NMR identification of a conserved Drp1 cardiolipin-binding motif essential for stress-induced mitochondrial fission.

Mitochondria form tubular networks that undergo coordinated cycles of fission and fusion. Emerging evidence suggests that a direct yet unresolved interaction of the mechanoenzymatic GTPase dynamin-related protein 1 (Drp1) with mitochondrial outer membrane-localized cardiolipin (CL), externalized under stress conditions including mitophagy, catalyzes essential mitochondrial hyperfragmentation. Here, using a comprehensive set of structural, biophysical, and cell biological tools, we have uncovered a CL-binding motif (CBM) conserved between the Drp1 variable domain (VD) and the unrelated ADP/ATP carrier (AAC/ANT) that intercalates into the membrane core to effect specific CL interactions. CBM mutations that weaken VD-CL interactions manifestly impair Drp1-dependent fission under stress conditions and induce "donut" mitochondria formation. Importantly, VD membrane insertion and GTP-dependent conformational rearrangements mediate only transient CL nonbilayer topological forays and high local membrane constriction, indicating that Drp1-CL interactions alone are insufficient for fission. Our studies establish the structural and mechanistic bases of Drp1-CL interactions in stress-induced mitochondrial fission.

Hypertension in Chronic Kidney Disease: An Update on Diagnosis and Management.

Hypertension (HTN) and chronic kidney disease (CKD) are pathophysiologic states that are intimately related, such that long-term HTN can lead to poor kidney function, and renal function decline can lead to worsening blood pressure (BP) control. HTN in CKD is caused by an interplay of factors, including salt and water retention, with extracellular volume expansion, sympathetic nervous system overactivity, renin-angiotensin-aldosterone system activation, and endothelial dysfunction. BP variability in the CKD population is significant, however, and thus requires close monitoring for appropriate management. With accumulating evidence, the diagnosis as well as management of HTN in CKD has been evolving in the last decade. In this comprehensive review based on current evidence and recommendations, we summarize the basics of pathophysiology, BP variability, diagnosis, and management of HTN in CKD with an emphasis on special populations with CKD.

Clinical genetic counselor experience in the adoption of telehealth in the United States and Canada during the COVID-19 pandemic.

The COVID-19 pandemic has significantly impacted the service delivery model (SDM) of clinical genetic counseling across the United States and Canada. A cross-sectional survey was distributed to 4,956 genetic counselors (GCs) from the American Board of Genetic Counselors and Canadian Association of Genetic Counselors mailing lists in August 2020 to assess the change in utilization of telehealth for clinical genetic counseling during the COVID-19 pandemic compared with prior to the pandemic. Data from 411 eligible clinical genetic counselors on GC attitudes and their experiences prior to and during the pandemic were collected and analyzed to explore the change in SDM, change in appointment characteristics, change in billing practices, GC perceived benefits and limitations of telehealth, and prediction of future trends in SDM in the post-pandemic era. The study showed the overall utilization of audiovisual and telephone encounters increased by 43.4% and 26.2%, respectively. The majority of respondents who provided audiovisual and telephone encounters reported increased patient volume compared with prior to the pandemic, with an average increase of 79.4% and 42.8%, respectively. There was an increase of 69.4% of GCs rendering genetic services from home offices. The percentage of participants who billed for telehealth services increased from 45.7% before the pandemic to 80.3% during the pandemic. The top GC perceived benefits of telehealth included safety for high-risk COVID patients (95.2%) and saved commute time for patients (94.7%). The top GC perceived limitations of telehealth included difficulty to conduct physician evaluation/coordinating with healthcare providers (HCP) (73.7%) and difficulty addressing non-English speaking patients (68.5%). Overall, 89.6% of GCs were satisfied with telehealth; however, 55.3% reported uncertainty whether the newly adopted SDM would continue after the pandemic subsides. Results from this study demonstrate the rapid adoption of telehealth for clinical genetic counseling services as a result of the COVID-19 pandemic, an increase in billing for these services, and support the feasibility of telehealth for genetic counseling as a longer term solution to reach patients who are geographically distant.

Tubers from patients with tuberous sclerosis complex are characterized by changes in microtubule biology through ROCK2 signalling.

