Lymphotropic nanoparticle magnetic resonance imaging for diagnosing metastatic lymph nodes in dogs with malignant head and neck tumours

Lymphotropic nanoparticle magnetic resonance imaging (LNMRI) utilises ultrasmall paramagnetic iron nanoparticles (USPIOs) for imaging of metastatic lymph nodes in patients afflicted with cancer. LNMRI has been shown to be a highly effective and accurate way to diagnose metastasis in humans but has not been commonly reported on in veterinary medicine. USPIOs are phagocytised by macrophages and then localised to lymph nodes where they create a susceptibility artefact on gradient echo MRI sequences. In this study dogs (n = 24) with naturally occurring head and neck tumours were imaged with LNMRI then had mandibular and retropharyngeal lymph nodes extirpated for histological analysis. Subjective and objective analysis of the LNMRI images was performed and imaging results compared to histology as the gold standard. A total of 149 lymph nodes were included in this study. The overall sensitivity, specificity and accuracy was 64%, 94.4% and 89.3% respectively. However, if dogs with mast cell tumours were excluded from analysis the sensitivity, specificity and accuracy rose to 85.7%, 95.7% and 94.6%. LNMRI is potentially an accurate way to determine the presence of lymph node metastasis in dogs with some types of head and neck tumours. However, LNMRI has only moderate accuracy in dogs with oral or mucocutaneous mast cell tumours in this region.

Awareness and interest in osteopathic manipulative treatment in allopathic medical students

CONTEXT

Osteopathic manipulative treatment (OMT) is utilized by clinicians to diagnose and treat a variety of musculoskeletal conditions including acute and chronic pain, and other medical conditions. Previous studies have examined attitudes of allopathic (MD) residents toward OMT and have implemented residency-based curricula; however, literature is lacking on the attitudes of MD students toward OMT.

OBJECTIVES

The objective of this study was to determine MD students' familiarity with OMT and to evaluate their interest in an elective osteopathic curriculum.

METHODS

A 15-item online survey was electronically sent to 600 MD students at a large allopathic academic medical center. The survey assessed familiarity with OMT, interest in OMT and in participating in an OMT elective, educational format preference, and interest in pursuing primary care. Educational demographics were also collected. Descriptive statistics and Fisher's exact test were utilized for categorical variables, and nonparametric tests were utilized for the ordinal and continuous variables.

RESULTS

A total of 313 MD students submitted responses (response rate=52.1 %), of which 296 (49.3 %) responses were complete and utilized for analysis. A total of 92 (31.1 %) students were aware of OMT as a modality in treating musculoskeletal disorders. Among the respondents who indicated "very interested" in learning a new pain treatment modality, the majority: (1) observed OMT in a prior clinical or educational setting (85 [59.9 %], p=0.02); (2) had a friend or family member treated by a DO physician (42 [71.2 %], p=0.01); (3) were pursuing a primary care specialty (43 [60.6 %], p=0.02); or (4) interviewed at an osteopathic medical school (47 [62.7 %], p=0.01). Among those interested in developing some OMT competency, the majority: (1) were pursuing a primary care specialty (36 [51.4 %], p=0.01); (2) applied to osteopathic schools (47 [54.0], p=0.002); or (3) interviewed at an osteopathic medical school (42 [56.8 %], p=0.001). A total of 230 (82.1 %) students were somewhat or very interested in a 2-week elective course in OMT; among all respondents, hands-on labs were the preferred method for delivery of OMT education (272 [94.1 %]).

CONCLUSIONS

The study found a strong interest in an OMT elective by MD students. These results will inform OMT curriculum development aimed at interested MD students and residents in order to provide them with OMT-specific theoretical and practical knowledge.

The effect of the COVID-19 pandemic on osteopathic education in ACGME-OR residencies from February 2020 to February 2021

CONTEXT

It remains to be determined exactly how the COVID-19 pandemic has and will continue to impact osteopathic resident education, in particular as it pertains to treatment with osteopathic manipulative medicine (OMM). Although the long-term effects of the pandemic cannot be determined yet, changes in current resident education can be analyzed.

OBJECTIVES

Here, we describe how the format, frequency, and environment of OMM training have changed in residency programs from prior to February 2020 to the "lockdown" period of February 2020 to June 2020, and then to the "recovery" period of July 2020 to February 2021.

