Mucosa-Associated Lymphoid Tissue Surgeries as a Possible Risk for Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis.

Background: Inflammatory bowel disease (IBD) is a group of chronic inflammatory gastrointestinal disorders that are caused by genetic susceptibility and environmental factors and affects a significant portion of the global population. The gut-associated lymphoid tissue (GALT) is known to play a crucial role in immune modulation and maintaining gut microbiota balance. Dysbiosis in the latter has a known link to IBD. Therefore, the increasing prevalence of adenoidectomy in children should be explored for its potential association with IBD. The objective of this paper was to assess the association between adenoid tissue removal and the risk of developing Crohn's disease (CD) and ulcerative colitis (UC). Methods: We conducted a pooled meta-analysis to evaluate the extended clinical outcomes in patients who underwent appendicectomy and tonsillectomy compared to those who did not. Our approach involved systematically searching the PubMed database for relevant observational studies written in English. We followed the Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines to collect data from various time periods, and to address the diversity in study results; we employed a random-effects analysis that considered heterogeneity. For outcomes, odds ratios (ORs) were pooled using a random-effects model. Results: Seven studies, out of a total of 114,537, met our inclusion criteria. Our meta-analysis revealed a significant association between appendicectomy and CD (OR: 1.57; 95% confidence interval (CI): 1.01 - 2.43; heterogeneity I2 = 93%). Similarly, we found a significant association between tonsillectomy and CD (OR: 1.93; 95% CI: 0.96 - 3.89; I2 = 62%). However, no significant association was observed between appendicectomy and UC (OR: 0.60; 95% CI: 0.24 - 1.47; I2 = 96%), while a modest association was found between tonsillectomy and UC (OR: 1.24; 95% CI: 1.18 - 1.30; I2 = 0%). Conclusions: In summary, we found that the trend of appendicectomy is linked to higher odds of CD, and tonsillectomy is more likely associated with increased odds for both CD and UC, with a risk of bias present.

Contribution of membrane raft redox signalling to visfatin-induced inflammasome activation and podocyte injury.

Recently we have shown that adipokine visfatin-induced NLRP3 inflammasome activation contributes to podocyte injury. However, the molecular mechanisms of how visfatin-induces the Nlrp3 inflammasome activation and podocyte damage is still unknown. The present study tested whether membrane raft (MR) redox signalling pathway plays a central role in visfatin-induced NLRP3 inflammasomes formation and activation in podocytes. Upon visfatin stimulation an aggregation of NADPH oxidase subunits, gp91phox and p47phox was observed in the membrane raft (MR) clusters, forming a MR redox signalling platform in podocytes. The formation of this signalling platform was blocked by prior treatment with MR disruptor MCD or NADPH oxidase inhibitor DPI. In addition, visfatin stimulation significantly increased the colocalization of Nlrp3 with Asc or Nlrp3 with caspase-1, IL-ß production, cell permeability in podocytes compared to control cells. Pretreatment with MCD, DPI, WEHD significantly abolished the visfatin-induced colocalization of NLRP3 with Asc or NLRP3 with caspase-1, IL-1ß production and cell permeability in podocytes. Furthermore, Immunofluorescence analysis demonstrated that visfatin treatment significantly decreased the podocin and nephrin expression (podocyte damage) and prior treatments with DPI, WEHD, MCD attenuated this visfatin-induced podocin and nephrin reduction. In conclusion, our results suggest that visfatin stimulates membrane raft clustering in the membrane of podocytes to form redox signaling platforms by aggregation and activation of NADPH oxidase subunits enhancing O2·- production and leading to NLRP3 inflammasome activation in podocytes and ultimate podocyte injury.

An Evaluation of Malaria Surveillance System in Punjab, India, 2020.