Most patients with tuberous sclerosis complex (TSC) develop cortical tubers that cause severe neurological disabilities. It has been suggested that defects in neuronal differentiation and/or migration underlie the appearance of tubers. However, the precise molecular alterations remain largely unknown. Here, by combining cytological and immunohistochemical analyses of tubers from nine TSC patients (four of them diagnosed with TSC2 germline mutations), we show that alteration of microtubule biology through ROCK2 signalling contributes to TSC neuropathology. All tubers showed a larger number of binucleated neurons than expected relative to control cortex. An excess of normal and altered cytokinetic figures was also commonly observed. Analysis of centrosomal markers suggested increased microtubule nucleation capacity, which was supported by the analysis of an expression dataset from cortical tubers and control cortex, and subsequently linked to under-expression of Rho-associated coiled-coil containing kinase 2 (ROCK2). Thus, augmented microtubule nucleation capacity was observed in mouse embryonic fibroblasts and human fibroblasts deficient in the Tsc2/TSC2 gene product, tuberin. Consistent with ROCK2 under-expression, microtubule acetylation was found to be increased with tuberin deficiency; this alteration was abrogated by rapamycin treatment and mimicked by HDAC6 inhibition. Together, the results of this study support the hypothesis that loss of TSC2 expression can alter microtubule organization and dynamics, which, in turn, deregulate cell division and potentially impair neuronal differentiation.

Interplay between BRCA1 and RHAMM regulates epithelial apicobasal polarization and may influence risk of breast cancer.

Differentiated mammary epithelium shows apicobasal polarity, and loss of tissue organization is an early hallmark of breast carcinogenesis. In BRCA1 mutation carriers, accumulation of stem and progenitor cells in normal breast tissue and increased risk of developing tumors of basal-like type suggest that BRCA1 regulates stem/progenitor cell proliferation and differentiation. However, the function of BRCA1 in this process and its link to carcinogenesis remain unknown. Here we depict a molecular mechanism involving BRCA1 and RHAMM that regulates apicobasal polarity and, when perturbed, may increase risk of breast cancer. Starting from complementary genetic analyses across families and populations, we identified common genetic variation at the low-penetrance susceptibility HMMR locus (encoding for RHAMM) that modifies breast cancer risk among BRCA1, but probably not BRCA2, mutation carriers: n = 7,584, weighted hazard ratio ((w)HR) = 1.09 (95% CI 1.02-1.16), p(trend) = 0.017; and n = 3,965, (w)HR = 1.04 (95% CI 0.94-1.16), p(trend) = 0.43; respectively. Subsequently, studies of MCF10A apicobasal polarization revealed a central role for BRCA1 and RHAMM, together with AURKA and TPX2, in essential reorganization of microtubules. Mechanistically, reorganization is facilitated by BRCA1 and impaired by AURKA, which is regulated by negative feedback involving RHAMM and TPX2. Taken together, our data provide fundamental insight into apicobasal polarization through BRCA1 function, which may explain the expanded cell subsets and characteristic tumor type accompanying BRCA1 mutation, while also linking this process to sporadic breast cancer through perturbation of HMMR/RHAMM.

Biomarker in Hepatocellular Carcinoma.

Liver cancer is one of the most prevalent types of cancer and a major contributor to the socioeconomic burden worldwide. The pathogenesis of hepatocellular carcinoma (HCC) is contributed by various etiological factors like virus infection, excessive alcohol consumption, exposure to toxins, or metabolic disorders. Majority of patients are diagnosed with late-stage HCC, which restricts its management to only palliative care. HCC, if diagnosed early, increases the survival and quality of life. Currently available biomarker (alpha-fetoproteins) have several limitations, that impede the early diagnosis and staging of cancer. This warrants the continous search in pursuit of a novel biomarker. Several research works in diverse areas have contributed to the identification of various novel biomarkers that have shown multifaceted application in early disease diagnosis, which further aid in targeted and effective therapy that can prevent cancer progression. This improves the overall health status of the patient along with significant reduction in caretaker's burden. With the aid of novel technologies, several biomarkers have been investigated and validated in mutliple preliminary research works. Therefore in this review, we have outlined various novel biomarkers that showed promising outcomes in their trials and we have highlighted the developing areas that act as game changers in cancer diagnosis and management.

Health-related Quality of Life in Patients With Liver Cirrhosis: A Randomized Study.