METHODS

A 19-question survey inquiring about the above three categories was emailed via SurveyMonkey to 282 Accreditation Council for Graduate Medical Education (ACGME) residency programs with osteopathic recognition at the end of January 2021.

RESULTS

Of the 282 programs surveyed, 24.5% (69) responded. Osteopathic neuromusculoskeletal medicine (ONMM) programs were excluded from the data analysis, resulting in a modified sample size of n=60. Responses indicated that residency programs dramatically decreased the frequency of OMM didactic education sessions (100.0% [60] reported offering OMM didactic education before the lockdown period; compared to 73.3% [44] during the lockdown period) and shifted their educational programs from an in-person-only environment (88.3% [53] before lockdown; 8.3% [5] during lockdown) to either a combined in-person/virtual platform (6.7% [4] before lockdown; 31.7% [19] during lockdown) or to a virtual-only platform (0.0% [0] before lockdown; 46.7% [28] during lockdown). During the recovery period, 91.7% (55) programs reported giving some form of OMM didactic education. The percentage of programs reporting in-person-only, combined in-person/virtual platform, and virtual-only didactic education were 3.3% (2), 53.3% (32), and 41.7% (25), respectively, during the recovery period. The preferred method of instruction changed from a combination of resident and attending lectures with a hands-on component (55.0%; 33) before lockdown, to the same but without a hands-on component (28.3%; 17) during lockdown, and back to the same but with a hands-on component (36.7%; 22) during the recovery period. Furthermore, the number of programs offering OMM didactic education [OMM patient care] at least once a month decreased from 70.0% (42) [78.3% (47)] before the lockdown period to 46.7% (28) [48.3% (29)] during the lockdown period. It then increased to 55.0% (33) [73.3% (44)] during the recovery period. Finally, before the lockdown period, programs offered OMM patient care predominantly in a combination of an inpatient/outpatient environment (63.3%; 38). The preferred patient care setting changed to an outpatient-only environment (43.3%; 26) during the lockdown period and then back to a combination of an inpatient/outpatient environment (45.0%; 27) during the recovery period.

CONCLUSIONS

This study demonstrates that programs have been dramatically impacted by the COVID-19 pandemic, by the augmentation of the osteopathic learning environment, and by the delivery of OMM to patient care within the training programs. These impacts were still present 1 year after the start of the pandemic. It will be imperative for ACGME Osteopathic Recognition (ACGME-OR) programs to continue an assessment of these impacts on resident physicians' learning and preparedness.

Mitochondrial Membranes and Mitochondrial Genome: Interactions and Clinical Syndromes

Mitochondria are surrounded by two membranes; the outer mitochondrial membrane and the inner mitochondrial membrane. They are unique organelles since they have their own DNA, the mitochondrial DNA (mtDNA), which is replicated continuously. Mitochondrial membranes have direct interaction with mtDNA and are therefore involved in organization of the mitochondrial genome. They also play essential roles in mitochondrial dynamics and the supply of nucleotides for mtDNA synthesis. In this review, we will discuss how the mitochondrial membranes interact with mtDNA and how this interaction is essential for mtDNA maintenance. We will review different mtDNA maintenance disorders that result from defects in this crucial interaction. Finally, we will review therapeutic approaches relevant to defects in mitochondrial membranes.

Retention of tissue texture change after cervical muscle energy and high velocity low amplitude intervention: implications for treatment intervals

CONTEXT

When choosing to incorporate osteopathic manipulative treatment (OMT) into a patient's care, the risk-to-benefit ratio, the choice of treatment technique, as well as the frequency of treatments are always taken into consideration. This has been even more important during the COVID-19 pandemic, in which social distancing has been the best preventative measure to decrease exposure. By increasing treatment intervals, one could not only limit possible exposure/spread of viruses but also decrease the overall cost to the system as well as to the individual. This is an expansion of a previous study in which quantifiable changes in cervical hysteresis characteristics post-OMT were documented utilizing a durometer (Ultralign SA201^®; Sigma Instruments; Cranberry, PA USA). This study compared two treatment modalities, muscle energy (ME) and high-velocity low-amplitude (HVLA) postcervical treatment. Subjects in this study were allowed to re-enroll, provided that they could be treated utilizing the alternate treatment modality. By allowing repeat subjects, analysis of the data for lasting effects of OMT could be observed.

OBJECTIVES

To determine whether a significant change in cervical hysteresis would be observed after each treatment regardless of a short treatment interval.

