Effects of the main green tea polyphenol epigallocatechin-3-gallate on cardiac involvement in patients with AL amyloidosis

Disease-modifying therapies for amyloid transthyretin cardiomyopathy: Current and emerging medications

Transthyretin amyloidosis (ATTR) is a rare disease that results in amyloid fibril misfolding and deposition in multiple organs, including the heart, leading to the development of ATTR cardiomyopathy (ATTR-CM), which is associated with poor outcomes. In the last decade, several disease-modifying medications are in advanced stages of clinical development or have been approved to treat ATTR-CM. The purpose of this review is to critically evaluate clinical trial data investigating the use of approved and investigational medications for the treatment of ATTR-CM. We performed a comprehensive literature search via PubMed and EMBASE to identify randomized controlled trials evaluating medications for the treatment of ATTR-CM published through August 2024. This narrative review describes the pathophysiology of ATTR-CM, highlights important screening and diagnostic work-up, and summarizes the existing clinical evidence resulting from our literature search. Several classes of disease-modifying medications are in development for ATTR-CM. The tetramer stabilizers and transthyretin silencers have proven to be the most effective therapies to date. Tafamidis and acoramidis are currently approved for ATTR-CM while vutrisiran approval for ATTR-CM may be forthcoming. Other disease-modifying medication classes in development include antisense oligonucleotides, gene editing therapies, and monoclonal antibodies. However, several unmet needs exist including the lack of cost-effectiveness due to the extremely high acquisition costs of these medications. Disease-modifying medications approved and in development to treat ATTR-CM offer hope for patients with this disease, but their lack of affordability is the biggest barrier to their use.

Optimizing drug therapies in cardiac amyloidosis

Cardiac amyloidosis (CA) is a form of infiltrative, restrictive cardiomyopathy that presents a diagnostic and therapeutic challenge in clinical practice. Historically, it has led to poor prognosis due to limited treatment options. However, advancements in disease awareness, diagnostic tools, and management approaches have led to the beginning of an era characterized by earlier diagnosis and a broader range of treatments. This article examines the advances in treating the two primary forms of cardiac amyloidosis: transthyretin cardiac amyloidosis (ATTR-CA) and light chain mediated cardiac amyloidosis (AL-CA). It highlights therapies for ATTR-CA that focus on interrupting the process of amyloid fibril formation. These therapies include transthyretin stabilizers, gene silencers, and monoclonal antibodies, which have shown the potential to improve patient outcomes and survival rates significantly. As of this writing, tafamidis is the sole Food and Drug Administration (FDA)--approved drug for ATTR-CA; however, experts anticipate several other drugs will gain approval within 1-2 years. Treatment strategies for AL-CA typically involve chemotherapy to inhibit the clonal cell type responsible for excessive AL amyloid fibril production. The prognosis for both types of amyloidosis primarily depends on how much the heart is affected, with most deaths occurring due to progressive heart failure. Effective care for CA patients requires collaboration among specialists from multiple disciplines, such as heart failure cardiology, electrophysiology, hematology/oncology, nephrology, neurology, pharmacology, and palliative care.

Current status and prospect of anti-amyloid fibril therapy in AL amyloidosis

Amyloid light-chain (AL) amyloidosis is a rare hematological disease that produces abnormal monoclonal immunoglobulin light chains to form amyloid fibrils that are deposited in tissues, resulting in organ damage and dysfunction. Advanced AL amyloidosis has a very poor prognosis with a high risk of early mortality. The combination of anti-plasma cell therapy and amyloid fibrils clearance is the optimal treatment strategy, which takes into account both symptoms and root causes. However, research on anti-amyloid fibrils lags far behind research on anti-plasma cells, and there is currently no approved treatment that could clear amyloid fibrils. Nevertheless, anti-amyloid fibril therapies are being actively investigated recently and have shown potential in clinical trials. In this review, we aim to outline the preclinical work and clinical efficacy of fibril-directed therapies for AL amyloidosis.

Hereditary gelsolin amyloidosis: a rare cause of cranial, peripheral and autonomic neuropathies linked to D187N and Y447H substitutions

INTRODUCTION

Hereditary gelsolin (AGel) amyloidosis is a systemic disease that is characterised by neurologic, ophthalmologic, dermatologic, and other organ involvements. We describe the clinical features with a focus on neurological manifestations in a cohort of patients with AGel amyloidosis referred to the Amyloidosis Centre in the United States.

METHODS

Fifteen patients with AGel amyloidosis were included in the study between 2005 and 2022 with the permission of the Institutional Review Board. Data were collected from the prospectively maintained clinical database, electronic medical records and telephone interviews.

RESULTS

Neurologic manifestations were featured in 15 patients: cranial neuropathy in 93%, peripheral and autonomic neuropathy in 57% and bilateral carpal tunnel syndrome in 73% of cases. A novel p.Y474H gelsolin variant featured a unique clinical phenotype that differed from the one associated with the most common variant of AGel amyloidosis.

DISCUSSION

We report high rates of cranial and peripheral neuropathy, carpal tunnel syndrome and autonomic dysfunction in patients with systemic AGel amyloidosis. The awareness of these features will enable earlier diagnosis and timely screening for end-organ dysfunction. The characterisation of pathophysiology will assist the development of therapeutic options in AGel amyloidosis.

Care of Patients With Transthyretin Amyloidosis: the Roles of Nutrition, Supplements, Exercise, and Mental Health

Transthyretin (ATTR) amyloidosis is a debilitating disease that results in organ failure and eventual death. As the disease progresses, patients experience neurologic, gastrointestinal, and cardiovascular symptoms that increasingly compromise their nutritional status and exercise capacity. These symptoms cause considerable emotional stress and mental health challenges for patients and caregivers. This review summarizes common symptoms and mechanisms associated with malnutrition and exercise intolerance, and sources of emotional stress, and offers therapeutic strategies to address these issues. Although earlier diagnosis and disease-specific treatment are central to caring for patients with ATTR amyloidosis, additional attention to symptom-focused treatments to improve nutritional status, maintain exercise tolerance and capacity, and improve and maintain mental health are also important. In conclusion, a team-based approach involving multiple clinicians and providers can offer more comprehensive and coordinated care, support, and education for patients and caregivers.