Background/Aims: Health-related quality of life (HRQoL) relates to how people perceive illness and treatment affects their physical health, emotional health, functional status, and social position. Along with clinical goals, HRQoL is significant. Therefore, the present study evaluates the effect of patient counseling and education on HRQoL of cirrhotic patients. Methods: This prospective study was conducted in a tertiary care center of coastal Karnataka, Kasturba Medical College, Manipal, Karnataka from October 2022 with a three-month follow-up. Patients with a confirmed diagnosis of liver cirrhosis visiting the outpatient department of age ≥18 were enrolled in the study and divided on the basis of compensated and decompensated cirrhosis. Patients were randomized into two groups i.e., case and control in compensated and decompensated group through the envelop method of randomization. The case group received patient education and counseling along with standard medical therapy. CLDQ was used to evaluate HRQoL scores on baseline and after the third month. Results: A total of 104 patients were enrolled with a mean age of 53.49 ± 11.25, with most being male (80.7%). Out of 104, 60 and 44 had compensated and decompensated cirrhosis. Case and control groups did not differ significantly on baseline. However, on follow-up, the compensated group showed significant improvement in abdominal symptoms, fatigue, and emotional functions. Meanwhile, the decompensated group showed significant improvement in activity, emotional function, and worry domain of CLDQ. Higher MELD scores were the significant factor associated with lower HRQoL scores. Conclusion: Patient education and counseling positively impacted the fatigue, emotional, and worry domain of the CLDQ. Hence, the present study recommends making an effort to promote patient counseling and education via leaflets or videos.

Factors Affecting and Promoting Health-related Quality of Life in Patients With Liver Cirrhosis: An Underestimated Domain in Patient Care.

Cirrhosis patients have poor health-related quality of life (HRQoL). To enhance medical care and therapeutic approaches, it is crucial to identify factors that alter HRQoL in patients with cirrhosis. The present study aims to identify the potential factors affecting and promoting HRQoL in patients with liver cirrhosis. Four databases were extensively searched, including PubMed, Scopus, Embase, and Google Scholar. All original articles with liver cirrhosis and factor-altering HRQoL were included. The present study showed that elderly age, female gender, low family income, low body mass index (BMI), presence of anxiety and depression, presence of cirrhosis complications including ascites, hepatic encephalopathy (HE), and abnormal endoscopic findings, high disease severity score, presence of sarcopenia, disturbed sleep pattern, muscle cramps, poor sexual health, and increased levels of bilirubin, prothrombin time, and albumin-bilirubin ratio were the significant factors associated with lower HRQoL scores. Meanwhile, physical exercise, liver transplant, stem cell therapy, mindfulness, and the use of probiotics, rifaximin, and lactulose were associated with increased HRQoL scores. The present study recommends more prospective or randomized control trials with interventions including health education, yoga, psychotherapy, and other potential factors promoting HRQoL in patients with liver cirrhosis. The present study also emphasizes that the treating physician should consider taking HRQoL into account when prescribing medical therapy.

Study of prevalence, risk factors for acute kidney injury, and mortality in liver cirrhosis patients.

INTRODUCTION: Acute kidney injury (AKI) occurs frequently in patients with end-stage liver disease and cirrhosis and is associated with increased short-term mortality. This study aims to study the prevalence and risk factors associated with AKI development and mortality in cirrhosis of liver patients. METHODOLOGY: In the current prospective study, hospitalized patients with liver cirrhosis from October 2021 to March 2023 were recruited. Demographic, clinical, and laboratory data were collected, which included, the etiology of cirrhosis, comorbidities, severity of liver disease, and relevant biochemical parameters. The patient was followed up for 90 days to record the clinical outcome. The statistical software SPSS was utilized to conduct the analysis. RESULTS: Of 364 liver cirrhosis patients, 25.2% (n, 92) had AKI and belonged to an average age of 51.54 ± 11.82 years. The majority of individuals in the study were males (90.4%), and alcohol (63.4%) was the most common etiology of liver cirrhosis. The present study showed that higher level of direct bilirubin (p = 0.011) and MELD score (p = 0.0001) were identified as significant risk factors for AKI development in patients with liver cirrhosis. Regarding mortality, the significant risk factors were the presence of AKI (p = 0.045) and MELD score (p = 0.025). Among AKI patients, 90-day mortality rates were higher in patients with acute tubular necrosis (p value = 0.010) and stage 3 AKI (p value = 0.001). CONCLUSION: AKI is common in cirrhosis of liver patients. Elevated levels of direct bilirubin and MELD score emerged as significant factors associated with AKI development. Furthermore, AKI and MELD scores were identified as independent risk factors for mortality at both 30 and 90 days. Survival rates were influenced by both the type and stage of AKI; AKI stage 3 and ATN patients had significantly higher mortality rate. Early AKI detection and management are crucial for reducing mortality risk in liver cirrhosis patients.

