate the effects of this single-celled parasite on health and its contribution to neurological disease.

Age-related diseases (ARDs) are the leading cause of death worldwide, and contribute to 90% of mortality in developed countries. Interestingly, the mortality rates of individual ARDs increase exponentially with age. Processes described by the exponential growth function typically involve a branching chain reaction or, more generally, a positive feedback loop. Here I propose that each ARD is mediated by one or several positive feedback loops (vicious cycles). I then identify critical vicious cycles in five major ARDs: atherosclerosis, hypertension, diabetes, Alzheimer’s and Parkinson’s. I also propose that the progression of ARDs can be halted by selectively interrupting the vicious cycles and suggest the most promising targets. An evolutionary perspective is also offered.

In this study, diabetogenic effects of long term Ochratoxin A (OTA) administration in rats were investigated and its role in the etiology of diabetes mellitus (DM) was examined utilizing 42 female Wistar rats for these purposes. The rats were divided into 3 different study and control groups according to the duration of the OTA administration. Rats received 45 μg OTA daily in their feed for 6, 9 and 24 weeks study groups. Three control groups without any treatment were also used in the same periods. Blood and pancreatic tissue samples were collected during the necropsy at the end of 6, 9 and 24 weeks. Plasma values of insulin, glucagon and glucose in study and control groups were determined. Pancreatic lesions were evaluated by histopathological examination; then insulin and glucagon expression in these lesions were determined by immunohistochemical methods. Statistically significant decrease in insulin levels in contrast to increases in glucagon and glucose levels in blood were observed. Slight degeneration in Langerhans islet cells were observed at the histopathological examination in all OTA treated groups. Immunohistochemistry of pancreatic tissue revealed decreased insulin and increased glucagon expression. This study demonstrated that OTA may cause pancreatic damage in Langerhans islet and predispose rats to DM.

Extracellular vesicle (EV) release, which occurs in most eukaryotic cells, has recently been associated with peptidylarginine deiminase (PAD)-driven protein deimination. Evidence points to the involvement of deiminated cytoskeletal proteins and changes in histone deimination. Both PADs and EVs are associated with various pathologies including cancers, autoimmune and neurodegenerative diseases. The elevated PAD expression observed in cancers may contribute to increase in EV shedding observed from cancer cells, contributing to cancer progression. Similarly, elevated PAD expression observed in neurodegenerative diseases may cause increased EV shedding and spread of neurodegenerative EV cargo, contributing to disease progression and pathologies. Pharmacological inhibition of PAD-mediated deimination using pan-PAD inhibitor Cl-amidine, reduced cellular EV release in prostate cancer cells, rendering them significantly more susceptible to chemotherapeutic drugs. Studies on models of central nervous system damage have demonstrated critical functional roles for PADs and neuroprotective effects using PAD inhibitors in vivo, while human neurodegenerative iPSC in vitro models showed evidence of increased protein deimination. Besides using refined PAD inhibitors to selectively manipulate EV biogenesis for novel combination therapies in cancer treatment, we also speculate how EV biogenesis could be targeted via the newly identified PAD-pathway to ameliorate neurodegenerative disease progression.