Polyphenols: Chemoprevention and therapeutic potentials in hematological malignancies

Polyphenols are one of the largest plant-derived natural product and they play an important role in plants' defense as well as in human health and disease. A number of them are pleiotropic molecules and have been shown to regulate signaling pathways, immune response and cell growth and proliferation which all play a role in cancer development. Hematological malignancies on the other hand, are cancers of the blood. While current therapies are efficacious, they are usually expensive and with unwanted side effects. Thus, the search for newer less toxic agents. Polyphenols have been reported to possess antineoplastic properties which include cell cycle arrest, and apoptosis via multiple mechanisms. They also have immunomodulatory activities where they enhance T cell activation and suppress regulatory T cells. They carry out these actions through such pathways as PI3K/Akt/mTOR and the kynurenine. They can also reverse cancer resistance to chemotherapy agents. In this review, i look at some of the molecular mechanism of action of polyphenols and their potential roles as therapeutic agents in hematological malignancies. Here i discuss their anti-proliferative and anti-neoplastic activities especially their abilities modulate signaling pathways as well as immune response in hematological malignancies. I also looked at clinical studies done mainly in the last 10-15 years on various polyphenol combination and how they enhance synergism. I recommend that further preclinical and clinical studies be carried out to ensure safety and efficacy before polyphenol therapies be officially moved to the clinics.

Left Ventricular Hypertrophy: Etiology-Based Therapeutic Options

Determining the etiologies of left ventricular hypertrophy (LVH) can be challenging due to the similarities of the different manifestations in clinical presentation and morphological features. Depending on the underlying cause, not only left ventricular mass but also left ventricular cavity size, or both, may increase. Patients with LVH remain asymptomatic for a few years, but disease progression will lead to the development of systolic or diastolic dysfunction and end-stage heart failure. As hypertrophied cardiac muscle disrupts normal conduction, LVH predisposes to arrhythmias. Distinguishing individuals with treatable causes of LVH is important for prevention of cardiovascular events and mortality. Athletic's heart with physiological LVH does not require treatment. Frequent causes of hypertrophy include etiologies due to pressure/volume overload, such as systemic hypertension, hypertrophic cardiomyopathy, or infiltrative cardiac processes such as amyloidosis, Fabry disease, and sarcoidosis. Hypertension and aortic valve stenosis are the most common causes of LVH. Management of LVH involves lifestyle changes, medications, surgery, and implantable devices. In this review we systematically summarize treatments for the different patterns of cardiac hypertrophy and their impacts on outcomes while informing clinicians on advances in the treatment of LVH due to Fabry disease, cardiac amyloidosis, and hypertrophic cardiomyopathy.

Effects of Green Tea (-)-Epigallocatechin-3-Gallate (EGCG) on Cardiac Function - A Review of the Therapeutic Mechanism and Potentials

Heart disease, the leading cause of death globally, refers to various illnesses that affect heart structure and function. Specific abnormalities affecting cardiac muscle contractility and remodeling and common factors including oxidative stress, inflammation, and apoptosis underlie the pathogenesis of heart diseases. Epidemiology studies have associated green tea consumption with lower morbidity and mortality of cardiovascular diseases, including heart and blood vessel dysfunction. Among the various compounds found in green tea, catechins are believed to play a significant role in producing benefits to cardiovascular health. Comprehensive literature reviews have been published to summarize the tea catechins' antioxidative, anti-inflammatory, and anti-apoptosis effects in the context of various diseases, such as cardiovascular diseases, cancers, and metabolic diseases. However, recent studies on tea catechins, especially the most abundant (-)-Epigallocatechin-3-Gallate (EGCG), revealed their capabilities in regulating cardiac muscle contraction by directly altering myofilament Ca2+ sensitivity on force development and Ca2+ ion handling in cardiomyocytes under both physiological and pathological conditions. In vitro and in vivo data also demonstrated that green tea extract or EGCG protected or rescued cardiac function, independent of their well-known effects against oxidative stress and inflammation. This minireview will focus on the specific effects of tea catechins on heart muscle contractility at the molecular and cellular level, revisit their effects on oxidative stress and inflammation in a variety of heart diseases, and discuss EGCG's potential as one of the lead compounds for new drug discovery for heart diseases.

Green Tea from the Far East to the Drug Store: Focus on the Beneficial Cardiovascular Effects

Cardiovascular diseases (CVD) are the leading cause of death worldwide. Evidence from observational and randomized controlled studies showing the potential benefits of green tea on lowering CVD risk has been emerging rapidly during the past few decades. These benefits include reduced risk for major cardiovascular events, lowering of blood pressure, decreased LDL cholesterol levels and weight loss. At the same time, the understanding of the physiological mechanisms behind these alterations is advancing. Consumption of green tea originated from China thousands of years ago, but since then, it expanded all over the world. Recent advances in understanding the role of tea polyphenols, mainly catechins, as mediators of tea's health benefits, have caused the emergence of various types of green tea extracts (GTE) on the market. While taking green tea is generally considered safe, there are concerns about the safety of using tea extracts. The present article reviews the current evidence of green tea consumption leading to reduced CVD risk, its potential biological mechanisms and the safety of using GTE.

Advances in pharmacotherapy for cardiac amyloidosis

INTRODUCTION

Amyloidosis is a group of progressive and devastating disorders resulting from extracellular deposition of misfolded proteins into tissues. When deposition of fibrils occurs in cardiac tissues, this systemic disease can lead to a very poor prognosis. Systemic amyloidosis can be acquired [light chain (AL) amyloidosis; AA amyloidosis], or hereditary [transthyretin (ATTR) amyloidosis]. Cardiac disease in amyloidosis is usually secondary to a systemic disease. The diagnosis of cardiac involvement is often delayed and yields an adverse prognosis.

AREAS COVERED

in this review, the authors report current literature on advances in pharmacotherapy for cardiac amyloidosis, mainly focused on AL and ATTR amyloidosis treatment.

EXPERT OPINION

Most pharmacological trials in amyloidosis patients, both AL and TTR, are directed to study the effects of drugs on polyneuropathy. However, since cardiac involvement carries a prominent negative survival impact in amyloidosis patients, future research should be more focused on amyloidosis cardiomyopathy as primary endpoint. Additionally, in AL amyloidosis therapies are mainly derived from experience on multiple myeloma treatment. In this specific setting, possible future research could particularly focus on immunotherapeutic agents able to optimize the standard chemotherapy results and, thus, allowing a larger population of patients to be treated by bone marrow stem cell transplantation.

The Role of Histone Acetylation and the Microbiome in Phytochemical Efficacy for Cardiovascular Diseases

Cardiovascular diseases (CVD) are the main cause of death worldwide and create a substantial financial burden. Emerging studies have begun to focus on epigenetic targets and re-establishing healthy gut microbes as therapeutic options for the treatment and prevention of CVD. Phytochemicals, commonly found in fruits and vegetables, have been shown to exert a protective effect against CVD, though their mechanisms of action remain incompletely understood. Of interest, phytochemicals such as curcumin, resveratrol and epigallocatechin gallate (EGCG) have been shown to regulate both histone acetylation and microbiome re-composition. The purpose of this review is to highlight the microbiome-epigenome axis as a therapeutic target for food bioactives in the prevention and/or treatment of CVD. Specifically, we will discuss studies that highlight how the three phytochemicals above alter histone acetylation leading to global changes in gene expression and CVD protection. Then, we will expand upon these phytochemicals to discuss the impact of phytochemical-microbiome-histone acetylation interaction in CVD.