Allosteric control of dynamin-related protein 1 through a disordered C-terminal Short Linear Motif.

The mechanochemical GTPase dynamin-related protein 1 (Drp1) catalyzes mitochondrial and peroxisomal fission, but the regulatory mechanisms remain ambiguous. Here we find that a conserved, intrinsically disordered, six-residue Short Linear Motif at the extreme Drp1 C-terminus, named CT-SLiM, constitutes a critical allosteric site that controls Drp1 structure and function in vitro and in vivo. Extension of the CT-SLiM by non-native residues, or its interaction with the protein partner GIPC-1, constrains Drp1 subunit conformational dynamics, alters self-assembly properties, and limits cooperative GTP hydrolysis, surprisingly leading to the fission of model membranes in vitro. In vivo, the involvement of the native CT-SLiM is critical for productive mitochondrial and peroxisomal fission, as both deletion and non-native extension of the CT-SLiM severely impair their progression. Thus, contrary to prevailing models, Drp1-catalyzed membrane fission relies on allosteric communication mediated by the CT-SLiM, deceleration of GTPase activity, and coupled changes in subunit architecture and assembly-disassembly dynamics.

Role of granulocyte colony stimulating factor in the treatment of cirrhosis of liver: a systematic review.

OBJECTIVE: We performed a systematic review to analyze the benefits of and risk factors associated with granulocyte colony stimulating factor (GCSF) in patients with liver cirrhosis. METHODS: PubMed, Scopus, and Embase were searched for randomized controlled trials and case-control studies that compared the use of GCSF with another treatment or control group. The Jadad and Newcastle-Ottawa scales were used to assess the risk of bias in the included studies. The primary outcome studied was mortality; and the secondary outcomes were the disease severity score, liver transplantation criteria, complications, CD34+ cell count, adverse events, and health-related quality of life (HRQOL). PROSPERO registration number CRD42023416014. RESULTS: The initial search yielded 2,235 studies, of which seven studies of 670 patients with liver cirrhosis were included. Multiple cycles of GCSF significantly improved the survival rate, disease severity score, CD34+ cell count, and HRQOL; and significantly reduced the incidences of liver transplantation, ascites, infection, and hepatic encephalopathy. Fatigue and backache were the most commonly reported adverse events. CONCLUSION: GCSF significantly improves the survival rate and disease severity scores, and reduces the incidence of complications in patients with liver cirrhosis. The administration of GCSF is likely to be effective in patients awaiting liver transplantation.

Thiopurine therapy in inflammatory bowel disease in the pandemic era: Safe or unsafe?

BACKGROUND: Inflammatory bowel disease (IBD) is a chronic inflammatory condition of the gastrointestinal tract. Crohn's disease (CD) and Ulcerative colitis (UC) are the two major types affecting millions across the globe. Various immunomodulatory drugs consisting of small molecules (thiopurines, methotrexate and tofacitinib) and biologics are used to treat IBD. Thiopurines (TP) are widely used in the treatment of IBD and it plays an important role both alone and in combination with anti-TNF agents as IBD maintenance therapy. Although the advent of biologics therapy has significantly advanced the management of IBD, TP remains the mainstay of treatment in resource-limited and low economic settings. However, the recently commenced pandemic has raised uncertainty over the safety of the use of immunosuppressant drugs such as TP among healthcare care providers and patients, as there is a scarcity of data on whether IBD patients are at higher risk of COVID-19 infection or more prone to its severe outcomes. AIM: This review aims to encapsulate evidence on the risk of COVID-19 infection and its severe prognosis in IBD patients on TP. Additionally, it also evaluates the role of TP in inhibiting the viral protease, a potential drug target, essential for the replication and pathogenesis of the virus. CONCLUSION: Emerging evidence suggests that TP therapy is safe during the current pandemic and does not carry an elevated risk when used as monotherapy or in combination with other IBD drugs. In-vitro studies demonstrate that TP is a potential therapeutic for present and future betacoronavirus pandemics.

