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Protein import and genome replication are essential processes for mitochondrial biogenesis and propagation. The J-domain proteins Pam16 and Pam18 regulate the presequence translocase of the mitochondrial inner membrane. In the protozoan Trypanosoma brucei, their counterparts are TbPam16 and TbPam18, which are essential for the procyclic form (PCF) of the parasite, though not involved in mitochondrial protein import. Here, we show that during evolution, the 2 proteins have been repurposed to regulate the replication of maxicircles within the intricate kDNA network, the most complex mitochondrial genome known. TbPam18 and TbPam16 have inactive J-domains suggesting a function independent of heat shock proteins. However, their single transmembrane domain is essential for function. Pulldown of TbPam16 identifies a putative client protein, termed MaRF11, the depletion of which causes the selective loss of maxicircles, akin to the effects observed for TbPam18 and TbPam16. Moreover, depletion of the mitochondrial proteasome results in increased levels of MaRF11. Thus, we have discovered a protein complex comprising TbPam18, TbPam16, and MaRF11, that controls maxicircle replication. We propose a working model in which the matrix protein MaRF11 functions downstream of the 2 integral inner membrane proteins TbPam18 and TbPam16. Moreover, we suggest that the levels of MaRF11 are controlled by the mitochondrial proteasome. Pam16 and Pam18 are conserved co-chaperones essential for mitochondrial protein import in eukaryotes, but not in the parasite Trypanosoma brucei. This study shows that the function of TbPam16/18 has been repurposed during evolution to regulate the replication of maxicircles within the T. brucei mitochondrial genome. [ABSTRACT FROM AUTHOR]

Metabolic syndrome (MetS) is associated with cardiovascular risk factors, such as insulin resistance, dyslipidaemia, hypertension and abdominal obesity. Given the growing need to investigate food supplements with positive health effects, this study was aimed at testing the benefits of a specific supplement for people with MetS. Fifty-eight subjects with MetS and T2DM or impaired glucose tolerance assuming metformin, were randomly assigned to take a food supplement of glucomannan, D-chiro-inositol, Cinnamomum zeylanicum blume and inulin at a daily fixed dose of 4 g orally for four months. Body weight, waist circumference, plasma lipid profile (total cholesterol, LDL, HDL and triglyc-erides), plasma glycaemic profile and visceral adiposity index (VAI) were measured at baseline and after four months of supplementation. After 16 weeks, in subjects with T2DM or insulin resistance who took the supplement (+ metformin), there was a significant reduction in body weight and BMI (p < 0.0001), serum insulin (p < 0.05) and the HOMA index (p < 0.01), as well as in the lipaemic pattern, with a significant improvement in total serum cholesterol (p < 0.005), triglycerides (p < 0.03) and LDL (p < 0.02). Our study shows that the food supplement tested is a valid and safe alternative therapeutic approach in the management of MetS and all its resulting risk factors, as its efficacy has been demonstrated across anthropometric, glucose, lipid and hepatic parameters. [ABSTRACT FROM AUTHOR]

Mitochondrial DNA replication is an essential process in most eukaryotes. Similar to the diversity in mitochondrial genome size and organization in the different eukaryotic supergroups, there is considerable diversity in the replication process of the mitochondrial DNA. In this review, we summarize the current knowledge of mitochondrial DNA replication and the associated factors in trypanosomes with a focus on Trypanosoma brucei , and provide a new model of minicircle replication for this protozoan parasite. The model assumes the mitochondrial DNA (kinetoplast DNA, kDNA) of T. brucei to be loosely diploid in nature and the replication of the genome to occur at two replication centers at the opposing ends of the kDNA disc (also known as antipodal sites, APS). The new model is consistent with the localization of most replication factors and in contrast to the current model, it does not require the assumption of an unknown sorting and transport complex moving freshly replicated DNA to the APS. In combination with the previously proposed sexual stages of the parasite in the insect vector, the new model provides a mechanism for maintenance of the mitochondrial genetic diversity. [ABSTRACT FROM AUTHOR]