Review on the Structures and Activities of Transthyretin Amyloidogenesis Inhibitors

Transthyretin (TTR) is a tetrameric protein, and its dissociation, aggregation, deposition, and misfolding are linked to several human amyloid diseases. As the main transporter for thyroxine (T4) in plasma and cerebrospinal fluid, TTR contains two T4-binding sites, which are docked with T4 and subsequently maintain the structural stability of TTR homotetramer. Affected by genetic disorders and detrimental environmental factors, TTR degrades to monomer and/or form amyloid fibrils. Reasonably, stabilization of TTR might be an efficient strategy for the treatment of TTR-related amyloidosis. However, only 10-25% of T4 in the plasma is bound to TTR under physiological conditions. Expectedly, T4 analogs with different structures aiming to bind to T4 pockets may displace the functions of T4. So far, a number of compounds including both natural and synthetic origin have been reported. In this paper, we summarized the potent inhibitors, including bisaryl structure-based compounds, flavonoids, crown ethers, and carboranes, for treating TTR-related amyloid diseases and the combination modes of some compounds binding to TTR protein.

Rod bipolar cells dysfunction occurs before ganglion cells loss in excitotoxin-damaged mouse retina

Progressive degeneration of retinal ganglion cells (RGCs) will cause a blinding disease. Most of the study is focusing on the RGCs itself. In this study, we demonstrate a decline of the presynaptic rod bipolar cells (RBCs) response precedes RGCs loss and a decrease of protein kinase Cα (PKCα) protein expression in RBCs dendrites, using whole-cell voltage-clamp, electroretinography (ERG) measurements, immunostaining and co-immunoprecipitation. We present evidence showing that N-methyl D-aspartate receptor subtype 2B (NR2B)/protein interacting with C kinase 1 (PICK1)-dependent degradation of PKCα protein in RBCs contributes to RBCs functional loss. Mechanistically, NR2B forms a complex with PKCα and PICK1 to promote the degradation of PKCα in a phosphorylation- and proteasome-dependent manner. Similar deficits in PKCα expression and response sensitivity were observed in acute ocular hypertension and optic never crush models. In conclusion, we find that three separate experimental models of neurodegeneration, often used to specifically target RGCs, disrupt RBCs function prior to the loss of RGCs. Our findings provide useful information for developing new diagnostic tools and treatments for retinal ganglion cells degeneration disease.

Use of novel therapies in the treatment of light chain amyloidosis

Immunoglobulin light-chain (AL) amyloidosis is a rare life-threatening disease caused by light chains that are toxic to vital organs such as the heart, kidneys, liver and peripheral nervous system, and that misfold and assemble as amyloid fibrils and deposit both in affected organs and systemically in the vasculature and other tissues. Patients afflicted by this disease have B-cell disorders, almost always related to clonal plasma cells in the bone marrow, the burden of which can range from small clones involving 5% or less of marrow cells to frank multiple myeloma. The goal of therapy is to eliminate the clonal plasma cells producing these toxic light chains to halt and possibly reverse symptomatic organ damage. While autologous stem cell transplantation can be a very effective treatment modality in AL, it has a limited role due to the frailty of this particular population. Conservative treatment in the form of chemotherapy has become the backbone of therapy. Bortezomib combined with alkylators has proven quite successful in inducing hematologic responses. However, despite these advances, tolerability and resistance continue to be an ongoing issue. Novel anti-plasma cell therapies such as ixazomib, carfilzomib, lenalidomide and pomalidomide are actively being combined and evaluated in clinical trials for efficacy and toxicity in this challenging patient population. Other approaches, such as monoclonal antibodies targeting surface proteins and amyloid deposits, are being tested and combined with novel agents. In this review, we will provide an overview of the clinical trials that have led to current treatment algorithms and will also discuss monoclonal antibodies currently under investigation and in various stages of clinical development.

Carpal tunnel syndrome and spinal canal stenosis: harbingers of transthyretin amyloid cardiomyopathy?

BACKGROUND

Carpal tunnel syndrome (CTS) and spinal canal stenosis can be frequently observed in the medical history of patients with transthyretin amyloidosis (ATTR), both in the hereditary (mt-ATTR) and wild-type (wt-ATTR) form. The aim of this retrospective single-center analysis was to determine the prevalence of these findings, delay to diagnosis of systemic amyloidosis and the prognostic value in a large cohort of patients with wt-ATTR and mt-ATTR amyloidosis.

METHODS

Medical records of 253 patients diagnosed with wt-ATTR, 136 patients with mt-ATTR and 77 asymptomatic gene carriers were screened for history of CTS and spinal canal stenosis and laboratory analysis, electrocardiography and echocardiographic results, respectively. Clinical follow-up was performed by phone assessment.

RESULTS

History of CTS was present in 77 patients (56%) with mt-ATTR, in 152 patients (60%) with wt-ATTR and even in 10 of the asymptomatic gene carriers (13%). Latency between carpal tunnel surgery and first diagnosis of systemic amyloidosis was significantly longer in wt-ATTR compared to mt-ATTR (117 ± 179 months vs. 66 ± 73 months; p = 0.02). In total, 36 patients (14%) with wt-ATTR and 7 patients (5%) with mt-ATTR had a history of clinically significant spinal canal stenosis. In the subgroup of mt-ATTR, patients with CTS had thicker IVS (19 ± 5 mm vs. 16 ± 5 mm, p < 0.05), higher LV mass index (225 ± 78 g vs. 193 ± 98 g, p < 0.05), lower Karnofsky index (78 ± 15% vs. 83 ± 17%, p < 0.05), and lower mitral annular plane systolic excursion (MAPSE; 9 ± 4 mm vs. 11 ± 5 mm, p < 0.05) compared to patients without CTS, whereas in wt-ATTR no significant differences could be observed. No significant difference in survival was observed between patients with and without CTS (wt-ATTR: 67 vs. 63 months, p = 0.45; mt-ATTR: 74 vs. 63 months, p = 0.60). A combination of CTS and spinal stenosis was present in 32 wt-ATTR patients (12%) and 3 mt-ATTR patients (2.2%).

CONCLUSIONS

The prevalence of CTS is high and the latency between CTS surgery and diagnosis of amyloidosis is long among patients with wt-ATTR and mt-ATTR. CTS might be predictive for future occurrence of systemic (predominantly cardiac) ATTR amyloidosis.