Exosomes in chronic liver disease.

Chronic liver disease (CLD) is the major cause of mortality and morbidity, particularly in developing countries. Although there has been a significant advancement in the identification and treatment of liver diseases over time, clinical results are not satisfactory in advanced liver disease. Thus, it is crucial to develop certain technology for early detection, and curative therapies and to investigate the molecular mechanisms behind CLD's pathogenesis. The study of exosomes in CLD is a rapidly developing field. They are structurally membrane-derived nano vesicles released by various cells. In CLD, exosomes released from injured hepatic cells affect intercellular communication, creating a microenvironment conducive to the illness's development. They also carry liver cell-specific proteins and miRNAs, which can be used as diagnostic biomarkers and treatment targets for various liver diseases. End-stage liver disease can only be treated by a liver transplant, however, the low availability of compatible organs, high expenses of treatment, and surgical complications significantly lower patient survival rates. Early diagnosis and therapeutic intervention of CLD positively affect the likelihood of curative treatment and high patient survival rates. Considering the possibility that exosomes could be employed as tools for disease diagnostics and clinical intervention, The current study briefly summarizes the roles of exosomes and their cargo in diagnosing and treating liver diseases.

Allosteric control of dynamin-related protein 1-catalyzed mitochondrial fission through a conserved disordered C-terminal Short Linear Motif.

The mechanochemical GTPase dynamin-related protein 1 (Drp1) catalyzes mitochondrial fission, but the regulatory mechanisms remain ambiguous. Here we found that a conserved, intrinsically disordered, six-residue Short Linear Motif at the extreme Drp1 C-terminus, named CT-SLiM, constitutes a critical allosteric site that controls Drp1 structure and function in vitro and in vivo. Extension of the CT-SLiM by non-native residues, or its interaction with the protein partner GIPC-1, constrains Drp1 subunit conformational dynamics, alters self-assembly properties, and limits cooperative GTP hydrolysis, leading to the fission of model membranes in vitro. In vivo, the availability of the native CT-SLiM is a requirement for productive mitochondrial fission, as both non-native extension and deletion of the CT-SLiM severely impair its progression. Thus, contrary to prevailing models, Drp1-catalyzed mitochondrial fission relies on allosteric communication mediated by the CT-SLiM, deceleration of GTPase activity, and coupled changes in subunit architecture and assembly-disassembly dynamics.

Novel biomarkers for prognosticating diabetic kidney disease progression.

The global burden of diabetic kidney disease (DKD) is escalating, and it remains as a predominant cause of the end-stage renal disease (ESRD). DKD is associated with increased cardiovascular disease and morbidity in all types of diabetes. Prediction of progression with albuminuria and eGFR is challenging in DKD, especially in non-proteinuric DKD patients. The pathogenesis of DKD is multifactorial characterized by injury to all components of the nephron, whereas albuminuria is an indicator of only glomerular injury. The limits in the diagnostic and prognostic value of urine albumin demonstrate the need for alternative and clinically significant early biomarkers, allowing more targeted and effective diabetic treatment, to reduce the burden of DKD and ESRD. Identification of biomarkers, based on multifactorial pathogenesis of DKD can be the crucial paradigm in the treatment algorithm of DKD patients. This review focuses on the potential biomarkers linked to DKD pathogenesis, particularly with the hope of broadening the diagnostic window to identify patients with different stages of DKD progression.

Novel Drugs for the Management of Hepatic Encephalopathy: Still a Long Journey to Travel.