Background: India accounted for 6% of global burden of malaria with 95% population residing in malaria endemic areas. However, Punjab is in the malaria elimination phase with annual parasite incidence (API) <1/1000 population. Objectives: We evaluated malaria surveillance system in Punjab using CDC's updated guidelines for evaluating public health surveillance systems to provide recommendations for strengthening the existing system and to overcome the challenges in the path of malaria free Punjab. Methods: We chose two districts of Punjab, Amritsar (lowest API) and Mansa (highest API), interviewed stakeholders, and performed a retrospective desk review. We evaluated the overall usefulness of the system and assessed seven attributes at state, district, health facility, and village level during July-August 2020. Results: In Punjab, there was progressive decline in the malaria cases from 2,955 cases in 2009 to 1,140 in 2019 and no malaria deaths since 2011. Regarding various attributes, overall score for flexibility was good (85.9%); average for simplicity (77%), acceptability (74%), data quality (74%), and timeliness (70%); and poor for representativeness (59%) and stability (57%). Conclusions: Malaria surveillance system was useful in analyzing the trends of morbidity and mortality and for generating data to drive policy decisions. To improve stability, representativeness, and acceptability, surveillance staff should not be engaged in supplemental work, and reports from private sector must be ensured. Supportive supervision and regular trainings should be carried out regarding reporting formats, guidelines, and timely epidemiological investigations to improve timeliness, data quality, and simplicity.

PCBP1 regulates alternative splicing of AARS2 in congenital cardiomyopathy.

Alanyl-transfer RNA synthetase 2 (AARS2) is a nuclear encoded mitochondrial tRNA synthetase that is responsible for charging of tRNA-Ala with alanine during mitochondrial translation. Homozygous or compound heterozygous mutations in the Aars2 gene, including those affecting its splicing, are linked to infantile cardiomyopathy in humans. However, how Aars2 regulates heart development, and the underlying molecular mechanism of heart disease remains unknown. Here, we found that poly(rC) binding protein 1 (PCBP1) interacts with the Aars2 transcript to mediate its alternative splicing and is critical for the expression and function of Aars2. Cardiomyocyte-specific deletion of Pcbp1 in mice resulted in defects in heart development that are reminiscent of human congenital cardiac defects, including noncompaction cardiomyopathy and a disruption of the cardiomyocyte maturation trajectory. Loss of Pcbp1 led to an aberrant alternative splicing and a premature termination of Aars2 in cardiomyocytes. Additionally, Aars2 mutant mice with exon-16 skipping recapitulated heart developmental defects observed in Pcbp1 mutant mice. Mechanistically, we found dysregulated gene and protein expression of the oxidative phosphorylation pathway in both Pcbp1 and Aars2 mutant hearts; these date provide further evidence that the infantile hypertrophic cardiomyopathy associated with the disorder oxidative phosphorylation defect type 8 (COXPD8) is mediated by Aars2. Our study therefore identifies Pcbp1 and Aars2 as critical regulators of heart development and provides important molecular insights into the role of disruptions in metabolism on congenital heart defects.

Conjunctival papilloma: a case report and a brief review of literature.

Background: Conjunctival papilloma commonly develops in infants and children. It is believed that the etiologic agent, human papillomavirus (HPV), gets implanted from the infected maternal birth canal in the conjunctival sac of the new borne while parturition. It grows as solitary or multiple pedunculated benign masses adjacent to the caruncle. It is uncommon but if growing in adults it grows on the limbal conjunctiva and could be malignant. Case Description: An Afro-American adult male developed two distinct conjunctival growths on his left lower lid. One growth was pedunculated and the second one sessile. The initial diagnosis of 'benign conjunctival papillomas' was made. Patient was recommended to wait and watch. After about two years the neoplasia had doubled their sizes. Surgical excisional biopsy was performed for diagnostic and therapeutic reasons. The tumor beds were treated with intra-operative cryotherapy using liquid nitrogen and applying double-freeze-thaw technique. Histopathology proved the masses to be benign and caused by HPV. Recurrence and seeding of virus during surgical excision leading to multiple new masses are dreaded complications during management of conjunctival papilloma. Though a short follow-up, yet after three months there were no signs of recurrence. Conclusions: A brief review of literature is presented to highlight the fact that rarely such conjunctival papillomas may develop at unusual sites and in adults. We believe that the uncommon demographic and anatomic presentation of this case is worth sharing with ophthalmic community.

mt-Ty 5'tiRNA regulates skeletal muscle cell proliferation and differentiation.