In the last decade, an increasing awareness was directed to the role of Vitamin D in non-skeletal and preventive roles for chronic diseases. Vitamin D is an essential hormone in regulating calcium/phosphorous balance and in the pathogenesis of inflammation, insulin resistance, and obesity. The main forms of vitamin D, Cholecalciferol (Vitamin D3) and Ergocalciferol (Vitamin D2) are converted into the active form (1,25-dihydroxyvitamin D) thanks to two hydroxylations in the liver, kidney, pancreas, and immune cells. Some anti-inflammatory cytokines are produced at higher levels by vitamin D, while some pro-inflammatory cytokines are released at lower levels. Toll-Like Receptor (TLR) expression is increased, and a pro-inflammatory state is also linked to low levels of vitamin D. Regardless of how it affects inflammation, various pathways suggest that vitamin D directly improves insulin sensitivity and secretion. The level of vitamin D in the body may change the ratio of pro- to anti-inflammatory cytokines, which would impact insulin action, lipid metabolism, and the development and function of adipose tissue. Many studies have demonstrated an inverse relationship between vitamin D concentrations and pro-inflammatory markers, insulin resistance, glucose intolerance, metabolic syndrome, obesity, and cardiovascular disease. It is interesting to note that several long-term studies also revealed an inverse correlation between vitamin D levels and the occurrence of diabetes mellitus. Vitamin D supplementation in people has controversial effects. While some studies demonstrated improvements in insulin sensitivity, glucose, and lipid metabolism, others revealed no significant effect on glycemic homeostasis and inflammation. This review aims to provide insight into the molecular basis of the relationship between vitamin D, insulin resistance, metabolic syndrome, type 1 and 2 diabetes, gestational diabetes, and cardiovascular diseases. [ABSTRACT FROM AUTHOR]

Trypanosoma brucei is a single celled eukaryotic parasite in the group of the Kinetoplastea. The parasite harbors a single mitochondrion with a singular mitochondrial genome that is known as the kinetoplast DNA (kDNA). The kDNA consists of a unique network of thousands of interlocked circular DNA molecules. To ensure proper inheritance of the kDNA to the daughter cells, the genome is physically linked to the basal body, the master organizer of the cell cycle in trypanosomes. The connection that spans, cytoplasm, mitochondrial membranes and the mitochondrial matrix is mediated by the Tripartite Attachment Complex (TAC). Using a combination of proteomics and RNAi we test the current model of hierarchical TAC assembly and identify TbmtHMG44 and TbKAP68 as novel candidates of a complex that connects the TAC to the kDNA. Depletion of TbmtHMG44 or TbKAP68 each leads to a strong kDNA loss but not missegregation phenotype as previously defined for TAC components. We demonstrate that the proteins rely on both the TAC and the kDNA for stable localization to the interface between these two structures. In vitro experiments suggest a direct interaction between TbmtHMG44 and TbKAP68 and that recombinant TbKAP68 is a DNA binding protein. We thus propose that TbmtHMG44 and TbKAP68 are part of a distinct complex connecting the kDNA to the TAC. Author summary: Trypanosoma brucei is a single celled eukaryote that is only distantly related to most other model organisms. It is important to study this group in order to understand which parts of their biology are conserved and which have diverged throughout evolution. T. brucei cells—like most eukaryotes—contain mitochondria. Trypanosomes however, only harbor one mitochondrion with a singular mitochondrial genome per cell. It has been shown that the mitochondrial genome in these organisms is physically linked to the base of the flagellum and that this linkage, which has been named Tripartite Attachment Complex (TAC), is required for proper distribution of the mitochondrial genome during cell division. In the current study we identify and characterize two novel components of a distinct complex involved in connecting the TAC to the mitochondrial DNA. [ABSTRACT FROM AUTHOR]

The immune response to infection plays a crucial role in the pathogenesis of COVID-19, but several patients develop a wide range of persistent symptoms, which is becoming a major global health and economic burden. However, reliable indicators are not yet available to predict the persistence of symptoms typical of the so-called long COVID. Our study aims to explore an eventual role of IL-6 levels as a marker of long COVID. Altogether, 184 patients admitted to the COVID Medicine Unit of the University Hospital in Palermo, Italy, from the 1st of September 2020, were analyzed. Patients were divided into two groups according to the IL-6 serum levels (normal or elevated), considering the serum IL-6 levels measured during the first four days of hospitalization. In our study, higher serum IL-6 levels were associated with a doubled higher risk of long COVID (OR = 2.05; 95% CI: 1.04–4.50) and, in particular, they were associated with a higher incidence of mobility decline (OR = 2.55; 95% CI: 1.08–9.40) and PTSD (OR = 2.38; 95% CI: 1.06–8.61). The analysis of our case series confirmed the prominent role of IL-6 levels in response to SARS-CoV-2 infection, as predictors not only of COVID-19 disease severity and unfavorable outcomes, but also long COVID development trends. [ABSTRACT FROM AUTHOR]

