Inhibitory to non-inhibitory evolution of the ζ subunit of the F1FO-ATPase of Paracoccus denitrificans and α-proteobacteria as related to mitochondrial endosymbiosis.

Introduction: The ζ subunit is a potent inhibitor of the F1FO-ATPase of Paracoccus denitrificans (PdF1FO-ATPase) and related α-proteobacteria different from the other two canonical inhibitors of bacterial (ε) and mitochondrial (IF1) F1FO-ATPases. ζ mimics mitochondrial IF1 in its inhibitory N-terminus, blocking the PdF1FO-ATPase activity as a unidirectional pawl-ratchet and allowing the PdF1FO-ATP synthase turnover. ζ is essential for the respiratory growth of P. denitrificans, as we showed by a Δζ knockout. Given the vital role of ζ in the physiology of P. denitrificans, here, we assessed the evolution of ζ across the α-proteobacteria class. Methods: Through bioinformatic, biochemical, molecular biology, functional, and structural analyses of several ζ subunits, we confirmed the conservation of the inhibitory N-terminus of ζ and its divergence toward its C-terminus. We reconstituted homologously or heterologously the recombinant ζ subunits from several α-proteobacteria into the respective F-ATPases, including free-living photosynthetic, facultative symbiont, and intracellular facultative or obligate parasitic α-proteobacteria. Results and discussion: The results show that ζ evolved, preserving its inhibitory function in free-living α-proteobacteria exposed to broad environmental changes that could compromise the cellular ATP pools. However, the ζ inhibitory function was diminished or lost in some symbiotic α-proteobacteria where ζ is non-essential given the possible exchange of nutrients and ATP from hosts. Accordingly, the ζ gene is absent in some strictly parasitic pathogenic Rickettsiales, which may obtain ATP from the parasitized hosts. We also resolved the NMR structure of the ζ subunit of Sinorhizobium meliloti (Sm-ζ) and compared it with its structure modeled in AlphaFold. We found a transition from a compact ordered non-inhibitory conformation into an extended α-helical inhibitory N-terminus conformation, thus explaining why the Sm-ζ cannot exert homologous inhibition. However, it is still able to inhibit the PdF1FO-ATPase heterologously. Together with the loss of the inhibitory function of α-proteobacterial ε, the data confirm that the primary inhibitory function of the α-proteobacterial F1FO-ATPase was transferred from ε to ζ and that ζ, ε, and IF1 evolved by convergent evolution. Some key evolutionary implications on the endosymbiotic origin of mitochondria, as most likely derived from α-proteobacteria, are also discussed.

Dual activation profile of monocytes is associated with protection in Mexican patients during SARS-CoV-2 disease.

The COVID-19 pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been one of the most catastrophic diseases observed in recent years. It has reported nearly 550 million cases worldwide, with more than 6.35 million deaths. In Mexico, an increased incidence and mortality of this disease were observed, where the immune response has been involved in the magnitude and severity. A critical version of the disease is accompanied by hyperinflammatory responses, with cytokine and defective cellular responses. A detailed understanding of the role of molecules and cells in the immune response during COVID-19 disease may help to generate effective protection mechanisms, improving those we already have. Here we analyzed blood samples obtained from patients at the Hospital Regional de Alta Especialidad de Ixtapaluca (HRAEI), Mexico, which were classified according to living guidance for clinical management of COVID-19 by the World Health Organization: asymptomatic, mild, severe, and critical disease. We observed increased interleukin (IL)-6 levels and a T-CD8+ and T-CD4+ cell reduction correlated with the critical disease version. Importantly, here, we described a significant reduction of CD11b+CD45highCD14low monocytes during severe disease, which displayed a non-classical profile, expressing IL-10, transforming growth factor (TGF)-ß, and indoleamine 2,3-dioxygenase (IDO)1 molecule. Moreover, CD11b+CD45highCD14low monocytes obtained from infected one-dose vaccinated patients (Pfizer® vaccine) who suffered minimal symptoms showed simultaneously a dual classical and no-classical profile expressing pro- and anti-inflammatory cytokines. These results suggest that blood monocytes expressing a dual pro- and anti-inflammatory profile might be a predictive marker for protection in the Mexican population during COVID-19 disease. KEY POINTS : • Exacerbated immune response is associated with COVID-19 severe disease. • Dual monocyte activation profile is crucial for predicting protection during COVID-19. • Vaccination is crucial to induce the dual activation profile in monocytes.