In this study, we sought to determine the role of tRNA-derived fragments in the regulation of gene expression during skeletal muscle cell proliferation and differentiation. We employed cell culture to examine the function of mt-Ty 5' tiRNAs. Northern blotting, RT-PCR as well as RNA-Seq, were performed to determine the effects of mt-Ty 5' tiRNA loss and gain on gene expression. Standard and transmission electron microscopy (TEM) were used to characterize cell and sub-cellular structures. mt-Ty 5'tiRNAs were found to be enriched in mouse skeletal muscle, showing increased levels in later developmental stages. Gapmer-mediated inhibition of tiRNAs in skeletal muscle C2C12 myoblasts resulted in decreased cell proliferation and myogenic differentiation; consistent with this observation, RNA-Seq, transcriptome analyses, and RT-PCR revealed that skeletal muscle cell differentiation and cell proliferation pathways were also downregulated. Conversely, overexpression of mt-Ty 5'tiRNAs in C2C12 cells led to a reversal of these transcriptional trends. These data reveal that mt-Ty 5'tiRNAs are enriched in skeletal muscle and play an important role in myoblast proliferation and differentiation. Our study also highlights the potential for the development of tiRNAs as novel therapeutic targets for muscle-related diseases.

Janus zirconium halide ZrXY (X, Y = Br, Cl and F) monolayers with high lattice thermal conductivity and strong visible-light absorption.

In this work, the structural, mechanical, and electronic properties of Janus zirconium halide monolayers have been systematically investigated using the first-principles calculations. After verifying the mechanical and dynamical stability of these monolayers, their electronic band structures have been predicted. These Janus monolayers have band gaps of 1.51-1.96 eV, which indicates their suitability for visible light absorption. The relaxation time and mobility of charge carriers are estimated using deformation potential theory, and the mobility of these monolayers has been predicted to be of the order ∼102 cm2 V-1 s-1. The lattice thermal conductivity has been calculated by solving the phonon Boltzmann transport equation using ShengBTE software. At 300 K, the in-plane lattice thermal conductivity has values of 76.94, 54.18, and 95.87 W m-1 K-1 for ZrBrCl, ZrBrF, and ZrClF monolayers, respectively. The higher group velocity and small anharmonic three-phonon scattering rate are the main reasons for the high lattice thermal conductivity of the ZrClF monolayer. The real and imaginary parts of the dielectric function are calculated to find the absorption coefficients and these monolayers have a high absorption coefficient of the order ∼106 cm-1 in the visible light range. Our results show that Janus zirconium halide monolayers are potential candidates for optoelectronic and photocatalytic applications.

Treating Deep Venous Thrombosis in a Background of Crohn's Disease: A Clinical Conundrum.

Deep venous thrombosis (DVT) commonly affects the lower extremities, often as a result of prolonged immobilization. However, upper limb DVT is an atypical presentation, typically associated with risk factors such as the use of a peripherally inserted central catheter (PICC) line. This case report describes an uncommon case of DVT management in a patient with Crohn's disease, a condition more frequently characterized by painful lower gastrointestinal symptoms and chronic diarrhea. A 22-year-old male with a history of Crohn's disease developed swelling and purplish discoloration at the brachial site of a PICC line site. Laboratory results indicated anemia with a hemoglobin level of 9.9 g/dL and a hematocrit of 31.9%. Doppler ultrasound confirmed the DVT in the left long axillary, left subclavian, and left long basilic veins. Given the patient's concurrent lower gastrointestinal bleeding, a cautious approach was required to balance the risks and benefits of anticoagulation. Upon recommendation by Hematology, a prophylactic dose of enoxaparin was initiated and subsequently escalated to a therapeutic dose as tolerated. The patient's condition was closely monitored, and he successfully reached the full therapeutic regimen without complications. This case underscores the importance of individualized DVT treatment strategies in the context of concurrent Crohn's disease, offering insights into managing anticoagulation in the presence of bleeding risks.

A Case of a Constricted Vessel: The Impact of Acute Myeloid Leukemia on the Superior Vena Cava.

Acute myeloid leukemia (AML) is the most prevalent form of leukemia in adults, with rising global incidence rates. AML usually presents with non-specific clinical features such as pallor, fever, and bleeding. This case report discusses a unique presentation of AML, where a 25-year-old female with a history of hypertension presented with unilateral facial swelling, chest pain, and shortness of breath. Radiologic investigations revealed a mediastinal mass encasing the superior vena cava (SVC), confirming the suspicion of SVC syndrome. Upon testing with a biopsy, the mass was found to be composed of immature myeloid cells confirming the diagnosis of myeloid sarcoma-associated AML. The patient's treatment involved a combination of surgical debridement, induction chemotherapy, supportive care, and management of complications. This case highlights that despite its common occurrence, AML may present with atypical clinical manifestations such as SVC syndrome, posing challenges in its diagnosis and timely management.