AL amyloidosis: advances in diagnostics and treatment

AL amyloidosis (light chain; previously also called primary amyloidosis) is a systemic disease characterized by an amyloid deposition process affecting many organs, and which still has unsatisfactory survival of patients. The monoclonal light chains kappa (κ) or lambda (λ) or their fragments form the fibrils that deposit and accumulate in different tissues. Renal involvement is very frequent in AL amyloidosis and can lead to the development of nephrotic syndrome followed by renal failure in some cases. AL amyloidosis ultimately leads to destruction of tissues and progressive disease. With recent advances in the treatment, the importance of an early diagnosis of amyloidosis and correct assessment of its type is high. Histologic confirmation is based on Congo red detection of amyloid deposits in tissues but AL amyloidosis must also be distinguished from other systemic forms of amyloidoses with renal involvement, such as AA amyloidosis, amyloidosis with heavy chain deposition, fibrinogen Aα or ALECT2 (leukocyte chemotactic factor 2) deposition. Immunofluorescence (IF) plays a key role here. IF on formalin-fixed paraffin-embedded tissue after protease digestion, immunohistochemistry or laser microdissection with mass spectrometry should complete the diagnosis in unclear cases. Standard treatment with melphalan and prednisolone or with cyclophosphamide and dexamethasone has been replaced with newer drugs used for the treatment of multiple myeloma—bortezomib, carfilzomib and ixazomib or thalidomide, lenalidomide and pomalidomide. High-dose melphalan supported by autologous stem cell transplantation remains the therapeutic option for patients with low-risk status. These new treatment options prolong survival from months to years and improve the prognosis in a majority of patients.

Inhibition of protein misfolding and aggregation by natural phenolic compounds

Protein misfolding and aggregation into fibrillar deposits is a common feature of a large group of degenerative diseases affecting the central nervous system or peripheral organs, termed protein misfolding disorders (PMDs). Despite their established toxic nature, clinical trials aiming to reduce misfolded aggregates have been unsuccessful in treating or curing PMDs. An interesting possibility for disease intervention is the regular intake of natural food or herbal extracts, which contain active molecules that inhibit aggregation or induce the disassembly of misfolded aggregates. Among natural compounds, phenolic molecules are of particular interest, since most have dual activity as amyloid aggregation inhibitors and antioxidants. In this article, we review many phenolic natural compounds which have been reported in diverse model systems to have the potential to delay or prevent the development of various PMDs, including Alzheimer's and Parkinson's diseases, prion diseases, amyotrophic lateral sclerosis, systemic amyloidosis, and type 2 diabetes. The lower toxicity of natural compounds compared to synthetic chemical molecules suggest that they could serve as a good starting point to discover protein misfolding inhibitors that might be useful for the treatment of various incurable diseases.

Epigallocatechin-3-gallate tolerability and impact on survival in a cohort of patients with transthyretin-related cardiac amyloidosis. A single-center retrospective study

Transthyretin-related (ATTR) cardiac amyloidosis is currently lacking a disease-modifying therapy. Despite demonstration of effectiveness in halting amyloid deposition, no study focused on epigallocatechin-3-gallate (EGCG) impact on patient survival. We sought to explore prognostic impact of EGCG in a cohort of lone cardiac ATTR patients. From the Florence Tuscan Regional Amyloid Centre database, we retrospectively selected ATTR patients treated with EGCG (675mg daily dose) for a minimum of 9 months, between March 2013 and December 2016. As a control group, we selected ATTR patients who received guideline-directed medical therapy alone. End point of the study was time to all cause death or cardiac transplantation. Sixty-five patients (30 treatment groups vs. 35 control groups) had a median follow-up of 691 days. There were no differences in baseline characteristics between groups. Five deaths occurred in EGCG group versus eight in control group; one patient underwent effective cardiac transplantation in EGCG group. There was no difference in survival estimates between EGCG and control group (60 ± 15% vs. 61 ± 12%, p = 0.276). EGCG was well tolerated, without major safety concerns. In a real-world cohort of ATTR patients with lone cardiac involvement, EGCG was a safe therapeutic option, but was not associated with survival improvement.

Recent advances in understanding and treating immunoglobulin light chain amyloidosis

Immunoglobulin (Ig) light chain (AL) amyloidosis is a clonal plasma cell disorder characterized by misfolded Ig light chain deposition in vital organs of the body, resulting in proteotoxicity and organ dysfunction. Owing to its diverse clinical presentations and a tendency to mimic common medical conditions, AL amyloidosis is often diagnosed late and results in dismal outcomes. Early referral to a specialized center with expertise in management of AL amyloidosis is always recommended. The availability of sensitive biomarkers and novel therapies is reforming our approach to how we manage AL amyloidosis. Treatment for patients with AL amyloidosis should be risk-adapted and customized on the basis of individual patient characteristics. In the future, approaches directed at amyloid fibril clearance in combination with agents that target plasma cells will be needed both to eradicate the malignant clone and to establish organ responses.

Novel Therapies in Light Chain Amyloidosis

Light chain (AL) amyloidosis is the most common form of amyloidosis involving the kidney. It is characterized by albuminuria, progressing to overt nephrotic syndrome and eventually end-stage renal failure if diagnosed late or ineffectively treated, and in most cases by concomitant heart involvement. Cardiac amyloidosis is the main determinant of survival, whereas the risk of dialysis is predicted by baseline proteinuria and glomerular filtration rate, and by response to therapy. The backbone of treatment is chemotherapy targeting the underlying plasma cell clone, that needs to be risk-adapted due to the frailty of patients with AL amyloidosis who have cardiac and/or multiorgan involvement. Low-risk patients (∼20%) can be considered for autologous stem cell transplantation that can be preceded by induction and/or followed by consolidation with bortezomib-based regimens. Bortezomib combined with alkylators, such as melphalan, preferred in patients harboring t(11;14), or cyclophosphamide, is used in most intermediate-risk patients, and with cautious dose escalation in high-risk subjects. Novel, powerful anti-plasma cell agents, such as pomalidomide, ixazomib, and daratumumab, prove effective in the relapsed/refractory setting, and are being moved to upfront therapy in clinical trials. Novel approaches based on small molecules interfering with the amyloidogenic process and on antibodies targeting the amyloid deposits gave promising results in preliminary uncontrolled studies, are being tested in controlled trials, and will likely prove powerful complements to chemotherapy. Finally, improvements in the understanding of the molecular mechanisms of organ damage are unveiling novel potential treatment targets, moving toward a cure for this dreadful disease.