Recruitment of M1 Macrophages May Not Be Critical for Protection against Colitis-Associated Tumorigenesis.

A close connection between inflammation and the risk of developing colon cancer has been suggested in the last few years. It has been estimated that patients diagnosed with some types of inflammatory bowel disease, such as ulcerative colitis or Crohn's disease, have up to a 30% increased risk of developing colon cancer. However, there is also evidence showing that the activation of anti-inflammatory pathways, such as the IL-4 receptor-mediated pathway, may favor the development of colon tumors. Using an experimental model of colitis-associated colon cancer (CAC), we found that the decrease in tumor development in global IL4Rα knockout mice (IL4RαKO) was apparently associated with an inflammatory response mediated by the infiltration of M1 macrophages (F480+TLR2+STAT1+) and iNOS expression in colon tissue. However, when we developed mice with a specific deletion of IL4Rα in macrophages (LysMcreIL4Rα-/lox mice) and subjected them to CAC, it was found that despite presenting a large infiltration of M1 macrophages into the colon, these mice were as susceptible to colon-tumorigenesis as WT mice. These data suggest that in the tumor microenvironment the absence of IL4Rα expression on macrophages, as well as the recruitment of M1 macrophages, may not be directly associated with resistance to developing colon tumors. Therefore, it is possible that IL4Rα expression in other cell types, such as colonic epithelial cells, could have an important role in promoting the development of colitis-associated colon tumorigenesis.

Serum levels of anticyclic citrullinated peptide antibodies, interleukin-6, tumor necrosis factor-α, and C-reactive protein are associated with increased carotid intima-media thickness: a cross-sectional analysis of a cohort of rheumatoid arthritis patients without cardiovascular risk factors.

UNLABELLED: The main cause of death in rheumatoid arthritis (RA) is cardiovascular events. We evaluated the relationship of anticyclic citrullinated peptide (anti-CCP) antibody levels with increased carotid intima-media thickness (cIMT) in RA patients. METHODS: Forty-five anti-CCP positive and 37 anti-CCP negative RA patients, and 62 healthy controls (HC) were studied. All groups were assessed for atherogenic index of plasma (AIP) and cIMT. Anti-CCP, C-reactive protein (CRP), and levels of tumor necrosis factor alpha (TNFα) and interleukin-6 (IL-6) were measured by enzyme-linked immunosorbent assay (ELISA). RESULTS: The anti-CCP positive RA patients showed increased cIMT compared to HC and anti-CCP negative (P < 0.001). Anti-CCP positive versus anti-CCP negative RA patients, had increased AIP, TNFα and IL-6 (P < 0.01), and lower levels of high density lipoprotein cholesterol (HDL-c) (P = 0.02). The cIMT correlated with levels of anti-CCP (r = 0.513, P = 0.001), CRP (r = 0.799, P < 0.001), TNFα (r = 0.642, P = 0.001), and IL-6 (r = 0.751, P < 0.001). In multiple regression analysis, cIMT was associated with CRP (P < 0.001) and anti-CCP levels (P = 0.03). CONCLUSIONS: Levels of anti-CCP and CRP are associated with increased cIMT and cardiovascular risk supporting a clinical role of the measurement of cIMT in RA in predicting and preventing cardiovascular events.

Review of antifungal therapy, part II: treatment rationale, including specific patient populations.