Nowadays, these complex patients with acute pathologies or who need to undergo diagnostic procedures, which incidentally have tested positive for Sars-CoV-2, represent about a third of those who access our hospitals, and almost all patients admitted to Internal Medicine COVID Units. Aiming to have a clear snapshot of the typical patient admitted to an Internal Medicine COVID ward during the 2022 wave of the pandemic, we investigated all patients admitted to our Internal Medicine COVID ward during the 1 SP st sp trimester of 2021 and compared them with those admitted during the 1 SP st sp trimester of 2022. Clinical risk management of sars-cov-2 positive patients admitted to an internal medicine ward. [Extracted from the article]

Management for HCV has undergone a notable change using direct-acting antiviral drugs (DAAs), which are safe and effective even in elderly. Here, we define impact of comorbidities, concomitant medication and drug–drug interactions in elder patients with HCV related disease before starting DAAs regimen. We analyzed data of 814 patients prospectively enrolled at our Unit within the web based model HCV Sicily Network. Out of 814, 590 were treated with DAAs and 414 of them were older than 65 years. We divided those 414 in two groups, one including 215 patients, aged between 65 and 74 years, and another with 199 patients, aged of 75 years and over. Charlson Comorbidity Index (CCI) was assessed for each patient; drug–drug interactions (DDI) and de-prescribing process were carried out appropriately. Within 414 patients included, percentage rates of women treated was higher than males, BMI was lower and cirrhosis was frequently reported in patients older than 75 years. Hypertension, diabetes mellitus, dyslipidemia (p < 0.0001), prostatic pathologies, kidney disease, gastrointestinal disease (p < 0.0001), osteoporosis (p < 0.01) and depression were most common co-morbidities. CCI showed lower scores in the first group as compared with the second one (p < 0.0001). Among drugs, statins were frequently suspended and anti-hypertensive often replaced. DAAs are useful and effective regardless of disease severity, comorbidities, medications and age. De-prescribing allows a stable reduction of number of medications taken with real improvement of quality of life. [ABSTRACT FROM AUTHOR]

Aims. To analyze the main etiological factors and some clinical features of patients with hepatocellular carcinoma (HCC) at diagnosis and to compare them with those we described ten years ago. Materials and Methods. We compared two groups of patients with HCC, Group 1 consisting of 132 patients (82 M, 50 F) diagnosed in the 2003–2008 period and Group 2 including 119 patients (82 M, 37 F) diagnosed in the 2013–2018 period. For all patients, age, sex, viral markers, alcohol consumption, serum alpha-fetoprotein (AFP) levels, and the main liver function parameters were recorded. The diagnosis of HCC was based on AASLD, EASL guidelines. The staging was classified according to the "Barcelona Clinic Liver Cancer staging system" (BCLC). Results. Mean age was 69.0 ± 8 years in Group 1 and 71.0 ± 9 in Group 2 (P < 0.05). HCV subjects were significantly older in Group 2 (P < 0.05), and there was no difference for those with other etiologies. The main etiology in the two groups was HCV 80% (Group 1) versus 73% (Group 2) (P = ns), and there was no difference for HBV. Nonviral etiology was higher in Group 2 versus Group 1 (17% versus 9%; P < 0.05). The Child class at diagnosis showed no difference between the two groups, whereas in Group 2 the HCC staging according to BCLC was less severe (P < 0.02). When comparing the viral versus post-NASH BCLC in patients of the second period alone, the staging was more severe in the latter (P < 0.01). AFP serum levels were normal in 37% of cases in Group 1 and in 67% in Group 2 (P < 0.0001) and were less frequently diagnostic in post-NASH than in other etiologies (P < 0.03). Conclusions. This study shows that over the last decade a number of features of patients with HCC in our region have changed, particularly age at onset, etiological factors, and staging of HCC. [ABSTRACT FROM AUTHOR]