Resveratrol Delivery via Gene Therapy: Entering the Modern Era

Resveratrol is a natural compound (an antioxidant) and exhibits numerous therapeutic activities. From a pharmacokinetic perspective, it is unclear whether resveratrol targets the site of action after oral administration because of quick metabolism and excretion that creates doubt on the biological application of the high doses characteristically used for clinical trials. However, these limitations act as a barrier and a challenge for the development of new delivery systems. Recently, gene delivery offers various advantages and has provided treatment options for diseases that are beyond the reach of traditional approaches. The objective of gene therapy for genetic diseases is to achieve durable expression of the therapeutic gene at a level sufficient to alleviate or cure disease symptoms with minimal adverse events. The perception of the molecular and cellular mechanisms steering to therapy and vector-related hindrances have caused in the progress of extremely complex gene delivery with enhanced protection and effectiveness. With the help of gene therapy, it could be possible to target the delivery of resveratrol directly into the host cells and bypass its pharmacokinetic limitations and enhancement of its therapeutic effect. This review is to provide a holistic view of the development of resveratrol gene treatment as a powerful option to treat various deadly diseases.

Nervous System-Systemic Crosstalk in SARS-CoV-2/COVID-19: A Unique Dyshomeostasis Syndrome.

SARS-CoV-2 infection is associated with a spectrum of acute neurological syndromes. A subset of these syndromes promotes higher in-hospital mortality than is predicted by traditional parameters defining critical care illness. This suggests that deregulation of components of the central and peripheral nervous systems compromises the interplay with systemic cellular, tissue and organ interfaces to mediate numerous atypical manifestations of COVID-19 through impairments in organismal homeostasis. This unique dyshomeostasis syndrome involves components of the ACE-2/1 lifecycles, renin-angiotensin system regulatory axes, integrated nervous system functional interactions and brain regions differentially sculpted by accelerated evolutionary processes and more primordial homeostatic functions. These biological contingencies suggest a mechanistic blueprint to define long-term neurological sequelae and systemic manifestations such as premature aging phenotypes, including organ fibrosis, tissue degeneration and cancer. Therapeutic initiatives must therefore encompass innovative combinatorial agents, including repurposing FDA-approved drugs targeting components of the autonomic nervous system and recently identified products of SARS-CoV-2-host interactions.

Survival of COVID-19 Patients With Respiratory Failure is Related to Temporal Changes in Gas Exchange and Mechanical Ventilation.

Background: Respiratory failure due to coronavirus disease of 2019 (COVID-19) often presents with worsening gas exchange over a period of days. Once patients require mechanical ventilation (MV), the temporal change in gas exchange and its relation to clinical outcome is poorly described. We investigated whether gas exchange over the first 5 days of MV is associated with mortality and ventilator-free days at 28 days in COVID-19. Methods: In a cohort of 294 COVID-19 patients, we used data during the first 5 days of MV to calculate 4 daily respiratory scores: PaO2/FiO2 (P/F), oxygenation index (OI), ventilatory ratio (VR), and Murray lung injury score. The association between these scores at early (days 1-3) and late (days 4-5) time points with mortality was evaluated using logistic regression, adjusted for demographics. Correlation with ventilator-free days was assessed (Spearman rank-order coefficients). Results: Overall mortality was 47.6%. Nonsurvivors were older (P < .0001), more male (P = .029), with more preexisting cardiopulmonary disease compared to survivors. Mean PaO2 and PaCO2 were similar during this timeframe. However, by days 4 to 5 values for all airway pressures and FiO2 had diverged, trending lower in survivors and higher in nonsurvivors. The most substantial between-group difference was the temporal change in OI, improving 15% in survivors and worsening 11% in nonsurvivors (P < .05). The adjusted mortality OR was significant for age (1.819, P = .001), OI at days 4 to 5 (2.26, P = .002), and OI percent change (1.90, P = .02). The number of ventilator-free days correlated significantly with late VR (-0.166, P < .05), early and late OI (-0.216, P < .01; -0.278, P < .01, respectively) and early and late P/F (0.158, P < .05; 0.283, P < .01, respectively). Conclusion: Nonsurvivors of COVID-19 needed increasing intensity of MV to sustain gas exchange over the first 5 days, unlike survivors. Temporal change OI, reflecting both PaO2 and the intensity of MV, is a potential marker of outcome in respiratory failure due to COVID-19.