METHODS

A total of 34 subjects were retrospectively noted to be repeat subjects from a larger, 213-subject study. These 34 subjects were repeat participants who were treated with two different direct-treatment modalities 7-10 days apart. Each subject was randomly assigned to receive a single-segmental ME or HVLA treatment technique directed toward a cervical (C) segment (C3-C5 only). Subjects were objectively measured pretreatment in all cervical segments utilizing the Ultralign SA201^®, then treated with cervical OMT to a single segment, and finally reassessed at all cervical levels with the Ultralign SA201^® posttreatment to assess for change in cervical hysteresis.

RESULTS

Statistically significant or suggestive changes (p-values 0.01-0.08) with good clinical effect size (0.30 or greater) were noted in all four components of the Ultralign SA201^® at multiple cervical levels after the first treatment, but only one component (frequency) had a statistically significant change after the second treatment (AA cervical level, p-value 0.01) with good clinical effect size (0.45). However, when comparing the post-first-treatment values to the pre-second-treatment values, no statistically significant differences (p-value 0.10 or higher) were observed between them.

CONCLUSIONS

Statistically significant changes were noted after the first treatment; however, when comparing cervical hysteresis changes after the first treatment to the cervical hysteresis values prior to the second treatment delivered 7-10 days later, there were no statistically significant or suggestive changes. This data suggest that several post-OMT changes noted after the first treatment were still in effect and may indicate that follow-up visits for direct manipulation may be deferred for a least two weeks.

PRAME immunohistochemistry is useful in the diagnosis of oral malignant melanoma

OBJECTIVES

While the incidence of cutaneous melanoma has dramatically increased in recent years, oral malignant melanoma (OMM) remains a rare form of noncutaneous melanoma with poor survival. PRAME (PReferentially expressed Antigen in MElanoma) is reported to have diagnostic and some prognostic utility in cutaneous melanomas and some head and neck malignancies. We sought to explore the diagnostic utility of PRAME in OMM.

METHODS

A total of ten specimens from eight unique cases of OMM were identified from the Oral Pathology Biopsy Service (OPBS) at University of Washington School of Dentistry between 2005 and 2019. For all cases, standard histology and immunohistochemistry stains were performed, including a stain against PRAME. The diagnoses were reviewed and confirmed by two pathologists. Clinical and epidemiologic features were described.

RESULTS

Patient ages ranged from 55 to 82. The group consisted of five males and three females. All eight cases were located on the hard palate. Six cases represented invasive melanoma while two were early melanoma in situ. PRAME immunohistochemistry was successfully performed on seven of eight cases: six were positive (86%), one was negative (14%) and one case lacked sufficient tissue for staining.

CONCLUSIONS

Our results suggest that PRAME immunohistochemistry may be useful in the diagnosis of OMM, including early melanoma in situ. Further studies with clinical follow-up and a larger number of cases are needed to explore prognostic value as well as the ability to distinguish between benign, intermediate and malignant melanocytic proliferations of the oral cavity.

Efficacy of osteopathic manipulative treatment in patients with Parkinson's disease: a narrative review

CONTEXT

Parkinson's disease (PD) is a neurodegenerative disease that leads to impaired motor and non-motor function in patients. PD is non-curative and gradually reduces quality of life, leading patients to seek treatment for symptom management. Osteopathic manipulative treatment (OMT) applies the biomechanical, neurologic, circulatory, metabolic, and psychosocial models in approaching and treating the major symptomatology of PD patients.

OBJECTIVES

This article evaluates the literature published in the past 10 years analyzing evidence on OMT and its functional application on gait, balance, motor function, bradykinesia, and autonomic dysfunctions, and to identify promising avenues for further investigation.

METHODS

The authors obtained studies from the research databases MEDLINE/PubMed, ScienceDaily, and EBSCO, as well as the Journal of American Osteopathic Association's published archives. Searches were conducted in December 2020 utilizing the search phrases "OMM" (osteopathic manipulative medicine), "OMT," "osteopathic," "Parkinson Disease," "manual therapy," "physical therapy," "training," "autonomics," "gait," and "balance." Articles published between 2010 and 2021 including subjects with Parkinson's disease and the use of OMT or any other form of manual therapy were included. Five authors independently performed literature searches and methodically resolved any disagreements over article selection together.

RESULTS

There were a total of 10,064 hits, from which 53 articles were considered, and five articles were selected based on the criteria.