Aims. To analyze the main etiological factors and some clinical features of patients with hepatocellular carcinoma (HCC) at diagnosis and to compare them with those we described ten years ago. Materials and Methods. We compared two groups of patients with HCC, Group 1 consisting of 132 patients (82 M, 50 F) diagnosed in the 2003–2008 period and Group 2 including 119 patients (82 M, 37 F) diagnosed in the 2013–2018 period. For all patients, age, sex, viral markers, alcohol consumption, serum alpha-fetoprotein (AFP) levels, and the main liver function parameters were recorded. The diagnosis of HCC was based on AASLD, EASL guidelines. The staging was classified according to the "Barcelona Clinic Liver Cancer staging system" (BCLC). Results. Mean age was 69.0 ± 8 years in Group 1 and 71.0 ± 9 in Group 2 (P < 0.05). HCV subjects were significantly older in Group 2 (P < 0.05), and there was no difference for those with other etiologies. The main etiology in the two groups was HCV 80% (Group 1) versus 73% (Group 2) (P = ns), and there was no difference for HBV. Nonviral etiology was higher in Group 2 versus Group 1 (17% versus 9%; P < 0.05). The Child class at diagnosis showed no difference between the two groups, whereas in Group 2 the HCC staging according to BCLC was less severe (P < 0.02). When comparing the viral versus post-NASH BCLC in patients of the second period alone, the staging was more severe in the latter (P < 0.01). AFP serum levels were normal in 37% of cases in Group 1 and in 67% in Group 2 (P < 0.0001) and were less frequently diagnostic in post-NASH than in other etiologies (P < 0.03). Conclusions. This study shows that over the last decade a number of features of patients with HCC in our region have changed, particularly age at onset, etiological factors, and staging of HCC. [ABSTRACT FROM AUTHOR]

The unicellular parasite Trypanosoma brucei harbors one mitochondrial organelle with a singular genome called the kinetoplast DNA (kDNA). The kDNA consists of a network of concatenated minicircles and a fewmaxicircles that formthe kDNAdisc. More than 30 proteins involved in kDNA replication have been described. However, several mechanistic questions are only poorly understood. Here, we describe and characterize minicircle replication factor 172 (MiRF172), a novel mitochondrial genome replication factor that is essential for cell growth and kDNA maintenance. By performing super-resolution microscopy, we show that MiRF172 is localized to the kDNA disc, facing the region between the genome and the mitochondrial membranes. We demonstrate that depletion of MiRF172 leads to a loss of minicircles and maxicircles. Detailed analysis suggests that MiRF172 is involved in the reattachment of replicated minicircles to the kDNA disc. Furthermore, we provide evidence that the localization of the replication factor MiRF172 not only depends on the kDNA itself, but also on the mitochondrial genome segregation machinery, suggesting an interaction between the two essential entities. [ABSTRACT FROM AUTHOR]

In almost all eukaryotes, mitochondria maintain their own genome. Despite the discovery more than 50 y ago, still very little is known about how the genome is correctly segregated during cell division. The protozoan parasite Trypanosoma brucei contains a single mitochondrion with a singular genome, the kinetoplast DNA (kDNA). Electron microscopy studies revealed the tripartite attachment complex (TAC) to physically connect the kDNA to the basal body of the flagellum and to ensure correct segregation of the mitochondrial genome via the basal bodies movement, during the cell cycle. Using superresolution microscopy, we precisely localize each of the currently known TAC components. We demonstrate that the TAC is assembled in a hierarchical order from the base of the flagellum toward the mitochondrial genome and that the assembly is not dependent on the kDNA itself. Based on the biochemical analysis, the TAC consists of several nonoverlapping subcomplexes, suggesting an overall size of the TAC exceeding 2.8 mDa. We furthermore demonstrate that the TAC is required for correct mitochondrial organelle positioning but not for organelle biogenesis or segregation. [ABSTRACT FROM AUTHOR]

Mitochondrial organelles need to be replicated during cell division. Many aspects of this process have been studied in great detail, however the actual size increase and the position of organelle growth are less well understood. We use the protozoan parasite Trypanosoma brucei that contains a single mitochondrion to study organelle biogenesis by fluorescence microscopy. From the analysis of more than 1000 T. brucei bloodstream form cells of a nonsynchronous population we conclude that the mitochondrial network mostly grows from two areas along the main organelle axis, posterior and anterior of the nucleus. Loops and branches from these two areas eventually fuse to build a complex network. Together with the appearance of the division fold in the posterior part of the cell, pruning of the mitochondrial network and finally separation into the two daughter cells occurs. Overall organelle biogenesis is not continuous during cell growth and occurs mostly in the last part of the cell cycle. Furthermore, using 3D STED super resolution microscopy we reconstruct the volume of the organelle and characterize the region where the mitochondrial genome is positioned by serial block face scanning electron microscopy. [ABSTRACT FROM AUTHOR]