Clinical Outcomes of COVID-19 Patients Treated with Convalescent Plasma or Remdesivir Alone and in Combination at a Community Hospital in California's Central Valley.

PURPOSE: The purpose of this study was to compare how treatment with convalescent plasma (CP) monotherapy, remdesivir (RDV) monotherapy, and combination therapy (CP + RDV) in patients with COVID-19 affected clinical outcomes. METHODS: Patients with COVID-19 infection who were admitted to the hospital received CP, RDV, or combination of both. Mortality, discharge disposition, hospital length of stay (LOS), intensive care unit (ICU) LOS, and total ventilation days were compared between each treatment group and stratified by ABO blood group. An exploratory analysis identified risk factors for mortality. Adverse effects were also evaluated. RESULTS: RDV monotherapy showed an increased chance of survival compared to combination therapy or CP monotherapy (p = 0.052). There were 15, 3, and 6 deaths in the CP, RDV, and combination therapy groups, respectively. The combination therapy group had the longest median ICU LOS (8, IQR 4.5-15.5, p = 0.220) and hospital LOS (11, IQR 7-15.5, p = 0.175). Age (p = 0.036), initial SOFA score (p = 0.013), and intubation (p = 0.005) were statistically significant predictors of mortality. Patients with type O blood had decreased ventilation days, ICU LOS, and total LOS. Thirteen treatment-related adverse events occurred. CONCLUSION: No significant differences in clinical outcomes were observed between patients treated with RDV, CP, or combination therapy. Elderly patients, those with a high initial SOFA score, and those who require intubation are at increased risk of mortality associated with COVID-19. Blood type did not affect clinical outcomes.

Preoperative Liver Function Guiding HCC Resection in Normal and Cirrhotic Liver.

BACKGROUND: Liver resection is the most effective available therapy for patients with hepatocellular carcinoma (HCC). The accurate selection of patients for surgery requires determination of technical resectability and the risk of recurrence, as well as assessment of liver function and functional reserve to avoid postoperative liver failure. Previous studies have underlined the effectiveness and reliability of the LiMAx® test to evaluate liver function preoperatively. Nevertheless, data concerning HCC evaluation are lacking. METHODS: From 2014 to 2019, 92 patients with HCC underwent additional assessment of liver function using the LiMAx test prior to decision for or against liver resection. Preoperative LiMAx results were compared between cirrhotic and noncirrhotic liver. The clinical decision for surgery was evaluated applying the various liver function parameters available. RESULTS: Forty-six patients underwent liver resection. The LiMAx results were higher in resected patients (388 vs. 322 µg/kg/h; p = 0.004). LiMAx values were an independent risk factor for the presence of liver cirrhosis in multivariate analysis. In 17 patients, surgical treatment was cancelled due to major impairment of liver function. Only 4 out of 46 resected patients presented with post-hepatectomy liver failure (PHLF) grade ≥B. Histologic assessment revealed liver cirrhosis in 10 resected patients without PHLF. CONCLUSION: Preoperative determination of liver function by the LiMAx test enables effective and safe patient selection for HCC resection in both cirrhotic and noncirrhotic liver.

Functional status of mechanically ventilated COVID-19 survivors at ICU and hospital discharge.

BACKGROUND: A significant number of COVID-19 patients have been treated using invasive mechanical ventilation (IMV). The ability to evaluate functional status of COVID-19 survivors early on at ICU and hospital discharge may enable identification of patients who may need medical and rehabilitation interventions. METHODS: The modified "Mental Status", ICU Mobility, and Barthel Index scores at ICU and hospital discharge were tabulated for 118 COVID-19 survivors treated with invasive mechanical ventilation (IMV). These functional scores were compared with pre-admission functional status, discharge durable medical equipment, discharge medical follow-up recommendation, duration on IMV, duration post-IMV, demographics, comorbidities, laboratory tests, and vital signs at ICU and hospital discharge. RESULTS: The majority of COVID-19 IMV patients were not functionally independent at hospital discharge (22% discharged with cane or rolling walker, 49% discharged with durable medical equipment, and 14% admitted to a rehabilitation facility), although 94% of these patients were functionally independent prior to COVID-19 illness. Half of the patients were discharged with supplemental oxygen equipment. The most prevalent medical follow-up recommendations were cardiology, vascular medicine, pulmonology, endocrinology, and neurology with many patients receiving multiple medical follow-up recommendations. Functional status improved from ICU discharge to hospital discharge (p < 0.001). Worse functional status at hospital discharge was associated with longer IMV duration, older age, male sex, higher number of comorbidities, and the presence of pre-existing comorbidities including hypertension, diabetes, chronic obstructive pulmonary disease, and immunosuppression (p < 0.05, ANOVA). CONCLUSIONS: The majority of IMV COVID-19 survivors were not functionally independent at discharge and required significant follow-up medical care. The COVID-19 circumstance has placed constraints on access to in-hospital rehabilitation. These findings underscore the need for prospective studies to ascertain the short- and long-term sequela in COVID-19 survivors.