This portion of the antifungal review focuses on treatment rationale and suggestions, including special populations such as the elderly, children, and pregnant and immunocompromised individuals. In elderly individuals, the pathogen may be associated with certain comorbidities; treatment should begin with local treatments such as debridement (mechanical or chemical) and a topical. In children, the pathogen most commonly isolated is Trichophyton rubrum. Children should be examined for concomitant tinea and treatment options can begin with a chemical debridement (non-painful) and a topical, with non-responders being treated with combination therapy as in adults. It is suggested that blood tests are monitored at baseline and every 4-8 weeks in children on systemic therapy. Terbinafine is the only systemic in category B and local therapies should be the primary treatment modalities in pregnancy. Prevalence of onychomycosis is high in immunocompromised patients with higher relapse rates after treatment. The same fungal infections that are seen in healthy populations are usually represented in the immunocompromised host. There is a stepwise approach that is suggested in the treatment of onychomycosis. Before treatment, several factors should be determined, which include risk for failure and compliance issues. Strategies for therapy include monotherapy, combination therapy, supplemental therapy, and intermittent therapy. Topical monotherapy is effective in early distal nail disease and for the prevention of reinfection of the cured nail. Combination therapy is an appropriate progression of therapy for patients who failed monotherapy or are at risk for failure. Combined therapies are shown to increase cure rates. Mechanical interventions are essential in reducing fungal burdens to allow other modalities to penetrate, especially in dermatophytomas and onycholysis.

Review of antifungal therapy and the severity index for assessing onychomycosis: part I.

This review outlines recent data on treatment modalities and outcomes with antifungal therapy in onychomycosis. Included are topical, mechanical, chemical and systemic treatments or a combination thereof. Topical treatments, or transungual drug delivery systems (TUDDS), including ciclopirox and amorolfine were shown to be effective if used alone for mild-moderate nail involvement. Specifically, superficial white onychomycosis (SWO) restricted to the dorsum of the nail plate and moderate distal lateral subungual onychomycosis (DLSO). Mechanical treatments were mostly effective as adjuncts to topical therapy which include nail avulsion and abrasion. In particular, partial nail avulsion aids topical therapy in DLSO and partial subungual onychomycosis for a more effective therapy. Chemical avulsion is a painless method of debridement which uses a keratinolysis formula that is effective only in limited and early disease. Systemic therapies have been shown to be effective with terbinafine and itraconazole is suggested as being the most cost-effective therapy. Systemic therapies require consideration of side effects and monitoring by both patient and physician prior to treatment application. An effective suggestion is the use of a topical with debridement for mild-moderate onychomycosis and systemic (terbinafine) plus topical for severe onychomycosis. Most treatment modalities will require long-term use from 3 to 9 months to be most effective, with strategies presented in Part II of this review.

Measures used in specifying psoriasis lesion(s), global disease and quality of life: a systematic review.

OBJECTIVE: To assess which measures are utilized to quantify lesions, disease severity, and quality of life in the current literature on psoriasis vulgaris. METHODS: A MEDLINE search was performed with the keyword 'psoriasis' and the following limits 'All Adult: 19+ years', 'published in the last 5 years', 'English', 'Randomized Controlled Trial', and 'Humans'. The 'Methods' section of the individual articles were reviewed for inclusion criteria that described the study participants' state of psoriasis or disease generalization at baseline, methods used to classify or measure psoriasis during the study, the primary and secondary endpoints, and the quality of life measures utilized in each study. RESULTS: A search resulted in a total of 180 articles, out of which 134 were utilized for the review. The criteria most commonly utilized were 'moderate to severe psoriasis', 'BSA >/=10%', 'mild to moderate psoriasis', and 'severe psoriasis'. PASI was the most commonly used measure to describe the extent of psoriasis. The most common QoL measure used was DLQI, being used in 54.8% of the articles that used some form of QoL measure/s. DISCUSSION: Various measures are being utilized for the same purpose of generalizing disease/lesion severity and determining 'quality of life'.