CONCLUSIONS

The progressive nature of PD places symptom management on the forefront of maintaining patients' quality of life. OMT has demonstrated the greatest efficacy on managing motor-related and neurologic symptoms and assists in treating the greater prevalence of somatic dysfunctions that arise from the disease. Research in this field remains limited and should be the target of future research.

GSK-3 Inhibitors in the Regulation and Control of Colon Carcinoma

BACKGROUND

Glycogen syntheis kinase (GSK-3) inhibitors are novel therapeutic agents for treating various types of cancer, such as breast, lung, and gastric cancer. No pathological changes have been found by the morphological examination of GSK-3.

OBJECTIVES

This review describes recent procedures using GSK-3 inhibitors, primarily in treating colon carcinoma. Furthermore, it also explains the mechanism of action of different GSK-3 inhibitors in treating various types of cancers and proposes some additional mechanisms may be useful for further research on GSK-3 inhibitors for cancers, including colon carcinoma.

RESULTS

The majority of the cancerous and pre-cancerous lesions are stimulated by the transformation of membrane-bound arachidonic acid (AA) to eicosanoids, a transformation that promotes for the viability, proliferation, and spread of cancer. GSK-3 inhibitors can reinstate hostility to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) responsiveness in gastric adenocarcinoma cells. GSK-3, the final enzyme in glycogen synthesis, is a serine/threonine kinase that phosphorylates varied sequences that are more than a hundred in number, within proteins in an array of heterogeneous pathways. It is an essential module of an exceptionally large number of cellular processes, playing a fundamental role in many metabolic processes and diseases. Many patients diagnosed with colon cancer achieve long-term remission with outstanding survival through the GSK-3 inhibitors.

CONCLUSION

Prior to the extensive application of these proposed mechanisms of GSK-3 inhibitor, further evaluation and clinical studies are needed. Only after the completion of appropriate clinical studies and morphological examinations, would extensive application be apprpriate.

Establishing causality in Salmonella-microbiota-host interaction: The use of gnotobiotic mouse models and synthetic microbial communities

Colonization resistance (CR), the ability to block infections by potentially harmful microbes, is a fundamental function of host-associated microbial communities and highly conserved between animals and humans. Environmental factors such as antibiotics and diet can disturb microbial community composition and thereby predispose to opportunistic infections. The most prominent is Clostridioides difficile, the causative agent of diarrhea and pseudomembranous colitis. In addition, the risk to succumb to infections with genuine human enteric pathogens like nontyphoidal Salmonella (NTS) is also increased by a low-diverse, diet or antibiotic-disrupted microbiota. Despite extensive microbial community profiling efforts, only a limited set of microorganisms have been causally linked with protection against enteric pathogens. Furthermore, it remains a challenge to predict colonization resistance from complex microbiome signatures due to context-dependent action of microorganisms. In the past decade, the study of NTS infection has led to the description of several fundamental principles of microbiota-host-pathogen interaction. In this review, I will give an overview on the current state of knowledge in this field and outline experimental approaches to gain functional insight to the role of specific microbes, functions and metabolites in Salmonella-microbiota-host interaction. In particular, I will highlight the value of mouse infection models, which, in combination with culture collections, synthetic communities and gnotobiotic models have become essential tools to screen for protective members of the microbiota and establishing causal relationship and mechanisms in infection research.

Characteristics and treatment of geriatric patients in an osteopathic neuromusculoskeletal medicine clinic

CONTEXT

Osteopathic manipulative medicine (OMM) is an adjunctive treatment approach available to geriatric patients, but few studies provide details about presenting conditions, treatments, and response to osteopathic manipulative treatment (OMT) in that patient population.

OBJECTIVES

To provide descriptive data on the presentation and management of geriatric patients receiving OMT at an outpatient osteopathic neuromusculoskeletal medicine (ONMM) clinic.

METHODS

Data were retrospectively collected from electronic health records (EHR) at a single outpatient clinic for clinical encounters with patients over 60 years of age who were treated with OMT between July 1, 2016, and June 30, 2019. Records were reviewed for demographic information, insurance type, presenting concerns, assessments, regions treated, OMT techniques used, and treatment response.