Factors affecting non-adherence to medical appointments among patients with hypertension at public health facilities in Punjab, India.

Daily adherence to antihypertensive medications is necessary to control hypertension. Under the State hypertension control program, hypertensive patients are enrolled in public health settings, provided with 30-day medication prescriptions, and advised to return to the health facility monthly. However, at least 50-60% of patients do not visit the health facility for their scheduled follow-up appointments. The authors aimed to document the major reasons for missed appointments and to characterize patient and health system barriers. By telephone, the authors interviewed 300 randomly selected patients who missed appointments for more than three consecutive months. Out of the 300, 206 were interviewed using a pre-structured questionnaire to explore patients' experiences along with medical record reviews from the patient database. Not feeling sick or not experiencing any symptoms (24.8%) was the major reason why patients did not return to the clinic, followed by far distance from the facility (22.3%). Among other reasons for missing follow-up appointments, lack of instructions/guidance from the facility (15.3%), acute illness among patients (8.3%), and long waiting time at the facilities (7%) were also documented. Most of these patients (55.4%) continued treatment from other sources, and a majority (54%) preferred private clinics. These results suggest the need for a more patient-centered care model, including education about hypertension as an asymptomatic but life-threatening condition and addressing the barrier of travel distance between a patient's home and the health facility. Further, introducing a reminder system using telephone calls, text messages, or home visits by health workers may increase the follow-up rate among patients.

India Hypertension Control Initiative-Hypertension treatment and blood pressure control in a cohort in 24 sentinel site clinics.

The India Hypertension Control Initiative (IHCI) is a multi-partner initiative, implementing and scaling up a public health hypertension control program across India. A cohort of 21,895 adult hypertension patients in 24 IHCI sentinel site facilities in four Indian states (Punjab, Madhya Pradesh, Maharashtra, and Telangana), registered from January 2018 until June 2019 were assessed at baseline and then followed up for blood pressure (BP) control and antihypertensive medication use. Among all registrations, 11 274 (51%) of the patients returned for a follow-up visit between July 2019 and September 2019. Among patients returning for follow-up, 26.3% had BP controlled at registration, and 59.8% had BP controlled at follow-up (p < .001). The absolute improvement in BP control was more than two times greater in primary care (48.1 percentage point increase) than secondary care facilities (22.9 percentage point increase). Most IHCI patients received prescriptions according to state-specific treatment protocols. This study demonstrates that a scalable public health hypertension control program can yield substantial BP control improvements, especially in primary care settings. However, high loss to follow-up limits population health impact; future efforts should focus on improving systems to increase the likelihood that patients will return to the clinic for routine hypertension care.

Tiny Regulators of Massive Tissue: MicroRNAs in Skeletal Muscle Development, Myopathies, and Cancer Cachexia.

Skeletal muscles are the largest tissues in our body and the physiological function of muscle is essential to every aspect of life. The regulation of development, homeostasis, and metabolism is critical for the proper functioning of skeletal muscle. Consequently, understanding the processes involved in the regulation of myogenesis is of great interest. Non-coding RNAs especially microRNAs (miRNAs) are important regulators of gene expression and function. MiRNAs are small (~22 nucleotides long) noncoding RNAs known to negatively regulate target gene expression post-transcriptionally and are abundantly expressed in skeletal muscle. Gain- and loss-of function studies have revealed important roles of this class of small molecules in muscle biology and disease. In this review, we summarize the latest research that explores the role of miRNAs in skeletal muscle development, gene expression, and function as well as in muscle disorders like sarcopenia and Duchenne muscular dystrophy (DMD). Continuing with the theme of the current review series, we also briefly discuss the role of miRNAs in cancer cachexia.