Light Chain Amyloidosis

Light chain (AL) amyloidosis is caused by a usually small plasma-cell clone that is able to produce the amyloidogenic light chains. They are able to misfold and aggregate, deposit in tissues in the form of amyloid fibrils and lead to irreversible organ dysfunction and eventually death if treatment is late or ineffective. Cardiac damage is the most important prognostic determinant. The risk of dialysis is predicted by the severity of renal involvement, defined by the baseline proteinuria and glomerular filtration rate, and by the response to therapy. The specific treatment is chemotherapy targeting the underlying plasma-cell clone. It needs to be risk-adapted, according to the severity of cardiac and/or multi-organ involvement. Autologous stem cell transplant (preceded by induction and/or followed by consolidation with bortezomib-based regimens) can be considered for low-risk patients (~20%). Bortezomib combined with alkylators is used in the majority of intermediate-risk patients, and with possible dose escalation in high-risk subjects. Novel, powerful anti-plasma cell agents were investigated in the relapsed/refractory setting, and are being moved to upfront therapy in clinical trials. In addition, the use of novel approaches based on antibodies targeting the amyloid deposits or small molecules interfering with the amyloidogenic process gave promising results in preliminary studies. Some of them are under evaluation in controlled trials. These molecules will probably add powerful complements to standard chemotherapy. The understanding of the specific molecular mechanisms of cardiac damage and the characteristics of the amyloidogenic clone are unveiling novel potential treatment approaches, moving towards a cure for this dreadful disease.

Heavy drinkers of Ilex paraguariensis beverages show lower lipid profiles but higher body weight

Obesity is a widely recognized risk factor for several diseases, reaching an epidemic magnitude worldwide. Natural polyphenols may improve blood lipids and body weight, but their clinical relevance in the general population remains unclear. Thus, we aimed to analyze the relationship of intake of Ilex paraguariensis (I. paraguariensis) beverages to lipid profiles and body weight in a large patient population. Patients were recruited to participate in an educational program to change habits to a healthy lifestyle. Anamnesis, clinical and laboratory assessments were conducted at study enrollment and during follow‐up. I. paraguariensis beverages were defined according to preparation as obtained by repeated cold water extraction (CWE), hot water infusions, or water and sugar decoction. Heavy drinkers were defined as those persons consuming >1 L/day of one or more preparation types. Participants (N = 18,287) aged ≥18 years entered the study. Overall prevalence of I. paraguariensis consumption was 91.2%. All three forms were drunk by 35.7%, whereas CWE + hot water infusion and CWE alone by 28.4% and 14.5% participants, respectively. Heavy CWE drinkers had lower total cholesterol (191.4 ± 49.4 vs. 194.6 ± 48.3 mg/dl, p = .02) and lower low‐density lipoprotein cholesterol (118.6 ± 38.9 vs. 121.2 ± 47.1 mg/dl, p = .001), but body weight was higher (81.1 ± 16.8 vs. 77.2 ± 16.4 kg, p < .0001) compared with moderate drinkers. Fasting glucose was lower (104.5 ± 48.7 vs. 107.2 ± 49.5 mg/dl, p < .001), and consumption of carbohydrates was higher (36.3% vs. 28.7%, p < .001). A low‐lipids high‐body‐weight paradox could be observed in a population of heavy drinkers of I. paraguariensis beverages. Induced hypoglycemia and compensatory higher intake of refined carbohydrates may represent a possible cause.

Systemic amyloidosis: novel therapies and role of biomarkers

Systemic amyloidosis is caused by misfolding and extracellular deposition of one of an ever-growing list of circulating proteins, resulting in vital organ dysfunction and eventually death. Despite different predisposing conditions, including plasma cell dyscrasias [immunoglobulin light chain (AL) amyloidosis], long-lasting inflammation [reactive (AA) amyloidosis] or mutations (hereditary amyloidoses), clinical manifestations are conspicuously overlapping and mimic more prevalent conditions, significantly complicating and often delaying the recognition of these rare, complex diseases. However, refined diagnostic and imaging approaches and the increasing role of biomarkers, which help in establishing the diagnosis, assessing the prognosis and evaluating the response to therapy, have considerably improved the management of these conditions. The pillar of anti-amyloid therapy remains the prompt reduction or elimination of the amyloidogenic precursor. This is accomplished by targeting the underlying condition, and recent improvements in the treatment of plasma cell disorders and chronic inflammatory conditions have positively reverberated onto the management of AL and AA amyloidosis, respectively. Moreover, recent, substantial improvements in the understanding of the molecular underpinnings of systemic amyloidosis have unveiled different key steps in the amyloidogenic cascade which can be valid therapeutic targets. These include stabilizers of the native conformation of the amyloidogenic precursor, inhibitors of fibrillogenesis, amyloid fibril disruptors and promoters of amyloid clearance. Innovative pharmacological strategies, including rational, structure-based drug design, gene knockdown and immunotherapy, but also repurposing of old, safe drugs with newly recognized anti-amyloid properties, are currently being pursued already in the clinical setting, holding the promise of dramatically improving the outcome of these dismal conditions in the near future.

AL amyloidosis: from molecular mechanisms to targeted therapies

Systemic amyloidosis is caused by misfolding and extracellular deposition of circulating proteins as amyloid fibrils, resulting in the dysfunction of vital organs. The most common systemic amyloidosis, light-chain (AL) amyloidosis, is caused by misfolded light chains produced by a small, dangerous B-cell clone. The process of amyloid formation, organ targeting, and damage is multifaceted and, after disease initiation, the complexity of the downstream pathogenic cascade increases, rendering its control a challenge. Because of the progressive nature of the disease, early diagnosis to prevent end-stage organ damage is vital. Improving awareness and systematic use of biomarkers of organ damage in screening populations at risk may improve the still unsatisfactory diagnostic process. Amyloid imaging is now emerging as an important companion of biomarkers in formulating the diagnosis and prognosis and monitoring the effects of therapy. An accurate diagnosis is the basis for appropriate therapy that is risk-adapted and response-tailored. Effective treatments targeting the clone and rapidly and profoundly reducing the amyloid light chains have produced marked improvements in overall survival, making AL amyloidosis the most successful model of all amyloidoses. New therapies targeting the amyloid deposits are now under development, together with novel agents modulating light chain aggregation and proteotoxicity. The future of AL amyloidosis treatment is combination therapy and will require an innovative collaborative model for a rapid translation from bench to bedside with the ultimate aim of achieving a cure for this complex disease.