RESULTS

There were 9,155 total clinical encounters with 1,238 unique patients found during the study period. More women than men were represented for overall encounters (6,910 [75.4%] vs. 2,254 [24.6%]) and unique patients (850 [68.7%] vs. 388 [31.3%]; both p<0.001). The mean (standard deviation, SD) number of encounters per patient per year was 4.5 (4.0) and increased with increasing age by decade (p<0.001). Medicare was the most common primary insurance (7,246 [79.2%]), with private insurance the most common secondary insurance (8,440 [92.2%]). The total number of presenting concerns was 12,020, and back concerns were most common (6,406 [53.3%]). The total number of assessments was 18,290; most were neuromusculoskeletal (17,271 [94.5%]) and in the thoracolumbar region (7,109 [38.9%]). The mean (SD) number of somatic dysfunction assessments per encounter was 5 (1.7); the thoracic region was the most documented and treated (7,263 [15.8%]). With up to 19 technique types per encounter, the total number of OMT techniques documented across all encounters was 43,862, and muscle energy (7,203 [16.4%]) was the most documented. The use of high-velocity, low-amplitude (HVLA) declined as age increased (p<0.001). The overall treatment response was documented in 7,316 (79.9%) encounters, and most indicated improvement (7,290 [99.6%]).

CONCLUSIONS

Our results showed that geriatric patients receiving OMT at our clinic were predominately presenting for neuromusculoskeletal concerns associated with back, neck, and extremity conditions, consistent with national epidemiological data for this population. The most common OMT techniques were also consistent with those used nationally by osteopathic medical students and practicing physicians. Future longitudinal studies are needed to determine the length of time improvement persists and the overall health impact experienced by geriatric patients receiving OMT.

Activation-dependent mitochondrial translocation of Foxp3 in human hepatocytes

Foxp3 is considered to be the master regulator for the development and function of regulatory T cells (Treg). Recently Foxp3, has been detected in extra lymphoid tissue, and in hepatocytes and has been associated with hepatocellular carcinoma (HCC), although its role has not been defined. Since it is expected that there is a relationship between protein localization, activity and cellular function, the aim of this study was to explore the subcellular localization of Foxp3 in resting and stimulated human hepatocytes. Foxp3 expression was measured by flow cytometry, subcellular fractioning, and immunofluorescence, and this data was used to track the shuttling of Foxp3 in different subcellular compartments in hepatocytes (HepG2 cell line), stimulated by using the PKC activators (PMA), core and preS1/2 antigen from hepatitis B virus (HBV). Our data shows that besides the nuclear location, mitochondrial translocation was detected after stimulation with PMA and at to a lesser extent, with preS1/2. In addition, Foxp3 is localizes at outer mitochondrial membrane. These results suggest a non-canonical role of Foxp3 in the mitochondrial compartment in human hepatocytes, and opens a new field about their role in liver damages during HBV infection.

Extramitochondrial OPA1 and adrenocortical function

We have previously described that silencing of the mitochondrial protein OPA1 enhances mitochondrial Ca(2+) signaling and aldosterone production in H295R adrenocortical cells. Since extramitochondrial OPA1 (emOPA1) was reported to facilitate cAMP-induced lipolysis, we hypothesized that emOPA1, via the enhanced hydrolysis of cholesterol esters, augments aldosterone production in H295R cells. A few OPA1 immunopositive spots were detected in ∼40% of the cells. In cell fractionation studies OPA1/COX IV (mitochondrial marker) ratio in the post-mitochondrial fractions was an order of magnitude higher than that in the mitochondrial fraction. The ratio of long to short OPA1 isoforms was lower in post-mitochondrial than in mitochondrial fractions. Knockdown of OPA1 failed to reduce db-cAMP-induced phosphorylation of hormone-sensitive lipase (HSL), Ca(2+) signaling and aldosterone secretion. In conclusion, OPA1 could be detected in the post-mitochondrial fractions, nevertheless, OPA1 did not interfere with the cAMP - PKA - HSL mediated activation of aldosterone secretion.