Hepatic encephalopathy (HE) is one of the reversible complications of chronic liver disease, associated with a higher mortality rate. In current clinical practice, treatment with rifaximin and lactulose/lactitol is the first line of treatment in HE. With the advance in pathophysiology, a new class of ammonia lowering drugs has been revealed to overcome the hurdle and disease burden. The mechanism of the novel agents differs significantly and includes the alteration in intestinal microbiota, intestinal endothelial integrity, oxidative stress, inflammatory markers, and modulation of neurotoxins. Most of the trials have reported promising results in the treatment and prevention of HE with fecal microbiota transplantation, albumin, probiotics, flumazenil, polyethylene glycol, AST-120, glycerol phenylbutyrate, nitazoxanide, branched-chain amino acid, naloxone, and acetyl-l-carnitine. However, their clinical use is limited due to the presence of major drawbacks in their study design, sample size, safety profile, bias, and heterogenicity. This study will discuss the novel therapeutic targets for HE in liver cirrhosis patients with supporting clinical trial data.

Predictors for oesophageal candidiasis in patients with liver cirrhosis.

Background and aim: Oesophageal candidiasis (OC) is one of the most common infections among patients with liver cirrhosis. The present study evaluates the potential predictors for OC among liver cirrhosis patients. Methodology: This retrospective study was conducted in the tertiary care centre of coastal Karnataka from January 2016 to April 2022. Patients aged 18 and above with a confirmed diagnosis of liver cirrhosis were selected. Patients were equally divided into two groups, i.e., case and control, based on the presence and absence of OC. Results: A total of 1513 patients with cirrhosis underwent upper gastrointestinal endoscopy. Of these, 50 (3.3%) were diagnosed with OC and taken into case group. An equal number of patients were selected in control group and matched for gender, age and etiology. Most participants were male (94%), with a mean age of 48.46±11.82 years. A lower serum creatinine value was noted among patients with OC. Binary logistic regression identified serum creatinine as an independent predictor for OC (OR: 7.65, 95% CI: 2.012-29.08; p-value: 0.003). The receiver operating characteristic curve for serum creatinine showed the highest significance with a cut-off of <0.86 mg/dL (AUC: 0.722). Conclusion: Serum creatinine is the independent predictor for OC among liver cirrhosis patients. The possible mechanism is that cirrhosis is a catabolic state in which muscle protein breakdown exceeds synthesis, resulting in decreased muscle mass and low creatinine levels. However, more prospective studies are required to evaluate the role of sarcopenia with OC among liver cirrhosis patients.

Microparticles in diabetic kidney disease.

Diabetic kidney disease (DKD) is the most common cause of renal failure and a major contributor to the socioeconomic burden in chronic kidney disease (CKD) patients worldwide. The pathogenesis of DKD involves all the structures in the nephron, and it is indicated by proteinuria, hypertension, and progressive decline in renal function, leading to substantial morbidity and mortality. Due to the limitations of currently available standard markers (albuminuria and glomerular filtration rate) in the diagnosis and clinical grading of DKD, it's time to have novel biomarkers for early detection, targeted and effective therapy to prevent the progression. Microparticles (MPs) are extracellular vesicles measuring 0.1-1 µm derived by cytoskeletal reorganization in the form of cytoplasmic blebs which alters the phospholipid cytochemistry of the cell membrane. They are shed during cell activation and apoptosis as well as plays an important role in cell-to-cell communication. Over the last few decades, both plasma and urinary MPs have been investigated, validated and the preliminary research looks promising. With alterations in their number and composition documented in clinical situations involving both Type1 and 2 diabetes mellitus, microparticles assay appears to be promising in early diagnosis and prognostication of DKD. We cover the basics of microparticles and their involvement in DKD in this review article.

Urinary neutrophil gelatinase-associated lipocalin: Acute kidney injury in liver cirrhosis.

Acute kidney injury (AKI) in liver cirrhosis is associated with poor clinical outcomes including an increased long and short-term mortality. The common type of AKI observed in patients with cirrhosis are prerenal AKI (PRA), hepatorenal syndrome (HRS) and acute tubular necrosis (ATN). Despite the growing knowledge and uniform definition for the diagnosis of AKI, there are several challenges including, early diagnosis and management. Precisely differentiating the type of AKI is critical, as therapies differ significantly. In this review, we summarize AKI in liver cirrhosis, their definition, pathophysiology and deficiencies of using the existing biomarker, serum creatinine. We outline the current clinical evidence on the novel biomarker urinary neutrophil gelatinase-associated lipocalin (uNGAL) and its potential role as a biomarker in the early detection, differentiation and prognostication of AKI. This review also briefly talks about other forthcoming biomarkers which hold promise in the management of AKI in liver cirrhosis.