Novel pharmacotherapies for cardiac amyloidosis

Amyloidosis refers to a range of protein misfolding disorders that can cause organ dysfunction through progressive fibril deposition. Cardiac involvement often leads to significant morbidity and mortality and increasingly has been recognized as an important cause of heart failure. The two main forms of cardiac amyloidosis, light chain (AL) and transthyretin (ATTR) amyloidosis, have distinct mechanisms of pathogenesis. Recent insights have led to the development of novel pharmacotherapies with the potential to significantly impact each disease. This review will summarize the preclinical and clinical data for these emerging treatments for AL and ATTR amyloidosis.

Clinical trials evaluating potential therapies for light chain (AL) amyloidosis

INTRODUCTION

The field of systemic amyloidosis is experiencing major advances in diagnostic and prognostic methods coupled with a growing availability in treatment options.

AREAS COVERED

Treatment of AL amyloidosis traditionally targeted the clonal plasma cells, in order to block further production of amyloidogenic light chains. Currently, a research focus is placed on targeting the already formed amyloid deposits using monoclonal antibodies against epitopes on such deposits. Encouraging results were obtained from the three investigated antibodies: NEOD001, 11-1F4 and anti-SAP, but further validation is required before these antibodies can be commercialized. In this paper, we review the current active clinical research in AL amyloidosis, which includes the monoclonal antibodies targeting amyloid deposits, daratumumab, Venetoclax, doxycycline, green tea, pomalidomide, carfilzomib and ixazomib.

EXPERT OPINION

Monoclonal antibodies, targeting either the amyloid deposits or the plasma cell compartment will likely be integrated into routine treatment practice given their encouraging results and minimal toxicity in the fragile population of AL amyloidosis. Other therapeutic options hold promise to the field as well, but toxicity will likely challenge their routine use. Early recognition remains the best option for outcome enhancement.

Epigallocatechin-3-gallate preferentially induces aggregation of amyloidogenic immunoglobulin light chains

Antibody light chain amyloidosis is a rare disease caused by fibril formation of secreted immunoglobulin light chains (LCs). The huge variety of antibody sequences puts a serious challenge to drug discovery. The green tea polyphenol epigallocatechin-3-gallate (EGCG) is known to interfere with fibril formation in general. Here we present solution- and solid-state NMR studies as well as MD simulations to characterise the interaction of EGCG with LC variable domains. We identified two distinct EGCG binding sites, both of which include a proline as an important recognition element. The binding sites were confirmed by site-directed mutagenesis and solid-state NMR analysis. The EGCG-induced protein complexes are unstructured. We propose a general mechanistic model for EGCG binding to a conserved site in LCs. We find that EGCG reacts selectively with amyloidogenic mutants. This makes this compound a promising lead structure, that can handle the immense sequence variability of antibody LCs.

Aggregation of Full-length Immunoglobulin Light Chains from Systemic Light Chain Amyloidosis (AL) Patients Is Remodeled by Epigallocatechin-3-gallate

Intervention into amyloid deposition with anti-amyloid agents like the polyphenol epigallocatechin-3-gallate (EGCG) is emerging as an experimental secondary treatment strategy in systemic light chain amyloidosis (AL). In both AL and multiple myeloma (MM), soluble immunoglobulin light chains (LC) are produced by clonal plasma cells, but only in AL do they form amyloid deposits in vivo We investigated the amyloid formation of patient-derived LC and their susceptibility to EGCG in vitro to probe commonalities and systematic differences in their assembly mechanisms. We isolated nine LC from the urine of AL and MM patients. We quantified their thermodynamic stabilities and monitored their aggregation under physiological conditions by thioflavin T fluorescence, light scattering, SDS stability, and atomic force microscopy. LC from all patients formed amyloid-like aggregates, albeit with individually different kinetics. LC existed as dimers, ∼50% of which were linked by disulfide bridges. Our results suggest that cleavage into LC monomers is required for efficient amyloid formation. The kinetics of AL LC displayed a transition point in concentration dependence, which MM LC lacked. The lack of concentration dependence of MM LC aggregation kinetics suggests that conformational change of the light chain is rate-limiting for these proteins. Aggregation kinetics displayed two distinct phases, which corresponded to the formation of oligomers and amyloid fibrils, respectively. EGCG specifically inhibited the second aggregation phase and induced the formation of SDS-stable, non-amyloid LC aggregates. Our data suggest that EGCG intervention does not depend on the individual LC sequence and is similar to the mechanism observed for amyloid-β and α-synuclein.

Phase 2 trial of daily, oral epigallocatechin gallate in patients with light-chain amyloidosis

Previous studies have suggested that an increase in mitochondrial reactive oxygen species may cause organ damage in patients with light-chain (AL) amyloidosis; however, this damage can be decreased by antioxidant-agent treatment. Epigallocatechin gallate (EGCG), the major natural catechin in green tea, has potent antioxidant activity. Because EGCG has recently been reported to have a favorable toxicity profile for treating amyloidosis, we sought to examine the clinical efficacy and toxicity of EGCG in patients with AL amyloidosis. Fifty-seven patients were randomly assigned to the EGCG and observation groups and observed for six months. There were no increases in grade 3-5 adverse events and EGCG therapy was well tolerated. Although a decrease in the urinary albumin level was found in the EGCG group in patients with obvious albuminuria after treatment initiation, its antioxidant activity may not be sufficient to clarify the potential effect of EGCG in patients with AL amyloidosis. Because some of the biological markers responsible for organ damage were well correlated to the level of antioxidant potential in patients' plasma, the status of oxidative stress in the blood may indicate the extent of organ damage in clinical situations.

Emerging Advances in the Management of Cardiac Amyloidosis

Amyloidosis is a disease in which proteins misfold, aggregate into fibrils, and deposit extracellularly disrupting organ architecture and function. There are two main types which affect the heart: light chain (AL) amyloidosis and transthyretin cardiac amyloidosis (ATTR). There is a misconception that cardiac amyloidosis has no effective treatment options. However, over the past decade, there has been extensive research and drug development. Outcomes are improving in AL amyloidosis with evolving chemotherapeutic regimens and novel monoclonal antibodies. In ATTR, therapies that decrease protein production, prevent dissociation, and promote clearance have the potential to slow or even halt a disease which is uniformly fatal. Selected patients may be candidates for heart and/or stem cell transplant and should be promptly referred to an experienced amyloid program. Herein, we discuss the emerging advances for the treatment of cardiac amyloidosis.

What is new in diagnosis and management of light chain amyloidosis?