Modulation of mitochondrial functions by the indirect antioxidant sulforaphane: a seemingly contradictory dual role and an integrative hypothesis

The chemotherapeutic isothiocyanate sulforaphane (SFN) was early linked to anticarcinogenic and antiproliferative activities. Soon after, this compound, derived from cruciferous vegetables, became an excellent and useful trial for anti-cancer research in experimental models including growth tumor, metastasis, and angiogenesis. Many subsequent reports showed modifications in mitochondrial signaling, functionality, and integrity induced by SFN. When cytoprotective effects were found in toxic and ischemic insult models, seemingly contradictory behaviors of SFN were discovered: SFN was inducing deleterious changes in cancer cell mitochondria that eventually would carry the cell to death via apoptosis and also was protecting noncancer cell mitochondria against oxidative challenge, which prevented cell death. In both cases, SFN exhibited effects on mitochondrial redox balance and phase II enzyme expression, mitochondrial membrane potential, expression of the family of B cell lymphoma 2 homologs, regulation of proapoptotic proteins released from mitochondria, activation/inactivation of caspases, mitochondrial respiratory complex activities, oxygen consumption and bioenergetics, mitochondrial permeability transition pore opening, and modulation of some kinase pathways. With the ultimate findings related to the induction of mitochondrial biogenesis by SFN, it could be considered that SFN has effects on mitochondrial dynamics that explain some divergent points. In this review, we list the reports involving effects on mitochondrial modulation by SFN in anti-cancer models as well as in cytoprotective models against oxidative damage. We also attempt to integrate the data into a mechanism explaining the various effects of SFN on mitochondrial function in only one concept, taking into account mitochondrial biogenesis and dynamics and making a comparison with the theory of reactive oxygen species threshold of cell death. Our interest is to achieve a complete view of cancer and protective therapies based on SFN that can be extended to other chemotherapeutic compounds with similar characteristics. The work needed to test this hypothesis is quite extensive.

Steroid hormone synthesis in mitochondria

Mitochondria are essential sites for steroid hormone biosynthesis. Mitochondria in the steroidogenic cells of the adrenal, gonad, placenta and brain contain the cholesterol side-chain cleavage enzyme, P450scc, and its two electron-transfer partners, ferredoxin reductase and ferredoxin. This enzyme system converts cholesterol to pregnenolone and determines net steroidogenic capacity, so that it serves as the chronic regulator of steroidogenesis. Several other steroidogenic enzymes, including 3β-hydroxysteroid dehydrogenase, 11β-hydroxylase and aldosterone synthase also reside in mitochondria. Similarly, the mitochondria of renal tubular cells contain two key enzymes participating in the activation and degradation of vitamin D. The access of cholesterol to the mitochondria is regulated by the steroidogenic acute regulatory protein, StAR, serving as the acute regulator of steroidogenesis. StAR action requires a complex multi-component molecular machine on the outer mitochondrial membrane (OMM). Components of this machine include the 18 kDa translocator protein (TSPO), the voltage-dependent anion chanel (VDAC-1), TSPO-associated protein 7 (PAP7, ACBD3), and protein kinase A regulatory subunit 1α (PKAR1A). The precise fashion in which these proteins interact and move cholesterol from the OMM to P450scc, and the means by which cholesterol is loaded into the OMM, remain unclear. Human deficiency diseases have been described for StAR and for all the mitochondrial steroidogenic enzymes, but not for the electron transfer proteins or for the components of the cholesterol import machine.

Lipids of mitochondria

A unique organelle for studying membrane biochemistry is the mitochondrion whose functionality depends on a coordinated supply of proteins and lipids. Mitochondria are capable of synthesizing several lipids autonomously such as phosphatidylglycerol, cardiolipin and in part phosphatidylethanolamine, phosphatidic acid and CDP-diacylglycerol. Other mitochondrial membrane lipids such as phosphatidylcholine, phosphatidylserine, phosphatidylinositol, sterols and sphingolipids have to be imported. The mitochondrial lipid composition, the biosynthesis and the import of mitochondrial lipids as well as the regulation of these processes will be main issues of this review article. Furthermore, interactions of lipids and mitochondrial proteins which are highly important for various mitochondrial processes will be discussed. Malfunction or loss of enzymes involved in mitochondrial phospholipid biosynthesis lead to dysfunction of cell respiration, affect the assembly and stability of the mitochondrial protein import machinery and cause abnormal mitochondrial morphology or even lethality. Molecular aspects of these processes as well as diseases related to defects in the formation of mitochondrial membranes will be described.