Light chain (AL) amyloidosis is caused by a usually small plasma cell clone producing a misfolded light chain that deposits in tissues. Survival is mostly determined by the severity of heart involvement. Recent studies are clarifying the mechanisms of cardiac damage, pointing to a toxic effect of amyloidogenic light chains and offering new potential therapeutic targets. The diagnosis requires adequate technology, available at referral centers, for amyloid typing. Late diagnosis results in approximately 30% of patients presenting with advanced, irreversible organ involvement and dying in a few months despite modern treatments. The availability of accurate biomarkers of clonal and organ disease is reshaping the approach to patients with AL amyloidosis. Screening of early organ damage based on biomarkers can help identify patients with monoclonal gammopathy of undetermined significance who are developing AL amyloidosis before they become symptomatic. Staging systems and response assessment based on biomarkers facilitate the design and conduction of clinical trials, guide the therapeutic strategy, and allow the timely identification of refractory patients to be switched to rescue therapy. Treatment should be risk-adapted. Recent studies are linking specific characteristics of the plasma cell clone to response to different types of treatment, moving toward patient-tailored therapy. In addition, novel anti-amyloid treatments are being developed that might be combined with anti-plasma cell chemotherapy.

Beyond the plasma cell: emerging therapies for immunoglobulin light chain amyloidosis

Systemic immunoglobulin light chain (LC) amyloidosis (AL) is a potentially fatal disease caused by immunoglobulin LC produced by clonal plasma cells. These LC form both toxic oligomers and amyloid deposits disrupting vital organ function. Despite reduction of LC by chemotherapy, the restoration of organ function is highly variable and often incomplete. Organ damage remains the major source of mortality and morbidity in AL. This review focuses on the challenges posed by emerging therapies that may limit the toxicity of LC and improve organ function by accelerating the resorption of amyloid deposits.

Immunoglobulin Light-Chain Amyloidosis: From Basics to New Developments in Diagnosis, Prognosis and Therapy

Immunoglobulin amyloid light-chain (AL) amyloidosis is the most common form of systemic amyloidosis, where the culprit amyloidogenic protein is immunoglobulin light chains produced by marrow clonal plasma cells. AL amyloidosis is an infrequent disease, and since presentation is variable and often nonspecific, diagnosis is often delayed. This results in cumulative organ damage and has a negative prognostic effect. AL amyloidosis can also be challenging on the diagnostic level, especially when demonstration of Congo red-positive tissue is not readily obtained. Since as many as 31 known amyloidogenic proteins have been identified to date, determination of the amyloid type is required. While several typing methods are available, mass spectrometry has become the gold standard for amyloid typing. Upon confirming the diagnosis of amyloidosis, a pursuit for organ involvement is essential, with a focus on heart involvement, even in the absence of suggestive symptoms for involvement, as this has both prognostic and treatment implications. Details regarding initial treatment options, including stem cell transplantation, are provided in this review. AL amyloidosis management requires a multidisciplinary approach with careful patient monitoring, as organ impairment has a major effect on morbidity and treatment tolerability until a response to treatment is achieved and recovery emerges.

Green tea extract as a treatment for patients with wild-type transthyretin amyloidosis: an observational study

BACKGROUND

Causative treatment of patients with wild-type transthyretin amyloid cardiomyopathy (wtATTR-CM) is lacking. Recent reports indicate the potential use of epigallocatechin-3-gallate (EGCG), the most abundant catechin in green tea, to inhibit amyloid fibril formation. We sought to investigate changes of cardiac function and morphology in patients with wtATTR-CM after consumption of green tea extract (GTE).

METHODS

Twenty-five male patients (71 [64; 80] years) with wtATTR-CM were submitted to clinical examination, echocardiography, cardiac magnetic resonance imaging (cMRI) (n=14), and laboratory testing before and after daily consumption of GTE capsules containing 600 mg epigallocatechin-3-gallate for at least 12 months.

RESULTS

A significant decrease of left ventricular (LV) myocardial mass by 6% (196 [100; 247] vs 180 [85; 237] g; P=0.03) by cMRI and total cholesterol by 8.4% (191 [118; 267] vs 173 [106; 287] mg/dL; P=0.006) was observed after a 1-year period of GTE consumption. LV ejection fraction by cMRI (53% [33%; 69%] vs 54% [28%; 71%]; P=0.75), LV wall thickness (17 [13; 21] vs 18 [14; 25] mm; P=0.1), and mitral annular plane systolic excursion (10 [5; 23] vs 8 [4; 13] mm; P=0.3) by echocardiography remained unchanged.

CONCLUSION

This study supports LV mass stabilization in patients with wtATTR-CM consuming GTE potentially indicating amyloid fibril reduction.

Novel strategies for the diagnosis and treatment of cardiac amyloidosis

Systemic amyloidoses are rare, complex diseases caused by misfolding of autologous protein. The presence of heart involvement is the most important prognostic determinant. The diagnosis of amyloid cardiac involvement relies on echocardiography and magnetic resonance imaging, while scintigraphy with bone tracers is helpful in differentiating light chain amyloidosis from other types of amyloidosis involving the heart. Although these diseases are fatal, effective treatments exist that can alter their natural history, provided that they are started before irreversible cardiac damage has occurred. Refined diagnostic techniques, accurate patients' stratification based on biomarkers of cardiac dysfunction, the availability of novel, more powerful drugs, and ultimately, the unveiling of the cellular mechanisms of cardiac damage created a favorable environment for a dramatic improvement in the treatment of this disease that we expect in the next few years.

Extract of Caragana sinica as a potential therapeutic option for increasing alpha-secretase gene expression

BACKGROUND

Alzheimer's disease represents one of the main neurological disorders in the aging population. Treatment options so far are only of symptomatic nature and efforts in developing disease modifying drugs by targeting amyloid beta peptide-generating enzymes remain fruitless in the majority of human studies. During the last years, an alternative approach emerged to target the physiological alpha-secretase ADAM10, which is not only able to prevent formation of toxic amyloid beta peptides but also provides a neuroprotective fragment of the amyloid precursor protein - sAPPalpha.

PURPOSE

To identify novel alpha-secretase enhancers from a library of 313 extracts of medicinal plants indigenous to Korea, a screening approach was used and hits were further evaluated for their therapeutic value.

METHODS

The extract library was screened for selective enhancers of ADAM10 gene expression using a luciferase-based promoter reporter gene assay in the human neuroblastoma cell line SH-SY5Y. Candidate extracts were then tested in wild type mice for acute behavioral effects using an open field paradigm. Brain and liver tissue from treated mice was biochemically analyzed for ADAM10 gene expression in vivo. An in vitro blood-brain barrier model and an in vitro ATPase assay were used to unravel transport properties of bioactive compounds from extract candidates. Finally, fractionation of the most promising extract was performed to identify biologically active components.

RESULTS

The extract of Caragana sinica (Buc'hoz) Rehder was identified as the best candidate from our screening approach. We were able to demonstrate that the extract is acutely applicable in mice without obvious side effects and induces ADAM10 gene expression in peripheral tissue. A hindered passage across the blood-brain barrier was detected explaining lack of cerebral induction of ADAM10 gene expression in treated mice. By fractionating C. sinica extract we identified alpha-viniferin as one of the biologically active components.

CONCLUSION

The extract of C. sinica and alpha-viniferin as one of its bioactive constituents might serve as novel therapeutic options for treating Alzheimer's disease by increasing ADAM10 gene expression. The identification of alpha-viniferin represents a promising starting point to achieve blood-brain barrier penetrance in the future.

Inhibition of Light Chain 6aJL2-R24G Amyloid Fiber Formation Associated with Light Chain Amyloidosis

Light chain amyloidosis (AL) is a deadly disease characterized by the deposition of monoclonal immunoglobulin light chains as insoluble amyloid fibrils in different organs and tissues. Germ line λ VI has been closely related to this condition; moreover, the R24G mutation is present in 25% of the proteins of this germ line in AL patients. In this work, five small molecules were tested as inhibitors of the formation of amyloid fibrils from the 6aJL2-R24G protein. We have found by thioflavin T fluorescence and transmission electron microscopy that EGCG inhibits 6aJL2-R24G fibrillogenesis. Furthermore, using nuclear magnetic resonance spectroscopy, dynamic light scattering, and isothermal titration calorimetry, we have determined that the inhibition is due to binding to the protein in its native state, interacting mainly with aromatic residues.

Extracellular remodeling in patients with wild-type amyloidosis consuming epigallocatechin-3-gallate: preliminary results of T1 mapping by cardiac magnetic resonance imaging in a small single center study

OBJECTIVES

T1 mapping by cardiac magnetic resonance imaging (CMR) is able to determine the extracellular volume fraction. Wild-type transthyretin amyloidosis (WT-ATTR) is characterized by extracellular amyloid deposition in the heart. Recent reports indicated a reduction of left ventricular (LV) myocardial mass in WT-ATTR after consumption of epigallocatechin-3-gallate, the main catechin in green tea. It remained unclear, whether reduction of LV myocardial mass reflects decrease of amyloid load or progressive atrophy of cardiomyocytes.

METHODS

This study included 7 male patients with CMR repetitively performed before and 12 months after daily consumption of green tea extract (600 mg epigallocatechin-3-gallate). Short axis slices as well as 2-, 3-, and 4-chamber views were acquired using SSFP sequences. T1 mapping was created out of 11 mid-ventricular short axis views with increasing inversion times using a single breath-hold modified look-locker inversion recovery sequence before and 15 min after Gadolinium contrast administration.

RESULTS

After 12 months, a significant decrease of LV myocardial mass [198 (160; 212) vs. 180 (142; 204) g; p < 0.05] was observed. Moreover, a significant decrease of native [T1 1110 (1072; 1150) ms vs. 1080 (970; 1101), p < 0.05 or p = 0.03] was noticed. The calculated extracellular volume decreased in 5 patients (62.5%) by 7% and increased in 2 patients (37.5%) by 9.5%, in trend resulting in a (not significant) decrease of median ECV by 2.4%. Left ventricular ejection fraction (LVEF) [57 (48; 65) vs. 55 (47; 64) %; p = 0.3] remained unchanged.

CONCLUSIONS

This study provided further evidence of LV myocardial mass reduction in patients with WT-ATTR daily consuming green tea extract. Additionally, this study gave first insights into the histomorphological correlate of LV mass reduction using T1 mapping. LV mass reduction appeared to be rather due to a decrease of amyloid load than atrophy of cardiomyocytes.

The Effect of (-)-Epigallo-catechin-(3)-gallate on Amyloidogenic Proteins Suggests a Common Mechanism

Studies on the interaction of the green tea polyphenol (-)-Epigallocatechin-3-gallate (EGCG) with fourteen disease-related amyloid polypeptides and prions Huntingtin, Amyloid-beta, alpha-Synuclein, islet amyloid polypeptide (IAPP), Sup35, NM25 and NM4, tau, MSP2, semen-derived enhancer of virus infection (SEVI), immunoglobulin light chains, beta-microglobulin, prion protein (PrP) and Insulin, have yielded a variety of experimental observations. Here, we analyze whether these observations could be explained by a common mechanism and give a broad overview of the published experimental data on the actions of EGCG. Firstly, we look at the influence of EGCG on aggregate toxicity, morphology, seeding competence, stability and conformational changes. Secondly, we screened publications elucidating the biochemical mechanism of EGCG intervention, notably the effect of EGCG on aggregation kinetics, oligomeric aggregation intermediates, and its binding mode to polypeptides. We hypothesize that the experimental results may be reconciled in a common mechanism, in which EGCG binds to cross-beta sheet aggregation intermediates. The relative position of these species in the energy profile of the amyloid cascade would determine the net effect of EGCG on aggregation and disaggregation of amyloid fibrils.

Investigating heart-specific toxicity of amyloidogenic immunoglobulin light chains: A lesson from C. elegans

Abnormalities in protein folding are involved in many localized and systemic diseases, all of which are characterized by insoluble amyloid formation and deposition. In immunoglobulin light chain (LC) amyloidosis, the most frequent systemic form of amyloidosis, the amyloid involvement of the heart dictates the prognosis and the elucidation of the mechanism of heart targeting and toxicity is essential for designing and testing new effective treatments. To this end, the availability of an appropriate animal model is crucial. We recently described the use of C. elegans as an innovative experimental system to investigate in vivo the pathogenic effects of monoclonal LC. This idea stems from the knowledge that the worm's pharynx is an "ancestral heart" with the additional ability to recognize stressor compounds. The feeding of worms with LC purified from patients suffering from cardiomyopathy, selectively and permanently impaired the pharyngeal function. This irreversible damage resulted in time, in a significant reduction in the lifespan of worms. We also reported that the ability of LC to generate reactive oxygen species was associated with their toxic effects and was counteracted by anti-oxidant compounds. This new nematode-based assay represents a promising model for elucidating the heart-specific toxicity of LC and for a rapid screening of new therapeutic strategies.

Novel drugs targeting transthyretin amyloidosis

Transthyretin amyloidosis (ATTR) is either a hereditary disease related to a mutation in the transthyretin gene that leads to neuropathy and/or cardiomyopathy or an acquired disease of the elderly that leads to restrictive cardiomyopathy. The prevalence of this disease is higher than once thought and awareness is likely to increase amongst physicians and in particular cardiologists. Until recently there have been no treatment options for this disease except to treat the heart failure with diuretics and the neuropathy symptomatically. However, there are several emerging pharmacologic therapies designed to slow or stop the progression of ATTR. This article reviews novel therapeutic drugs that work at different points in the pathogenesis of this disease attempting to change its natural history and improve outcomes.