Mitochondrial defects and oxidative stress in Alzheimer disease and Parkinson disease

Alzheimer disease (AD) and Parkinson disease (PD) are the two most common age-related neurodegenerative diseases characterized by prominent neurodegeneration in selective neural systems. Although a small fraction of AD and PD cases exhibit evidence of heritability, among which many genes have been identified, the majority are sporadic without known causes. Molecular mechanisms underlying neurodegeneration and pathogenesis of these diseases remain elusive. Convincing evidence demonstrates oxidative stress as a prominent feature in AD and PD and links oxidative stress to the development of neuronal death and neural dysfunction, which suggests a key pathogenic role for oxidative stress in both AD and PD. Notably, mitochondrial dysfunction is also a prominent feature in these diseases, which is likely to be of critical importance in the genesis and amplification of reactive oxygen species and the pathophysiology of these diseases. In this review, we focus on changes in mitochondrial DNA and mitochondrial dynamics, two aspects critical to the maintenance of mitochondrial homeostasis and function, in relationship with oxidative stress in the pathogenesis of AD and PD.

Repeated administration of AC-5216, a ligand for the 18 kDa translocator protein, improves behavioral deficits in a mouse model of post-traumatic stress disorder

Post-traumatic stress disorder (PTSD) is a severely disabling anxiety disorder that may occur following exposure to a serious traumatic event. It is a psychiatric condition that can afflict anyone who has experienced a life-threatening or violent event. Previous studies have shown that changes in 18 kDa translocator protein (TSPO) expression (or function), a promising target for treating neurological disorders without benzodiazepine-like side effects, may correlate with PTSD. However, few studies have investigated the anti-PTSD effects of TSPO ligands. AC-5216, a ligand for TSPO, induces anxiolytic- and anti-depressant-like effects in animal models. The present study aimed to determine whether AC-5216 ameliorates PTSD behavior in mice. Following the training session consisting of exposure to inescapable electric foot shocks, animals were administered AC-5216 daily during the behavioral assessments, i.e., situational reminders (SRs), the open field (OF) test, the elevated plus-maze (EPM) test, and the staircase test (ST). The results indicated that exposure to foot shocks induced long-term behavioral deficiencies in the mice, including freezing and anxiety-like behavior, which were significantly ameliorated by repeated treatment with AC-5216 but without any effect on spontaneous locomotor activity or body weight. In summary, this study demonstrated the anti-PTSD effects of AC-5216 treatment, suggesting that TSPO may represent a therapeutic target for anti-PTSD drug discovery and that TSPO ligands may be a promising new class of drugs for the future treatment of PTSD.

Mitochondrial dysfunction and sarcopenia of aging: from signaling pathways to clinical trials

Sarcopenia, the age-related loss of muscle mass and function, imposes a dramatic burden on individuals and society. The development of preventive and therapeutic strategies against sarcopenia is therefore perceived as an urgent need by health professionals and has instigated intensive research on the pathophysiology of this syndrome. The pathogenesis of sarcopenia is multifaceted and encompasses lifestyle habits, systemic factors (e.g., chronic inflammation and hormonal alterations), local environment perturbations (e.g., vascular dysfunction), and intramuscular specific processes. In this scenario, derangements in skeletal myocyte mitochondrial function are recognized as major factors contributing to the age-dependent muscle degeneration. In this review, we summarize prominent findings and controversial issues on the contribution of specific mitochondrial processes - including oxidative stress, quality control mechanisms and apoptotic signaling - on the development of sarcopenia. Extramuscular alterations accompanying the aging process with a potential impact on myocyte mitochondrial function are also discussed. We conclude with presenting methodological and safety considerations for the design of clinical trials targeting mitochondrial dysfunction to treat sarcopenia. Special emphasis is placed on the importance of monitoring the effects of an intervention on muscle mitochondrial function and identifying the optimal target population for the trial. This article is part of a Directed Issue entitled: Molecular basis of muscle wasting.

Anoikis molecular pathways and its role in cancer progression

Anoikis is a programmed cell death induced upon cell detachment from extracellular matrix, behaving as a critical mechanism in preventing adherent-independent cell growth and attachment to an inappropriate matrix, thus avoiding colonizing of distant organs. As anchorage-independent growth and epithelial-mesenchymal transition, two features associated with anoikis resistance, are vital steps during cancer progression and metastatic colonization, the ability of cancer cells to resist anoikis has now attracted main attention from the scientific community. Cancer cells develop anoikis resistance due to several mechanisms, including change in integrins' repertoire allowing them to grow in different niches, activation of a plethora of inside-out pro-survival signals as over-activation of receptors due to sustained autocrine loops, oncogene activation, growth factor receptor overexpression, or mutation/upregulation of key enzymes involved in integrin or growth factor receptor signaling. In addition, tumor microenvironment has also been acknowledged to contribute to anoikis resistance of bystander cancer cells, by modulating matrix stiffness, enhancing oxidative stress, producing pro-survival soluble factors, triggering epithelial-mesenchymal transition and self-renewal ability, as well as leading to metabolic deregulations of cancer cells. All these events help cancer cells to inhibit the apoptosis machinery and sustain pro-survival signals after detachment, counteracting anoikis and constituting promising targets for anti-metastatic pharmacological therapy. This article is part of a Special Section entitled: Cell Death Pathways.

Mitochondrial membrane lipid remodeling in pathophysiology: a new target for diet and therapeutic interventions

Mitochondria are arbiters in the fragile balance between cell life and death. These organelles present an intricate membrane system, with a peculiar lipid composition and displaying transverse as well as lateral asymmetry. Some lipids are synthesized inside mitochondria, while others have to be imported or acquired in the form of precursors. Here, we review different processes, including external interventions (e.g., diet) and a range of biological events (apoptosis, disease and aging), which may result in alterations of mitochondrial membrane lipid content. Cardiolipin, the mitochondria lipid trademark, whose biosynthetic pathway is highly regulated, will deserve special attention in this review. The modulation of mitochondrial membrane lipid composition, especially by diet, as a therapeutic strategy for the treatment of some pathologies will be also addressed.

Effects of side-stream tobacco smoke and smoke extract on glutathione- and oxidative DNA damage repair-deficient mice and blood cells

Cigarette smoke causes direct oxidative DNA damage as well as indirect damage through inflammation. Epidemiological studies show a strong relationship between secondhand smoke and cancer; however, the mechanisms of secondhand smoke-induced cancer are not well understood. Animal models with either (i) deficient oxidative DNA damage repair, or (ii) a decreased capacity to combat oxidative stress may help determine the pathways important in mitigating damage caused by smoke. In this study, we used mice lacking Ogg1 and Myh, both of which are involved in base excision repair by removing oxidatively damaged DNA bases. Gclm-deficient mice, which have decreased levels of glutathione (GSH), were used to look at the role of smoke-induced oxidative damage. Ex vivo experiments show significantly elevated levels of DNA single-strand breaks and chromosomal aberrations in peripheral blood lymphocytes from Ogg1(-/-)Myh(-/-) double knockout mice compared to wild type (WT) mice after 24h of exposure to cigarette smoke extract (CSE). The average γH2AX foci per cell was significantly elevated 3h after exposure to CSE in cells from Ogg1(-/-)Myh(-/-) double knockout mice compared to wildtype mice. In vivo we found that all mice had increased markers of DNA damage after exposure to side-stream tobacco smoke (SSTS). Ogg1(-/-)Myh(-/-) and Gclm(-/-) mice had altered levels of peripheral blood glutathione after SSTS exposure whereas wild type mice did not. This may be due to differential regulation of glutathione synthesis in the lung. We also found that Ogg1(-/-)Myh(-/-) mice had a decreased lifespan after oral gavage with benzo[a]pyrene compared to wildtype mice and sham-exposed Ogg1(-/-)Myh(-/-) mice. Our results are important in investigating the roles of oxidative stress and oxidative DNA damage repair in cigarette smoke-induced cancers and characterizing the role of genetic polymorphisms in smoke-related disease susceptibility.

Create and preserve: proteostasis in development and aging is governed by Cdc48/p97/VCP

The AAA-ATPase Cdc48 (also called p97 or VCP) acts as a key regulator in proteolytic pathways, coordinating recruitment and targeting of substrate proteins to the 26S proteasome or lysosomal degradation. However, in contrast to the well-known function in ubiquitin-dependent cellular processes, the physiological relevance of Cdc48 in organismic development and maintenance of protein homeostasis is less understood. Therefore, studies on multicellular model organisms help to decipher how Cdc48-dependent proteolysis is regulated in time and space to meet developmental requirements. Given the importance of developmental regulation and tissue maintenance, defects in Cdc48 activity have been linked to several human pathologies including protein aggregation diseases. Thus, addressing the underlying disease mechanisms not only contributes to our understanding on the organism-wide function of Cdc48 but also facilitates the design of specific medical therapies. In this review, we will portray the role of Cdc48 in the context of multicellular organisms, pointing out its importance for developmental processes, tissue surveillance, and disease prevention. This article is part of a Special Issue entitled: Ubiquitin-Proteasome System. Guest Editors: Thomas Sommer and Dieter H. Wolf.